FIX: json decoder bug jdec was crashing when string had spaces

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "test/mingw-std-threads"]
+	path = test/mingw-std-threads
+	url = https://github.com/meganz/mingw-std-threads.git

include/com/sequencer.h

@@ -0,0 +1,524 @@
+/*!
+ * \file com/sequencer.h
+ * \brief
+ *      A script based automation tool for send/receive communications
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_COM_SEQUENCER_H_
+#define TBX_COM_SEQUENCER_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+#include <cont/range.h>
+
+#include <ctime>
+#include <array>
+#include <string_view>
+#include <type_traits>
+#include <utility>
+#include <tuple>
+
+namespace tbx {
+
+/*!
+ * \class sequencer
+ * \brief
+ *      A CRTP base class to provide the sequencer functionality.
+ *
+ * Sequencer is a script engine with receive/transmit functionalities based on predicates. It has:
+ *  - A program counter like variable named \c step.
+ *  - \c step actions like NEXT, GOTO exit with status etc...
+ *  - Input data match predicates to trigger those actions.
+ *  - Input data handlers to trigger external functionality on predicate match
+ *  - Output data handlers to "edit" data before transmiting them
+ *  - A small predicate set provided to the user. (starts_with, ends_with, contains).
+ *
+ * Sequencer can automate communication with a terminal-like device such as AT-command modems, can
+ * be used to implement communication protocols, or even small http servers.
+ *
+ * It can operate based on a script array and handle the outgoing commands and incoming responses.
+ * The user can create matching rules on received data and hook handlers and actions on them.
+ *
+ * The derived class (implementation) has to provide:
+ *  1) size_t get(Data_t* data);
+ *     This function return 0 or a number of Data_t items. The data points to buffer for the input data.
+ *
+ *  3) size_t contents_ (Data_t* data);
+ *     This function return 0 or a number of Data_t items without removing them from the implementer's container
+ *     The data points to buffer for the input data.
+ *
+ *  2) size_t put(const Data_t* data, size_t n);
+ *     This function sends to implementation the data pointed by \c data witch have size \c n.
+ *
+ *  4) clock_t clock();
+ *     This function return a number to be used as time. The units of this function may be arbitrary but they
+ *     match the units in \c record_t::timeout field.
+ *
+ * \tparam Impl_t   The type of derived class
+ * \tparam Data_t   The char-like stream item type. Usually \c char
+ * \tparam N        The size of the sequence buffer to temporary store each line from get().
+ *
+ * \note
+ *      We need access to derived class container to sneaky get a range of the data beside
+ *      the normal data flow, in order to implement the \see control_t::DETECT operation.
+ */
+template <typename Impl_t, typename Data_t, size_t N>
+class sequencer {
+    _CRTP_IMPL(Impl_t);
+
+    //! \name Public types
+    //! @{
+    public:
+        using value_type    = Data_t;
+        using pointer_type  = Data_t*;
+        using size_type     = size_t;
+        using string_view   = std::basic_string_view<Data_t>;
+
+        /*!
+         * The sequencer engine status. A variable of this type is returned by
+         * \see action_().
+         */
+        enum class seq_status_t {
+            CONTINUE,   //!< Means we keep looping
+            EXIT        //!< Means, we exit with status the one indicated by \c action_t of the \c record_t
+        };
+
+        //! \enum control_t
+        //! \brief The control type of the script entry.
+        enum class control_t {
+            NOP,        //!< No command, dont send or expect anything, used for delays
+            SEND,       //!< Send data to implementation through put()
+            EXPECT,     //!< Expects data from implementation via get()
+            OR_EXPECT,  //!< Expects data from implementation via get() in conjunction with previous EXPECT
+            DETECT,     //!< Detects data into rx buffer without receiving them via contents()
+            OR_DETECT,  //!< Detects data into rx buffer without receiving them via contents() in conjunction with
+                        //!< previous DETECT
+            OTHERWISE   //!< An "else" path if the EXPECT[, OR_EXPECT[, OR_EXPECT ... ]] block timesout.
+
+            //! \note
+            //! The \c DETECT extra incoming channel serve the purpose of sneak into receive
+            //! buffer and check for data without getting them. This is useful when the receive driver
+            //! is buffered with a delimiter and we seek for data that don't follow the delimiter pattern.
+            //!
+            //! For example:
+            //! A modem sends responses with '\n' termination but for some "special" command it opens a cursor
+            //! lets say ">$ " without '\n' at the end.
+        };
+
+        //! \enum action_t
+        //! \brief
+        //!     Possible response actions for the sequencer. This is the
+        //!     equivalent of changing the program counter of the sequencer
+        //!     and is composed by a type and a value.
+        //!
+        struct action_t {
+            enum {
+                NO =0,      //!< Do not change sequencer's step
+                NEXT,       //!< Go to next sequencer step. In case of EXPECT/DETECT block of records
+                            //!< skip the entire block of EXPECT[, OR_EXPECT[, OR_EXPECT ...]] and go
+                            //!< to the next (non OR_*) control record.
+                GOTO,       //!< Manually sets the step counter to the number of the \c step member.
+                EXIT,       //!< Instruct for an exit returning the action.value as status
+            } type;
+            size_t value;   //!< Used by \c GOTO to indicate the next sequencer's step.
+        };
+
+        //! A no_action action_t
+        static constexpr action_t no_action  = {action_t::NO, 0};
+        //! A next action_t
+        static constexpr action_t next       = {action_t::NEXT, 0};
+        //! A goto action_t template
+        template <size_t GOTO>
+        static constexpr action_t go_to      = {action_t::GOTO, static_cast<size_t>(GOTO)};
+
+        //! An exit ok action_t
+        static constexpr action_t exit_ok    = {action_t::EXIT, 0};
+        //! An exit error action_t
+        static constexpr action_t exit_error = {action_t::EXIT, static_cast<size_t>(-1)};
+        //! A generic exit action_t template
+        template <size_t Status>
+        static constexpr action_t exit       = {action_t::EXIT, static_cast<size_t>(Status)};
+
+        /*!
+         * Match binary predicate function pointer type.
+         * Expects two string views and return a boolean.
+         * It is used by EXPECT/DETECT blocks to trigger their {handler, action} pair.
+         */
+        using match_ft   = bool (*) (const string_view haystack, const string_view needle);
+
+        /*!
+         *  Send/Receive handler function pointer type.
+         *  Expects a pointer to buffer and a size and returns status.
+         *  It is used on predicate match on EXPECT/DETECT blocks, or as data wrapper on SEND blocks.
+         */
+        using handler_ft = void (*) (const Data_t*, size_t);
+
+        /*!
+         * \struct record_t
+         * \brief
+         *      Describes the sequencer's script record entry (line).
+         */
+        struct record_t {
+            control_t   control;    //!< The control type of the entry
+            string_view token;      //!< String view to token data. [MUST BE null terminated].
+                                    //!< This is passed as 2nd argument to match predicate on EXPECT/DETECT, or as
+                                    //! {data, size} pair to SEND handler and put_().
+                                    //!< If unused set it to ""
+            match_ft    match;      //!< Match predicate to used in EXPECT/DETECT blocks
+                                    //!< If unused set it to nullptr
+            handler_ft  handler;    //!< The handler to called if the match is successful, or before put_()
+                                    //!< If unused set it to nullptr
+            action_t    action;     //!< Indicates the step manipulation if the match is successful or after NOP and put_()
+            clock_t     timeout;    //!< Timeout in CPU time
+        };
+
+        /*!
+         * \struct script_t
+         * \brief
+         *      Describes the sequencer's script.
+         *
+         * The user can create arrays as the example bellow to act as a script.
+         * \code
+         * Seq s;
+         * const Seq::script_t<4> script = {{
+         *     {Seq::control_t::NOP,       "",         Seq::nil,       Seq::nil, {Seq::action_t::GOTO, 1},       1000},
+         *
+         *     {Seq::control_t::SEND,      "ATE0\r\n", Seq::nil,       Seq::nil, {Seq::action_t::NEXT, 0},       0},
+         *     {Seq::control_t::EXPECT,    "OK\r\n",   Seq::ends_with, Seq::nil, {Seq::action_t::EXIT_OK, 0},    1000},
+         *     {Seq::control_t::OR_EXPECT, "ERROR",    Seq::contains,  Seq::nil, {Seq::action_t::EXIT_ERROR, 0}, 0}
+         * }};
+         * s.run(script);
+         * \endcode
+         */
+        template <size_t Nrecords>
+        using script_t = std::array<record_t, Nrecords>;
+
+
+        /*!
+         * \brief
+         *       Check if the \c stream1 is equal to \c stream2
+         * \param stream1    The stream in witch we search [The input buffer]
+         * \param stream2    What we search [The record's token]
+         * \return           True on success, false otherwise
+         */
+        static constexpr auto equals = [](const string_view stream1, const string_view stream2) noexcept -> bool {
+            return (stream1 == stream2);
+        };
+
+        /*!
+         * \brief
+         *       Check if the \c stream starts with the \c prefix
+         * \param stream     The stream in witch we search [The input buffer]
+         * \param prefix     What we search [The record's token]
+         * \return           True on success, false otherwise
+         */
+        static constexpr auto starts_with = [](const string_view stream, const string_view prefix) noexcept -> bool {
+            return (stream.rfind(prefix, 0) != string_view::npos);
+        };
+
+        /*!
+         * \brief
+         *       Check if the \c stream ends with the \c postfix
+         * \param stream     The stream in witch we search [The input buffer]
+         * \param postfix    What we search [The record's token]
+         * \return           True on success, false otherwise
+         */
+        static constexpr auto ends_with = [](const string_view stream, const string_view postfix) -> bool {
+            if (stream.size() < postfix.size())
+                return false;
+            return (
+                stream.compare(
+                    stream.size() - postfix.size(),
+                    postfix.size(),
+                    postfix) == 0
+                );
+        };
+
+        /*!
+         * \brief
+         *       Check if the \c haystack contains the \c needle
+         * \param haystack   The stream in witch we search [The input buffer]
+         * \param needle     What we search [The record's token]
+         * \return           True on success, false otherwise
+         */
+        static constexpr auto contains = [](const string_view haystack, const string_view needle) noexcept -> bool {
+            return (haystack.find(needle) != string_view::npos);
+        };
+
+        //! Always false predicate
+        static constexpr auto always_true = [](const string_view s1, const string_view s2) noexcept -> bool {
+            (void)s1; (void)s2;
+            return true;
+        };
+
+        //! Always false predicate
+        static constexpr auto always_false = [](const string_view s1, const string_view s2) noexcept -> bool {
+            (void)s1; (void)s2;
+            return false;
+        };
+
+        //! Empty predicate or handler
+        static constexpr auto nil = nullptr;
+    //! @}
+
+
+
+    //! \name Object lifetime
+    //!@{
+    protected:
+       ~sequencer () = default;                             //!< \brief Allow destructor from derived only
+       constexpr sequencer () noexcept = default;           //!< \brief A default constructor from derived only
+       sequencer(const sequencer&) = delete;                //!< No copies
+       sequencer& operator= (const sequencer&) = delete;    //!< No copy assignments
+    //!@}
+
+    //! \name Sequencer interface requirements for implementer
+    //! @{
+    private:
+       size_t get_ (Data_t* data) { return impl().get (data); }
+       size_t contents_ (Data_t* data) { return impl().contents(data); }
+       size_t put_ (const Data_t* data, size_t n) { return impl().put (data, n); }
+       clock_t clock_ () noexcept { return impl().clock(); }
+    //! @}
+
+    //! \name Private functionality
+    //! @{
+    private:
+
+       /*!
+        * Check if there is a handler and call it
+        * \param handler    The handler to check
+        * \param buffer     String view to buffer to pass to handler
+        * \return           True if handler is called
+        */
+       constexpr bool handle_ (handler_ft handler, const string_view buffer = string_view{}) {
+           if (handler != nullptr) {
+               handler (buffer.begin(), buffer.size());
+               return true;
+           }
+           return false;
+       }
+
+       /*!
+        * \brief
+        *   Return the new sequencer's step value and the sequencer's loop status as pair.
+        *
+        * \param script         Reference to entire script.
+        * \param step           The current step
+        * \return               new step - status pair
+        */
+       template <size_t Steps>
+       constexpr std::pair<size_t, seq_status_t> action_ (const script_t<Steps>& script, size_t step) {
+           control_t skip_while{};
+           size_t s;
+
+           switch (script[step].action.type) {
+               default:
+               case action_t::NO:                   return std::make_pair(step, seq_status_t::CONTINUE);
+               case action_t::NEXT:
+                   switch (script[step].control) {
+                       case control_t::NOP:         return std::make_pair(++step, seq_status_t::CONTINUE);
+                       case control_t::SEND:        return std::make_pair(++step, seq_status_t::CONTINUE);
+                       case control_t::EXPECT:
+                       case control_t::OR_EXPECT:   skip_while = control_t::OR_EXPECT; break;
+                       case control_t::DETECT:
+                       case control_t::OR_DETECT:   skip_while = control_t::OR_DETECT; break;
+                       case control_t::OTHERWISE:   skip_while = control_t::OTHERWISE; break;
+                   }
+                   s = step;
+                   while (script[++s].control == skip_while)
+                       ;
+                                                    return std::make_pair(s, seq_status_t::CONTINUE);
+               case action_t::GOTO:                 return std::make_pair(script[step].action.value, seq_status_t::CONTINUE);
+               case action_t::EXIT:                 return std::make_pair(script[step].action.value, seq_status_t::EXIT);
+
+           }
+       }
+
+        template <size_t Steps>
+        size_t expect_end (const script_t<Steps>& script, size_t step) {
+            while ((++step < Steps) && (script[step].control == control_t::OR_EXPECT)) ;
+            return step;
+        }
+
+        template <size_t Steps>
+        size_t detect_end (const script_t<Steps>& script, size_t step) {
+            while ((++step < Steps) && (script[step].control == control_t::OR_DETECT)) ;
+            return step;
+        }
+    //! @}
+
+
+    public:
+
+       //! \return   The buffer size of the sequencer
+       constexpr size_t size() const noexcept { return N; }
+
+       /*!
+        * \brief
+        *       A static functionality to provide access to sequencer's inner matching mechanism.
+        *       Checks the \c buffer against \c handle and calls its action if needed.
+        *
+        * \param buffer     The buffer to check (1st parameter to match)
+        * \param token      String view to check against buffer (2nd parameter to match)
+        * \param handler    Function pointer to match predicate to use
+        * \param handle     Reference to handle to call on match
+        *
+        * \return           True on match, false otherwise
+        */
+       constexpr bool check_handle (const string_view buffer, const string_view token, match_ft match, handler_ft handle) {
+           if (match != nullptr && match(buffer, token))
+               return handle_ (handle, buffer);
+           return false;
+       }
+
+       /*!
+        * \brief
+        *   Run the script array
+        *
+        * The main sequencer functionality. It starts with the first entry of the array.
+        *
+        * - If the record is \c NOP it executes the action after the timeout.
+        *   \c NOP uses {\c action_t, \c timeout}.
+        * - If the record is \c SEND passes the token to handler (if any), then to put_() and executes the action after that.
+        *   \c SEND uses {\c token, \c handler, \c action_t}
+        * - If the record is \c EXCEPT it continuously try to receive data using \see get_()
+        *     * If no data until timeout, exit with failure
+        *     * On data reception for this record AND for each OR_EXPECT that follows, calls the match predicate
+        *       by passing the received data and token.
+        *       On predicate match
+        *         - Calls the handler if there is one
+        *         - Executes the action. No farther EXPECT, OR_EXPECT, ... checks are made.
+        * - If the record is \c DETECT it continuously try to receive data using \see contents_()
+        *     * If no data until timeout, exit with failure
+        *     * On data reception for this record AND for each OR_DETECT that follows, calls the match predicate
+        *       by passing the received data and token.
+        *       On predicate match
+        *         - Calls the handler if there is one
+        *         - Executes the action. No farther DETECT, OR_DETECT, ... checks are made.
+        *
+        * \tparam Steps     The number of records of the script
+        *
+        * \param script     Reference to script to run
+        * \return           The status of entire operation as described above
+        *   \arg            0       Success
+        *   \arg   (size_t)-1       Failure
+        *   \arg        other       Arbitrary return status
+        */
+       template <size_t Steps>
+       size_t run (const script_t<Steps>& script) {
+           Data_t buffer[N];
+           size_t resp_size;
+
+           size_t step =0, p_step =0;
+           clock_t mark = clock_();
+
+           seq_status_t status{seq_status_t::CONTINUE}; do {
+               if (step >= Steps)
+                   return exit_error.value;
+               const record_t& record = script[step];   // get reference ot current line
+
+               if (step != p_step) {                    // renew time marker in each step
+                   p_step = step;
+                   mark = clock_();
+               }
+               switch (record.control) {
+                   default:
+                   case control_t::NOP:
+                       if ((clock_() - mark) >= record.timeout)
+                           std::tie(step, status) = action_ (script, step);
+                       break;
+
+                   case control_t::SEND:
+                       if (record.handler != nullptr)
+                           record.handler(record.token.data(), record.token.size());
+                       if (put_(record.token.data(), record.token.size()) != record.token.size())
+                	       return exit_error.value;
+                	   std::tie(step, status) = action_ (script, step);
+                       break;
+
+                   case control_t::EXPECT:
+                   case control_t::OR_EXPECT:
+                       resp_size = get_(buffer);
+                       if (resp_size) {
+                           for (size_t s = step ; s < expect_end(script, step) ; ++s) {
+                               if (script[s].match != nullptr && script[s].match({buffer, resp_size}, script[s].token)) {
+                                   handle_ (script[s].handler, {buffer, resp_size});
+                                   std::tie(step, status) = action_ (script, s);
+                                   break;
+                               }
+                           }
+                       }
+                       if (record.timeout && (clock_() - mark) >= record.timeout) {
+                           size_t s = expect_end(script, step);
+                           if ((s < Steps) && (script[s].control == control_t::OTHERWISE)) {
+                               handle_ (script[s].handler, {buffer, resp_size});
+                               std::tie(step, status) = action_ (script, s);
+                           } else {
+                               return exit_error.value;
+                           }
+                       }
+                       break;
+
+                   case control_t::DETECT:
+                   case control_t::OR_DETECT:
+                       resp_size = contents_(buffer);
+                       if (resp_size) {
+                           for (size_t s = step ; s < detect_end(script, step) ; ++s) {
+                               if (script[s].match != nullptr && script[s].match({buffer, resp_size}, script[s].token)) {
+                                   handle_ (script[s].handler, {buffer, resp_size});
+                                   std::tie(step, status) = action_ (script, s);
+                                   break;
+                               }
+                           }
+                       }
+                       if (record.timeout && (clock_() - mark) >= record.timeout) {
+                           size_t s = detect_end(script, step);
+                           if ((s < Steps) && (script[s].control == control_t::OTHERWISE)) {
+                               handle_ (script[s].handler, {buffer, resp_size});
+                               std::tie(step, status) = action_ (script, s);
+                           } else {
+                               return exit_error.value;
+                           }
+                       }
+                       break;
+
+                   case control_t::OTHERWISE:
+                       handle_ (script[step].handler, {buffer, resp_size});
+                       std::tie(step, status) = action_ (script, step);
+                       break;
+               } // switch (record.control)
+
+           } while ( status == seq_status_t::CONTINUE);
+
+           return step; // step here is set by action_ as the return status
+       }
+};
+
+
+}
+#endif /* TBX_COM_SEQUENCER_H_ */

include/cont/deque.h

@@ -33,8 +33,9 @@
 
 #include <core/core.h>
 #include <core/ring_iterator.h>
-
+#include <cont/range.h>
 #include <array>
+#include <atomic>
 
 namespace tbx {
 
@@ -52,14 +53,19 @@ namespace tbx {
  *
  * \tparam Data_t       The char-like queued item type. Usually \c char
  * \tparam N            The size of deque
+ * \tparam SemiAtomic   True for semi-atomic operation. In that case the \c ring_iterator is also atomic.
+ * \note
+ *      SemiAtomic means it is safe to access different ends from different threads. For example one thread can
+ *      push only from front and another can pop from back to implement a queue.
  */
-template <typename Data_t, size_t N>
+template <typename Data_t, size_t N, bool SemiAtomic =false>
 class deque {
     public:
         // meta-identity type
         using type              = deque<Data_t, N>;
         using buffer_t          = std::array<Data_t, N+1>;  // We need N+1 spaces ring buffer for N spaces deque
-        using iterator_t        = ring_iterator<Data_t*, N+1>;
+        using iterator_t        = ring_iterator<Data_t*, N+1, SemiAtomic>;
+        using range_t           = range<iterator_t>;
 
         // STL
         using value_type        = Data_t;
@@ -76,24 +82,32 @@ class deque {
     //! @{
     public:
         //! Default constructor
-        deque () noexcept :
+        constexpr deque () noexcept :
             data_{},
             f{data_.data(), N},
-            r{data_.data()} { }
+            r{data_.data()} {
+                if constexpr (SemiAtomic)
+                    std::atomic_thread_fence(std::memory_order_release);
+            }
 
         //! fill contructor
-        deque(const Data_t& value) noexcept {
+        constexpr deque(const Data_t& value) noexcept {
             data_.fill(value);
             f = iterator(data_.data(), N);
             r = iterator(data_.data(), N);
+            if constexpr (SemiAtomic)
+                std::atomic_thread_fence(std::memory_order_release);
         }
 
         //! Initializer list contructor
         template <typename ...It>
-        deque(It&& ...it) noexcept :
+        constexpr deque(It&& ...it) noexcept :
             data_{{std::forward<It>(it)...}},
-            f(data_.data(), sizeof...(It)),
+            f(data_.data(), N),
-            r(data_.data(), sizeof...(It)) { }
+            r(data_.data(), sizeof...(It)) {
+                if constexpr (SemiAtomic)
+                    std::atomic_thread_fence(std::memory_order_release);
+            }
 
         deque(const deque&) = delete;                   //!< No copies
         deque& operator= (const deque&) = delete;       //!< No copy assignments
@@ -103,38 +117,42 @@ class deque {
     //! \name Iterators
     //! @{
     public:
-        iterator begin() noexcept               { return f+1; }
+        constexpr iterator begin() noexcept               { iterator ret = f; return ++ret; }
-        const_iterator begin() const noexcept   { return f+1; }
+        constexpr const_iterator begin() const noexcept   { iterator ret = f; return ++ret; }
-        const_iterator cbegin() const noexcept  { return f+1; }
+        constexpr const_iterator cbegin() const noexcept  { iterator ret = f; return ++ret; }
 
-        iterator end() noexcept                 { return r; }
+        constexpr iterator end() noexcept                 { return r; }
-        const_iterator end() const noexcept     { return r; }
+        constexpr const_iterator end() const noexcept     { return r; }
-        const_iterator cend() const noexcept    { return r; }
+        constexpr const_iterator cend() const noexcept    { return r; }
 
-        reverse_iterator rbegin() noexcept              { return r; }
+        constexpr reverse_iterator rbegin() noexcept              { return r; }
-        const_reverse_iterator rbegin() const noexcept  { return r; }
+        constexpr const_reverse_iterator rbegin() const noexcept  { return r; }
-        const_reverse_iterator crbegin() const noexcept { return r; }
+        constexpr const_reverse_iterator crbegin() const noexcept { return r; }
 
-        reverse_iterator rend() noexcept                { return f+1; }
+        constexpr reverse_iterator rend() noexcept                { reverse_iterator ret = f; return ++ret; }
-        const_reverse_iterator rend() const noexcept    { return f+1; }
+        constexpr const_reverse_iterator rend() const noexcept    { reverse_iterator ret = f; return ++ret; }
-        const_reverse_iterator crend() const noexcept   { return f+1; }
+        constexpr const_reverse_iterator crend() const noexcept   { reverse_iterator ret = f; return ++ret; }
     //! @}
 
     //! \name Capacity
     //! @{
     public:
         //! \return The size of the deque. The items currently in queue.
-        size_t size() noexcept {
+        constexpr size_t size() noexcept {
-            return full() ? N: (r - f) -1;
+            return r - (f +1);
+        }
+        constexpr size_t size() const noexcept {
+            return r - (f +1);
         }
         //! \return The maximum size of the deque. The items the queue can hold.
-        size_t max_size() noexcept { return N; }
+        constexpr size_t max_size() noexcept { return N; }
         //! \return The capacity of the deque. The items the queue can hold.
-        size_t capacity() noexcept { return N; }
+        constexpr size_t capacity() noexcept { return N; }
         //! \return True if the deque is empty
-        bool   empty()    noexcept { return size() == 0 ? true : false; }
+        constexpr bool   empty()    noexcept { return size() == 0 ? true : false; }
         //! \return True if the deque is full
-        bool   full()     noexcept { return (r == f) ? true : false; }
+        constexpr bool   full()     noexcept { return size() == N ? true : false; }
+
     //! @}
 
     //! \name Member access
@@ -142,44 +160,58 @@ class deque {
     public:
         //! \brief  Clears-empty the deque and return it to init state, without
         //!         really deleting the contents.
-        void clear() noexcept {
+        constexpr void clear() noexcept {
             f = iterator_t(data_.data(), N);
             r = iterator_t(data_.data());
+            if constexpr (SemiAtomic)
+                std::atomic_thread_fence(std::memory_order_release);
         }
         //! \brief      Push an item in the front of the deque
         //! \param it   The item to push
-        void push_front (const Data_t& it) {
+        constexpr void push_front (const Data_t& it) noexcept {
             if (full())     return;
-            *f-- = it;
+            *f = it;
-        }
+            --f;        // keep this separate for thread safety
-        //! \brief      Extract an item from the front of the deque and remove it from the deque
-        //! \param it   The item to push
-        Data_t pop_front () {
-            if (empty())    return Data_t{};
-            return *++f;
         }
         //! \brief      Push an item in the back of the deque
         //! \param it   The item to push
-        void push_back (const Data_t& it) {
+        constexpr void push_back (const Data_t& it) noexcept {
             if (full())     return;
-            *r++ = it;
+            *r = it;
+            ++r;        // keep this separate for thread safety
+        }
+        //! \brief      Extract an item from the front of the deque and remove it from the deque
+        //! \param it   The item to push
+        constexpr Data_t pop_front () noexcept {
+            if (empty())    return Data_t{};
+            return *++f;
         }
         //! \brief      Extract an item from the back of the deque and remove it from the deque
         //! \param it   The item to push
-        Data_t pop_back () {
+        constexpr Data_t pop_back () noexcept {
             if (empty())    return Data_t{};
             return *--r;
         }
 
         //! \brief      Get a reference to the item in the front of the deque without extracting it.
         //! \return     Reference to the item
-        Data_t& front() noexcept { return *(f+1); }
+        constexpr Data_t& front() noexcept { iterator_t it = f; return *++it; }
-        const Data_t& front() const noexcept { return *(f+1); }
+        constexpr const Data_t& front() const noexcept { iterator_t it = f; return *++it; }
 
         //! \brief      Get a reference to the item in the front of the deque without extracting it.
         //! \return     Reference to the item
-        Data_t& back() noexcept { return *(r-1); }
+        constexpr Data_t& back() noexcept { iterator_t it = r; return *--it; }
-        const Data_t& back() const noexcept { return *(r-1); }
+        constexpr const Data_t& back() const noexcept { iterator_t it = r; return *--it; }
+
+        //! \brief      Get a pointer to the begin of the items on the deque
+        //! \return
+        constexpr Data_t* data() noexcept { return &front(); }
+        constexpr const Data_t* data() const noexcept { return &front(); }
+
+        //! \brief      Get a range for the data in queue
+        //! \return     A begin-end iterator pair struct
+        constexpr range_t contents () noexcept { iterator_t b = f; return {++b, r}; }
+        constexpr const range_t contents () const noexcept { iterator_t b = f; return {++b, r}; }
 
     //! @}
     private:

include/cont/edeque.h

@@ -56,16 +56,21 @@ namespace tbx {
  *    \c Fn
  *
  * \tparam Data_t       The char-like queued item type. Usually \c char
- * \tparam N        The size of deque
+ * \tparam N            The size of edeque
+ * \tparam SemiAtomic   True for semi-atomic operation. In that case the \c ring_iterator is also atomic.
  * \tparam Fn           The type of Callable
+ * \note
+ *      SemiAtomic means it is safe to access different ends from different threads. For example one thread can
+ *      push only from front and another can pop from back to implement a queue.
  */
-template <typename Data_t, size_t N, typename Fn = std::function<void()>>
+template <typename Data_t, size_t N, bool SemiAtomic =false, typename Fn = std::function<void()>>
-class edeque : public deque<Data_t, N> {
+class edeque : public deque<Data_t, N, SemiAtomic> {
     public:
         // meta-identity types
-        using type                  = edeque<Data_t, N>;
+        using type                  = edeque<Data_t, N, SemiAtomic, Fn>;
-        using base_type             = deque<Data_t, N>;
+        using base_type             = deque<Data_t, N, SemiAtomic>;
         using callable_t            = Fn;
+        using range_t               = typename base_type::range_t;
 
         // STL
         using value_type            = typename base_type::value_type;
@@ -89,7 +94,11 @@ class edeque : public deque<Data_t, N> {
         enum class size_match { DISABLED =0, EQ, NE, LT, LE, GT, GE };
         //! \enum data_match
         //! The type of matching for data based match
-        enum class data_match { DISABLED =0, MATCH, MISMATCH};
+        enum class data_match { DISABLED =0, MATCH_PUSH, MATCH_POP, MISMATCH_PUSH, MISMATCH_POP};
+
+//        TODO: trigger mode for one-shot or repeated functionality
+//        enum class trigger_mode { ONE_SHOT, REPEATED };
+
         //! \struct size_trigger
         //! Size trigger data type
         struct size_trigger {
@@ -117,19 +126,19 @@ class edeque : public deque<Data_t, N> {
     //! @{
     public:
         //! Default constructor
-        edeque () noexcept :
+        constexpr edeque () noexcept :
             base_type() { }
 
-        //!
+        //! Size trigger constructor
-        edeque (size_match match, size_t size, callable_t&& fn) :
+        constexpr edeque (size_match match, size_t size, callable_t&& fn) noexcept :
             base_type(),
             mode_{match_mode::SIZE},
             callback_{std::forward<callable_t>(fn)} {
             trigger_.tsize.type = match;
             trigger_.tsize.size = size;
         }
-
+        //! Data trigger constructor
-        edeque (data_match match, Data_t value, callable_t&& fn) :
+        constexpr edeque (data_match match, Data_t value, callable_t&& fn) noexcept :
             base_type(),
             mode_{match_mode::DATA},
             callback_{std::forward<callable_t>(fn)} {
@@ -144,7 +153,7 @@ class edeque : public deque<Data_t, N> {
         //! \brief
         //!     Manually checks the size trigger and calls it we have match.
         //! \return     True if the callable has called.
-        bool check_trigger () {
+        bool check_trigger () noexcept {
             return check_trigger_size_();
         }
 
@@ -154,7 +163,7 @@ class edeque : public deque<Data_t, N> {
         //! \param match    The match type
         //! \param size     The size for with we check against
         //! \param fn       The callable to call on match
-        void set_trigger (size_match match, size_t size, callable_t&& fn) {
+        void set_trigger (size_match match, size_t size, callable_t&& fn) noexcept {
             mode_               = match_mode::SIZE;
             trigger_.tsize.type = match;
             trigger_.tsize.size = size;
@@ -167,7 +176,7 @@ class edeque : public deque<Data_t, N> {
         //! \param match    The match type
         //! \param value    The value for with we check against
         //! \param fn       The callable to call on match
-        void set_trigger (data_match match, Data_t value, callable_t&& fn) {
+        void set_trigger (data_match match, Data_t value, callable_t&& fn) noexcept {
             mode_               = match_mode::DATA;
             trigger_.tdata.type = match;
             trigger_.tdata.value= value;
@@ -175,36 +184,36 @@ class edeque : public deque<Data_t, N> {
         }
 
         //! \brief Manually clears the trigger
-        void clear_trigger () {
+        void clear_trigger () noexcept {
             mode_       = match_mode{};
             trigger_    = trigger{};
             callback_   = callable_t{};
         }
     //! @}
 
-    //!  \name Base class overwrites
+    //!  \name Base class uses and overwrites
     //! @{
-        void push_front (const Data_t& it) {
+        void push_front (const Data_t& it) noexcept {
             base_type::push_front(it);
-            check_trigger_async_(it);
+            check_trigger_push_async_(it);
         }
-        Data_t pop_front () {
+        void push_back (const Data_t& it) noexcept {
+            base_type::push_back(it);
+            check_trigger_push_async_(it);
+        }
+        Data_t pop_front () noexcept {
             Data_t t = base_type::pop_front();
-            check_trigger_async_(t);
+            check_trigger_pop_async_(t);
             return t;
         }
-        void push_back (const Data_t& it) {
+        Data_t pop_back () noexcept {
-            base_type::push_back(it);
-            check_trigger_async_(it);
-        }
-        Data_t pop_back () {
             Data_t t = base_type::pop_back();
-            check_trigger_async_(t);
+            check_trigger_pop_async_(t);
             return t;
         }
     //! @}
 
-    //! \name Public interface
+    //! \name Private functionality
     //! @{
     private:
         //! \brief
@@ -230,28 +239,53 @@ class edeque : public deque<Data_t, N> {
         }
 
         //! \brief
-        //!     Manually checks the data trigger and calls it we have match.
+        //!     Manually checks the data trigger on push and calls it we have match.
         //! \param  it  The item to check against
         //! \return     True if the callable has called.
-        bool check_trigger_value_ (const Data_t& it) {
+        bool check_trigger_push_value_ (const Data_t& it) {
             bool match;
             switch (trigger_.tdata.type) {
                 default:
                 case data_match::DISABLED:      match = false;  break;
-                case data_match::MATCH:     match = (it == trigger_.tdata.value); break;
+                case data_match::MATCH_PUSH:    match = (it == trigger_.tdata.value); break;
-                case data_match::MISMATCH:  match = (it != trigger_.tdata.value); break;
+                case data_match::MISMATCH_PUSH: match = (it != trigger_.tdata.value); break;
             }
             if (match)
                 callback_();
             return match;
         }
 
-        //! Wrapper for both triggers
+        //! \brief
-        bool check_trigger_async_ (const Data_t& it) {
+        //!     Manually checks the data trigger on pop and calls it we have match.
+        //! \param  it  The item to check against
+        //! \return     True if the callable has called.
+        bool check_trigger_pop_value_ (const Data_t& it) {
+            bool match;
+            switch (trigger_.tdata.type) {
+                default:
+                case data_match::DISABLED:      match = false;  break;
+                case data_match::MATCH_POP:     match = (it == trigger_.tdata.value); break;
+                case data_match::MISMATCH_POP:  match = (it != trigger_.tdata.value); break;
+            }
+            if (match)
+                callback_();
+            return match;
+        }
+
+        //! Wrapper for both triggers at push
+        bool check_trigger_push_async_ (const Data_t& it) {
             switch (mode_) {
                 default:
                 case match_mode::SIZE:  return check_trigger_size_();
-                case match_mode::DATA:  return check_trigger_value_(it);
+                case match_mode::DATA:  return check_trigger_push_value_(it);
+            }
+        }
+        //! Wrapper for both triggers at pop
+        bool check_trigger_pop_async_ (const Data_t& it) {
+            switch (mode_) {
+                default:
+                case match_mode::SIZE:  return check_trigger_size_();
+                case match_mode::DATA:  return check_trigger_pop_value_(it);
             }
         }
     //! @}

include/cont/equeue.h

@@ -0,0 +1,146 @@
+/*!
+ * \file cont/equeue.h
+ * \brief
+ *      A queue with event based callables based on edeque.
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_CONT_EQUQUE_H_
+#define TBX_CONT_EQUQUE_H_
+
+#include <core/core.h>
+#include <cont/edeque.h>
+
+namespace tbx {
+
+/*!
+ * \class equeue
+ * \brief
+ *      A statically allocated queue based on edeque with size and data matching
+ *      event based callables.
+ *
+ * We use the \ref edeque::push_back() and \ref edeque::pop_front() pair from edeque's
+ * functionality, so at the \c push the increment performed after the insertion.
+ * Similarly at the \c pop the decrement performed before the exctraction. This way also
+ * the \ref edeque::front() and \ref edeque::back() stay the same ;)
+ *
+ * We also provide stream operators.
+ *
+ * \tparam Data_t       The char-like queued item type. Usually \c char
+ * \tparam N            The size of edeque
+ * \tparam SemiAtomic   True for semi-atomic operation. In that case the \c ring_iterator is also atomic.
+ * \tparam Fn           The type of Callable
+ * \note
+ *      SemiAtomic means it is safe to for one thread to  push only from front and another can pop.
+ */
+template <typename Data_t, size_t N, bool SemiAtomic =false, typename Fn = std::function<void()>>
+class equeue : public edeque<Data_t, N, SemiAtomic, Fn> {
+    public:
+        // meta-identity types
+        using equeue_t              = equeue<Data_t, N, SemiAtomic, Fn>;
+        using base_type             = edeque<Data_t, N, SemiAtomic, Fn>;
+        using range_t               = typename base_type::range_t;
+
+        // STL
+        using value_type            = typename base_type::value_type;
+        using reference             = typename base_type::reference;
+        using const_reference       = typename base_type::const_reference;
+        using pointer               = typename base_type::pointer;
+        using const_pointer         = typename base_type::const_pointer;
+        using iterator              = typename base_type::iterator;
+        using const_iterator        = typename base_type::const_iterator;
+        using reverse_iterator      = typename base_type::reverse_iterator;
+        using const_reverse_iterator= typename base_type::const_reverse_iterator;
+
+    //! \name Constructor / Destructor
+    //! @{
+    public:
+        //! Default constructor
+        constexpr equeue () noexcept : base_type() { }
+
+        //! Forward constructor
+        template <typename ...It>
+        constexpr equeue(It&& ...it) noexcept : base_type(std::forward<It>(it)...) { }
+
+    //! @}
+
+    //! \name Member access
+    //! @{
+    public:
+        //! \brief      Push an item in the back of the queue
+        //! \param it   The item to push
+        void push (const Data_t& it) noexcept {
+            base_type::push_back(it);
+        }
+
+        //! \brief      Extract an item from the front of the queue and remove it from the queue
+        //! \param it   The item to push
+        Data_t pop () noexcept {
+            return base_type::pop_front();
+        }
+
+        //! \brief      Push an item in the back of the queue
+        //! \param it   The item to push
+        equeue_t& operator<< (const Data_t& it) noexcept {
+            push(it);
+            return *this;
+        }
+
+        //! \brief      Push an item in the back of the queue
+        //! \param it   The item to push
+        equeue_t& operator>> (Data_t& it) noexcept {
+            it = pop();
+            return *this;
+        }
+
+    //! @}
+
+};
+
+/*!
+ * \brief
+ *      Pop an item from the front of the queue.
+ *
+ *  This definition enables the "data << equeue" syntax for pop operation
+ *
+ *  \tparam Data_t      The char-like queued item type. Usually \c char
+ *  \tparam N           The size of queue
+ *  \tparam SemiAtomic  True for semi-atomic operation. In that case the \c ring_iterator is also atomic.
+ *  \tparam Fn          The type of Callable
+ *
+ *  \param it       The item to write to
+ *  \param q        The queue to read from
+ *  \return         Reference to the returned item
+ */
+template <typename Data_t, size_t N, bool SemiAtomic =false, typename Fn = std::function<void()>>
+Data_t& operator<< (Data_t& it, equeue<Data_t, N, SemiAtomic, Fn>& q) noexcept {
+    it = q.pop();
+    return it;
+}
+
+}
+
+#endif /* TBX_CONT_EQUQUE_H_ */

include/cont/queue.h

@@ -37,7 +37,7 @@
 namespace tbx {
 
 /*!
- * \class deque
+ * \class queue
  * \brief
  *      A statically allocated queue based on deque.
  *
@@ -49,14 +49,18 @@ namespace tbx {
  * We also provide stream operators.
  *
  * \tparam Data_t       The char-like queued item type. Usually \c char
- * \tparam N        The size of deque
+ * \tparam N            The size of queue
+ * \tparam SemiAtomic   True for semi-atomic operation. In that case the \c ring_iterator is also atomic.
+ * \note
+ *      SemiAtomic means it is safe to for one thread to  push only from front and another can pop.
  */
-template <typename Data_t, size_t N>
+template <typename Data_t, size_t N, bool SemiAtomic =false>
-class queue : public deque<Data_t, N> {
+class queue : public deque<Data_t, N, SemiAtomic> {
     public:
         // meta-identity types
-        using queue_t               = queue<Data_t, N>;
+        using queue_t               = queue<Data_t, N, SemiAtomic>;
-        using base_type             = deque<Data_t, N>;
+        using base_type             = deque<Data_t, N, SemiAtomic>;
+        using range_t               = typename base_type::range_t;
 
         // STL
         using value_type            = typename base_type::value_type;
@@ -73,14 +77,14 @@ class queue : public deque<Data_t, N> {
     //! @{
     public:
         //! Default constructor
-        queue () noexcept : base_type() { }
+        constexpr queue () noexcept : base_type() { }
 
         //! fill contructor
-        queue(const Data_t& value) noexcept : base_type(value) { }
+        constexpr queue(const Data_t& value) noexcept : base_type(value) { }
 
         //! Initializer list contructor
         template <typename ...It>
-        queue(It&& ...it) noexcept : base_type(std::forward<It>(it)...) { }
+        constexpr queue(It&& ...it) noexcept : base_type(std::forward<It>(it)...) { }
 
     //! @}
 
@@ -89,34 +93,52 @@ class queue : public deque<Data_t, N> {
     public:
         //! \brief      Push an item in the back of the queue
         //! \param it   The item to push
-        void push (const Data_t& it) {
+        constexpr void push (const Data_t& it) noexcept {
             base_type::push_back(it);
         }
 
         //! \brief      Extract an item from the front of the queue and remove it from the queue
         //! \param it   The item to push
-        Data_t pop () {
+        constexpr Data_t pop () noexcept {
             return base_type::pop_front();
         }
 
         //! \brief      Push an item in the back of the queue
         //! \param it   The item to push
-        queue_t& operator<< (const Data_t& it) {
+        constexpr queue_t& operator<< (const Data_t& it) noexcept {
             push(it);
             return *this;
         }
 
-        //! \brief      Push an item in the back of the queue
+        //! \brief      Pop an item from the front of the queue
-        //! \param it   The item to push
+        //! \param it   The item to write to
-        queue_t& operator>> (Data_t& it) {
+        constexpr queue_t& operator>> (Data_t& it) noexcept {
             it = pop();
             return *this;
         }
-
     //! @}
-
 };
 
+/*!
+ * \brief
+ *      Pop an item from the front of the queue.
+ *
+ *  This definition enables the "data << queue" syntax for pop operation
+ *
+ *  \tparam Data_t      The char-like queued item type. Usually \c char
+ *  \tparam N           The size of queue
+ *  \tparam SemiAtomic  True for semi-atomic operation. In that case the \c ring_iterator is also atomic.
+ *
+ *  \param it       The item to write to
+ *  \param q        The queue to read from
+ *  \return         Reference to the returned item
+ */
+template <typename Data_t, size_t N, bool SemiAtomic =false>
+constexpr Data_t& operator<< (Data_t& it, queue<Data_t, N, SemiAtomic>& q) noexcept {
+    it = q.pop();
+    return it;
 }
 
+} // namespace tbx
+
 #endif /* TBX_CONT_QUQUE_H_ */

include/cont/range.h

@@ -0,0 +1,64 @@
+/*!
+ * \file cont/range.h
+ * \brief
+ *      A plain definition of a range struct with agregate initialization
+ *      and begin-end pairs.
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_CONT_RANGE_H_
+#define TBX_CONT_RANGE_H_
+
+#include <core/core.h>
+
+namespace tbx {
+
+/*!
+ * \brief
+ *  A plain definition of a range struct with begin-end pairs.
+ *
+ * \tparam Iter_t   The iterator type of the range
+ */
+template <typename Iter_t>
+struct range {
+    Iter_t  b{}, e{};
+
+//    range () = default;
+//    range (const Iter_t& first, const Iter_t& last) noexcept :
+//        b(first), e(last) { }
+//    range (Iter_t first, Iter_t last) noexcept :
+//        b(first), e(last) { }
+
+    Iter_t begin()              { return b; }
+    const Iter_t begin() const  { return b; }
+    const Iter_t cbegin() const { return b; }
+    Iter_t end()                { return e; }
+    const Iter_t end() const    { return e; }
+    const Iter_t cend() const   { return e; }
+};
+
+}
+#endif /* TBX_CONT_RANGE_H_ */

include/cont/span.h

@@ -0,0 +1,607 @@
+/*
+ * This is an implementation of C++20's std::span
+ * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/n4820.pdf
+ */
+
+//          Copyright Tristan Brindle 2018.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#ifndef TBX_CONT_SPAN_H_
+#define TBX_CONT_SPAN_H_
+
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <type_traits>
+
+#ifndef TBX_SPAN_NO_EXCEPTIONS
+// Attempt to discover whether we're being compiled with exception support
+#if !(defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND))
+#define TBX_SPAN_NO_EXCEPTIONS
+#endif
+#endif
+
+#ifndef TBX_SPAN_NO_EXCEPTIONS
+#include <cstdio>
+#include <stdexcept>
+#endif
+
+// Various feature test macros
+
+#if __cplusplus >= 201703L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
+#define TBX_SPAN_HAVE_CPP17
+#endif
+
+#if __cplusplus >= 201402L || (defined(_MSVC_LANG) && _MSVC_LANG >= 201402L)
+#define TBX_SPAN_HAVE_CPP14
+#endif
+
+namespace tbx {
+
+// Establish default contract checking behavior
+#if !defined(TBX_SPAN_THROW_ON_CONTRACT_VIOLATION) &&                          \
+    !defined(TBX_SPAN_TERMINATE_ON_CONTRACT_VIOLATION) &&                      \
+    !defined(TBX_SPAN_NO_CONTRACT_CHECKING)
+#if defined(NDEBUG) || !defined(TBX_SPAN_HAVE_CPP14)
+#define TBX_SPAN_NO_CONTRACT_CHECKING
+#else
+#define TBX_SPAN_TERMINATE_ON_CONTRACT_VIOLATION
+#endif
+#endif
+
+#if defined(TBX_SPAN_THROW_ON_CONTRACT_VIOLATION)
+struct contract_violation_error : std::logic_error {
+    explicit contract_violation_error(const char* msg) : std::logic_error(msg)
+    {}
+};
+
+inline void contract_violation(const char* msg)
+{
+    throw contract_violation_error(msg);
+}
+
+#elif defined(TBX_SPAN_TERMINATE_ON_CONTRACT_VIOLATION)
+[[noreturn]] inline void contract_violation(const char* /*unused*/)
+{
+    std::terminate();
+}
+#endif
+
+#if !defined(TBX_SPAN_NO_CONTRACT_CHECKING)
+#define TBX_SPAN_STRINGIFY(cond) #cond
+#define TBX_SPAN_EXPECT(cond)                                                  \
+    cond ? (void) 0 : contract_violation("Expected " TBX_SPAN_STRINGIFY(cond))
+#else
+#define TBX_SPAN_EXPECT(cond)
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP17) || defined(__cpp_inline_variables)
+#define TBX_SPAN_INLINE_VAR inline
+#else
+#define TBX_SPAN_INLINE_VAR
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP14) ||                                            \
+    (defined(__cpp_constexpr) && __cpp_constexpr >= 201304)
+#define TBX_SPAN_HAVE_CPP14_CONSTEXPR
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP14_CONSTEXPR)
+#define TBX_SPAN_CONSTEXPR14 constexpr
+#else
+#define TBX_SPAN_CONSTEXPR14
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP14_CONSTEXPR) &&                                  \
+    (!defined(_MSC_VER) || _MSC_VER > 1900)
+#define TBX_SPAN_CONSTEXPR_ASSIGN constexpr
+#else
+#define TBX_SPAN_CONSTEXPR_ASSIGN
+#endif
+
+#if defined(TBX_SPAN_NO_CONTRACT_CHECKING)
+#define TBX_SPAN_CONSTEXPR11 constexpr
+#else
+#define TBX_SPAN_CONSTEXPR11 TBX_SPAN_CONSTEXPR14
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP17) || defined(__cpp_deduction_guides)
+#define TBX_SPAN_HAVE_DEDUCTION_GUIDES
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP17) || defined(__cpp_lib_byte)
+#define TBX_SPAN_HAVE_STD_BYTE
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP17) || defined(__cpp_lib_array_constexpr)
+#define TBX_SPAN_HAVE_CONSTEXPR_STD_ARRAY_ETC
+#endif
+
+#if defined(TBX_SPAN_HAVE_CONSTEXPR_STD_ARRAY_ETC)
+#define TBX_SPAN_ARRAY_CONSTEXPR constexpr
+#else
+#define TBX_SPAN_ARRAY_CONSTEXPR
+#endif
+
+#ifdef TBX_SPAN_HAVE_STD_BYTE
+using byte = std::byte;
+#else
+using byte = unsigned char;
+#endif
+
+#if defined(TBX_SPAN_HAVE_CPP17)
+#define TBX_SPAN_NODISCARD [[nodiscard]]
+#else
+#define TBX_SPAN_NODISCARD
+#endif
+
+TBX_SPAN_INLINE_VAR constexpr std::size_t dynamic_extent = SIZE_MAX;
+
+template <typename ElementType, std::size_t Extent = dynamic_extent>
+class span;
+
+namespace detail {
+
+template <typename E, std::size_t S>
+struct span_storage {
+    constexpr span_storage() noexcept = default;
+
+    constexpr span_storage(E* p_ptr, std::size_t /*unused*/) noexcept
+       : ptr(p_ptr)
+    {}
+
+    E* ptr = nullptr;
+    static constexpr std::size_t size = S;
+};
+
+template <typename E>
+struct span_storage<E, dynamic_extent> {
+    constexpr span_storage() noexcept = default;
+
+    constexpr span_storage(E* p_ptr, std::size_t p_size) noexcept
+        : ptr(p_ptr), size(p_size)
+    {}
+
+    E* ptr = nullptr;
+    std::size_t size = 0;
+};
+
+// Reimplementation of C++17 std::size() and std::data()
+#if defined(TBX_SPAN_HAVE_CPP17) ||                \
+    defined(__cpp_lib_nonmember_container_access)
+using std::data;
+using std::size;
+#else
+template <class C>
+constexpr auto size(const C& c) -> decltype(c.size())
+{
+    return c.size();
+}
+
+template <class T, std::size_t N>
+constexpr std::size_t size(const T (&)[N]) noexcept
+{
+    return N;
+}
+
+template <class C>
+constexpr auto data(C& c) -> decltype(c.data())
+{
+    return c.data();
+}
+
+template <class C>
+constexpr auto data(const C& c) -> decltype(c.data())
+{
+    return c.data();
+}
+
+template <class T, std::size_t N>
+constexpr T* data(T (&array)[N]) noexcept
+{
+    return array;
+}
+
+template <class E>
+constexpr const E* data(std::initializer_list<E> il) noexcept
+{
+    return il.begin();
+}
+#endif // TBX_SPAN_HAVE_CPP17
+
+#if defined(TBX_SPAN_HAVE_CPP17) || defined(__cpp_lib_void_t)
+using std::void_t;
+#else
+template <typename...>
+using void_t = void;
+#endif
+
+template <typename T>
+using uncvref_t =
+    typename std::remove_cv<typename std::remove_reference<T>::type>::type;
+
+template <typename>
+struct is_span : std::false_type {};
+
+template <typename T, std::size_t S>
+struct is_span<span<T, S>> : std::true_type {};
+
+template <typename>
+struct is_std_array : std::false_type {};
+
+template <typename T, std::size_t N>
+struct is_std_array<std::array<T, N>> : std::true_type {};
+
+template <typename, typename = void>
+struct has_size_and_data : std::false_type {};
+
+template <typename T>
+struct has_size_and_data<T, void_t<decltype(detail::size(std::declval<T>())),
+                                   decltype(detail::data(std::declval<T>()))>>
+    : std::true_type {};
+
+template <typename C, typename U = uncvref_t<C>>
+struct is_container {
+    static constexpr bool value =
+        !is_span<U>::value && !is_std_array<U>::value &&
+        !std::is_array<U>::value && has_size_and_data<C>::value;
+};
+
+template <typename T>
+using remove_pointer_t = typename std::remove_pointer<T>::type;
+
+template <typename, typename, typename = void>
+struct is_container_element_type_compatible : std::false_type {};
+
+template <typename T, typename E>
+struct is_container_element_type_compatible<
+    T, E,
+    typename std::enable_if<
+        !std::is_same<typename std::remove_cv<decltype(
+                          detail::data(std::declval<T>()))>::type,
+                      void>::value>::type>
+    : std::is_convertible<
+          remove_pointer_t<decltype(detail::data(std::declval<T>()))> (*)[],
+          E (*)[]> {};
+
+template <typename, typename = size_t>
+struct is_complete : std::false_type {};
+
+template <typename T>
+struct is_complete<T, decltype(sizeof(T))> : std::true_type {};
+
+} // namespace detail
+
+template <typename ElementType, std::size_t Extent>
+class span {
+    static_assert(std::is_object<ElementType>::value,
+                  "A span's ElementType must be an object type (not a "
+                  "reference type or void)");
+    static_assert(detail::is_complete<ElementType>::value,
+                  "A span's ElementType must be a complete type (not a forward "
+                  "declaration)");
+    static_assert(!std::is_abstract<ElementType>::value,
+                  "A span's ElementType cannot be an abstract class type");
+
+    using storage_type = detail::span_storage<ElementType, Extent>;
+
+public:
+    // constants and types
+    using element_type = ElementType;
+    using value_type = typename std::remove_cv<ElementType>::type;
+    using size_type = std::size_t;
+    using difference_type = std::ptrdiff_t;
+    using pointer = element_type*;
+    using const_pointer = const element_type*;
+    using reference = element_type&;
+    using const_reference = const element_type&;
+    using iterator = pointer;
+    using reverse_iterator = std::reverse_iterator<iterator>;
+
+    static constexpr size_type extent = Extent;
+
+    // [span.cons], span constructors, copy, assignment, and destructor
+    template <
+        std::size_t E = Extent,
+        typename std::enable_if<(E == dynamic_extent || E <= 0), int>::type = 0>
+    constexpr span() noexcept
+    {}
+
+    TBX_SPAN_CONSTEXPR11 span(pointer ptr, size_type count)
+        : storage_(ptr, count)
+    {
+        TBX_SPAN_EXPECT(extent == dynamic_extent || count == extent);
+    }
+
+    TBX_SPAN_CONSTEXPR11 span(pointer first_elem, pointer last_elem)
+        : storage_(first_elem, last_elem - first_elem)
+    {
+        TBX_SPAN_EXPECT(extent == dynamic_extent ||
+                        last_elem - first_elem ==
+                            static_cast<std::ptrdiff_t>(extent));
+    }
+
+    template <std::size_t N, std::size_t E = Extent,
+              typename std::enable_if<
+                  (E == dynamic_extent || N == E) &&
+                      detail::is_container_element_type_compatible<
+                          element_type (&)[N], ElementType>::value,
+                  int>::type = 0>
+    constexpr span(element_type (&arr)[N]) noexcept : storage_(arr, N)
+    {}
+
+    template <std::size_t N, std::size_t E = Extent,
+              typename std::enable_if<
+                  (E == dynamic_extent || N == E) &&
+                      detail::is_container_element_type_compatible<
+                          std::array<value_type, N>&, ElementType>::value,
+                  int>::type = 0>
+    TBX_SPAN_ARRAY_CONSTEXPR span(std::array<value_type, N>& arr) noexcept
+        : storage_(arr.data(), N)
+    {}
+
+    template <std::size_t N, std::size_t E = Extent,
+              typename std::enable_if<
+                  (E == dynamic_extent || N == E) &&
+                      detail::is_container_element_type_compatible<
+                          const std::array<value_type, N>&, ElementType>::value,
+                  int>::type = 0>
+    TBX_SPAN_ARRAY_CONSTEXPR span(const std::array<value_type, N>& arr) noexcept
+        : storage_(arr.data(), N)
+    {}
+
+    template <
+        typename Container, std::size_t E = Extent,
+        typename std::enable_if<
+            E == dynamic_extent && detail::is_container<Container>::value &&
+                detail::is_container_element_type_compatible<
+                    Container&, ElementType>::value,
+            int>::type = 0>
+    constexpr span(Container& cont)
+//        : storage_(detail::data(cont), detail::size(cont))
+        : storage_(cont.data(), cont.size())
+    {}
+
+    template <
+        typename Container, std::size_t E = Extent,
+        typename std::enable_if<
+            E == dynamic_extent && detail::is_container<Container>::value &&
+                detail::is_container_element_type_compatible<
+                    const Container&, ElementType>::value,
+            int>::type = 0>
+    constexpr span(const Container& cont)
+        : storage_(detail::data(cont), detail::size(cont))
+    {}
+
+    constexpr span(const span& other) noexcept = default;
+
+    template <typename OtherElementType, std::size_t OtherExtent,
+              typename std::enable_if<
+                  (Extent == OtherExtent || Extent == dynamic_extent) &&
+                      std::is_convertible<OtherElementType (*)[],
+                                          ElementType (*)[]>::value,
+                  int>::type = 0>
+    constexpr span(const span<OtherElementType, OtherExtent>& other) noexcept
+        : storage_(other.data(), other.size())
+    {}
+
+    ~span() noexcept = default;
+
+    TBX_SPAN_CONSTEXPR_ASSIGN span&
+    operator=(const span& other) noexcept = default;
+
+    // [span.sub], span subviews
+    template <std::size_t Count>
+    TBX_SPAN_CONSTEXPR11 span<element_type, Count> first() const
+    {
+        TBX_SPAN_EXPECT(Count <= size());
+        return {data(), Count};
+    }
+
+    template <std::size_t Count>
+    TBX_SPAN_CONSTEXPR11 span<element_type, Count> last() const
+    {
+        TBX_SPAN_EXPECT(Count <= size());
+        return {data() + (size() - Count), Count};
+    }
+
+    template <std::size_t Offset, std::size_t Count = dynamic_extent>
+    using subspan_return_t =
+        span<ElementType, Count != dynamic_extent
+                              ? Count
+                              : (Extent != dynamic_extent ? Extent - Offset
+                                                          : dynamic_extent)>;
+
+    template <std::size_t Offset, std::size_t Count = dynamic_extent>
+    TBX_SPAN_CONSTEXPR11 subspan_return_t<Offset, Count> subspan() const
+    {
+        TBX_SPAN_EXPECT(Offset <= size() &&
+                        (Count == dynamic_extent || Offset + Count <= size()));
+        return {data() + Offset,
+                Count != dynamic_extent ? Count : size() - Offset};
+    }
+
+    TBX_SPAN_CONSTEXPR11 span<element_type, dynamic_extent>
+    first(size_type count) const
+    {
+        TBX_SPAN_EXPECT(count <= size());
+        return {data(), count};
+    }
+
+    TBX_SPAN_CONSTEXPR11 span<element_type, dynamic_extent>
+    last(size_type count) const
+    {
+        TBX_SPAN_EXPECT(count <= size());
+        return {data() + (size() - count), count};
+    }
+
+    TBX_SPAN_CONSTEXPR11 span<element_type, dynamic_extent>
+    subspan(size_type offset, size_type count = dynamic_extent) const
+    {
+        TBX_SPAN_EXPECT(offset <= size() &&
+                        (count == dynamic_extent || offset + count <= size()));
+        return {data() + offset,
+                count == dynamic_extent ? size() - offset : count};
+    }
+
+    // [span.obs], span observers
+    constexpr size_type size() const noexcept { return storage_.size; }
+
+    constexpr size_type size_bytes() const noexcept
+    {
+        return size() * sizeof(element_type);
+    }
+
+    TBX_SPAN_NODISCARD constexpr bool empty() const noexcept
+    {
+        return size() == 0;
+    }
+
+    // [span.elem], span element access
+    TBX_SPAN_CONSTEXPR11 reference operator[](size_type idx) const
+    {
+        TBX_SPAN_EXPECT(idx < size());
+        return *(data() + idx);
+    }
+
+    TBX_SPAN_CONSTEXPR11 reference front() const
+    {
+        TBX_SPAN_EXPECT(!empty());
+        return *data();
+    }
+
+    TBX_SPAN_CONSTEXPR11 reference back() const
+    {
+        TBX_SPAN_EXPECT(!empty());
+        return *(data() + (size() - 1));
+    }
+
+    constexpr pointer data() const noexcept { return storage_.ptr; }
+
+    // [span.iterators], span iterator support
+    constexpr iterator begin() const noexcept { return data(); }
+
+    constexpr iterator end() const noexcept { return data() + size(); }
+
+    TBX_SPAN_ARRAY_CONSTEXPR reverse_iterator rbegin() const noexcept
+    {
+        return reverse_iterator(end());
+    }
+
+    TBX_SPAN_ARRAY_CONSTEXPR reverse_iterator rend() const noexcept
+    {
+        return reverse_iterator(begin());
+    }
+
+private:
+    storage_type storage_{};
+};
+
+#ifdef TBX_SPAN_HAVE_DEDUCTION_GUIDES
+
+/* Deduction Guides */
+template <class T, size_t N>
+span(T (&)[N])->span<T, N>;
+
+template <class T, size_t N>
+span(std::array<T, N>&)->span<T, N>;
+
+template <class T, size_t N>
+span(const std::array<T, N>&)->span<const T, N>;
+
+template <class Container>
+span(Container&)->span<typename Container::value_type>;
+
+template <class Container>
+span(const Container&)->span<const typename Container::value_type>;
+
+#endif // TCB_HAVE_DEDUCTION_GUIDES
+
+template <typename ElementType, std::size_t Extent>
+constexpr span<ElementType, Extent>
+make_span(span<ElementType, Extent> s) noexcept
+{
+    return s;
+}
+
+template <typename T, std::size_t N>
+constexpr span<T, N> make_span(T (&arr)[N]) noexcept
+{
+    return {arr};
+}
+
+template <typename T, std::size_t N>
+TBX_SPAN_ARRAY_CONSTEXPR span<T, N> make_span(std::array<T, N>& arr) noexcept
+{
+    return {arr};
+}
+
+template <typename T, std::size_t N>
+TBX_SPAN_ARRAY_CONSTEXPR span<const T, N>
+make_span(const std::array<T, N>& arr) noexcept
+{
+    return {arr};
+}
+
+template <typename Container>
+constexpr span<typename Container::value_type> make_span(Container& cont)
+{
+    return {cont};
+}
+
+template <typename Container>
+constexpr span<const typename Container::value_type>
+make_span(const Container& cont)
+{
+    return {cont};
+}
+
+template <typename ElementType, std::size_t Extent>
+span<const byte, ((Extent == dynamic_extent) ? dynamic_extent
+                                             : sizeof(ElementType) * Extent)>
+as_bytes(span<ElementType, Extent> s) noexcept
+{
+    return {reinterpret_cast<const byte*>(s.data()), s.size_bytes()};
+}
+
+template <
+    class ElementType, size_t Extent,
+    typename std::enable_if<!std::is_const<ElementType>::value, int>::type = 0>
+span<byte, ((Extent == dynamic_extent) ? dynamic_extent
+                                       : sizeof(ElementType) * Extent)>
+as_writable_bytes(span<ElementType, Extent> s) noexcept
+{
+    return {reinterpret_cast<byte*>(s.data()), s.size_bytes()};
+}
+
+template <std::size_t N, typename E, std::size_t S>
+constexpr auto get(span<E, S> s) -> decltype(s[N])
+{
+    return s[N];
+}
+
+} // namespace tbx
+
+namespace std {
+
+template <typename ElementType, size_t Extent>
+class tuple_size<tbx::span<ElementType, Extent>>
+    : public integral_constant<size_t, Extent> {};
+
+template <typename ElementType>
+class tuple_size<tbx::span<
+    ElementType, tbx::dynamic_extent>>; // not defined
+
+template <size_t I, typename ElementType, size_t Extent>
+class tuple_element<I, tbx::span<ElementType, Extent>> {
+public:
+    static_assert(Extent != tbx::dynamic_extent &&
+                      I < Extent,
+                  "");
+    using type = ElementType;
+};
+
+} // end namespace std
+
+#endif // TBX_CONT_SPAN_H_

include/core/ring_iterator.h

@@ -35,10 +35,11 @@
 
 #include <iterator>
 #include <type_traits>
+#include <atomic>
 
 namespace tbx {
 
-template<typename Iter_t, size_t N>
+template<typename Iter_t, size_t N, bool Atomic=false>
 class ring_iterator {
     //! \name STL iterator traits "forwarding"
     //! @{
@@ -58,16 +59,16 @@ class ring_iterator {
     //! \name Constructor / Destructor
     //! @{
     public:
-        ring_iterator(const Iter_t base =nullptr) noexcept :
+        constexpr ring_iterator(const Iter_t base =nullptr) noexcept :
             base_(base), iter_(base) { }
 
-        ring_iterator(const Iter_t base, size_t elem) noexcept :
+        constexpr ring_iterator(const Iter_t base, size_t elem) noexcept :
             base_(base), iter_(base + elem) { }
 
-        ring_iterator(const ring_iterator& it) noexcept :
+        constexpr ring_iterator(const ring_iterator& it) noexcept :
             base_(it.base_), iter_(it.iter_) { }
 
-        ring_iterator& operator= (const ring_iterator& it) noexcept {
+        constexpr ring_iterator& operator= (const ring_iterator& it) noexcept {
             base_ = it.base_;
             iter_ = it.iter_;
             return *this;
@@ -77,18 +78,21 @@ class ring_iterator {
     //! \name Forward iterator requirements
     //! @{
     public:
-        reference operator*() const noexcept {
+        constexpr reference operator*() const noexcept {
             return *iter_;
         }
-        pointer operator->() const noexcept {
+
+        constexpr pointer operator->() const noexcept {
             return iter_;
         }
-        ring_iterator& operator++() noexcept {
+
+        constexpr ring_iterator& operator++() noexcept {
             if (static_cast<size_t>(++iter_ - base_) >= N)
                 iter_ = base_;
             return *this;
         }
-        ring_iterator operator++(int) noexcept {
+
+        constexpr ring_iterator operator++(int) noexcept {
             ring_iterator it = *this;
             if (static_cast<size_t>(++iter_ - base_) >= N)
                 iter_ = base_;
@@ -99,12 +103,12 @@ class ring_iterator {
     //! \name Bidirectional iterator requirements
     //! @{
     public:
-        ring_iterator& operator--() noexcept {
+        constexpr ring_iterator& operator--() noexcept {
             if (--iter_ < base_)
                 iter_ = base_ + N -1;
             return *this;
         }
-        ring_iterator operator--(int) noexcept {
+        constexpr ring_iterator operator--(int) noexcept {
             ring_iterator it = *this;
             if (--iter_ < base_)
                 iter_ = base_ + N -1;
@@ -114,33 +118,34 @@ class ring_iterator {
 
     //! \name Random access iterator requirements
     //! @{
-        reference operator[](difference_type n) const noexcept {
+        constexpr reference operator[](difference_type n) const noexcept {
             difference_type k = iter_ - base_;          // ptrdiff from base_
             return (static_cast<size_t>(k + n) < N) ?
                 base_[k + n] :      // on range
                 base_[k + n - N];   // out of range, loop
         }
-        ring_iterator& operator+=(difference_type n) noexcept {
+        constexpr ring_iterator& operator+=(difference_type n) noexcept {
             difference_type k = iter_ - base_;          // ptrdiff from base_
             iter_ += (static_cast<size_t>(k + n) < N) ?
                 n :                 // on range
                 n - N;              // out of range, loop
             return *this;
         }
-        ring_iterator operator+(difference_type n) const noexcept {
+
+        constexpr ring_iterator operator+(difference_type n) const noexcept {
             difference_type k = iter_ - base_;          // ptrdiff from base_
             return (static_cast<size_t>(k + n) < N) ?
                 ring_iterator(base_, k + n) :           // on range
                 ring_iterator(base_, k + n - N);        // out of range, loop
         }
-        ring_iterator& operator-=(difference_type n) noexcept {
+        constexpr ring_iterator& operator-=(difference_type n) noexcept {
             difference_type k = iter_ - base_;          // ptrdiff from base_
             iter_ -= ((k - n) < 0)?
                 n - N:                                  // out of range, loop
                 n;                                      // on range
             return *this;
         }
-        ring_iterator operator-(difference_type n) const noexcept {
+        constexpr ring_iterator operator-(difference_type n) const noexcept {
             difference_type k = iter_ - base_;          // ptrdiff from base_
             return ((k - n) < 0) ?
                 ring_iterator(base_, k - n + N) :       // out of range, loop
@@ -150,16 +155,19 @@ class ring_iterator {
 
     //! \name Data members and access
     //! @{
-        const Iter_t& base() const noexcept {
+        constexpr const Iter_t& base() const noexcept {
             return base_;
         }
-        const Iter_t& iter() const noexcept {
+        constexpr const Iter_t& iter() const noexcept {
             return iter_;
         }
-        size_t size() noexcept {
+        constexpr size_t size() noexcept {
             return N;
         }
 
+        constexpr operator Iter_t() noexcept { return iter_; }
+        constexpr operator const Iter_t() const noexcept { return iter_; }
+
     protected:
         Iter_t base_;
         Iter_t iter_;
@@ -222,6 +230,224 @@ noexcept {
 }
 
 
+
+
+
+
+template<typename Iter_t, size_t N>
+class ring_iterator<Iter_t, N, true> {
+    //! \name STL iterator traits "forwarding"
+    //! @{
+    protected:
+        using traits_type = std::iterator_traits<Iter_t>;
+
+    public:
+        using iterator_type     = Iter_t;
+        using iterator_category = typename traits_type::iterator_category;
+        using value_type        = typename traits_type::value_type;
+        using difference_type   = typename traits_type::difference_type;
+        using reference         = typename traits_type::reference;
+        using pointer           = typename traits_type::pointer;
+    //! @}
+
+
+    //! \name Constructor / Destructor
+    //! @{
+    public:
+        constexpr ring_iterator(const Iter_t base =nullptr) noexcept :
+            base_(base), iter_(base) { }
+
+        constexpr ring_iterator(const Iter_t base, size_t elem) noexcept :
+            base_(base), iter_(base + elem) { }
+
+        constexpr ring_iterator(const ring_iterator& it) noexcept :
+            base_(it.base_) {
+            iter_ =  it.iter_.load(std::memory_order_acquire);
+        }
+
+        constexpr ring_iterator& operator= (const ring_iterator& it) noexcept {
+            base_ = it.base_;
+            iter_ = it.iter_.load(std::memory_order_acquire);
+            return *this;
+        }
+    //! @}
+
+    //! \name Forward iterator requirements
+    //! @{
+    public:
+        constexpr reference operator*() const noexcept {
+            return *iter_.load(std::memory_order_acquire);
+        }
+
+        constexpr pointer operator->() const noexcept {
+            return iter_.load(std::memory_order_acquire);
+        }
+
+        constexpr ring_iterator& operator++() noexcept {
+            Iter_t itnew, it = iter_.load(std::memory_order_acquire);
+            do {
+                itnew = it;
+                if (static_cast<size_t>(++itnew - base_) >= N)
+                    itnew = base_;
+            } while (!iter_.compare_exchange_weak(it, itnew, std::memory_order_acq_rel));
+            return *this;
+        }
+        constexpr ring_iterator operator++(int) noexcept {
+            ring_iterator ret = *this;
+            Iter_t itnew, it = iter_.load(std::memory_order_acquire);
+            do {
+                itnew = it;
+                if (static_cast<size_t>(++itnew - base_) >= N)
+                    itnew = base_;
+            } while (!iter_.compare_exchange_weak(it, itnew, std::memory_order_acq_rel));
+            return ret;
+        }
+    //! @}
+
+    //! \name Bidirectional iterator requirements
+    //! @{
+    public:
+        constexpr ring_iterator& operator--() noexcept {
+            Iter_t itnew, it = iter_.load(std::memory_order_acquire);
+            do {
+                itnew = it;
+                if (--itnew < base_)
+                    itnew = base_ + N -1;
+            } while (!iter_.compare_exchange_weak(it, itnew, std::memory_order_acq_rel));
+            return *this;
+        }
+        constexpr ring_iterator operator--(int) noexcept {
+            ring_iterator ret = *this;
+            Iter_t itnew, it = iter_.load(std::memory_order_acquire);
+            do {
+                itnew = it;
+                if (--itnew < base_)
+                    itnew = base_ + N -1;
+            } while (!iter_.compare_exchange_weak(it, itnew, std::memory_order_acq_rel));
+            return ret;
+        }
+    //! @}
+
+    //! \name Random access iterator requirements
+    //! @{
+        constexpr reference operator[](difference_type n) const noexcept {
+            difference_type k = iter_.load(std::memory_order_acquire) - base_; // ptrdiff from base_
+            return (static_cast<size_t>(k + n) < N) ?
+                base_[k + n] :                          // on range
+                base_[k + n - N];                       // out of range, loop
+        }
+        constexpr ring_iterator& operator+=(difference_type n) noexcept {
+            Iter_t itnew, it = iter_.load(std::memory_order_acquire);
+            do {
+                itnew = it;
+                difference_type k = it - base_;         // ptrdiff from base_
+                itnew += (static_cast<size_t>(k + n) < N) ?
+                    n :                                 // on range
+                    n - N;                              // out of range, loop
+            } while (!iter_.compare_exchange_weak(it, itnew, std::memory_order_acquire));
+            return *this;
+        }
+        constexpr ring_iterator operator+(difference_type n) const noexcept {
+            difference_type k = iter_.load(std::memory_order_acquire) - base_; // ptrdiff from base_
+            return (static_cast<size_t>(k + n) < N) ?
+                ring_iterator(base_, k + n) :           // on range
+                ring_iterator(base_, k + n - N);        // out of range, loop
+        }
+        constexpr ring_iterator& operator-=(difference_type n) noexcept {
+            Iter_t itnew, it = iter_.load(std::memory_order_acquire);
+            do {
+                itnew = it;
+                difference_type k = it - base_;         // ptrdiff from base_
+                itnew -= ((k - n) < 0)?
+                    n - N:                              // out of range, loop
+                    n;                                  // on range
+            } while (!iter_.compare_exchange_weak(it, itnew, std::memory_order_acquire));
+            return *this;
+        }
+        constexpr ring_iterator operator-(difference_type n) const noexcept {
+            difference_type k = iter_.load(std::memory_order_acquire) - base_; // ptrdiff from base_
+            return ((k - n) < 0) ?
+                ring_iterator(base_, k - n + N) :       // out of range, loop
+                ring_iterator(base_, k - n);            // on range
+        }
+    //! @}
+
+    //! \name Data members and access
+    //! @{
+        constexpr const Iter_t& base() const noexcept {
+            return base_;
+        }
+        constexpr const Iter_t iter() const noexcept {
+            return iter_.load(std::memory_order_acquire);
+        }
+        constexpr size_t size() noexcept {
+            return N;
+        }
+
+        constexpr operator Iter_t() noexcept { return iter_.load(std::memory_order_acquire); }
+        constexpr operator const Iter_t() const noexcept { return iter_.load(std::memory_order_acquire); }
+
+    protected:
+        Iter_t base_;
+        std::atomic<Iter_t> iter_;
+    //! @}
+};
+
+// Forward iterator requirements
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator==(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept {
+    return lhs.iter() == rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator!=(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept {
+    return lhs.iter() != rhs.iter();
+}
+
+// Random access iterator requirements
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator<(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept {
+    return lhs.iter() < rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator<=(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept {
+    return lhs.iter() <= rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator>(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept {
+    return lhs.iter() > rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator>=(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept {
+    return lhs.iter() >= rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline auto operator-(const ring_iterator<Iter_L, N, true>& lhs, const ring_iterator<Iter_R, N, true>& rhs)
+noexcept
+-> decltype(lhs.iter() - rhs.iter()) {
+    auto diff = lhs.iter() - rhs.iter();
+    return diff < 0 ?
+            diff + N :  // loop
+            diff;       // no loop
+}
+
+template<typename Iter, size_t N>
+inline ring_iterator<Iter, N, true> operator+(std::ptrdiff_t lhs, const ring_iterator<Iter, N, true>& rhs)
+noexcept {
+    ring_iterator<Iter, N, true> it(rhs.iter());
+    return it += lhs;
+}
+
 } //namespace tbx;
 
 #endif /* TBX_CORE_RING_ITERATOR_H_ */

include/drv/cli_device.h

@@ -0,0 +1,495 @@
+/*!
+ * \file drv/cli_device.h
+ * \brief
+ *      command line device driver functionality as CRTP base class
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_DRV_CLI_DEVICE_H_
+#define TBX_DRV_CLI_DEVICE_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+#include <cont/equeue.h>
+#include <com/sequencer.h>
+
+#include <cstring>
+#include <cstdlib>
+
+#include <algorithm>
+#include <utility>
+#include <atomic>
+
+namespace tbx {
+
+/*!
+ * \class cli_device
+ * \brief
+ *      Its a base class for command-line based devices
+ *
+ * Inherits the sequencer functionality and provides a command interface for sending
+ * commands and parse the response.
+ *
+ * \example implementation example
+ * \code
+ * class BG95 : public cli_device<BG95, 256> {
+ *     using base_type = cli_device<BG95, 256>;
+ *     using Queue     = equeue<typename base_type::value_type, 256, true>;
+ *         Queue RxQ{};
+ *         std::atomic<size_t> lines{};
+ *     public:
+ *         // cli_device driver requirements
+ *         BG95() noexcept :
+ *             RxQ(Queue::data_match::MATCH_PUSH, base_type::delimiter, [&](){
+ *                 lines.fetch_add(1, std::memory_order_acq_rel);
+ *             }), lines(0) { }
+ *         void feed(char x) { RxQ << x; } // To be used inside ISR
+ *         size_t get(char* data, bool wait =false) {
+ *             do {
+ *                 if (lines.load(std::memory_order_acquire)) {
+ *                     size_t n =0;
+ *                     do{
+ *                         *data << RxQ;
+ *                         ++n;
+ *                     } while (*data++ != base_type::delimiter);
+ *                     lines.fetch_sub(1, std::memory_order_acq_rel);
+ *                     return n;
+ *                 }
+ *             } while (wait);
+ *             return 0;
+ *         }
+ *         size_t contents(char* data) {
+ *             char* nullpos = std::copy(RxQ.begin(), RxQ.end(), data);
+ *             *nullpos =0;
+ *             return nullpos - data;
+ *         }
+ *         size_t put (const char* data, size_t n) {
+ *             // send data to BG95
+ *             return n;
+ *         }
+ *         clock_t clock() noexcept { //return CPU time }
+ * };
+ * \endcode
+ *
+ * \tparam Impl_t       The type of derived class
+ * \tparam N            The size of the queue buffer for the receive/command interface
+ * \tparam Delimiter    The incoming data delimiter [default line buffered -- Delimiter = '\n']
+ */
+template<typename Impl_t, size_t N, char Delimiter ='\n'>
+class cli_device
+        : public sequencer<cli_device<Impl_t, N, Delimiter>, char, N>{
+        _CRTP_IMPL(Impl_t);
+
+        // local type dispatch
+        using base_type     = sequencer<cli_device, char, N>;
+
+    //! \name Public types
+    //! @{
+    public:
+        using value_type    = char;
+        using pointer_type  = char*;
+        using size_type     = size_t;
+        using string_view   = typename base_type::string_view;
+
+        using action_t      = typename base_type::action_t;
+        using control_t     = typename base_type::control_t;
+        using match_ft      = typename base_type::match_ft;
+        using handler_ft    = typename base_type::handler_ft;
+        template<size_t Nm>
+        using script_t      = typename base_type::template script_t<Nm>;
+
+        //! Publish delimiter
+        constexpr static char delimiter = Delimiter;
+
+        enum Flush_t { Keep =0, Flush };
+        enum Receive_t { Get =0, Detect };
+
+        //! Required types for inetd async handler operation
+        //! @{
+
+        /*!
+         * inetd handler structure for asynchronous incoming data dispatching
+         */
+        struct inetd_handler_t {
+            string_view token;      //!< The token we match against
+            match_ft    match;      //!< The predicate we use to match
+            handler_ft  handler;    //!< The handler to call on match
+        };
+        //! Alias template for the async handler array
+        template <size_t Nm>
+        using inetd_handlers    = std::array<inetd_handler_t, Nm>;
+        //! @}
+    //! @}
+
+    //! \name object lifetime
+    //!@{
+    protected:
+        //!< \brief A default constructor from derived only
+        cli_device() noexcept = default;
+        ~cli_device () = default;                           //!< \brief Allow destructor from derived only
+        cli_device(const cli_device&) = delete;             //!< No copies
+        cli_device& operator= (const cli_device&) = delete; //!< No copy assignments
+    //!@}
+
+    //! \name Sequencer interface requirements
+    //!     Forwarded to implementer the calls and cascade the the incoming channel
+    //! @{
+    friend base_type;
+
+    private:
+        size_t get_ (char* data) {
+            return impl().get (data);
+        }
+        size_t get (char* data) {
+            return receive (data);
+        }
+        size_t contents (char* data) {
+            return impl().contents(data);
+        }
+        size_t put (const char* data, size_t n) {
+            return impl().put (data, n);
+        }
+        clock_t clock () noexcept {
+            return impl().clock();
+        }
+    //! @}
+
+    //! \name Private functionality
+    //! @{
+    private:
+
+        //! typelist "container". A container of template parameter type arguments
+        template <typename... Ts>
+        struct typelist {
+            using type = typelist;   //!< act as identity
+        };
+
+        //! front functionality: get the first type of the typelist "container"
+        template <typename L>
+        struct front_impl {
+            using type = void;
+        };
+
+        template <typename Head, typename... Tail>
+        struct front_impl<typelist<Head, Tail...>> {
+            using type = Head;
+        };
+
+        //! Return the first element in \c typelist \c List.
+        //!
+        //! Complexity \f$ O(1) \f$.
+        template <typename List>
+        using front = typename front_impl<List>::type;
+
+        /*!
+         * Convert the text pointed by \c str to a value and store it to
+         * \c value. The type of conversion is deduced by the compiler
+         * \tparam  T       The type of the value
+         * \param str       pointer to string with the value
+         * \param value     pointer to converted value
+         */
+        template<typename T>
+        void extract_ (const char* str, T* value) {
+            static_assert (
+                    std::is_same_v<std::remove_cv_t<T>, int>
+                ||  std::is_same_v<std::remove_cv_t<T>, double>
+                ||  std::is_same_v<std::remove_cv_t<T>, char>,
+                "Not supported conversion type.");
+            if constexpr (std::is_same_v<std::remove_cv_t<T>, int>) {
+                *value = std::atoi(str);
+            } else if (std::is_same_v<std::remove_cv_t<T>, double>) {
+                *value = std::atof(str);
+            } else if (std::is_same_v<std::remove_cv_t<T>, char>) {
+                std::strcpy(value, str);
+            }
+        }
+        //! Specialization (as overload function) to handle void* types
+        void extract_ (const char* str, void* value) noexcept {
+            (void)*str; (void)value;
+        }
+
+        /*!
+         * Parse a chunk of the buffer based on \c expected character
+         *
+         * Tries to match the \c *expected character in buffer and if so it copies the
+         * character to token.
+         * If the \c *expected is the \c Marker character, copy the entire chunk of the buffer
+         * up to the character that matches the next expected character (expected[1]).
+         * If there is no next expected character or if its not found in the buffer,
+         * copy the entire buffer.
+         *
+         * \tparam  Marker  The special character to indicate chunk extraction
+         *
+         * \param expected  The character to parse/remove from the buffer
+         * \param buffer    The buffer we parse
+         * \param token     Pointer to store the parsed tokens
+         * \return          A (number of characters parsed, marker found) pair
+         */
+        template <char Marker>
+        std::pair<size_t, bool> parse_ (const char* expected, const string_view buffer, char* token) {
+            do {
+                if (*expected == Marker) {
+                    // We have Marker. Copy the entire chunk of the buffer
+                    // up to the character that matches the next expected character (expected[1]).
+                    // If there is none next expected character or if its not found in the buffer,
+                    // copy the entire buffer.
+                    auto next = std::find(buffer.begin(), buffer.end(), expected[1]);
+                    char* nullpos = std::copy(buffer.begin(), next, token);
+                    *nullpos =0;
+                    return std::make_pair(next - buffer.begin(), true);
+                }
+                else if (*expected == buffer.front()) {
+                    // We have character match, copy the character to token and return 1 (the char size)
+                    *token++ = buffer.front();
+                    *token =0;
+                    return std::make_pair(1, false);
+                }
+            } while (0);
+
+            // Fail to parse
+            *token =0;
+            return std::make_pair(0, false);
+        }
+
+    //! @}
+
+    //! \name public functionality
+    //! @{
+    public:
+
+        //! Clears the incoming data buffer
+        void clear () noexcept {
+            rx_q.clear();
+            streams_.store(size_t(0), std::memory_order_release);
+        }
+
+        //! \return     Returns the size of the incoming data buffer
+        size_t size() noexcept {
+            return rx_q.size();
+        }
+
+        /*!
+         * \brief
+         *   Transmit data to modem
+         * \param data   Pointer to data to send
+         * \param n      The size of data buffer
+         * \return       The number of transmitted chars
+         */
+        size_t transmit (const char* data, size_t n) {
+            if (data == nullptr)
+                return 0;
+            return put (data, n);
+        }
+
+        /*!
+         * \brief
+         *   Transmit data to modem
+         * \param data   Pointer to data to send
+         * \return       The number of transmitted chars
+         */
+        size_t transmit (const char* data) {
+            if (data == nullptr)
+                return 0;
+            return put (data, std::strlen(data));
+        }
+
+        /*!
+         * \brief
+         *   Try to receive data from modem. If there are data copy them to \c data pointer and return
+         *   the size. Otherwise return zero. In the case \c wait is true block until there are data to get.
+         *
+         * \param data   Pointer to data buffer to write
+         * \param wait   Flag to select blocking / non-blocking functionality
+         * \return       The number of copied data.
+         */
+        size_t receive (char* data, bool wait =false) {
+            do {
+                if (streams_.load(std::memory_order_acquire)) {
+                    size_t n =0;
+                    do {
+                        *data << rx_q;
+                        ++n;
+                    } while (*data++ != delimiter);
+                    *data =0;
+                    streams_.fetch_sub(1, std::memory_order_acq_rel);
+                    return n;
+                }
+            } while (wait);  // on wait flag we block until available stream
+            return 0;
+        }
+
+        /*!
+         * Analyze the response of a command based on \c expected.
+         *
+         * Tries to receive data via get() path with timeout and match them against expected string_view.
+         * For each Marker inside the expected string the value gets extracted, converted and
+         * copied to \c vargs pointer array.
+         *
+         * \param expected      The expected string view
+         * \param timeout       the timeout in CPU time
+         * \param vargs         Pointer to variable arguments array
+         * \param nargs         Size of variable arguments array
+         * \return
+         */
+        template<Receive_t Recv, char Marker, typename T>
+        bool response (const string_view expected, clock_t timeout, T* vargs, size_t nargs) {
+            char buffer[N], token[N], *pbuffer = buffer;
+
+            size_t v =0, sz =0;
+            for (auto ex = expected.begin() ; ex != expected.end() ;  ) {
+                clock_t mark = clock();                     // mark the time
+                while (sz <= 0) {                           // if buffer is empty get buffer with timeout
+                    if constexpr (Recv == Get)
+                        sz = receive(buffer);
+                    else
+                        sz = contents(buffer);
+                    pbuffer = buffer;
+                    if ((timeout != 0 )&& ((clock() - mark) >= timeout))
+                        return false;
+                }
+                // try to parse
+                auto [step, marker] = parse_<Marker> (ex, {pbuffer, sz}, token);
+                if (!step)
+                    return false;                           // discard buffer and fail
+
+                if (marker && v < nargs)
+                    extract_(token, vargs[v++]);
+
+                pbuffer += step;
+                sz      -= (step <= sz) ? step: sz;
+                ++ex;
+            }
+            return true;
+        }
+
+        /*!
+         * \brief
+         *      Send a command to modem and check if the response matches to \c expected.
+         *
+         * This function executes 3 steps.
+         *  - Clears the incoming buffer if requested by template parameter
+         *  - Sends the command to device
+         *  - Waits to get the response and parse it accordingly to \c expected \see response()
+         *
+         * The user can mark spots inside the expected string using the \c Marker ['%'] character.
+         * These spots will be extracted to tokens upon parsing. If the user passes \c values parameters,
+         * then the extracted tokens will be converted to the type of the \c values (\c Ts) and copied to them
+         * one by one. If the values are less than spots, the rest of the tokens get discarded.
+         *
+         * \param cmd       The command to send (null terminated)
+         * \param expected  The expected response
+         * \param timeout   The timeout in CPU time (leave it for 0 - no timeout)
+         * \param values    The value pointer arguments to get the converted tokens
+         *
+         * \tparam Flush    Flag to indicate if we Flush the buffer before command or not
+         * \tparam Marker   The marker character
+         * \tparam Ts       The type of the values to read from response marked with \c Marker
+         * \warning         The types MUST be the same
+         *
+         * \return          True on success
+         *
+         * \example examples
+         * \code
+         *    Derived cli;
+         *    int status;
+         *    char str[32];
+         *
+         *    // discard 3 lines and expect OK\r\n at the end with 1000[CPU time] timeout
+         *    cli.command("AT+CREG?\r\n", "%%%OK\r\n", 1000);
+         *
+         *    // extract a number from response without timeout (blocking)
+         *    cli.command<Flush>("AT+CREG?\r\n", "\r\n+CREG: 0,%\r\n\r\nOK\r\n", 0, &status);
+         *
+         *    // extract a number and discard the last 2 lines
+         *    cli.command<Flush>("AT+CREG?\r\n", "\r\n+CREG: 0,%\r\n%%", 1000, &status);
+         *
+         *    // discard first line, read the 2nd to str, discard the 3rd line.
+         *    // expect the last to be "OK\r\n"
+         *    cli.command<Flush>("AT+CREG?\r\n", "", 100000);
+         *    cli.command<Keep>("", "%",  1000);
+         *    cli.command<Keep>("", "%%", 1000, str);
+         *    cli.command<Keep>("", "OK\r\n",  1000);
+         * \endcode
+         */
+        template<Receive_t Recv =Get, Flush_t Flsh =Flush, char Marker = '%', typename ...Ts>
+        bool command (const string_view cmd, const string_view expected, clock_t timeout, Ts* ...values) {
+            constexpr size_t Nr = sizeof...(Ts);
+
+            front<typelist<Ts...>>* vargs[Nr] = {values...};        // read all args to local buffer
+            if constexpr (Flsh == Flush) {
+                clear ();
+            }
+            if (transmit(cmd.data(), cmd.size()) != cmd.size())     // send command
+                return false;
+            // parse the response and return the status
+            return response<Recv, Marker>(expected, timeout, vargs, Nr);
+        }
+
+        /*!
+         * \brief
+         *   inetd daemon functionality provided as member function of the driver. This should be running
+         *   in the background either as consecutive calls from an periodic ISR with \c loop = false, or
+         *   as a thread in an RTOS environment with \c loop = true.
+         *
+         * \tparam Nm            The number of handler array entries
+         *
+         * \param async_handles  Reference to asynchronous handler array
+         * \param loop           Flag to indicate blocking mode. If true blocking.
+         */
+        template <size_t Nm =0>
+        void inetd (bool loop =true, const inetd_handlers<Nm>* inetd_handlers =nullptr) {
+            std::array<char, N> buffer;
+            size_t resp_size;
+            do {
+                if ((resp_size = get_(buffer.data())) != 0) {
+                    // on data check for async handlers
+                    bool match = false;
+                    if (inetd_handlers != nullptr) {
+                        for (auto& h : *inetd_handlers)
+                            match |= base_type::check_handle({buffer.data(), resp_size}, h.token, h.match, h.handler);
+                    }
+                    // if no match forward data to receive channel.
+                    if (!match) {
+                        char* it = buffer.data();
+                        do {
+                            rx_q << *it;
+                        } while (*it++ != delimiter);
+                        streams_.fetch_add(1, std::memory_order_acq_rel);
+                    }
+                }
+            } while (loop);
+        }
+
+    //! @}
+
+    private:
+        equeue<char, N, true> rx_q{};
+        std::atomic<size_t>   streams_{};
+};
+
+} // namespace tbx;
+
+#endif /* #ifndef TBX_DRV_CLI_DEVICE_H_ */

include/drv/gpio.h

@@ -0,0 +1,107 @@
+/*!
+ * \file drv/gpio.h
+ * \brief
+ *      A STM32 gpio wrapper class
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_DRV_GPIO_H_
+#define TBX_DRV_GPIO_H_
+
+#include <core/core.h>
+
+namespace tbx {
+
+    /*!
+     * CRTP class for gpio digital input-output.
+     *
+     * The derived class requirements are:
+     *  - bool read_impl ()
+     *  - void write_impl(bool)
+     *
+     * \tparam  Impl_t  The type of derived class
+     */
+    template <typename Impl_t>
+    class DigitalInOut {
+    public:
+            _CRTP_IMPL(Impl_t);
+
+        /*!
+         * \name Object lifetime
+         */
+        //! @{
+        protected:
+            DigitalInOut() noexcept = default;
+            ~DigitalInOut() = default;
+            DigitalInOut(const DigitalInOut&)             = delete;   //!< No copy constructions
+            DigitalInOut operator=(const DigitalInOut&)   = delete;   //!< No copies
+
+        //! @}
+
+        //! \name Public interface
+        //! @{
+        public:
+            //! Reads the state of the pin. This is true for both input and output pins.
+            //! \return     The state of the pin
+            bool read () noexcept { return impl().read_impl (); }
+            //! Write a new state to pin. If the pin is set for output, otherwise this state will remain
+            //! to pin registers and reflect to the pin state if we select output mode
+            void write (bool state) noexcept { impl().write_impl(state); }
+
+            //! Implicit conversion to bool for reading operations
+            operator bool () noexcept {
+                return read();
+            }
+            //! Stream from bool for write operations
+            DigitalInOut& operator<< (bool state) noexcept {
+                write(state);
+                return *this;
+            }
+            //! Right stream to bool for read operations
+            DigitalInOut& operator>> (bool& state) noexcept {
+                state = read();
+                return *this;
+            }
+        //! @}
+    };
+
+    /*!
+     * This definition enables the "data << pin" syntax for read operation
+     *
+     * \tparam Impl_t   The derived class type of the DigitalInOut
+     *
+     * \param lhs   Left hand site operand
+     * \param rhs   Right hand site operand
+     * \return      The read value
+     */
+    template<typename Impl_t>
+    bool operator<<(bool& lhs, DigitalInOut<Impl_t>& rhs) noexcept {
+        lhs = rhs.read();
+        return lhs;
+    }
+}
+
+#endif //#ifndef TBX_DRV_STM32GPIO_H_

include/drv/liquid_crystal.h

@@ -0,0 +1,536 @@
+/*!
+ * \file drv/liquid_crystal.h
+ * \brief
+ *      A liquid crystal display driver
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_DRV_LIQUID_CRYSTAL_H_
+#define TBX_DRV_LIQUID_CRYSTAL_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+#include <utils/print.h>
+
+#include <type_traits>
+#include <ctime>
+
+namespace tbx {
+
+    /*!
+     * \class liquid_crystal
+     * \brief
+     *      A CRTP driver class for liquid crystal display with parallel interface,
+     *      based on Hitachi HD44780 (Samsung KS0066U, or compatible).
+     *
+     * The driver inherits from Print
+     * The Implementation requirements are:
+     *  - void bus_impl(data);          To set the 4bit/8bit bus
+     *  - void rs_pin_impl(state);      To set/clear RS pin
+     *  - void en_pin_impl(state);      To set/clear EN pin
+     *  - void power_pin_impl(state);   To set/clear PWR pin
+     *  - void bl_pin_impl(state);      To set/clear BackLight pin
+     *  - void delay_usec_impl(usec);   To provide delay in usec
+     *
+     * \tparam Impl_t       The derived class
+     * \tparam Lines        The lines of the LCD
+     * \tparam Columns      The coluns of the LCD
+     * \tparam BusSize      The LCD bus size (4 or 8 bits)
+     */
+    template <typename Impl_t, size_t Lines, size_t Columns, size_t BusSize =4>
+    class liquid_crystal : public Print<liquid_crystal<Impl_t, Lines, Columns, BusSize>, char>{
+        friend Print<liquid_crystal, char>;
+        _CRTP_IMPL(Impl_t);
+        static_assert((BusSize == 4) || (BusSize == 8), "BusSize must be either 4 or 8.");
+
+    public:
+        constexpr static size_t lines   = Lines;
+        constexpr static size_t columns = Columns;
+        /*!
+         * Public enumerator to be used as argument to the init() function.
+         * Selects the font size and thus the number of active lines
+         */
+        enum class FontSize :uint8_t { dots_5x8, dots_5x10 };
+    private:
+
+        // Commands
+        constexpr static uint8_t Cmd_cls        = 0x01;
+        constexpr static uint8_t Cmd_RetHome    = 0x02;
+        constexpr static uint8_t Cmd_EntryMode  = 0x04;
+        constexpr static uint8_t Cmd_DispCtrl   = 0x08;
+        constexpr static uint8_t Cmd_Shift      = 0x10;
+        constexpr static uint8_t Cmd_FunSet     = 0x20;
+        constexpr static uint8_t Cmd_SetGRamAddr= 0x40;
+        constexpr static uint8_t Cmd_SetDRamAddr= 0x80;
+
+        /*
+         *  Entry Mode Set -----> 0  0  0  0      0  1  I/D  S
+         *  ----------------------------------------------------
+         *  I/D = 1 Increment Curs
+         *        0 Decrement
+         *  S   = 1 Display shift
+         *        0 Not
+         */
+        constexpr static uint8_t Entry_Right    = 0x00;
+        constexpr static uint8_t Entry_Left     = 0x02;
+        constexpr static uint8_t Entry_ShiftInc = 0x01;
+        constexpr static uint8_t Entry_ShiftDec = 0x00;
+
+        /*
+         *  DispOnOffControll -->  0  0  0  0     1  D  C  B
+         *  -------------------------------------------------
+         *  D = Display On
+         *  C = Cursor On
+         *  B = Blinking On
+         */
+        constexpr static uint8_t Display_On     = 0x04;
+        constexpr static uint8_t Display_Off    = 0x00;
+        constexpr static uint8_t Cursor_On      = 0x02;
+        constexpr static uint8_t Cursor_Off     = 0x00;
+        constexpr static uint8_t Blink_On       = 0x01;
+        constexpr static uint8_t Blink_Off      = 0x00;
+
+        /*
+         *  Cursor/Display Shift --> 0  0  0  1   S/C R/L  x  x
+         *  ---------------------------------------------------
+         *  S/C = 1 Display Shift
+         *        0 Cursor Shift
+         *  R/L = 1 Shift Right
+         *        0 Shift left
+         */
+        constexpr static uint8_t DisMove_Display= 0x08;
+        constexpr static uint8_t DisMove_Cursor = 0x00;
+        constexpr static uint8_t DisMove_Right  = 0x04;
+        constexpr static uint8_t DisMove_Left   = 0x00;
+
+        /*
+         *  FunctionSet     ------>  0  0  1 DL   N   F   x  x
+         *  ---------------------------------------------------
+         *  DL = 1 8bit
+         *       0 4bit
+         *  N  = 1 2 lines
+         *       0 1 line
+         *  F  = 1 5x10 dots
+         *       0 5x8 dots
+         */
+        constexpr static uint8_t FunSet_8bitMode= 0x10;
+        constexpr static uint8_t FunSet_4bitMode= 0x00;
+        constexpr static uint8_t FunSet_2Line   = 0x08;
+        constexpr static uint8_t FunSet_1Line   = 0x00;
+        constexpr static uint8_t FunSet_5x10dots= 0x04;
+        constexpr static uint8_t FunSet_5x8dots = 0x00;
+
+        /*!
+         * \brief
+         *      Helper class to keep track of the display cursor. As we dont read the cursor
+         *      position on the display, in order to implement backspace operation we need to
+         *      keep track the cursor position manually.
+         */
+        struct Cursor {
+            uint8_t inc_x() noexcept {
+                if (++x_ > Columns)  x_ =1;
+                return x_;
+            }
+            uint8_t dec_x() noexcept {
+                if (--x_ < 1)        x_ =Columns;
+                return x_;
+            }
+            uint8_t inc_y () noexcept {
+                if (++y_ > max_lines) y_ =1;
+                return y_;
+            }
+            uint8_t dec_y () noexcept {
+                if (--y_ < 1)        y_ =max_lines;
+                return y_;
+            }
+            uint8_t operator++() noexcept { return inc_x(); }
+            uint8_t operator--() noexcept { return dec_x(); }
+            void set(uint8_t x, uint8_t y) noexcept {
+                x_ = x;
+                y_ = y;
+            }
+            uint8_t get_x() noexcept { return x_; }
+            uint8_t get_y() noexcept { return y_; }
+            void set_lines (uint8_t l) noexcept { max_lines = l; }
+        private:
+            uint8_t x_, y_;
+            uint8_t max_lines;
+        };
+    private:
+        //! \name Implementation requirements
+        //! @{
+        void BUS (uint8_t data)   { impl().bus_impl(data); }
+        void RS_Pin (bool state)  { impl().rs_pin_impl(state); }
+        void EN_Pin (bool state)  { impl().en_pin_impl(state); }
+        void PWR_Pin (bool state) { impl().power_pin_impl(state); }
+        void BL_Pin (bool state)  { impl().bl_pin_impl(state); }
+        void delay_usec(size_t usec) {
+            impl().delay_usec_impl(usec);
+        }
+        //! @}
+
+        //! \name Print interface requirements
+        //! @{
+        size_t write_impl (const char* str, size_t size) {
+            size_t ret =0;
+            while (*str && ret < size) {
+                putchar (*str++);
+                ++ret;
+            }
+            return ret;
+        }
+        size_t write_impl (const char ch) {
+            return (putchar(ch) == ch) ? 1:0;
+        }
+        //! @}
+
+    protected:
+        //! \name Object lifetime
+        //! @{
+        liquid_crystal() noexcept   = default;      //!< Construct from derived only
+        //~liquid_crystal()           = default;
+        liquid_crystal(const liquid_crystal&)               = delete;   //!< No copies
+        liquid_crystal& operator= (const liquid_crystal&)   = delete;   //!< No copies
+        //! @}
+
+    private:
+        //! Send enable pulse to display
+        void pulse_enable () {
+            EN_Pin(0);
+            delay_usec (2);     // time to settle BUS pin voltages
+            EN_Pin(1);
+            delay_usec (2);     // >450 [nsec]
+            EN_Pin(0);
+            delay_usec (50);    // > 37 [usec]
+        }
+
+        //! Writes 4/8bit data to display and pulse the EN pin
+        //! \param  data    The data to write
+        void write_bits (uint8_t data) {
+            if constexpr (BusSize == 4) BUS (data & 0x0F);
+            else                        BUS (data);
+            pulse_enable ();
+        }
+
+        /*!
+         * \brief
+         *      Sends commands or character to display by controlling RS pin
+         * \param data  The data to send
+         * \param mode  Character/command mode (RS pin state)
+         */
+        void send (uint8_t data, uint8_t mode) {
+            RS_Pin (mode);
+            if constexpr (BusSize == 4) {
+                write_bits (data >> 4);
+                write_bits (data & 0x0F);
+            } else {
+                write_bits (data);
+            }
+        }
+        //! Send a command to display
+        void command (uint8_t c)   { send(c, 0); }
+        //! Send a character to display
+        void character (uint8_t c) { send(c, 1); }
+
+    public:
+        //! \name Public API
+        //! @{
+
+        /*!
+         * \brief
+         *      Initialize the display. After construction the object is valid but reflects the init state
+         *      of display configuration. In order for the display to be functional it needs initialization.
+         *      So the user has to call this function. This function requires a settled environment, so usually
+         *      its called after main().
+         * \param mode      4bit or 8bit mode
+         * \param fontSize  5x8 or 5x10 dots font size.
+         */
+        void init (FontSize fontSize =FontSize::dots_5x8) {
+            disp_mode_    = disp_mode_init_;    // Set values to LCD's startup configuration
+            disp_control_ = disp_control_init_;
+            disp_function_=disp_function_init_;
+
+            // Read user configuration
+            if constexpr (BusSize == 4)
+                // note: keep this runtime, so the disp_function reflects lcd's configuration state
+                disp_function_ &= ~FunSet_8bitMode;
+            else
+                disp_function_ |= FunSet_8bitMode;
+
+            if (fontSize == FontSize::dots_5x10) {
+                disp_function_ |= FunSet_5x10dots;
+                disp_function_ &= ~FunSet_2Line;
+                cursor_.set_lines(Lines>>1);
+            } else {
+                disp_function_ &= ~FunSet_5x10dots;
+                disp_function_ |= FunSet_2Line;
+                cursor_.set_lines(Lines);
+            }
+
+            // start with All-zeros
+            BUS (0);  EN_Pin(0); RS_Pin(0); BL_Pin(0);
+
+            delay_usec(100000);
+            if constexpr (BusSize == 4) {
+                // 4bit BUS
+                write_bits (0x03);                      // 1t try
+                delay_usec(20000);
+                write_bits (0x03);                      // 2nd try
+                delay_usec(5000);
+                write_bits (0x03);                      // 3rd try
+                delay_usec(5000);
+                write_bits (0x02);                      // We set 4 bit interface
+                delay_usec (10000);
+            } else {
+                // 8bit BUS
+                write_bits (Cmd_FunSet | disp_function_);   // 1st try
+                delay_usec(20000);
+                write_bits (Cmd_FunSet | disp_function_);   // 2nd try
+                delay_usec(5000);
+                write_bits (Cmd_FunSet | disp_function_);   // 3rd try
+                delay_usec(5000);
+            }
+            command (Cmd_FunSet | disp_function_);      // Finally we set #lines and font size
+            delay_usec(5000);
+
+            command (Cmd_DispCtrl | Display_Off);   // Display off
+            delay_usec(5000);
+            command (Cmd_cls);                      // Clear screen
+            delay_usec(5000);
+            command (Cmd_EntryMode | disp_mode_);   // Entry mode set
+            delay_usec(5000);
+
+            command (Cmd_RetHome);                  // Return home
+            delay_usec(10000);
+            display(true);                          // Finally display On, done.
+            cursor_.set(1, 1);
+        }
+
+        //! Utility function to enable/disable power to display. This has an effect IFF there is a
+        //! power pin on the board
+        void power (bool en) {
+            PWR_Pin(en);
+        }
+
+        //! Utility function to enable/disable backlight. This has an effect IFF there is a
+        //! backlight pin on the board
+        void backlight (bool en) {
+            BL_Pin(en);
+        }
+
+        //! Utility function to send on/off command to display.
+        void display (bool en) {
+            if (en)     disp_control_ |= Display_On;
+            else        disp_control_ &= ~Display_On;
+
+            command (Cmd_DispCtrl | disp_control_);
+            delay_usec(100);
+        }
+
+        //! Utility function to enable/disable display cursor.
+        void cursor (bool en) {
+            if (en)     disp_control_ |= Cursor_On;
+            else        disp_control_ &= ~Cursor_On;
+
+            command (Cmd_DispCtrl | disp_control_);
+            delay_usec(100);
+        }
+
+        //! Utility function to enable/disable cursor blinking.
+        void blink (bool en) {
+            if (en)     disp_control_ |= Blink_On;
+            else        disp_control_ &= ~Blink_On;
+
+            command (Cmd_DispCtrl | disp_control_);
+            delay_usec(100);
+        }
+
+        //! Utility function to enable/disable autoscroll.
+        void autoscroll (bool en) {
+            if (en)     disp_mode_ |= Entry_ShiftInc;
+            else        disp_mode_ &= ~Entry_ShiftInc;
+
+            command (Cmd_EntryMode | disp_mode_);
+            delay_usec(100);
+        }
+
+        /*!
+         * \brief
+         *      Tool to set display cursor
+         * \param x     The column position (starting with 1)
+         * \param y     The line position (starting with 1 at the top of the display)
+         */
+        void set_cursor (uint8_t x, uint8_t y) {
+            uint8_t offset;
+            switch (y) {
+               default:
+               case 1: offset = 0x0;   break;
+               case 2: offset = 0x40;  break;
+               case 3: offset = 0x0  + Columns; break;
+               case 4: offset = 0x40 + Columns; break;
+            }
+            command( Cmd_SetDRamAddr | offset | (x-1));
+            cursor_.set(x, y);
+        }
+
+        //! Utility function to set left to right entry mode.
+        //! \note
+        //!     This is the default
+        void set_left_to_right () {
+            disp_mode_ |= Entry_Left;
+            command (Cmd_EntryMode | disp_mode_);
+            delay_usec(100);
+        }
+
+        //! Utility function to set right to left entry mode.
+        void set_right_to_left () {
+            disp_mode_ &= ~Entry_Left;
+            command (Cmd_EntryMode | disp_mode_);
+            delay_usec(100);
+        }
+
+        //! Command to scroll display left one position
+        void scroll_left () {
+            command (Cmd_Shift | DisMove_Display | DisMove_Left);
+        }
+
+        //! Command to scroll display right one position
+        void scroll_right () {
+            command (Cmd_Shift | DisMove_Display | DisMove_Right);
+        }
+
+        //! Clears the display and return home
+        void clear() {
+            command (Cmd_cls);
+            cursor_.set(1, 1);
+            delay_usec(2000);
+        }
+
+        //! return home without clearing the display
+        void home() {
+            command (Cmd_RetHome);
+            cursor_.set(1, 1);
+            delay_usec(2000);
+        }
+
+        /*!
+         * \brief
+         *      Create custom character and store it to LCD.
+         * \param location  The location to store the character [0..7] allowed
+         * \param charmap   The character map buffer with the font
+         */
+        void create_char (uint8_t location, uint8_t charmap[]) {
+            location &= 0x7;        // we only have 8 locations 0-7
+            command(Cmd_SetGRamAddr | (location << 3));
+            for (size_t i=0; i<8; ++i) {
+                character(charmap[i]);
+            }
+        }
+
+        /*!
+         * \brief
+         *    Send an ascii character to liquid crystal display.
+         * \param  ch     the character to send
+         * \return the character send.
+         *
+         * \note
+         *    This is the driver's "putchar()" functionality to glue.
+         *    Tailor this function to redirect stdout to display.
+         */
+        int putchar (int ch) {
+            // LCD Character dispatcher
+            switch (ch) {
+                case 0:
+                    // don't send null termination to device
+                    break;
+                case '\n':
+                    cursor_.inc_y();
+                    set_cursor (1, cursor_.get_y());
+                    break;
+                case '\r':
+                    set_cursor (1, cursor_.get_y());
+                    break;
+                case '\v':
+                    home ();
+                    break;
+                case '\f':
+                    clear();
+                    break;
+                case '\b':
+                    --cursor_;
+                    set_cursor (cursor_.get_x(), cursor_.get_y());
+                    character (' ');
+                    --cursor_;
+                    set_cursor (cursor_.get_x(), cursor_.get_y());
+                    break;
+                default:
+                    character (ch);
+                    ++cursor_;
+                    break;
+            }
+            //ANSI C (C99) compatible mode
+            return ch;
+        }
+        //! @}
+
+    private:
+        //! \name Data members
+        //! @{
+
+        //! The init entry mode of the display after power up
+        static constexpr uint8_t disp_mode_init_    = Entry_Left | Entry_ShiftDec;
+        //! The init control mode of the display after power up
+        static constexpr uint8_t disp_control_init_ = Display_Off | Cursor_Off | Blink_Off;
+        //! The init function set of the display after power up
+        static constexpr uint8_t disp_function_init_= FunSet_8bitMode | FunSet_1Line | FunSet_5x8dots;
+
+        Cursor cursor_{};
+        uint8_t disp_mode_ {disp_mode_init_};
+        uint8_t disp_control_ {disp_control_init_};
+        uint8_t disp_function_ {disp_function_init_};
+        /*!
+         * \note
+         *  When the display powers up, it is configured as follows:
+         *  1. Display clear
+         *  2. Function set: 0x10
+         *     DL = 1; 8-bit interface data
+         *     N = 0; 1-line display
+         *     F = 0; 5x8 dot character font
+         *  3. Display on/off control: 0x00
+         *     D = 0; Display off
+         *     C = 0; Cursor off
+         *     B = 0; Blinking off
+         *  4. Entry mode set: 0x02
+         *     I/D = 1; Increment by 1
+         *     S = 0; No shift
+         */
+
+        //! @}
+    };
+
+}
+
+#endif /* TBX_DRV_LIQUID_CRYSTAL_H_ */

include/drv/sd_spi.h

@@ -0,0 +1,720 @@
+/*!
+ * \file drv/sd_spi.h
+ * \brief
+ *      SD card driver using SPI interface
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_DRV_SD_SPI_H_
+#define TBX_DRV_SD_SPI_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+
+//#include <drv/diskio.h>
+
+#include <ctime>
+#include <utility>
+
+namespace tbx {
+
+/*!
+ *
+ * http://elm-chan.org/docs/mmc/mmc_e.html
+ *
+ * CRTP requirements
+ *  bool WP_impl ();                // write protect,      true => write protect
+ *  bool CD_impl ();                // check disk present, true => present
+ *  void CS_impl (bool select);     // Chip select,        true => select
+ *  void PWR_impl(bool state);      // SD power,           true => power the card
+ *  data_type SPI_rw_impl (data_type);      // SPI read-write functionality
+ *  bool SPI_set_clk_impl(uint32_t clk);    // SPI set clock functionality
+ *  clock_t clock_impl();           // get system's CPU time
+ */
+template <typename Impl_t>
+class sd_card {
+    _CRTP_IMPL(Impl_t);
+
+    using data_type = uint8_t;
+
+    // Driver settings
+    constexpr static clock_t SD_WaitTimeout = 500;      // 500 [CPU time]
+    constexpr static clock_t SD_PowerTimeout= 250;      // 250 [CPU time]
+    constexpr static clock_t SD_RxTimeout   = 100;      // 100 [CPU time]
+    constexpr static clock_t SD_InitTimeout = 2000;     // 2000 [CPU time]
+    constexpr static uint32_t MaxInitClock  = 400000;   // 400000 [Hz]
+
+    // MMC/SDC definitions
+    constexpr static data_type CMD_MSB      = 0x40;
+    constexpr static data_type CMD_CRC_LSB  = 0x01;
+
+    constexpr static data_type CMD0         = (CMD_MSB | 0);    //!< GO_IDLE_STATE
+    constexpr static data_type CMD1         = (CMD_MSB | 1);    //!< SEND_OP_COND (MMC)
+    constexpr static data_type CMD8         = (CMD_MSB | 8);    //!< SEND_IF_COND
+    constexpr static data_type CMD9         = (CMD_MSB | 9);    //!< SEND_CSD
+    constexpr static data_type CMD10        = (CMD_MSB | 10);   //!< SEND_CID
+    constexpr static data_type CMD12        = (CMD_MSB | 12);   //!< STOP_TRANSMISSION
+    constexpr static data_type CMD16        = (CMD_MSB | 16);   //!< SET_BLOCKLEN
+    constexpr static data_type CMD17        = (CMD_MSB | 17);   //!< READ_SINGLE_BLOCK
+    constexpr static data_type CMD18        = (CMD_MSB | 18);   //!< READ_MULTIPLE_BLOCK
+    constexpr static data_type CMD23        = (CMD_MSB | 23);   //!< SET_BLOCK_COUNT (MMC)
+    constexpr static data_type CMD24        = (CMD_MSB | 24);   //!< WRITE_BLOCK
+    constexpr static data_type CMD25        = (CMD_MSB | 25);   //!< WRITE_MULTIPLE_BLOCK
+    constexpr static data_type CMD55        = (CMD_MSB | 55);   //!< APP_CMD
+    constexpr static data_type CMD58        = (CMD_MSB | 58);   //!< READ_OCR
+
+    constexpr static data_type ACMD13       = (0xC0 + 13);      //!< SD_STATUS (SDC)
+    constexpr static data_type ACMD23       = (0xC0 + 23);      //!< SET_WR_BLK_ERASE_COUNT (SDC)
+    constexpr static data_type ACMD41       = (0xC0 + 41);      //!< SEND_OP_COND (SDC)
+
+    constexpr static data_type R1_READY_STATE      = 0x00;      //!< status for card in the ready state
+    constexpr static data_type R1_IDLE_STATE       = 0x01;      //!< status for card in the idle state
+    constexpr static data_type R1_ILLEGAL_COMMAND  = 0x04;      //!< status bit for illegal command
+    constexpr static data_type DATA_START_BLOCK    = 0xFE;      //!< start data token for read or write single block
+    constexpr static data_type STOP_TRAN_TOKEN     = 0xFD;      //!< stop token for write multiple blocks
+    constexpr static data_type WRITE_MULTIPLE_TOKEN= 0xFC;      //!< start data token for write multiple blocks
+    constexpr static data_type DATA_RES_MASK       = 0x1F;      //!< mask for data response tokens after a write block operation
+    constexpr static data_type DATA_RES_ACCEPTED   = 0x05;      //!< write data accepted token
+
+    // MMC card type flags (MMC_GET_TYPE)
+    //! \note
+    //! These types are compatible with FatFS types
+    constexpr static data_type CT_NONE      = 0x00;
+    constexpr static data_type CT_MMC       = 0x01;             //!< MMC ver 3
+    constexpr static data_type CT_SD1       = 0x02;             //!< SD ver 1
+    constexpr static data_type CT_SD2       = 0x04;             //!< SD ver 2
+    constexpr static data_type CT_SDC       = (CT_SD1|CT_SD2);  //!< SD
+    constexpr static data_type CT_BLOCK     = 0x08;             //!< Block addressing
+
+public:
+
+    enum status_t : uint8_t {
+        ST_OK         =0,
+        ST_NOINIT    = 1,
+        ST_NODISK    = 2,
+        ST_WRPROTECT = 3,
+        ST_ERROR     = 4
+    };
+
+    enum ioctl_cmd {
+        // Fatfs compatibility
+        IOCTL_SYNC              =0,     //!< Flush disk cache (for write functions)
+        IOCTL_GET_SECTOR_COUNT  =1,     //!< Get media size (for only f_mkfs())
+        IOCTL_GET_SECTOR_SIZE   =2,     //!< Get sector size (for multiple sector size (_MAX_SS >= 1024))
+        IOCTL_GET_BLOCK_SIZE    =3,     //!< Get erase block size (for only f_mkfs())
+        IOCTL_ERASE_SECTOR      =4,     //!< Force erased a block of sectors (for only _USE_ERASE)
+
+        // Generics
+        IOCTL_POWER             =5,     //!< Get/Set power status
+        IOCTL_LOCK              =6,     //!< Lock/Unlock media removal
+        IOCTL_EJECT             =7,     //!< Eject media
+        IOCTL_FORMAT            =8,     //!< Create physical format on the media
+
+        // SD/MMC specific
+        IOCTL_MMC_GET_TYPE      =10,    //!< Get card type
+        IOCTL_MMC_GET_CSD       =11,    //!< Get CSD
+        IOCTL_MMC_GET_CID       =12,    //!< Get CID
+        IOCTL_MMC_GET_OCR       =13,    //!< Get OCR
+        IOCTL_MMC_GET_SDSTAT    =14,    //!< Get SD status
+    };
+
+public:
+    sd_card() :
+        status{ST_NOINIT} { }
+
+    sd_card(const sd_card&)             = delete;
+    sd_card& operator=(const sd_card&)  = delete;
+
+private:
+
+    /*!
+     * \brief
+     *    Calculate the maximum data transfer rate per one data line
+     *    from the CSD.
+     *    TRAN_SPEED is the CSD[103..96]
+     *
+     *    TRAN_SPEED bit code
+     * ---------------------------------------------------
+     *    2:0     | transfer rate unit
+     *            | 0=100kbit/s, 1=1Mbit/s, 2=10Mbit/s,
+     *            | 3=100Mbit/s, 4... 7=reserved
+     *  ---------------------------------------------------
+     *    6:3     | time value
+     *  --------------------------------------------------
+     *    7       | Reserved
+     *
+     * \param      csd  Pointer to CSD array 128bit.
+     * \return     The maximum spi baud rate.
+     */
+    uint32_t csd2bautrate (data_type *csd) {
+        data_type  brmul = 0;
+        uint32_t br = 100000;     // 100Kbit
+
+        // Mask [2..0] bits of TRAN_SPEED
+        brmul = csd[3] & 0x07;
+        while (brmul--)
+            br *= 10;
+        return br;
+    }
+
+    void delay (clock_t t) {
+        clock_t mark = impl().clock_impl();
+        while (impl().clock_impl() - mark < t)
+            ;
+    }
+
+    /*!
+     * \brief Check if SD Card is present.
+     * \return        The sd card present status
+     *    \arg  false   Is NOT present
+     *    \arg  true    Is present.
+     */
+    bool is_present () {
+        return impl().CD_impl();
+    }
+
+    /*!
+     * \brief Check if SD Card is write protected.
+     * \return        The write protect status
+     *    \arg  false   Is NOT write protected
+     *    \arg  true    Is write protected.
+     */
+    bool is_write_protected () {
+        return impl().WP_impl();
+    }
+
+    /*!
+     * \brief Powers up or down the SD Card.
+     * \param   on    On/Off flag.
+     * \return        The new power state state
+     */
+    bool power (bool on) {
+        impl().PWR_impl(on);
+        return pwr_flag = on;
+    }
+
+    /*!
+     * \brief Check if SD Card is powered.
+     * \return        The power status
+     *    \arg  false The drive is not powered
+     *    \arg  true  The drive is powered
+     */
+    bool power () { return pwr_flag; }
+
+    /*!
+     * \brief Chip-select control
+     * \param   state   True to Select, false to de-select.
+     */
+    void select() {
+        spi_tx(0xFF);
+        impl().CS_impl(false);
+        spi_tx(0xFF);
+    }
+
+    /*!
+     * \brief De-select SD Card and release SPI bus
+     * \return        None.
+     */
+    void release () {
+        spi_tx(0xFF);
+        impl().CS_impl(true);
+        spi_tx(0xFF);
+    }
+
+    /*!
+     * \brief Transmit a byte to SD/MMC via SPI
+     * \param   data  The data to send to the SPI bus.
+     */
+    void spi_tx (data_type data) {
+        impl().SPI_rw_impl (data);
+    }
+
+    /*!
+     * \brief Receive a byte to SD/MMC via SPI.
+     * \return        The data received from SPI bus.
+     */
+    data_type spi_rx () {
+        return impl().SPI_rw_impl (0xFF);
+    }
+
+    /*!
+     * \brief Keep calling spi_rx until response \c resp.
+     *
+     * \param  resp     the response we wait for
+     * \param  timeout  timeout for the operation
+     * \return
+     *    \arg  true  Ready
+     *    \arg  false NOT ready.
+     */
+    bool spi_wait_for (data_type resp, clock_t timeout) {
+        data_type res;
+        clock_t mark = impl().clock_impl();
+
+        do
+           res = spi_rx ();
+        while ((res != resp) && ((impl().clock_impl() - mark) < timeout));
+
+        return (res == resp);
+    }
+
+    bool activate (bool state) {
+        if (state) {
+            power(true);                    // power on with delay
+            delay (SD_PowerTimeout);
+            impl().CS_impl(1);              // make sure CS is high
+            for (size_t i=0 ; i<10 ; ++i)   // 80 dummy clocks with DI high
+                spi_tx(0xFF);
+            status = ST_NOINIT;             // mark the status
+        }
+        else {
+            power(false);                   // power off
+            impl().CS_impl(0);              // keep CS pin voltage low
+            status = ST_NOINIT;             // mark the status
+        }
+        return state;
+    }
+
+    /*!
+     * \brief
+     *    Receive a data packet from MMC/SD
+     *
+     * \param   buffer  Pointer to data buffer to store received data
+     * \param   n       Byte count (must be multiple of 4)
+     * \return          The operation status
+     *    \arg  false   Fail
+     *    \arg  true    Success.
+     */
+    bool rx_datablock (data_type* buffer, size_t n) {
+
+        if (! spi_wait_for(DATA_START_BLOCK, SD_RxTimeout))
+            return false;
+
+        /*!
+         * Receive the data block into buffer and make sure
+         * we receive multiples of 4
+         */
+        n += (n%4) ? 4-(n%4):0;
+        for ( ; n>0 ; --n)
+           *buffer++ = spi_rx ();
+
+        spi_rx ();  // Discard CRC
+        spi_rx ();
+        return true;
+    }
+
+    /*!
+     * \brief
+     *    Transmit a data block (512bytes) to MMC/SD
+     *
+     * \param   buffer  Pointer to 512 byte data block to be transmitted
+     * \param   token   Data/Stop token
+     * \return          The operation status
+     *    \arg  false   Fail
+     *    \arg  true    Success.
+     */
+    bool tx_datablock (const data_type* buffer, data_type token) {
+        if (!spi_wait_for(0xFF, SD_WaitTimeout))
+            return false;
+
+        spi_tx(token);              // transmit data token
+        if (token != STOP_TRAN_TOKEN) {
+            // if its data token, transmit the 512 byte block
+            size_t cnt = 512;
+            do
+                spi_tx(*buffer++);
+            while (--cnt);
+            spi_tx(0xFF);           // CRC (Dummy)
+            spi_tx(0xFF);
+            data_type r = spi_rx(); // Receive data response
+            if ((r & DATA_RES_MASK) != DATA_RES_ACCEPTED) // If not accepted, return with error
+                return false;
+        }
+        return true;
+    }
+
+    /*!
+     * \brief
+     *    Send a command packet to SD/MMC and return the response
+     *
+     * \param   cmd     Command byte
+     * \param   arg     Argument
+     * \return          The response as operation status
+     */
+    data_type command (data_type cmd, uint32_t arg) {
+        data_type n, r;
+
+        if (cmd & 0x80) {
+           /*!
+            * SD_ACMD<n> is the command sequence of CMD55-SD_CMD<n>
+            */
+           cmd &= 0x7F;
+           r = command (CMD55, 0);
+           if (r > 1)
+               return r;
+        }
+
+        // Send command packet
+        spi_tx (cmd);                   // Start + Command index
+        spi_tx ((data_type)(arg>>24));  // Argument [31..24]
+        spi_tx ((data_type)(arg>>16));  // Argument [23..16]
+        spi_tx ((data_type)(arg>>8));   // Argument [15..8]
+        spi_tx ((data_type)arg);        // Argument [7..0]
+
+        if (cmd == CMD0)      n = 0x94; // Valid CRC for CMD0(0)
+        else if (cmd == CMD8) n = 0x86; // Valid CRC for CMD8(0x1AA)
+        else                   n = 0x00;
+        spi_tx (n | CMD_CRC_LSB);
+
+        // Receive command response
+        if (cmd == CMD12)
+           spi_rx ();    // Skip a stuff byte when stop reading
+
+        // Wait for a valid response in timeout of 0xFF attempts
+        size_t nn = 0xFF;
+        do
+           r = spi_rx ();
+        while ((r & 0x80) && --nn);
+
+        return r;       // Return with the response value
+    }
+
+    bool do_command_until (data_type done, data_type cmd, uint32_t arg, clock_t timeout) {
+        clock_t mark = impl().clock_impl();
+        data_type ret;
+        do
+            ret = command (cmd, arg);
+        while (ret != done && impl().clock_impl() - mark < timeout);
+        return ret == done;
+    }
+
+public:
+    bool get_CSD (data_type* csd) {
+        bool ret = false;
+        select();                                                           // select card's CS
+        if (command (CMD9, 0) == R1_READY_STATE && rx_datablock (csd, 16))  // READ_CSD
+            ret = true;
+        release();                                                          // release card's CS
+        return ret;
+    }
+
+    bool get_CID (data_type* cid) {
+        bool ret = false;
+        select();                                                           // select card's CS
+        if (command (CMD10, 0) == R1_READY_STATE && rx_datablock (cid, 16)) // READ_CID
+            ret = true;
+        release();                                                          // release card's CS
+        return ret;
+    }
+
+    bool get_OCR (data_type* ocr) {
+        bool ret = false;
+        select();                                                           // select card's CS
+        // Receive OCR as an R3 response (4 bytes)
+        if (command (CMD58, 0) == 0) {   // READ_OCR
+            for (size_t n = 0; n < 4; ++n)
+                *ocr++ = spi_rx ();
+            ret = true;
+        }
+        release();                                                          // release card's CS
+        return ret;
+    }
+
+//    bool get_SDSTAT (data_type* sdstat) {
+//        bool ret = false;
+//        select();                                                           // select card's CS
+//        if (command (ACMD13, 0) == 0) {  // SD_STATUS
+//           spi_rx ();
+//           if (rx_datablock (sdstat, 64))
+//              ret = true;
+//        }
+//        release();                                                          // release card's CS
+//        return ret;
+//    }
+
+    bool sync () {
+        select();                                       // select card's CS
+        bool st = spi_wait_for(0xFF, SD_WaitTimeout);   // flush
+        release();                                      // release card's CS
+        return st;
+    }
+
+    size_t sector_count() {
+        size_t ret =0;
+        data_type csd[16];
+
+        select();                                       // select card's CS
+        if (get_CSD(csd)) {
+            if ((csd[0] >> 6) == 1) {
+                // SDC version 2.00
+                size_t csize = csd[9] + ((uint16_t)csd[8] << 8) + 1;
+                ret = csize << 10;
+            }
+            else {
+                // SDC version 1.XX or MMC
+                uint8_t n = (csd[5] & 15) + ((csd[10] & 128) >> 7) + ((csd[9] & 3) << 1) + 2;
+                size_t csize = (csd[8] >> 6) + ((uint16_t)csd[7] << 2) + ((uint16_t)(csd[6] & 3) << 10) + 1;
+                ret = csize << (n - 9);
+            }
+        }
+        release();                                      // release card's CS
+        return ret;
+    }
+
+    size_t sector_size() const { return 512; }
+
+    size_t block_size() {
+        size_t ret =0;
+        data_type csd[16];
+
+        select();                                       // select card's CS
+        if (card_type & CT_SD2) {
+            // SDC version 2.00
+            if (command (ACMD13, 0) == R1_READY_STATE) {
+                spi_rx ();                              // Read SD status
+                if (rx_datablock (csd, 16)) {           // Read partial block
+                    for (size_t n = 64 - 16; n; n--)    // Purge trailing data
+                        spi_rx ();
+                    ret = 16UL << (csd[10] >> 4);
+                }
+            }
+        }
+        else {
+            // SDC version 1.XX or MMC
+            if (get_CSD(csd)) {                         // Read CSD
+                if (card_type & CT_SD1)                 // SDC version 1.XX
+                    ret = (((csd[10] & 63) << 1) + ((uint16_t)(csd[11] & 128) >> 7) + 1) << ((csd[13] >> 6) - 1);
+                else                                    // MMC
+                    ret = ((uint16_t)((csd[10] & 124) >> 2) + 1) * (((csd[11] & 3) << 3) + ((csd[11] & 224) >> 5) + 1);
+            }
+        }
+        release();                                      // release card's CS
+        return ret;
+    }
+
+    /*!
+     * \brief
+     *    De-Initialize SD Drive.
+     * \return  None
+     */
+    void deinit () {
+        card_type   = data_type{};
+        status      = status_t{};
+        activate (0);   // finally power off the card
+    }
+
+    /*!
+     * \brief
+     *    Initialize SD Drive.
+     *
+     * \return  The status of the operation
+     *    \arg  false   On error.
+     *    \arg  true    On success.
+     */
+    bool init () {
+        uint32_t clk;
+        data_type ocr[4], csd[16];
+
+        clk = 400000;                       // Start at lower clk
+        impl().SPI_set_clk_impl(clk);
+
+        activate (0);                       // Initially power off the card
+        if (!is_present()) {                // check for presence
+            status = ST_NODISK;
+            return false;
+        }
+        activate (1);                       // activate and wait for PowerTimeout delay
+
+        select();                           // select card
+        data_type type = CT_NONE;
+
+        if (command (CMD0, 0) == R1_IDLE_STATE) {   // Command to enter Idle state
+            if (command (CMD8, 0x1AA) == 1) {       // check SD version
+                // SDHC
+                for (size_t n=0 ; n<4 ; ++n)                // Get trailing return value of R7 response
+                    ocr[n] = spi_rx ();
+                if (ocr[2] == 0x01 && ocr[3] == 0xAA) {
+                    // Wait for leaving idle state (ACMD41 with HCS bit)
+                    bool st = do_command_until(R1_READY_STATE, ACMD41, 1UL << 30, SD_InitTimeout);
+
+                    if (st && get_OCR(ocr))
+                        type = (ocr[0] & 0x40) ? CT_SD2 | CT_BLOCK : CT_SD2;
+                }
+            } else {
+                data_type cmd;
+                // SDSC or MMC
+                if (command (ACMD41, 0) <= 1) {  // SDSC
+                    type = CT_SD1; cmd = ACMD41;
+                } else { // MMC
+                    type = CT_MMC; cmd = CMD1;
+                }
+                // Wait for leaving idle state (ACMD41 || CMD1)
+                bool st = do_command_until(R1_READY_STATE, cmd, 0, SD_InitTimeout);
+                // On failure, set R/W block length to 512 (For FAT compatibility)
+                if (!st || command (CMD16, 512) != R1_READY_STATE)
+                    type = CT_NONE;
+            }
+        }
+        card_type = type;
+        release ();    // Initialization ended
+
+        if (type != CT_NONE) {
+            // Success
+            get_CSD(csd);
+            clk = csd2bautrate(csd);
+            impl().SPI_set_clk_impl(clk);
+            status = ST_OK;
+            return true;
+        }
+        else {
+            activate(0);
+            return false;
+        }
+    }
+
+    status_t get_status () const { return status; }
+
+    /*!
+     * \brief
+     *    Read Sector(s)
+     *
+     * \param   sector Start sector number (LBA)
+     * \param   buf    Pointer to the data buffer to store read data
+     * \param   count  Sector (512 bytes) count (1..255)
+     * \return  The status of the operation
+     *    \arg  false       On error.
+     *    \arg  true        On success.
+     */
+    bool read (size_t sector, data_type *buf, size_t count) {
+
+        if (status != ST_OK)    return false;
+
+        if (!(card_type & CT_BLOCK))                        // Convert to byte address if needed
+            sector *= 512;
+        select();
+        if (count == 1) {                                   //Single block read
+            if (command (CMD17, sector) == 0)
+                if (rx_datablock (buf, 512))
+                    count = 0;
+        }
+        else {                                              // Multiple block read
+            if (command (CMD18, sector) == 0) {
+                do {
+                    if (!rx_datablock (buf, 512))
+                        break;
+                    buf += 512;
+                } while (--count);
+                command (CMD12, 0);                 // STOP_TRANSMISSION
+            }
+        }
+       release ();
+       return (count == 0);
+    }
+
+    /*!
+     * \brief
+     *    Write Sector(s)
+     *
+     * \param   sector Start sector number (LBA)
+     * \param   buf    Pointer to the data to be written
+     * \param   count  Sector(512 bytes) count (1..255)
+     * \return  The status of the operation
+     *    \arg  false       On error.
+     *    \arg  true        On success.
+     */
+    bool write (size_t sector, const data_type *buf, size_t count) {
+
+       if (!count)              return false;
+       if (status != ST_OK)     return false;
+
+       if (!(card_type & CT_BLOCK))                         // Convert to byte address if needed
+           sector *= 512;
+
+       select();
+       if (count == 1) {                                    // Single block write
+           if ((command (CMD24, sector) == 0) && tx_datablock (buf, 0xFE))
+               count = 0;
+       } else {                                             // Multiple block write
+           if (card_type & CT_SDC)
+               command (ACMD23, count);
+           if (command (CMD25, sector) == 0) {
+               do {
+                   if (!tx_datablock (buf, WRITE_MULTIPLE_TOKEN))
+                       break;
+                   buf += 512;
+               } while (--count);
+               if (!tx_datablock (0, STOP_TRAN_TOKEN))      // STOP token
+                   count = 1;
+           }
+       }
+       release ();
+       return (count == 0);
+    }
+
+    bool ioctl (ioctl_cmd cmd, void* buffer) {
+        switch (cmd) {
+            // SD/MMC specific
+            case IOCTL_MMC_GET_TYPE:    *(data_type*)buffer = card_type;    return true;
+            case IOCTL_MMC_GET_CSD:     return get_CSD ((data_type*)buffer);
+            case IOCTL_MMC_GET_CID:     return get_CID ((data_type*)buffer);
+            case IOCTL_MMC_GET_OCR:     return get_OCR ((data_type*)buffer);
+            case IOCTL_MMC_GET_SDSTAT:  return false;
+
+            // Generic
+            case IOCTL_POWER:
+                switch (*(data_type*)buffer) {
+                    case 0: *((data_type*)buffer+1) = (data_type)activate(0); return true;
+                    case 1: *((data_type*)buffer+1) = (data_type)activate(0); return true;
+                    case 2: *((data_type*)buffer+1) = (data_type)power();     return true;
+                    default: return false;
+                }
+                break;
+            case IOCTL_LOCK:
+            case IOCTL_EJECT:
+            case IOCTL_FORMAT:
+                return false;
+
+            // FatFS compatibility
+            case IOCTL_SYNC:            return sync();
+            case IOCTL_GET_SECTOR_COUNT:return (*(size_t*) buffer = sector_count() != 0);
+            case IOCTL_GET_SECTOR_SIZE: return (*(size_t*) buffer = sector_size() != 0);
+            case IOCTL_GET_BLOCK_SIZE:  return (*(size_t*) buffer = block_size() != 0);
+            case IOCTL_ERASE_SECTOR:    return false;
+
+            default:
+                return false;
+        }
+    }
+
+private:
+    data_type   card_type{};
+    status_t    status{};
+    bool        pwr_flag{};
+
+};
+
+} // namespace tbx
+
+#endif /* TBX_DRV_SD_SPI_H_ */

include/tbx.h

@@ -0,0 +1,50 @@
+/*!
+ * \file tbx.h
+ * \brief
+ *     Main tbx header
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+#ifndef TBX_H_
+#define TBX_H_
+
+#include <com/sequencer.h>
+
+#include <cont/deque.h>
+#include <cont/edeque.h>
+#include <cont/queue.h>
+#include <cont/equeue.h>
+
+#include <utils/json.h>
+#include <utils/shared.h>
+#include <utils/print.h>
+#include <utils/timer_delay.h>
+
+#include <drv/cli_device.h>
+#include <drv/liquid_crystal.h>
+#include <drv/gpio.h>
+#include <drv/sd_spi.h>
+
+#endif /* TBX_H_ */

include/utils/json.h

@@ -0,0 +1,224 @@
+/*!
+ * \file files.h
+ * \brief
+ *      File functionality header
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * All Rights Reserved.
+ *
+ * NOTICE:  All information contained herein is, and remains
+ * the property of Christos Choutouridis. The intellectual
+ * and technical concepts contained herein are proprietary to
+ * Christos Choutouridis and are protected by copyright law.
+ * Dissemination of this information or reproduction of this material
+ * is strictly forbidden unless prior written permission is obtained
+ * from Christos Choutouridis.
+ * </dd></dl>
+ */
+#ifndef JSON_H_
+#define JSON_H_
+
+#include <cstddef>
+#include <cstdlib>
+#include <cstring>
+#include <cctype>
+#include <type_traits>
+#include <string_view>
+#include <array>
+
+using size_t = std::size_t;
+
+struct jpair_t {
+    std::string_view key;
+    std::string_view value;
+};
+
+template<size_t N>
+struct json_dec_t {
+
+    using string_view = std::string_view;
+
+    json_dec_t(const char* buffer, size_t size) noexcept :
+    buffer_(buffer, size), valid_(true) {
+        enum state_t {
+            ST=0, KEY, COLON, VALUE, SP
+        } state = ST;
+
+        size_t pairs =0;
+        char* begin = nullptr;
+        int s =0;
+        bool str_value = false;     // flag to indicate the value is string
+
+        for (size_t i=0 ; i<size ; ++i) {
+            switch (state) {
+                case ST:
+                    if (std::isspace(buffer[i]))
+                        continue;   // skip white space
+                    if (buffer[i] == '{')
+                        state = KEY;
+                    break;
+
+                case KEY:
+                    if (pairs >= N) {
+                        valid_ = false;
+                        break;
+                    }
+                    if (std::isspace(buffer[i]))
+                        continue;   // skip white space
+                    if (buffer[i] == '\"') {
+                        if (!begin)
+                            begin = (char*)&buffer[i+1];
+                        else {
+                            s = (char*)&buffer[i] - begin;
+                            if (s > 0)
+                                pairs_[pairs].key = std::string_view{begin, (size_t)s};
+                            else
+                                pairs_[pairs].key = std::string_view{};
+                            begin =nullptr;
+                            s =0;
+                            state = COLON;
+                        }
+                    }
+                    else if (buffer[i] == '}')
+                        return;
+                    break;
+
+                case COLON:
+                    if (std::isspace(buffer[i]))
+                        continue;   // skip white space
+                    if (buffer[i] == ':')
+                        state = VALUE;
+                    else {
+                        valid_ = false;
+                        return;
+                    }
+                    break;
+
+                case VALUE:
+                    if (pairs >= N) {
+                        valid_ = false;
+                        break;
+                    }
+                    if (!begin && std::isspace(buffer[i]))          // consume pre-spaces
+                        continue;
+                    else if (!begin && !std::isspace(buffer[i])) {  // first character
+                        if (buffer[i] == '\"') {
+                            begin = (char*)&buffer[i+1];
+                            str_value = true;
+                        }
+                        else {
+                            begin = (char*)&buffer[i];
+                            str_value = false;
+                        }
+                    }
+                    else if (begin) {
+                        if (str_value && (buffer[i] == '\"')) {
+                            s  = (char*)&buffer[i] - begin;
+                            if (s > 0)
+                                pairs_[pairs].value = std::string_view{begin, (size_t)s};
+                            else
+                                pairs_[pairs].value = std::string_view{};
+                            ++pairs;
+                            begin =nullptr;
+                            s =0;
+                            state = SP;
+                        }
+                        else if (!str_value && (std::isspace(buffer[i]) || buffer[i] == ',' || buffer[i] == '}')) {
+                            s  = (char*)&buffer[i] - begin;
+                            if (s > 0)
+                                pairs_[pairs].value = std::string_view{begin, (size_t)s};
+                            else
+                                pairs_[pairs].value = std::string_view{};
+                            ++pairs;
+                            begin =nullptr;
+                            s =0;
+                            if (std::isspace(buffer[i]))
+                                state = SP;
+                            else if (buffer[i] == ',')
+                                state = KEY;
+                            else if (buffer[i] == '}')
+                                return;
+                        }
+                    }
+                    break;
+
+                case SP:
+                    if (std::isspace(buffer[i]))
+                        continue;   // skip white space
+                    else if (buffer[i] == ',')
+                        state = KEY;
+                    else if (buffer[i] == '}')
+                        return;
+                    else {
+                        valid_ = false;
+                        return;
+                    }
+                    break;
+            }
+        }
+    }
+    template<typename T>
+    T get (const char* key) {
+        T t{};
+        for (auto& it : pairs_) {
+            if (it.key.compare(key) == 0) {
+                extract_(it.value, &t);
+                break;
+            }
+        }
+        return t;
+    }
+    bool is_valid() const { return valid_; }
+
+private:
+    /*!
+     * Convert the text pointed by \c str to a value and store it to
+     * \c value. The type of conversion is deduced by the compiler
+     * \tparam  T       The type of the value
+     * \param str       pointer to string with the value
+     * \param value     pointer to converted value
+     */
+    void extract_(std::string_view str, bool* value) {
+        *value = (
+            !std::strncmp(str.data(), "true", str.size()) ||
+            !std::strncmp(str.data(), "True", str.size()) ||
+            !std::strncmp(str.data(), "TRUE", str.size()) ||
+            !std::strncmp(str.data(), "1", str.size())
+        ) ? true : false;
+    }
+    void extract_(std::string_view str, int* value) {
+        *value = std::atoi(str.data());
+    }
+    void extract_(std::string_view str, unsigned int* value) {
+        *value = (unsigned int)std::atoi(str.data());
+    }
+    void extract_(std::string_view str, long* value) {
+        *value = std::atol(str.data());
+    }
+    void extract_(std::string_view str, unsigned long* value) {
+        *value = (unsigned long)std::atol(str.data());
+    }
+    void extract_(std::string_view str, double* value) {
+        *value = std::atof(str.data());
+    }
+    void extract_(std::string_view str, char** value) {
+        *value = (char*)str.data();
+    }
+    void extract_(std::string_view str, string_view* value) {
+        *value = str;
+    }
+    //! Specialization (as overload function) to handle void* types
+    void extract_ (const char* str, void* value) noexcept {
+        (void)*str; (void)value;
+    }
+private:
+    std::string_view        buffer_;
+    std::array<jpair_t, N>  pairs_;
+    bool                    valid_;
+};
+
+
+
+#endif /* JSON_H_ */

include/utils/print.h

@@ -0,0 +1,314 @@
+/*!
+ * \file utils/print.h
+ * \brief
+ *      A CRTP base class to provide print interface
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_UTILS_PRINT_H_
+#define TBX_UTILS_PRINT_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+
+#include <cstring>
+#include <math.h>
+#include <string_view>
+#include <type_traits>
+#include <utility>
+#include <limits>
+
+namespace tbx {
+
+    /*!
+     * \class Print
+     * \brief
+     *      A CRTP print interface
+     *
+     * Requirements:
+     *  - size_t write_impl(const Char_t* buffer, size_t size) : Return the number of \c Char_t written
+     *  - size_t write_impl(const Char_t ch) : Return the number of \c Char_t written (normally one).
+     *
+     * \tparam Impl_t       The derived type
+     * \tparam Char_t       The char type to use
+     */
+    template <typename Impl_t, typename Char_t>
+    class Print {
+        _CRTP_IMPL(Impl_t);
+
+    public:
+        using value_type        = Char_t;
+        using pointer_type      = Char_t*;
+        using iterator_type     = Char_t*;
+        using const_iterator_type = const Char_t*;
+        using difference_type   = std::ptrdiff_t;
+        using size_type         = size_t;
+        using str_view_t        = std::basic_string_view<Char_t>;
+
+        //! Enumerator for number base formating
+        enum class Base {
+            BIN =2, OCT =8, DEC =10, HEX =16
+        };
+
+    private:
+        //! \name CRTP requirements
+        //! @{
+        size_t write_(const Char_t* buffer, size_t size) {
+            return impl().write_impl(buffer, size);
+        }
+        size_t write_(const Char_t ch) {
+            return impl().write_impl(ch);
+        }
+        //! @}
+
+    protected:
+        Print() noexcept = default;     //!< Construct from derived only
+
+    private:
+        //! Helper tool to convert strong enums to their underlying type
+        template <typename E>
+        constexpr typename std::underlying_type_t<E> value(E e) noexcept {
+            return static_cast<typename std::underlying_type_t<E>>(e);
+        }
+
+        size_t print_unsigned(unsigned long n, Base base);  // integer conversion base tool
+        size_t print_double(double number, uint8_t digits); // double conversion base tool
+
+    public:
+        /*!
+         * \brief
+         *      Prints a string view
+         * \param str   The string view to print
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(const str_view_t str) {
+            return write_(str.data(), str.size());
+        }
+
+        /*!
+         * \brief
+         *      Prints a string
+         * \param str   Pointer to string to print
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(const Char_t* str) {
+            if (str == nullptr)
+                return 0;
+            return write_(str, std::strlen(str));
+        }
+
+        /*!
+         * \brief
+         *      Prints a buffer of size \c size. If there is a null termination
+         *      before the end of the buffer, prints up to termination.
+         *
+         * \param str       Pointer to string buffer to print
+         * \param size      The size of buffer
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(const Char_t* str, size_t size) {
+            if (str == nullptr)
+                return 0;
+            return write_(str, size);
+        }
+
+        /*!
+         * \brief
+         *      Prints a \c Char_t
+         * \param ch    The Char_t to print
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(Char_t ch) {
+            return write_ (ch);
+        }
+
+        /*!
+         * \brief
+         *      Convert and print a long.
+         * \param n     The number to print
+         * \param base  The number base to use for conversion.
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(long n, Base base =Base::DEC) {
+            size_t cnt =0;
+            if (n < 0) {
+                n = -n;
+                cnt = write_ ('-');
+            }
+            return cnt + print_unsigned((unsigned long)n, base);
+        }
+
+        /*!
+         * \brief
+         *      Convert and print an int.
+         * \param n     The number to print
+         * \param base  The number base to use for conversion.
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(int n, Base base= Base::DEC) {
+            return print ((long)n, base);
+        }
+
+        /*!
+         * \brief
+         *      Convert and print an unsigned long.
+         * \param n     The number to print
+         * \param base  The number base to use for conversion.
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(unsigned long n, Base base= Base::DEC) {
+            return print_unsigned ((unsigned long)n, base);
+        }
+
+        /*!
+         * \brief
+         *      Convert and print an unsigned int.
+         * \param n     The number to print
+         * \param base  The number base to use for conversion.
+         * \return      The number of printed \c Char_t
+         */
+        size_t print(unsigned int n, Base base= Base::DEC) {
+            return print_unsigned ((unsigned long)n, base);
+        }
+
+        /*!
+         * \brief
+         *      Convert and print adouble
+         * \param n         The number to print
+         * \param digits    The number of decimal digits to print
+         * \return          The number of printed \c Char_t
+         */
+        size_t print(double n, uint8_t digits = 2) {
+            return print_double (n, digits);
+        }
+
+        /*!
+         * \brief
+         *      Perfect forwarder to print functionality with a new line termination
+         * \tparam Ts   The types of parameters
+         * \param args  The arguments to pass
+         * \return      The number of printed \c Char_t
+         */
+        template <typename ...Ts>
+        size_t println(Ts&& ...args) {
+            size_t r = print (std::forward<Ts>(args)...);
+            r += write_ ('\n');
+            return r;
+        }
+    };
+
+    /*!
+     * \brief
+     *      Converts and prints an unsigned long
+     *
+     * \tparam Impl_t       The derived type
+     * \tparam Char_t       The char type to use
+     *
+     * \param n     The number to print
+     * \param base  The number base to use
+     * \return      The number of printed \c Char_t
+     */
+    template <typename Impl_t, typename Char_t>
+    size_t Print<Impl_t, Char_t>::print_unsigned(unsigned long n, Base base) {
+        Char_t buf[8 *sizeof(Char_t) * sizeof(long) + 1]; // Assumes 8-bit chars plus zero byte.
+        Char_t *str = &buf[sizeof(buf) - 1];
+
+        *str = '\0';
+
+        do {
+            Char_t c = n % value(base);
+            n /= value(base);
+
+            *--str = c < 10 ? c + '0' : c + 'A' - 10;
+        } while(n);
+
+        return write_(str, std::strlen(str));
+    }
+
+    /*!
+     * \brief
+     *      Converts and prints a double
+     *
+     * \note
+     *  Internally, this implementation uses a long to store the integer part of the number.
+     *  Thus overflows for numbers bigger than std::numeric_limits<long>::max() / min().
+     *  For these numbers it prints "ovf" instead.
+     *
+     * \tparam Impl_t       The derived type
+     * \tparam Char_t       The char type to use
+     *
+     * \param n         The number to print
+     * \param digits    The number of decimal digits to print
+     * \return          The number of printed \c Char_t
+     */
+    template <typename Impl_t, typename Char_t>
+    size_t Print<Impl_t, Char_t>::print_double(double number, uint8_t digits)  {
+        size_t n = 0;
+
+        if (std::isnan(number))     return print("nan");
+        if (std::isinf(number))     return print("inf");
+        if (number > (double)std::numeric_limits<long>::max())
+            return print ("ovf");
+        if (number < (double)std::numeric_limits<long>::min())
+            return print ("-ovf");
+
+        // Handle negative numbers
+        if (number < 0.0) {
+            n += write_ ('-');
+            number = -number;
+        }
+
+        // Round correctly so that print(1.999, 2) prints as "2.00"
+        double rounding = 0.5;
+        for (uint8_t i=0; i<digits; ++i)
+            rounding /= 10.0;
+
+        number += rounding;
+
+        // Extract the integer part of the number and print it
+        unsigned long int_part = (unsigned long)number;
+        double remainder       = number - (double)int_part;
+        n += print(int_part);
+
+        // Print the decimal point, but only if there are digits beyond
+        if (digits > 0) {
+            n += print('.');
+        }
+
+        // Extract digits from the remainder one at a time
+        while (digits-- > 0) {
+            remainder *= 10.0;
+            unsigned int toPrint = (unsigned int)(remainder);
+            n += print(toPrint);
+            remainder -= toPrint;
+        }
+
+        return n;
+    }
+
+
+}
+#endif /* TBX_UTILS_PRINT_H_ */

include/utils/sequencer.h

@@ -1,359 +0,0 @@
-/*!
- * \file utils/sequencer.h
- * \brief
- *      A terminal-like device communication automation tool
- *
- * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
- *
- * <dl class=\"section copyright\"><dt>License</dt><dd>
- * The MIT License (MIT)
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- * </dd></dl>
- */
-
-#ifndef TBX_UTILS_SEQUENCER_H_
-#define TBX_UTILS_SEQUENCER_H_
-
-
-#include <core/core.h>
-#include <core/crtp.h>
-#include <ctime>
-#include <array>
-#include <string_view>
-
-namespace tbx {
-
-/*!
- * \class sequencer_t
- * \brief
- *      A CRTP base class to provide the sequencer functionality.
- *
- * Sequencer can automate communication with a terminal-like device such as AT-command modems etc...
- * It can operate based on a script array and handle the outgoing commands and incoming responses.
- * The user can create matching rules on received data and hook handlers and actions on them.
- *
- * The derived class (implementation) has to provide:
- *  1) size_t get(Data_t* data);
- *     This function return 0 or a number of Data_t items. The data points to buffer for the input data.
- *  2) size_t put(const Data_t* data, size_t n);
- *     This function sends to implementation the data pointed by \c data witch have size \c n.
- *  3) clock_t clock();
- *     This function return a number to be used as time. The units of this function may be arbitrary but they
- *     match the units in \c record_t::timeout field.
- *
- * \tparam Impl_t   The type of derived class
- * \tparam Data_t   The char-like stream item type. Usually \c char
- * \tparam N        The size of the sequence buffer to temporary store each line from get().
- */
-template <typename Impl_t, typename Data_t, size_t N>
-class sequencer_t {
-    _CRTP_IMPL(Impl_t);
-
-    using str_view_t = std::basic_string_view<Data_t>;
-
-    //! \name Public types
-    //! @{
-    public:
-        //! \enum status_t
-        //! \brief The sequencer run status
-        enum class status_t {
-            OK, ERROR
-        };
-
-
-        //! \enum action_t
-        //! \brief Possible response actions for the sequencer
-        enum class action_t {
-            NO, NEXT, GOTO, EXIT_OK, EXIT_ERROR
-        };
-
-        //! \enum control_t
-        //! \brief The control type of the script entry.
-        enum class control_t {
-            NOP,    //!< No command, dont send or expect anything, used for delays
-            SEND,   //!< Send data to implementation
-            EXPECT  //!< Expects data from implementation
-        };
-
-        //! \enum match_t
-        //! \brief Token match types
-        enum class match_t {
-            NO, STARTS_WITH, ENDS_WITH, CONTAINS, nSTARTS_WITH, nENDS_WITH, nCONTAINS
-        };
-
-        /*!
-         *  Match handler function pointer type.
-         *  Expects a pointer to buffer and a size and returns status
-         */
-        using handler_ft = status_t (*) (const Data_t*, size_t);
-
-        /*!
-         * \struct block_t
-         * \brief
-         *      The script line block.
-         *
-         * Each script "line" contains up to 2 blocks for matching functionality. Each block
-         * has a token and a matching type. If the response matches the token, the sequencer calls
-         * the handler and perform the action.
-         */
-        struct block_t {
-            std::basic_string_view<Data_t>
-                                token;          //!< The token for the match
-            match_t             match_type;     //!< The matching type functionality
-            handler_ft          handler;        //!< The handler to called if the match is successful.
-            action_t            action;         //!< The action to be performer if the match is successful
-            size_t              idx;            //!< The index for the action_t::GOTO action. Otherwise can be left 0.
-        };
-
-        /*!
-         * \struct record_t
-         * \brief
-         *      Describes the sequencer's script record entry (line).
-         *
-         * Each line consist from a control, 2 blocks and a timeout. The control says if we send or receive data.
-         * The blocks contain the data and the matching information. And the timeout guards the entire line.
-         *
-         * The user can create arrays as the example bellow to act as a script.
-         * \code
-         *  const std::array<Seq::record_t, 8> script = {{
-         *  / * 0 * / {Seq::control_t::NOP,  {"",         Seq::match_t::NO, nullptr, Seq::action_t::GOTO, 1}, 1000},  //delay 1000 clocks
-         *  / * 1 * / {Seq::control_t::SEND, {"ATE0\r\n", Seq::match_t::NO, nullptr, Seq::action_t::NEXT, 0}, 1000},
-         *  / * 2 * / {Seq::control_t::EXPECT, {{
-         *                {"OK\r\n", Seq::match_t::ENDS_WITH,   nullptr, Seq::action_t::NEXT, 0},
-         *                {"ERROR",  Seq::match_t::CONTAINS,    nullptr, Seq::action_t::EXIT_ERROR, 0} }},
-         *                1000
-         *            },
-         *            // ...
-         *  }};
-         * \endcode
-         */
-        struct record_t {
-            control_t               control;    //!< The type of the entry
-            std::array<block_t, 2>  block;      //!< The matching block
-            clock_t                 timeout;    //!< Timeout in CPU time
-        };
-    //! @}
-
-
-
-    //! \name Constructor / Destructor
-    //!@{
-    protected:
-       ~sequencer_t () = default;                               //!< \brief Allow destructor from derived only
-       sequencer_t () = default;                                //!< \brief A default constructor from derived only
-       sequencer_t(const sequencer_t&) = delete;                //!< No copies
-       sequencer_t& operator= (const sequencer_t&) = delete;    //!< No copy assignments
-    //!@}
-
-    //! \name Sequencer interface requirements for implementer
-    //! @{
-    private:
-       size_t get_ (Data_t* data) { return impl().get (data); }
-       size_t put_ (const Data_t* data, size_t n) { return impl().put (data, n); }
-       clock_t clock_ () { return impl().clock(); }
-    //! @}
-
-    //! \name Private functionality
-    //! @{
-    private:
-       /*!
-        * \brief
-        *       Check if the \c stream starts with the \c prefix
-        * \param stream     The stream in witch we search
-        * \param prefix     What we search
-        * \return           True on success, false otherwise
-        */
-       bool starts_with_ (const str_view_t stream, const str_view_t prefix) {
-           return (stream.rfind(prefix, 0) != str_view_t::npos);
-       }
-
-       /*!
-        * \brief
-        *       Check if the \c stream ends with the \c postfix
-        * \param stream     The stream in witch we search
-        * \param postfix    What we search
-        * \return           True on success, false otherwise
-        */
-       bool ends_with_ (const str_view_t stream, const str_view_t postfix) {
-           return (
-               stream.compare(
-                   stream.size() - postfix.size(),
-                   postfix.size(),
-                   postfix) == 0
-               );
-       }
-
-       /*!
-        * \brief
-        *       Check if the \c haystack contains the \c needle
-        * \param haystack   The stream in witch we search
-        * \param needle     What we search
-        * \return           True on success, false otherwise
-        */
-       bool contains_ (const str_view_t haystack, const str_view_t needle) {
-           return (haystack.find(needle) != str_view_t::npos);
-       }
-       /*!
-        * \brief
-        *   Return the new sequencer's step value.
-        *
-        * Step is index to the sequencer's script array.
-        *
-        * \param current_idx    The current step value
-        * \param action         The advancing type
-        * \param go_idx         The new value of the step in the case of GOTO type
-        * \return               The new sequencer's step value
-        */
-       size_t step_ (size_t current_idx, action_t action, size_t go_idx =0) {
-           switch (action) {
-               default:
-               case action_t::NO:   return current_idx;
-               case action_t::NEXT: return ++current_idx;
-               case action_t::GOTO: return go_idx;
-               case action_t::EXIT_OK:
-               case action_t::EXIT_ERROR:
-                                    return 0;
-           }
-       }
-       /*!
-        * \brief
-        *   Checks if the \c needle matches the \c haystack.
-        *
-        * \param type       The type of matching functionality
-        * \param haystack   The stream in witch we search
-        * \param needle     The stream we search
-        * \return           True on match
-        */
-       bool match_(match_t type, const str_view_t haystack, const str_view_t needle) {
-           switch (type) {
-               default:
-               case match_t::NO:            return true;
-               case match_t::STARTS_WITH:   return starts_with_(haystack, needle);
-               case match_t::ENDS_WITH:     return ends_with_(haystack, needle);
-               case match_t::CONTAINS:      return contains_(haystack, needle);
-               case match_t::nSTARTS_WITH:  return !starts_with_(haystack, needle);
-               case match_t::nENDS_WITH:    return !ends_with_(haystack, needle);
-               case match_t::nCONTAINS:     return !contains_(haystack, needle);
-           }
-       }
-    //! @}
-
-
-    public:
-       /*!
-        * \brief
-        *   Run the script array
-        *
-        * The main sequencer functionality. It starts with the first entry of the array.
-        * - If the entry is \c NOP it executes the action after the timeout.
-        *   \c token and \c handler are discarded.
-        * - If the entry is \c SEND it uses the first block's token to send and executes the action after that.
-        *   \c timeout is discarded.
-        * - If the entry is \c EXCEPTS it continuously try to receive data using implementation's get until one
-        *   of the blocks match.
-        *   On match:
-        *     - Calls the handler if there is one
-        *     - Executes the action
-        *     - Skips the next block if there is one
-        *   If there is no match on timeout it return status_t::EXIT_ERROR
-        *
-        * \tparam Steps     The number of steps of the script
-        * \param script     Reference to script to run
-        * \return           The status of entire operation as described above
-        */
-       template <size_t Steps>
-       status_t run (const std::array<record_t, Steps>& script) {
-           Data_t buffer[N];
-           size_t resp_size;
-
-           clock_t mark = clock_();
-           for (size_t step =0, p_step =0 ; step < Steps ; ) {
-               const record_t& it = script[step];
-
-               if (step != p_step) {
-                   p_step = step;
-                   mark = clock_();
-               }
-               switch (it.control) {
-                   default:
-                   case control_t::NOP:
-                       if ((clock_() - mark) >= it.timeout) {
-                           switch (it.block[0].action) {
-                               case action_t::EXIT_OK:      return status_t::OK;
-                               case action_t::EXIT_ERROR:   return status_t::ERROR;
-                               default:
-                                   step = step_(step, it.block[0].action, it.block[0].idx);
-                                   break;
-                           }
-                       }
-                       break;
-
-                   case control_t::SEND:
-                       put_(it.block[0].token.data(), it.block[0].token.size());
-                       switch (it.block[0].action) {
-                           case action_t::EXIT_OK:      return status_t::OK;
-                           case action_t::EXIT_ERROR:   return status_t::ERROR;
-                           default:
-                               step = step_(step, it.block[0].action, it.block[0].idx);
-                               break;
-                       }
-                       break;
-
-                   case control_t::EXPECT:
-                       resp_size = get_(buffer);
-                       if (resp_size) {
-                           for (auto& block : it.block) {
-                               if (match_(block.match_type, buffer, block.token)) {
-                                   if (block.handler != nullptr)
-                                       block.handler(buffer, resp_size);
-                                   switch (block.action) {
-                                       case action_t::EXIT_OK:      return status_t::OK;
-                                       case action_t::EXIT_ERROR:   return status_t::ERROR;
-                                       default:
-                                           step = step_(step, block.action, block.idx);
-                                           break;
-                                   }
-                                   break;
-                               }
-                           }
-                       }
-                       if ((clock_() - mark) >= it.timeout)
-                           return status_t::ERROR;
-                       break;
-               } // switch (it.control)
-           }
-           return status_t::OK;
-       }
-};
-
-/*!
- * An "empty" block for convenience.
- */
-template <typename Impl_t, typename Data_t, size_t N>
-constexpr typename sequencer_t<Impl_t, Data_t, N>::block_t Sequencer_null_block = {
-    "",
-    sequencer_t<Impl_t, Data_t, N>::match_t::NO,
-    nullptr,
-    sequencer_t<Impl_t, Data_t, N>::action_t::NO,
-    0
-};
-
-}
-#endif /* TBX_UTILS_SEQUENCER_H_ */

include/utils/shared.h

@@ -0,0 +1,107 @@
+/*!
+ * \file utils/shared.h
+ * \brief
+ *      A CRTP base class to provide acquire/release functionality for shared resources
+ *      without handle pointers.
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_UTILS_SHARED_H_
+#define TBX_UTILS_SHARED_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+
+#include <utility>
+
+namespace tbx {
+
+/*!
+ * A CRTP base class to provide acquire/release functionality for shared resources
+ * without handle pointers.
+ *
+ * \example
+ * \code
+ * class GPIOClock : public shared<GPIOClock> {
+ *     friend shared<GPIOClock>;
+ *     void acquire_impl() { // HAL enable gpio clock }
+ *     void release_impl() { // HAL disable gpio clock }
+ * };
+ * GPIOClock clk;
+ * class Pin {
+ *     Pin() {
+ *         clk.acquire();
+ *         // init pin
+ *     }
+ *     ~Pin() {
+ *         // de-init pin
+ *         clk.release();
+ *     }
+ * };
+ * \endcode
+ *
+ * \tparam Impl_t   The derived class type
+ */
+template <typename Impl_t>
+class shared {
+        _CRTP_IMPL(Impl_t);
+        int count {};   //!< acquisition counter
+
+    protected:
+        shared() noexcept               = default;
+        shared(const shared&)           = delete;   //!< No copies
+        shared operator=(const shared&) = delete;   //!< No copies
+
+    public:
+        /*!
+         * Acquires the recourse. If it is the first call to acquire the resource we actually acquire it.
+         * Otherwise we just keep track of how many acquisition have made.
+         *
+         * \tparam Ts   The types of possible arguments
+         * \param args  Possible arguments to pass to acquire_impl() of derived class
+         */
+        template <typename ...Ts>
+        void acquire (Ts&&... args) {
+            if (!count++)   impl().acquire_impl(std::forward<Ts>(args)...);
+        }
+        /*!
+         * Release the recourse. On every call we decrease the count of acquisitions. If we reach zero
+         * we actually release the resource.
+         *
+         * \tparam Ts   The types of possible arguments
+         * \param args  Possible arguments to pass to release_impl() of derived class
+         */
+        template <typename ...Ts>
+        void release (Ts&&... args) noexcept {
+            if (--count <= 0) {
+                impl().release_impl(std::forward<Ts>(args)...);
+                count =0;
+            }
+        }
+};
+
+}
+#endif /* TBX_UTILS_SHARED_H_ */

include/utils/timer_delay.h

@@ -0,0 +1,333 @@
+/*!
+ * \file utils/timer_delay.h
+ * \brief
+ *      A CRTP timer delay utility
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_UTILS_TIMER_DELAY_H_
+#define TBX_UTILS_TIMER_DELAY_H_
+
+#include <core/core.h>
+#include <core/crtp.h>
+
+#include <type_traits>
+
+namespace tbx {
+
+    /*!
+     * \class timer_delay
+     * \brief
+     *      A CRTP hw timer based, delay implementation.
+     *
+     * CRTP requirements:
+     *  - int set_frequency_impl (size_t freq, Counter_t ticks)
+     *    Initialize and start the hw timer with tick frequency \c freq and reload value \c ticks
+     *  - volatile Counter_t* get_value_ptr_impl (Counter_t discard)
+     *    Return a pointer to hw timer counter value register. The \c discard argument should discarded.
+     *
+     * \tparam Impl_t       The derived class
+     * \tparam Counter_t    The hw timer's type
+     */
+    template <typename Impl_t, typename Counter_t>
+    class timer_delay {
+        _CRTP_IMPL(Impl_t);
+        using value_t  = volatile Counter_t;
+        using marker_t = std::make_signed_t<std::remove_cv_t<Counter_t>>;
+
+    //! \name CRTP requirements
+    //! @{
+    private:
+        int set_frequency (size_t freq, Counter_t ticks) {
+            return impl().set_frequency_impl(freq, ticks);
+        }
+        volatile Counter_t* get_value_ptr (Counter_t discard = Counter_t{}) {
+            return impl().get_value_ptr_impl (discard);
+        }
+    //! @}
+
+    //! \name Object lifetime
+    //! @{
+    protected:
+        //! \brief
+        //!     Create and initialize
+        //! \param freq     The required hw timer's frequency
+        //! \param ticks    The required timer's reload value
+        timer_delay (size_t freq, Counter_t ticks) {
+            init (freq, ticks);
+        }
+        timer_delay() noexcept = default;                       //!< Default object is valid, but non-usable
+        timer_delay(const timer_delay&)             = delete;   //!< No copies
+        timer_delay& operator=(const timer_delay&)  = delete;   //!< No copies
+        //! \note
+        //! We are not initializing the timer via default ctor, in order to be able to
+        //! declare a timer_delay object globally and initialize it after the call to main().
+    //! @}
+
+    private:
+        //! Period to frequency compile time tool
+        constexpr Counter_t period2freq (double period) noexcept {
+            return (Counter_t)(1 / period);
+        }
+
+        /*!
+         * \brief   Return the systems best approximation for ticks per msec
+         * \return  The calculated value or zero if no calculation can apply
+         */
+        Counter_t ticks_per_msec () {
+            Counter_t tck = (Counter_t)(frequency / period2freq(0.001));
+            return (tck <= 1) ? 1 : tck;
+        }
+
+        /*!
+         * \brief   Return the systems best approximation for ticks per usec
+         * \return  The calculated value or zero if no calculation can apply
+         */
+        Counter_t ticks_per_usec () {
+            Counter_t tck = (Counter_t)(frequency / period2freq(0.000001));
+            return (tck <= 1) ? 1 : tck;
+        }
+
+        /*!
+         * \brief   Return the systems best approximation for ticks per usec
+         * \return  The calculated value or zero if no calculation can apply
+         */
+        Counter_t ticks_per_100nsec () {
+            Counter_t tck = (Counter_t)(frequency / period2freq(0.0000001));
+            return (tck <= 1) ? 1 : tck;
+        }
+
+    public:
+        /*!
+         * \brief
+         *      Initializes both object members and hw timer.
+         *
+         * \param freq      The required hw timer's frequency
+         * \param ticks     The required timer's reload value
+         * \return
+         */
+        bool init (size_t freq, Counter_t ticks) {
+            if (set_frequency(freq, ticks))
+                return false;
+            volatile Counter_t* v = get_value_ptr();
+
+            value     = (v != nullptr) ? v : value;
+            frequency = freq;
+            max_ticks = ticks;
+            tp1ms  = ticks_per_msec();
+            tp1us  = ticks_per_usec();
+            tp100ns= ticks_per_100nsec();
+            return true;
+        }
+
+        /*!
+         * \brief
+         *    A code based delay implementation, using hw timer for timing.
+         *    This is NOT accurate but it ensures that the time passed is always
+         *    more than the requested value.
+         *    The delay values are multiplications of 1 msec.
+         * \param   msec     Time in msec for delay
+         */
+        void delay_ms (int msec) {
+            marker_t m, m2, m1 = (marker_t)*value;
+
+            msec *= tp1ms;
+
+            // Eat the time difference from msec value.
+            do {
+                m2 = (marker_t)(*value);
+                m = m2 - m1;
+                msec -= (m>=0) ? m : max_ticks + m;
+                m1 = m2;
+            } while (msec>0);
+        }
+
+        /*!
+         * \brief
+         *    A code based delay implementation, using hw timer for timing.
+         *    This is NOT accurate but it ensures that the time passed is always
+         *    more than the requested value.
+         *    The delay values are multiplications of 1 usec.
+         * \param   usec     Time in usec for delay
+         */
+        void delay_us (int usec) {
+            marker_t m, m2, m1 = (marker_t)*value;
+
+            usec *= tp1us;
+            if ((marker_t)(*value) - m1 > usec) // Very small delays may return here.
+            return;
+
+            // Eat the time difference from usec value.
+            do {
+                m2 = (marker_t)(*value);
+                m = m2 - m1;
+                usec -= (m>=0) ? m : max_ticks + m;
+                m1 = m2;
+            } while (usec>0);
+        }
+
+        /*!
+         * \brief
+         *    A code based delay implementation, using hw timer for timing.
+         *    This is NOT accurate but it ensures that the time passed is always
+         *    more than the requested value.
+         *    The delay values are multiplications of 100 nsec.
+         * \param   _100nsec     Time in 100nsec for delay
+         */
+        void delay_100ns (int _100nsec) {
+            marker_t m, m2, m1 = (marker_t)*value;
+
+            _100nsec *= tp100ns;
+            if ((marker_t)(*value) - m1 > _100nsec) // Very small delays may return here.
+                return;
+
+            // Eat the time difference from _100nsec value.
+            do {
+                m2 = (marker_t)(*value);
+                m = m2 - m1;
+                _100nsec -= (m>=0) ? m : max_ticks + m;
+                m1 = m2;
+            } while (_100nsec>0);
+        }
+
+        /*!
+         * \brief
+         *    A code based polling version delay implementation, using hw timer for timing.
+         *    This is NOT accurate but it ensures that the time passed is always
+         *    more than the requested value.
+         *    The delay values are multiplications of 1 msec.
+         * \param   msec     Time in msec for delay
+         * \return  The status of ongoing delay
+         *    \arg  false:    Delay time has passed
+         *    \arg  true:     Delay is ongoing, keep calling
+         */
+        bool check_msec (int msec) {
+            static marker_t m1=-1, cnt;
+            marker_t m, m2;
+
+            if (m1 == -1) {
+                m1 = *value;
+                cnt = tp1ms * msec;
+            }
+
+            // Eat the time difference from msec value.
+            if (cnt>0) {
+                m2 = (marker_t)(*value);
+                m = m2-m1;
+                cnt -= (m>=0) ? m : max_ticks + m;
+                m1 = m2;
+                return 1;   // wait
+            } else {
+                m1 = -1;
+                return 0;   // do not wait any more
+            }
+        }
+
+        /*!
+         * \brief
+         *    A code based polling version delay implementation, using hw timer for timing.
+         *    This is NOT accurate but it ensures that the time passed is always
+         *    more than the requested value.
+         *    The delay values are multiplications of 1 usec.
+         * \param   usec     Time in usec for delay
+         * \return  The status of ongoing delay
+         *    \arg  false:    Delay time has passed
+         *    \arg  true:     Delay is ongoing, keep calling
+         */
+        bool check_usec (int usec) {
+            static marker_t m1=-1, cnt;
+            marker_t m, m2;
+
+            if (m1 == -1) {
+                m1 = *value;
+                cnt = tp1us * usec;
+            }
+
+            // Eat the time difference from usec value.
+            if (cnt>0) {
+                m2 = (marker_t)(*value);
+                m = m2-m1;
+                cnt -= (m>=0) ? m : max_ticks + m;
+                m1 = m2;
+                return 1;   // wait
+            } else {
+                m1 = -1;
+                return 0;   // do not wait any more
+            }
+        }
+
+
+        /*!
+         * \brief
+         *    A code based polling version delay implementation, using hw timer for timing.
+         *    This is NOT accurate but it ensures that the time passed is always
+         *    more than the requested value.
+         *    The delay values are multiplications of 100 nsec.
+         * \param
+         *    _100nsec     Time in 100nsec for delay
+         * \return  The status of ongoing delay
+         *    \arg  false:    Delay time has passed
+         *    \arg  true:     Delay is ongoing, keep calling
+         */
+        bool check_100nsec (int _100nsec) {
+            static marker_t m1=-1, cnt;
+            marker_t m, m2;
+
+            if (m1 == -1) {
+                m1 = *value;
+                cnt = tp100ns * _100nsec;
+            }
+
+            // Eat the time difference from _100nsec value.
+            if (cnt>0) {
+                m2 = (marker_t)(*value);
+                m = m2-m1;
+                cnt -= (m>=0) ? m : max_ticks + m;
+                m1 = m2;
+                return 1;   // wait
+            }
+            else {
+                m1 = -1;
+                return 0;   // do not wait any more
+            }
+        }
+
+    private:
+        static constexpr Counter_t zero = 0;    //!< A always zero place
+
+        value_t*    value {(value_t*)&zero};    //!< Pointer to hw timer's counter register
+                                                //!< We initialize it to &zero to avoid nullptr dereference
+        size_t      frequency{};                //!< The frequency of the timer
+        Counter_t   max_ticks{};                //!< The reload value of the timer
+        Counter_t   tp1ms{};                    //!< ticks per ms temporary variable
+        Counter_t   tp1us{};                    //!< ticks per us temporary variable
+        Counter_t   tp100ns{};                  //!< ticks per 100ns temporary variable
+    };
+
+
+} // namespace tbx
+
+#endif /* TBX_UTILS_TIMER_DELAY_H_ */

test/.gitignore

@@ -0,0 +1,8 @@
+# Binaries
+bin/
+# Eclipse related
+/Debug/
+.settings/
+.project
+.cproject
+

test/Makefile

@@ -85,7 +85,9 @@ SRC_FILES_LIST  :=
 
 # Include directories list(space seperated). Relative path
 INC_DIR_LIST    := ../include gtest
-                   
+ifeq ($(OS), Windows_NT)
+	INC_DIR_LIST += mingw-std-threads
+endif
 # Exclude files list(space seperated). Filenames only.
 # EXC_FILE_LIST := bad.cpp old.cpp
 
@@ -104,10 +106,13 @@ ODUMP           := objdump
 OCOPY           := objcopy
 
 # Compiler flags for debug and release
-DEB_CFLAGS      := -std=c++17 -DDEBUG -g3 -Wall -Wextra
+DEB_CFLAGS      := -std=gnu++17 -DDEBUG -g3 -Wall -Wextra -fmessage-length=0
-REL_CFLAGS      := -std=c++17 -Wall -Wextra -O2
+REL_CFLAGS      := -std=gnu++17 -Wall -Wextra -O2 -fmessage-length=0
 # Pre-defines
-# PRE_DEFS := MYCAB=1729 SUPER_MODE
+PRE_DEFS        :=
+ifeq ($(OS), Windows_NT)
+	PRE_DEFS    += WIN_TRHEADS
+endif
 
 # ============== Linker settings ==============
 # Linker flags
@@ -183,8 +188,8 @@ $(BUILD_DIR)/$(TARGET): $(OBJ)
 	@mkdir -p $(@D)
 	@echo Linking to target: $(TARGET)
 	$(DOCKER) $(CXX) $(LDFLAGS) $(MAP_FLAG) -o $(@D)/$(TARGET) $(OBJ)
-	$(DOCKER) $(ODUMP) -h -S $(BUILD_DIR)/$(TARGET) > $(BUILD_DIR)/$(basename $(TARGET)).list 
+#	$(DOCKER) $(ODUMP) -h -S $(BUILD_DIR)/$(TARGET) > $(BUILD_DIR)/$(basename $(TARGET)).list
-	$(DOCKER) $(OCOPY) -O ihex $(BUILD_DIR)/$(TARGET) $(BUILD_DIR)/$(basename $(TARGET)).hex
+#	$(DOCKER) $(OCOPY) -O ihex $(BUILD_DIR)/$(TARGET) $(BUILD_DIR)/$(basename $(TARGET)).hex
 	@echo
 	@echo Print size information
 	@$(CSIZE) $(@D)/$(TARGET)
@@ -216,9 +221,24 @@ build-clang: $(BUILD_DIR)/$(TARGET)
 .PHONY: debug
 debug: $(BUILD_DIR)/$(TARGET)
 
+
+.PHONY: test_asan
+test_asan: CFLAGS := $(REL_CFLAGS)
+test_asan: CFLAGS  += -g3 -fsanitize=address -fsanitize=leak -fsanitize=bounds-strict
+test_asan: LDFLAGS += -fsanitize=address -fsanitize=leak -fsanitize=bounds-strict
+test_asan: $(BUILD_DIR)/$(TARGET)
+
+
+.PHONY: test_tsan
+test_asan: CFLAGS := $(REL_CFLAGS)
+test_tsan: CFLAGS  += -g3 -fsanitize=thread
+test_tsan: LDFLAGS += -fsanitize=thread
+test_tsan: $(BUILD_DIR)/$(TARGET)
+
+
 .PHONY: release
-release: CFLAGS := $(REL_FLAGS)
+release: CFLAGS := $(REL_CFLAGS)
-release: clean $(BUILD_DIR)/$(TARGET)
+release: $(BUILD_DIR)/$(TARGET)
 
 .PHONY: all
 all: clean release

test/main.cpp

@@ -26,9 +26,12 @@
  *
  */
 #include <gtest/gtest.h>
+#include <exception>
 
-GTEST_API_ int main(int argc, char **argv) {
+GTEST_API_ int main(int argc, char **argv) try {
    testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
 }
-
+catch (std::exception& e) {
+    std::cout << "Exception: " << e.what() << '\n';
+}

test/tests/cli_device.cpp

@@ -0,0 +1,422 @@
+/*!
+ * \file cli_device.cpp
+ *
+ * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ *
+ */
+#include <drv/cli_device.h>
+#include <gtest/gtest.h>
+
+#include <cont/equeue.h>
+
+#include <cstring>
+#include <utility>
+#include <type_traits>
+#ifndef WIN_TRHEADS
+#include <mutex>
+#include <thread>
+#else
+#include <mingw.thread.h>
+#include <mingw.mutex.h>
+#endif
+
+namespace test_cli_device {
+   using namespace tbx;
+
+   // test settings
+   constexpr size_t Size  = 128;
+   using data_type        = char;
+
+   // cli_device implementer mock. We simulate a BG95 ATmodem for that purpose
+   template<size_t N>
+   class BG95 : public cli_device<BG95<N>, N> {
+	   using base_type = cli_device<BG95<N>, N>;
+	   using Queue     = equeue<typename base_type::value_type, N, true>;
+
+       public:
+           enum class event {
+               MQTT_DISCONNECT, MQTT_RXDATA
+           };
+       // simulated modem operation
+       private:
+           struct cmd_pair {
+               const char *cmd;
+               const char *resp;
+           };
+           struct event_pair {
+               event e;
+               const char* resp;
+           };
+
+           std::array<cmd_pair, 20> cmd_map = {{
+                   {"",                                             ""},
+                   {"ERROR",                                        "\r\nERROR\r\n"},
+                   {"ATE0\r\n",                                     "\r\nATE0\r\nOK\r\n"},
+                   {"AT\r\n",                                       "\r\nOK\r\n"},
+                   {"AT+QCFG=\"nwscanseq\"\r\n",                    "\r\n+QCFG: \"nwscanseq\",020301\r\n"},
+                   {"AT+QCFG=\"nwscanseq\",010302\r\n",             "\r\nOK\r\n"},
+                   {"AT+CREG?\r\n",                                 "\r\n+CREG: 0,5\r\n\r\nOK\r\n"},
+                   {"AT+CSQ\r\n",                                   "\r\n+CSQ: 19,99\r\n\r\nOK\r\n"},
+                   {"AT+QNWINFO\r\n",                               "\r\n+QNWINFO: \"EDGE\",\"20201\",\"GSM 1800\",865\r\n\r\nOK\r\n"},
+                   // Files
+                   {"AT+QFLST\r\n",                                 "\r\n+QFLST: \"cacert.pem\",1220\r\n+QFLST: \"security/\",2\r\nOK\r\n"},
+                   // MQTT config
+                   {"AT+QSSLCFG=\"ignorelocaltime\",2,1\r\n",       "\r\nOK\r\n"},
+                   {"AT+QSSLCFG=\"seclevel\",2,1\r\n",              "\r\nOK\r\n"},
+                   {"AT+QSSLCFG=\"sslversion\",2,4\r\n",            "\r\nOK\r\n"},
+                   {"AT+QSSLCFG=\"ciphersuite\",2\r\n",             "\r\n+QSSLCFG: \"ciphersuite\",2,0XFFFF\r\n\r\nOK\r\n"},
+                   {"AT+QMTCFG=\"ssl\",0,1,2\r\n",                  "\r\nOK\r\n"},
+                   {"AT+QMTCFG=\"keepalive\",0,3600\r\n",           "\r\nOK\r\n"},
+                   // MQTT
+                   {"AT+QMTOPEN=0,\"server.com\",8883\r\n",         "\r\nOK\r\n\r\n+QMTOPEN: 0,0\r\n"},
+                   {"AT+QMTCONN=0,\"myID\",\"user\",\"pass\"\r\n",  "\r\nOK\r\n\r\n+QMTCONN: 0,0,0\r\n"},
+                   {"AT+QMTSUB=0,1,\"/path/topic1\",2\r\n",         "\r\nOK\r\n\r\n+QMTSUB: 0,1,0,2\r\n"},
+                   {"AT+QMTPUB=0,0,0,0,\"/path/topic2\",9\r\n",     "\r\n> \r\nOK\r\n\r\n+QMTPUB: 0,0,0\r\n"},
+           }};
+           std::array<event_pair, 2> event_map {{
+                   {event::MQTT_DISCONNECT,     "\r\n+QMTSTAT: 0,1\r\n"},
+                   {event::MQTT_RXDATA,         "\r\n+QMTRECV: 0,1,\"/path/topic1\",\"BR: hello to all of my subscribers\""}
+           }};
+           const char* cmd_responce (const char* cmd) {
+               if (cmd != nullptr) {
+                   for (auto& it : cmd_map) {
+                       if (!std::strcmp(it.cmd, cmd))
+                           return it.resp;
+                   }
+               }
+               return cmd_map[1].resp;
+           }
+           const char* event_responce (const event e) {
+               for (auto& it : event_map) {
+                   if (e == it.e)
+                       return it.resp;
+               }
+               return nullptr;  // non reachable
+           }
+
+           // data
+           Queue RxQ{};
+           std::atomic<size_t> lines{};
+           clock_t t=0;
+
+       public:
+           // cli_device driver requirements
+           BG95() noexcept :
+               RxQ(Queue::data_match::MATCH_PUSH, base_type::delimiter, [&](){
+                   lines.fetch_add(1, std::memory_order_acq_rel);
+               }), lines(0) { }
+
+           size_t get(char* data, bool wait =false) {
+               do {
+                   if (lines.load(std::memory_order_acquire)) {
+                       size_t n =0;
+                       do{
+                           *data << RxQ;
+                           ++n;
+                       } while (*data++ != base_type::delimiter);
+                       lines.fetch_sub(1, std::memory_order_acq_rel);
+                       return n;
+                   }
+               } while (wait);
+               return 0;
+           }
+           size_t contents(char* data) {
+               char* nullpos = std::copy(RxQ.begin(), RxQ.end(), data);
+               *nullpos =0;
+               return nullpos - data;
+           }
+           size_t put (const char* data, size_t n) {
+               const char* reply = cmd_responce (data);
+               while (*reply)
+                   RxQ << *reply++;
+               return n;
+           }
+
+           clock_t clock() noexcept { return ++t; }
+           void clear_clock() noexcept { t=0; }
+
+           // extra helper for testing purposes
+           void async (event e) {
+               const char* reply =event_responce (e);
+               while (*reply)
+                   RxQ << *reply++;
+           }
+   };
+
+   // Behavior flag
+   bool handler_flag = false;
+   void handler (const char* data, size_t n) {
+       (void)*data;
+       (void)n;
+       handler_flag = true;
+   }
+   void clear_flag () {
+       handler_flag = false;
+   }
+
+   TEST(Tcli_device, traits) {
+       EXPECT_EQ ( std::is_default_constructible<BG95<Size>>::value, true);
+       EXPECT_EQ ( std::is_nothrow_default_constructible<BG95<Size>>::value, true);
+       EXPECT_EQ (!std::is_copy_constructible<BG95<Size>>::value, true);
+       EXPECT_EQ (!std::is_copy_assignable<BG95<Size>>::value, true);
+
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::value_type, data_type>), true);
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::pointer_type, data_type*>), true);
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::size_type, size_t>), true);
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::string_view, std::basic_string_view<data_type>>), true);
+
+   }
+
+   /*
+    * Test inetd in non blocking mode
+    */
+   TEST(Tcli_device, txrx_inetd) {
+       BG95<Size> modem;
+       char buffer[Size];
+       size_t s =0;
+
+       const BG95<Size>::inetd_handlers<2> async = {{
+           {"+QMTSTAT:", BG95<Size>::starts_with, handler},
+           {"+QMTRECV",  BG95<Size>::contains,    handler},
+       }};
+
+       s = modem.transmit("", std::strlen(""));
+       EXPECT_EQ (s, 0UL);
+       s = modem.transmit("");
+       EXPECT_EQ (s, 0UL);
+       s = modem.transmit(nullptr);
+       EXPECT_EQ (s, 0UL);
+
+       clear_flag();
+       modem.inetd(false, &async);
+       EXPECT_EQ (handler_flag, false);
+       modem.async(BG95<Size>::event::MQTT_DISCONNECT);
+       modem.inetd(false, &async);     // parse "\r\n"
+       EXPECT_EQ (handler_flag, false);
+       modem.inetd(false, &async);      // parse "+QMT*\r\n"  and dispatch to handler()
+       EXPECT_EQ (handler_flag, true);
+       clear_flag();                    // nothing to parse
+       modem.inetd(false, &async);
+       modem.inetd(false, &async);
+       modem.inetd(false, &async);
+       EXPECT_EQ (handler_flag, false);
+       EXPECT_NE (modem.receive(buffer), 0UL);  // "\r\n" in buffer
+       EXPECT_EQ (std::strcmp(buffer, "\r\n"), 0);
+
+       clear_flag();
+       modem.inetd(false, &async);
+       EXPECT_EQ (handler_flag, false);
+       modem.transmit("AT+CSQ\r\n", 8);
+       EXPECT_EQ (modem.receive(buffer), 0UL);
+       modem.inetd(false, &async);      // parse "\r\n"
+       EXPECT_NE (modem.receive(buffer), 0UL);
+       EXPECT_EQ (std::strcmp(buffer, "\r\n"), 0);
+       modem.inetd(false, &async);      // parse "+CSQ: 19,99\r\n"
+       EXPECT_NE (modem.receive(buffer), 0UL);
+       EXPECT_EQ (std::strcmp(buffer, "+CSQ: 19,99\r\n"), 0);
+       modem.inetd(false, &async);      // parse "\r\n"
+       EXPECT_NE (modem.receive(buffer), 0UL);
+       EXPECT_EQ (std::strcmp(buffer, "\r\n"), 0);
+       modem.inetd(false, &async);      // parse "OK\r\n"
+       EXPECT_NE (modem.receive(buffer), 0UL);
+       EXPECT_EQ (std::strcmp(buffer, "OK\r\n"), 0);
+       modem.inetd(false, &async);      // nothing to parse
+       modem.inetd(false, &async);
+       modem.inetd(false, &async);
+       EXPECT_EQ (modem.receive(buffer), 0UL);
+   }
+
+   TEST(Tcli_device, run) {
+       BG95<Size> modem;
+
+       using Control = BG95<Size>::control_t;
+
+       const BG95<Size>::script_t<4> script = {{
+           {Control::NOP,      "",          BG95<Size>::nil,         BG95<Size>::nil,  BG95<Size>::go_to<1>,   100000},
+           {Control::SEND,     "ATE0\r\n",  BG95<Size>::nil,         BG95<Size>::nil,  BG95<Size>::next,       0},
+           {Control::EXPECT,   "OK\r\n",    BG95<Size>::ends_with,   BG95<Size>::nil,  BG95<Size>::exit_ok,    100000},
+           {Control::OR_EXPECT,"ERROR",     BG95<Size>::contains,    BG95<Size>::nil,  BG95<Size>::exit_error, 0}
+       }};
+
+       std::mutex m;
+       m.lock();
+       std::thread th1 ([&](){
+           do
+               modem.inetd(false);
+           while (!m.try_lock());
+           m.unlock();
+       });
+       EXPECT_EQ (modem.run(script), BG95<Size>::exit_ok.value);
+       m.unlock();    // stop and join inetd
+       th1.join();
+   }
+
+   TEST(Tcli_device, clear_size) {
+       BG95<Size> modem;
+       char buffer[Size];
+
+       modem.clear();
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (modem.receive(buffer), 0UL);
+
+       modem.transmit("abcd", 4);
+       modem.inetd(false);
+       modem.inetd(false);
+       EXPECT_NE (modem.size(), 0UL);
+       modem.clear();
+       EXPECT_EQ (modem.size(), 0UL);
+
+   }
+
+   TEST(Tcli_device, command_non_extraction) {
+       BG95<Size> modem;
+       char buffer[Size];
+
+       std::mutex m;
+       m.lock();
+       std::thread th1 ([&](){
+           do
+               modem.inetd(false);
+           while (!m.try_lock());
+           m.unlock();
+       });
+
+       auto run_receive = [&](size_t times) -> size_t {
+           size_t s =0;
+           for (size_t i=0 ; i<times ; ++i)
+               s += modem.receive(buffer);
+           return s;
+       };
+
+       EXPECT_EQ (modem.command("", "", 0), true);          // returns: ""
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command("", "abcd", 100000), false);// returns: ""
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command("abcd", "", 0), true);      // returns: "\r\nERROR\r\n"
+       EXPECT_GT (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command("AT\r\n", "Something else", 100000), false);// returns: "\r\nOK\r\n"
+       EXPECT_GT (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command("AT\r\n", "\r\nOK\r\n", 100000), true);     // returns: "\r\nOK\r\n"
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command("AT\r\n", "%OK\r\n", 100000), true);        // returns: "\r\nOK\r\n"
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       // returns: "\r\n+CREG: 0,5\r\n\r\nOK\r\n
+       EXPECT_EQ (modem.command<BG95<Size>::flush>("AT+CREG?\r\n", "%OK\r\n", 0), false);
+       EXPECT_GT (run_receive(100000), 0UL);
+
+       // returns: "\r\n+CREG: 0,5\r\n\r\nOK\r\n
+       EXPECT_EQ (modem.command<BG95<Size>::flush>("AT+CREG?\r\n", "%%%OK\r\n", 0), true);
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       // returns: "\r\n+CREG: 0,5\r\n\r\nOK\r\n
+       EXPECT_EQ (modem.command<BG95<Size>::flush>("AT+CREG?\r\n", "%", 0), true);
+       EXPECT_GT (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command<BG95<Size>::flush>("AT\r\n", "%%", 0), true);   // returns: "\r\nOK\r\n"
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       EXPECT_EQ (modem.command<BG95<Size>::flush>("AT\r\n", "%%%", 10000), false); // returns: "\r\nOK\r\n"
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       // returns: "\r\n+CREG: 0,5\r\n\r\nOK\r\n
+       EXPECT_EQ (modem.command<modem.flush>("AT+CREG?\r\n", "", 0), true);
+       EXPECT_EQ (modem.command<modem.keep>("", "%", 0), true);
+       EXPECT_EQ (modem.command<modem.keep>("", "%%", 0), true);
+       EXPECT_EQ (modem.command<modem.keep>("", "%", 0), true);
+       EXPECT_EQ (modem.command<modem.keep>("", "%", 10000), false);
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       m.unlock();    // stop and join inetd
+       th1.join();
+   }
+
+   TEST(Tcli_device, command_extraction) {
+       BG95<Size> modem;
+       char buffer[Size];
+
+       std::mutex m;
+       m.lock();
+       std::thread th1 ([&](){
+           do
+               modem.inetd(false);
+           while (!m.try_lock());
+           m.unlock();
+       });
+
+       auto run_receive = [&](size_t times) -> size_t {
+           size_t s =0;
+           for (size_t i=0 ; i<times ; ++i)
+               s += modem.receive(buffer);
+           return s;
+       };
+
+       int status1, status2;
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n+CREG: 0,%\r\n\r\nOK\r\n", 100000, &status1), true);
+       EXPECT_EQ (status1, 5);
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n+CREG: %,%\r\n\r\nOK\r\n", 100000, &status1, &status2), true);
+       EXPECT_EQ (status1, 0);
+       EXPECT_EQ (status2, 5);
+
+       char substr1[32], substr2[32];
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n%\r\n\r\n%\r\n", 100000, substr1, substr2), true);
+       EXPECT_EQ (std::strcmp("+CREG: 0,5", substr1), 0);
+       EXPECT_EQ (std::strcmp("OK", substr2), 0);
+
+       // returns: "\r\n+CREG: 0,5\r\n\r\nOK\r\n
+       EXPECT_EQ (modem.command<modem.flush>("AT+CREG?\r\n", "", 100000), true);
+       EXPECT_EQ (modem.command<modem.keep>("", "%", 100000, substr1), true);
+       EXPECT_EQ (std::strcmp("\r\n", substr1), 0);
+
+       EXPECT_EQ (modem.command<modem.keep>("", "%%", 100000, substr1, substr2), true);
+       EXPECT_EQ (std::strcmp("+CREG: 0,5\r\n", substr1), 0);
+       EXPECT_EQ (std::strcmp("\r\n", substr2), 0);
+
+       EXPECT_EQ (modem.command<modem.keep>("", "%", 100000, substr1), true);
+       EXPECT_EQ (std::strcmp("OK\r\n", substr1), 0);
+
+       EXPECT_EQ (modem.command<modem.keep>("", "%", 10000), false);
+
+       EXPECT_EQ (modem.size(), 0UL);
+       EXPECT_EQ (run_receive(100000), 0UL);
+
+       m.unlock();    // stop and join inetd
+       th1.join();
+
+   }
+}

test/tests/deque.cpp

@@ -29,19 +29,69 @@
  *
  */
 #include <cont/deque.h>
+#include <cont/span.h>
 #include <gtest/gtest.h>
 
+#include <array>
+#include <type_traits>
+#include <cstring>
+#ifndef WIN_TRHEADS
+#include <mutex>
+#include <thread>
+#else
+#include <mingw.thread.h>
+#include <mingw.mutex.h>
+#endif
+
 namespace Tdeque {
     using namespace tbx;
 
+    template <typename>
+    struct is_span : std::false_type {};
 
+    template <typename T, std::size_t S>
+    struct is_span<tbx::span<T, S>> : std::true_type {};
+
+    template <typename>
+    struct is_std_array : std::false_type {};
+
+    template <typename T, std::size_t N>
+    struct is_std_array<std::array<T, N>> : std::true_type {};
+
+    template <typename, typename = void>
+    struct has_size_and_data : std::false_type {};
+
+    template <typename T>
+    struct has_size_and_data<T, std::void_t<decltype(std::declval<T>().size()),
+                                            decltype(std::declval<T>().data())>>
+        : std::true_type {};
+
+    // Concept
+    TEST(Tdeque, concept) {
+        using deque_t = deque<int, 8>;
+
+        EXPECT_EQ ( std::is_default_constructible<deque_t>::value, true);
+        EXPECT_EQ ( std::is_nothrow_default_constructible<deque_t>::value, true);
+        EXPECT_EQ (!std::is_copy_constructible<deque_t>::value, true);
+        EXPECT_EQ (!std::is_copy_assignable<deque_t>::value, true);
+
+        EXPECT_EQ (true, !is_span<deque_t>::value);
+        EXPECT_EQ (true, !is_std_array<deque_t>::value);
+        EXPECT_EQ (true, !std::is_array<deque_t>::value);
+        EXPECT_EQ (true,  has_size_and_data<deque_t>::value);
+    }
     // Test construction
     TEST(Tdeque, contruct) {
         deque<int, 8> q1;
         deque<int, 8> q2{1, 2, 3, 4, 5, 6, 7, 8};
+        deque<int, 8> q3{1, 2, 3, 4, 5};
 
         EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (0UL, q1.size());
         EXPECT_EQ (8UL, q2.capacity());
+        EXPECT_EQ (8UL, q2.size());
+        EXPECT_EQ (8UL, q3.capacity());
+        EXPECT_EQ (5UL, q3.size());
     }
 
     // simple push-pop functionality
@@ -187,5 +237,233 @@ namespace Tdeque {
         EXPECT_EQ(6, check_it);         // run through all
 
     }
+    TEST (Tdeque, range) {
+        deque<int, 8> q1{1, 2, 3, 4, 5, 6, 7, 8};
+        int check_it=1;
 
+        for (auto& it : q1.contents())
+            EXPECT_EQ(it, check_it++);
+
+        EXPECT_EQ(9, check_it);         // run through all
+    }
+
+
+    // Concept
+    TEST(Tdeque, concept_atomic) {
+        using deque_t = deque<int, 8, true>;
+
+        EXPECT_EQ (true, !is_span<deque_t>::value);
+        EXPECT_EQ (true, !is_std_array<deque_t>::value);
+        EXPECT_EQ (true, !std::is_array<deque_t>::value);
+        EXPECT_EQ (true,  has_size_and_data<deque_t>::value);
+    }
+    // Test construction
+    TEST(Tdeque, contruct_atomic) {
+        deque<int, 8, true> q1;
+        deque<int, 8, true> q2{1, 2, 3, 4, 5, 6, 7, 8};
+        deque<int, 8, true> q3{1, 2, 3, 4, 5};
+
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (8UL, q2.capacity());
+        EXPECT_EQ (8UL, q2.size());
+        EXPECT_EQ (8UL, q3.capacity());
+        EXPECT_EQ (5UL, q3.size());
+    }
+
+    // simple push-pop functionality
+    TEST(Tdeque, push_pop_atomic) {
+        deque<int, 8, true> q1;
+        deque<int, 8, true> q2{1, 2, 3, 4, 5, 6, 7, 8};
+
+        q1.push_front(1);
+        q1.push_front(2);
+        EXPECT_EQ (1, q1.pop_back());
+        EXPECT_EQ (2, q1.pop_back());
+
+        q1.push_back(1);
+        q1.push_back(2);
+        EXPECT_EQ (1, q1.pop_front());
+        EXPECT_EQ (2, q1.pop_front());
+
+        q1.push_front(2);
+        q1.push_back(3);
+        q1.push_front(1);
+        q1.push_back(4);
+
+        for (int i=1 ; i<= 4 ; ++i)
+            EXPECT_EQ ((int)i, q1.pop_front());
+    }
+
+    // front-back
+    TEST(Tdeque, front_back_atomic) {
+        deque<int, 8, true> q1;
+        deque<int, 8, true> q2{1, 2, 3, 4, 5, 6, 7, 8};
+
+        q1.push_front(2);
+        q1.push_front(1);
+        q1.push_back(3);
+        q1.push_back(4);
+
+        EXPECT_EQ (1, q1.front());
+        EXPECT_EQ (4, q1.back());
+        EXPECT_EQ (1, q2.front());
+        EXPECT_EQ (8, q2.back());
+    }
+
+    // capacity
+    TEST(Tdeque, capacity_atomic) {
+        deque<int, 8, true> q1;
+        deque<int, 8, true> q2{1, 2, 3, 4, 5, 6, 7, 8};
+
+        q1.push_back(1);
+        q1.clear();
+        EXPECT_EQ (true, q1.empty());
+        EXPECT_EQ (true, q2.full());
+
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q2.capacity());
+
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (8UL, q2.size());
+
+        q1.push_back(2);
+        EXPECT_EQ (1UL, q1.size());
+        q1.push_front(1);
+        EXPECT_EQ (2UL, q1.size());
+
+        q1.pop_back();
+        EXPECT_EQ (1UL, q1.size());
+        q1.pop_front();
+        EXPECT_EQ (0UL, q1.size());
+    }
+
+    // push-pop limits
+    TEST (Tdeque, push_pop_limits_atomic) {
+        deque<int, 8, true> q1;
+        deque<int, 8, true> q2{1, 2, 3, 4, 5, 6, 7, 8};
+
+        EXPECT_EQ (int{}, q1.pop_back());
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (true, q1.empty());
+        EXPECT_EQ (false, q1.full());
+
+        EXPECT_EQ (int{}, q1.pop_front());
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (true, q1.empty());
+        EXPECT_EQ (false, q1.full());
+
+        q2.push_front(0);
+        EXPECT_EQ (1, q2.front());
+        EXPECT_EQ (8, q2.back());
+        EXPECT_EQ (8UL, q2.size());
+        EXPECT_EQ (false, q2.empty());
+        EXPECT_EQ (true, q2.full());
+
+        q2.push_back(9);
+        EXPECT_EQ (1, q2.front());
+        EXPECT_EQ (8, q2.back());
+        EXPECT_EQ (8UL, q2.size());
+        EXPECT_EQ (false, q2.empty());
+        EXPECT_EQ (true, q2.full());
+    }
+
+    // iterators
+    TEST (Tdeque, iterators_atomic) {
+        deque<int, 8, true> q1{1, 2, 3, 4, 5, 6, 7, 8};
+        int check_it=1;
+
+        EXPECT_EQ (q1.begin().base(), q1.end().base());
+        EXPECT_NE (q1.begin().iter(), q1.end().iter());
+        EXPECT_EQ (1, *q1.begin());
+        EXPECT_EQ (true, (q1.begin() == ++q1.end()));   // loop edge iterators
+
+        for (auto it = q1.begin() ; it != q1.end() ; ++it)
+            EXPECT_EQ(*it, check_it++);
+        EXPECT_EQ(9, check_it);         // run through all
+
+        EXPECT_EQ (1, q1.front());      // queue stays intact
+        EXPECT_EQ (8, q1.back());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
+
+        q1.pop_front();
+        q1.pop_back();
+
+        check_it=2;
+        for (auto& it : q1)
+            EXPECT_EQ(it, check_it++);
+        EXPECT_EQ(8, check_it);         // run through all
+
+        EXPECT_EQ (2, q1.front());      // queue stays intact
+        EXPECT_EQ (7, q1.back());
+        EXPECT_EQ (6UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (false, q1.full());
+
+        deque<int, 8, true> q2;
+        q2.push_front(2);
+        q2.push_front(1);
+        q2.push_back(3);
+        q2.push_back(4);
+        q2.push_back(5);
+        check_it =1;
+        for (auto& it : q2)
+            EXPECT_EQ(it, check_it++);
+        EXPECT_EQ(6, check_it);         // run through all
+
+    }
+    TEST (Tdeque, range_atomic) {
+        deque<int, 8, true> q1{1, 2, 3, 4, 5, 6, 7, 8};
+        int check_it=1;
+
+        for (auto& it : q1.contents())
+            EXPECT_EQ(it, check_it++);
+
+        EXPECT_EQ(9, check_it);         // run through all
+    }
+
+    TEST(Tdeque, race) {
+        constexpr size_t N = 1000000;
+        deque<int, N, true> q;
+        int result[N];
+
+        auto push_front = [&](){
+            for (size_t i=1 ; i<=N ; ++i)   q.push_front(i);
+        };
+        auto push_back = [&](){
+            for (size_t i=1 ; i<=N ; ++i)   q.push_back(i);
+        };
+        auto pop_front = [&](){
+            for (size_t i=0 ; i<N ; ) {
+                result[i] = q.pop_front();
+                if (result[i] != int{})
+                    ++i;
+            }
+        };
+        auto pop_back = [&](){
+            for (size_t i=0 ; i<N ; ) {
+                result[i] = q.pop_back();
+                if (result[i] != int{})
+                    ++i;
+            }
+        };
+
+        std::memset(result, 0, sizeof result);
+        std::thread th1 (push_front);
+        std::thread th2 (pop_back);
+        th1.join();
+        th2.join();
+        for (size_t i=0 ; i<N ; ++i)
+            EXPECT_EQ (result[i], (int)i+1);
+
+        std::memset(result, 0, sizeof result);
+        std::thread th3 (push_back);
+        std::thread th4 (pop_front);
+        th3.join();
+        th4.join();
+        for (size_t i=0 ; i<N ; ++i)
+            EXPECT_EQ (result[i], (int)i+1);
+    }
 }

test/tests/edeque.cpp

@@ -1,7 +1,7 @@
 /*!
  * \file deque.cpp
  * \brief
- *      Unit tests for deque
+ *      Unit tests for edeque
  *
  * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
  *
@@ -33,7 +33,7 @@
 
 #include <functional>
 
-namespace Tdeque {
+namespace Tedeque {
     using namespace tbx;
 
     int global_flag =0;
@@ -60,10 +60,16 @@ namespace Tdeque {
         Edeque e3(Edeque::size_match::EQ, 7, vfun);
         edeque<T, 8> e4(edeque<T, 8>::size_match::EQ, 2, vfoo{});
 
+        edeque<int, 8> q1;
+        edeque<int, 8> q2(edeque<int, 8>::size_match::DISABLED, 0, nullptr);
+
         EXPECT_EQ (8UL, e1.capacity());
         EXPECT_EQ (8UL, e2.capacity());
         EXPECT_EQ (8UL, e3.capacity());
         EXPECT_EQ (8UL, e4.capacity());
+
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q2.capacity());
     }
 
     TEST (Tedeque, base_class) {
@@ -126,15 +132,15 @@ namespace Tdeque {
         e1.check_trigger();         // manual trigger attempt
         EXPECT_EQ (false, flag);    // [SIZE triggers are auto clear]
 
-        Edeque e2(Edeque::data_match::MATCH, 42, [&](){ flag = true; });
+        Edeque e2(Edeque::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
         flag = false;
         e2.clear_trigger();
         EXPECT_EQ (false, flag);
         e2.push_back(42);           // push 42, no-trigger cleared
         EXPECT_EQ (false, flag);
-        e2.set_trigger(Edeque::data_match::MATCH, 42, [&](){ flag = true; });
+        e2.set_trigger(Edeque::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
         EXPECT_EQ (false, flag);    // no spurious triggers
-        e2.pop_back();              // pop 42, trigger
+        e2.push_back(42);           // push 42, trigger
         EXPECT_EQ (true, flag);
 
         flag = false;
@@ -230,8 +236,8 @@ namespace Tdeque {
         using Edeque = edeque<int, 8>;
         bool flag{};
 
-        // data_match::MATCH (item == 42)
+        // data_match::MATCH_PUSH (item == 42)
-        Edeque ee(Edeque::data_match::MATCH, 42, [&](){ flag = true; });
+        Edeque ee(Edeque::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
 
         flag = false;
         ee.push_back(7);            // 7
@@ -240,14 +246,28 @@ namespace Tdeque {
         EXPECT_EQ (true, flag);
 
         flag = false;
+        ee.pop_back();              // pop:42, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.push_back(42);           // push:42, re-trigger
+        EXPECT_EQ (true, flag);
+
+        // data_match::MATCH_POP (item == 42)
+        flag = false;
+        ee.clear_trigger();
+        ee.set_trigger(Edeque::data_match::MATCH_POP, 42, [&](){ flag = true; });
+        ee.push_back(7);            // 7
+        EXPECT_EQ (false, flag);
+        ee.push_back(42);           // push:42, no-trigger
+        EXPECT_EQ (false, flag);
         ee.pop_back();              // pop:42, trigger
         EXPECT_EQ (true, flag);
 
-        // data_match::MATCH (item != 42)
+        // data_match::MISMATCH_PUSH (item != 42)
         flag = false;
         ee.clear();
+        ee.clear_trigger();
         ee.push_back(7);            // 7
-        ee.set_trigger(Edeque::data_match::MISMATCH, 42, [&](){ flag = true; });
+        ee.set_trigger(Edeque::data_match::MISMATCH_PUSH, 42, [&](){ flag = true; });
         EXPECT_EQ (false, flag);    // no spurious triggers
         ee.push_back(42);           // 42, no-trigger
         EXPECT_EQ (false, flag);
@@ -257,5 +277,279 @@ namespace Tdeque {
         flag = false;
         ee.push_back(1);            // 1, re-trigger
         EXPECT_EQ (true, flag);
+
+        // data_match::MISMATCH_POP (item != 42)
+        flag = false;
+        ee.clear();
+        ee.clear_trigger();
+        ee.push_back(7);            // ->7
+        ee.pop_back();              // <-7
+        ee.set_trigger(Edeque::data_match::MISMATCH_POP, 42, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        ee.push_back(42);           // ->42, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.push_back(0);            // ->0, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.pop_back();              // pop:0, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        ee.push_back(0);
+        ee.pop_back();              // pop:0, re-trigger
+        EXPECT_EQ (true, flag);
+    }
+
+    // atomic
+    TEST (Tedeque, construct_atomic) {
+        using Edeque = edeque<int, 8, true>;
+        struct T { int a,b; };
+        int local{};
+
+        Edeque e1(Edeque::size_match::GE, 3, [](){
+            ++global_flag;
+        });
+        Edeque e2(Edeque::size_match::GE, 3, [&](){
+            ++local;
+        });
+        Edeque e3(Edeque::size_match::EQ, 7, vfun);
+        edeque<T, 8> e4(edeque<T, 8>::size_match::EQ, 2, vfoo{});
+
+        edeque<int, 8, true> q1;
+        edeque<int, 8, true> q2(edeque<int, 8, true>::size_match::DISABLED, 0, nullptr);
+
+        EXPECT_EQ (8UL, e1.capacity());
+        EXPECT_EQ (8UL, e2.capacity());
+        EXPECT_EQ (8UL, e3.capacity());
+        EXPECT_EQ (8UL, e4.capacity());
+
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q2.capacity());
+    }
+
+    TEST (Tedeque, base_class_atomic) {
+        using Edeque = edeque<int, 8, true>;
+
+        Edeque e1(Edeque::size_match::GE, 3, [](){
+            ++global_flag;
+        });
+
+        // Access of base class functionality
+        EXPECT_EQ (8UL, e1.capacity());
+        EXPECT_EQ (0UL, e1.size());
+        EXPECT_EQ (true, e1.empty());
+        EXPECT_EQ (false, e1.full());
+
+        e1.push_back(7);
+        EXPECT_EQ (7, e1.front());
+        EXPECT_EQ (7, e1.back());
+        EXPECT_EQ (7, e1.pop_front());
+
+        e1.push_front(42);
+        EXPECT_EQ (42, e1.front());
+        EXPECT_EQ (42, e1.back());
+        EXPECT_EQ (42, e1.pop_back());
+
+        e1.push_back(1);
+        e1.push_back(2);
+        e1.push_back(3);
+
+        int check_it=1;
+        for (auto it = e1.begin() ; it != e1.end() ; ++it)
+            EXPECT_EQ(*it, check_it++);
+        EXPECT_EQ(4, check_it);         // run through all
+    }
+
+    TEST (Tedeque, set_clear_check_trigger_atomic) {
+        using Edeque = edeque<int, 8, true>;
+        bool flag{};
+
+        Edeque e1(Edeque::size_match::GE, 1, [&](){ flag = true; });
+
+        flag = false;
+        e1.clear_trigger();
+        EXPECT_EQ (false, flag);
+        e1.push_back(1);            // 1,  no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        flag = false;
+        e1.clear();
+        e1.clear_trigger();
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e1.push_back(1);            // 1
+        e1.push_back(2);            // 2
+        e1.set_trigger(Edeque::size_match::GE, 1, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e1.check_trigger();         // manual trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        e1.check_trigger();         // manual trigger attempt
+        EXPECT_EQ (false, flag);    // [SIZE triggers are auto clear]
+
+        Edeque e2(Edeque::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+        flag = false;
+        e2.clear_trigger();
+        EXPECT_EQ (false, flag);
+        e2.push_back(42);           // push 42, no-trigger cleared
+        EXPECT_EQ (false, flag);
+        e2.set_trigger(Edeque::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e2.push_back(42);           // push 42, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        e2.push_back(42);           // push 42, re-trigger [DATA re-triggers]
+        EXPECT_EQ (true, flag);
+    }
+
+    TEST (Tedeque, size_triggers_atomic) {
+        using Edeque = edeque<int, 8, true>;
+        bool flag{};
+
+        // size_match::GE (size()>= 2)
+        Edeque ee(Edeque::size_match::GE, 2, [&](){ flag = true; });
+
+        flag = false;
+        ee.clear();
+        ee.push_back(1);            // 1
+        EXPECT_EQ (false, flag);
+        ee.push_back(2);            // 2, trigger
+        EXPECT_EQ (true, flag);
+        flag = false;
+        ee.push_back(3);            // 3, no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        // size_match::GT (size()> 1)
+        flag = false;
+        ee.clear();
+        ee.set_trigger(Edeque::size_match::GT, 1, [&](){ flag = true; });
+        ee.push_back(1);            // 1
+        EXPECT_EQ (false, flag);
+        ee.push_back(2);            // 2, trigger
+        EXPECT_EQ (true, flag);
+        flag = false;
+        ee.push_back(3);            // 3, no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        // size_match::LE (size()<= 1)
+        flag = false;
+        ee.clear();
+        ee.push_back(1);            // 1
+        ee.push_back(2);            // 2
+        ee.push_back(3);            // 3
+        ee.set_trigger(Edeque::size_match::LE, 1, [&](){ flag = true; });
+        ee.pop_front();             // 2
+        EXPECT_EQ (false, flag);
+        ee.pop_front();             // 1, trigger
+        EXPECT_EQ (true, flag);
+        flag = false;
+        ee.pop_front();             // 0, no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        // size_match::LT (size()< 2)
+        flag = false;
+        ee.clear();
+        ee.push_back(1);            // 1
+        ee.push_back(2);            // 2
+        ee.push_back(3);            // 3
+        ee.set_trigger(Edeque::size_match::LT, 2, [&](){ flag = true; });
+        ee.pop_front();             // 2
+        EXPECT_EQ (false, flag);
+        ee.pop_front();             // 1, trigger
+        EXPECT_EQ (true, flag);
+        flag = false;
+        ee.pop_front();             // 0, no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        // size_match::EQ (size()== 2)
+        flag = false;
+        ee.clear();
+        ee.set_trigger(Edeque::size_match::EQ, 2, [&](){ flag = true; });
+        ee.push_back(1);            // 1
+        EXPECT_EQ (false, flag);
+        ee.push_back(2);            // 2, trigger
+        EXPECT_EQ (true, flag);
+        flag = false;
+        ee.push_back(3);            // 3
+        ee.pop_front();             // 2, no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        // size_match::NE (size()!= 0)
+        flag = false;
+        ee.clear();
+        ee.set_trigger(Edeque::size_match::NE, 0, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);
+        ee.push_back(1);            // 1, trigger
+        EXPECT_EQ (true, flag);
+        flag = false;
+        ee.push_back(2);            // 2, no-trigger
+        EXPECT_EQ (false, flag);
+    }
+
+    TEST (Tedeque, data_triggers_atomic) {
+        using Edeque = edeque<int, 8, true>;
+        bool flag{};
+
+        // data_match::MATCH_PUSH (item == 42)
+        Edeque ee(Edeque::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+
+        flag = false;
+        ee.push_back(7);            // 7
+        EXPECT_EQ (false, flag);
+        ee.push_back(42);           // push:42, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        ee.pop_back();              // pop:42, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.push_back(42);           // push:42, re-trigger
+        EXPECT_EQ (true, flag);
+
+        // data_match::MATCH_POP (item == 42)
+        flag = false;
+        ee.clear_trigger();
+        ee.set_trigger(Edeque::data_match::MATCH_POP, 42, [&](){ flag = true; });
+        ee.push_back(7);            // 7
+        EXPECT_EQ (false, flag);
+        ee.push_back(42);           // push:42, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.pop_back();              // pop:42, trigger
+        EXPECT_EQ (true, flag);
+
+        // data_match::MISMATCH_PUSH (item != 42)
+        flag = false;
+        ee.clear();
+        ee.clear_trigger();
+        ee.push_back(7);            // 7
+        ee.set_trigger(Edeque::data_match::MISMATCH_PUSH, 42, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        ee.push_back(42);           // 42, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.push_back(0);            // 0, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        ee.push_back(1);            // 1, re-trigger
+        EXPECT_EQ (true, flag);
+
+        // data_match::MISMATCH_POP (item != 42)
+        flag = false;
+        ee.clear();
+        ee.clear_trigger();
+        ee.push_back(7);            // ->7
+        ee.pop_back();              // <-7
+        ee.set_trigger(Edeque::data_match::MISMATCH_POP, 42, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        ee.push_back(42);           // ->42, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.push_back(0);            // ->0, no-trigger
+        EXPECT_EQ (false, flag);
+        ee.pop_back();              // pop:0, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        ee.push_back(0);
+        ee.pop_back();              // pop:0, re-trigger
+        EXPECT_EQ (true, flag);
     }
 }

test/tests/equeue.cpp

@@ -0,0 +1,317 @@
+/*!
+ * \file equeue.cpp
+ * \brief
+ *      Unit tests for equeue
+ *
+ * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ *
+ */
+#include <cont/equeue.h>
+#include <gtest/gtest.h>
+
+namespace Tequeue {
+    using namespace tbx;
+
+    int global_flag =0;
+
+    // Callable mocks
+    void vfun(void) { ++global_flag; }
+
+    struct vfoo {
+       void operator() (void) { ++global_flag; }
+    };
+
+    // Test construction
+    TEST(Tequeue, contruct) {
+        using Equeue = equeue<int, 8>;
+        struct T { int a,b; };
+        int local{};
+
+        Equeue e1(Equeue::size_match::GE, 3, [](){
+            ++global_flag;
+        });
+        Equeue e2(Equeue::size_match::GE, 3, [&](){
+            ++local;
+        });
+        Equeue e3(Equeue::size_match::EQ, 7, vfun);
+        equeue<T, 8> e4(equeue<T, 8>::size_match::EQ, 2, vfoo{});
+
+        equeue<int, 8> q1;
+        equeue<int, 8> q2(equeue<int, 8>::size_match::DISABLED, 0, nullptr);
+
+        EXPECT_EQ (8UL, e1.capacity());
+        EXPECT_EQ (8UL, e2.capacity());
+        EXPECT_EQ (8UL, e3.capacity());
+        EXPECT_EQ (8UL, e4.capacity());
+
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q2.capacity());
+    }
+
+    // simple push-pop functionality
+    TEST(Tequeue, base_class) {
+        using Equeue = equeue<int, 8>;
+
+        Equeue e1(Equeue::size_match::GE, 3, [](){
+            ++global_flag;
+        });
+
+        // Access of base class functionality
+        EXPECT_EQ (8UL, e1.capacity());
+        EXPECT_EQ (0UL, e1.size());
+        EXPECT_EQ (true, e1.empty());
+        EXPECT_EQ (false, e1.full());
+
+        e1.push(42);
+        EXPECT_EQ (42, e1.front());
+        EXPECT_EQ (42, e1.back());
+        EXPECT_EQ (42, e1.pop());
+
+        e1.push(1);
+        e1.push(2);
+        e1.push(3);
+
+        int check_it=1;
+        for (auto it = e1.begin() ; it != e1.end() ; ++it)
+            EXPECT_EQ(*it, check_it++);
+        EXPECT_EQ(4, check_it);         // run through all
+
+    }
+
+    // trigger functionality
+    TEST (Tequeue, set_clear_check_trigger) {
+        using Equeue = equeue<int, 8>;
+        bool flag{};
+
+        Equeue e1(Equeue::size_match::GE, 1, [&](){ flag = true; });
+
+        flag = false;
+        e1.clear_trigger();
+        EXPECT_EQ (false, flag);
+        e1.push_back(1);            // 1,  no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        flag = false;
+        e1.clear();
+        e1.clear_trigger();
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e1.push_back(1);            // 1
+        e1.push_back(2);            // 2
+        e1.set_trigger(Equeue::size_match::GE, 1, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e1.check_trigger();         // manual trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        e1.check_trigger();         // manual trigger attempt
+        EXPECT_EQ (false, flag);    // [SIZE triggers are auto clear]
+
+        Equeue e2(Equeue::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+        flag = false;
+        e2.clear_trigger();
+        EXPECT_EQ (false, flag);
+        e2.push_back(42);           // push 42, no-trigger cleared
+        EXPECT_EQ (false, flag);
+        e2.set_trigger(Equeue::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e2.push_back(42);           // push 42, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        e2.push_back(42);           // push 42, re-trigger [DATA re-triggers]
+        EXPECT_EQ (true, flag);
+    }
+
+    // stream push-pop
+    TEST(Tequeue, stream_push_pop) {
+        equeue<int, 8> q1;
+
+        q1 << 1 << 2 << 3 << 4 << 5 << 6 << 7 << 8;
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
+
+        q1 << 9;                        // try to insert in full queue
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
+
+        int check_it=1;
+        for (auto it = q1.begin() ; it != q1.end() ; ++it)
+            EXPECT_EQ(*it, check_it++);
+        EXPECT_EQ(9, check_it);         // run through all
+
+        for (int i =1 ; i <= 8 ; ++i) {
+            check_it << q1;
+            EXPECT_EQ(i, check_it);
+        }
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (true, q1.empty());
+        EXPECT_EQ (false, q1.full());
+
+        q1 >> check_it;
+        EXPECT_EQ (int{}, check_it);
+    }
+
+    // atomic
+    // Test construction
+    TEST(Tequeue, contruct_atomic) {
+        using Equeue = equeue<int, 8, true>;
+        struct T { int a,b; };
+        int local{};
+
+        Equeue e1(Equeue::size_match::GE, 3, [](){
+            ++global_flag;
+        });
+        Equeue e2(Equeue::size_match::GE, 3, [&](){
+            ++local;
+        });
+        Equeue e3(Equeue::size_match::EQ, 7, vfun);
+        equeue<T, 8> e4(equeue<T, 8>::size_match::EQ, 2, vfoo{});
+
+        equeue<int, 8, true> q1;
+        equeue<int, 8, true> q2(equeue<int, 8, true>::size_match::DISABLED, 0, nullptr);
+
+        EXPECT_EQ (8UL, e1.capacity());
+        EXPECT_EQ (8UL, e2.capacity());
+        EXPECT_EQ (8UL, e3.capacity());
+        EXPECT_EQ (8UL, e4.capacity());
+
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q2.capacity());
+    }
+
+    // simple push-pop functionality
+    TEST(Tequeue, base_class_atomic) {
+        using Equeue = equeue<int, 8, true>;
+
+        Equeue e1(Equeue::size_match::GE, 3, [](){
+            ++global_flag;
+        });
+
+        // Access of base class functionality
+        EXPECT_EQ (8UL, e1.capacity());
+        EXPECT_EQ (0UL, e1.size());
+        EXPECT_EQ (true, e1.empty());
+        EXPECT_EQ (false, e1.full());
+
+        e1.push(42);
+        EXPECT_EQ (42, e1.front());
+        EXPECT_EQ (42, e1.back());
+        EXPECT_EQ (42, e1.pop());
+
+        e1.push(1);
+        e1.push(2);
+        e1.push(3);
+
+        int check_it=1;
+        for (auto it = e1.begin() ; it != e1.end() ; ++it)
+            EXPECT_EQ(*it, check_it++);
+        EXPECT_EQ(4, check_it);         // run through all
+
+    }
+
+    // trigger functionality
+    TEST (Tequeue, set_clear_check_trigger_atomic) {
+        using Equeue = equeue<int, 8, true>;
+        bool flag{};
+
+        Equeue e1(Equeue::size_match::GE, 1, [&](){ flag = true; });
+
+        flag = false;
+        e1.clear_trigger();
+        EXPECT_EQ (false, flag);
+        e1.push_back(1);            // 1,  no-trigger cleared
+        EXPECT_EQ (false, flag);
+
+        flag = false;
+        e1.clear();
+        e1.clear_trigger();
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e1.push_back(1);            // 1
+        e1.push_back(2);            // 2
+        e1.set_trigger(Equeue::size_match::GE, 1, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e1.check_trigger();         // manual trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        e1.check_trigger();         // manual trigger attempt
+        EXPECT_EQ (false, flag);    // [SIZE triggers are auto clear]
+
+        Equeue e2(Equeue::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+        flag = false;
+        e2.clear_trigger();
+        EXPECT_EQ (false, flag);
+        e2.push_back(42);           // push 42, no-trigger cleared
+        EXPECT_EQ (false, flag);
+        e2.set_trigger(Equeue::data_match::MATCH_PUSH, 42, [&](){ flag = true; });
+        EXPECT_EQ (false, flag);    // no spurious triggers
+        e2.push_back(42);           // push 42, trigger
+        EXPECT_EQ (true, flag);
+
+        flag = false;
+        e2.push_back(42);           // push 42, re-trigger [DATA re-triggers]
+        EXPECT_EQ (true, flag);
+    }
+
+    // stream push-pop
+    TEST(Tequeue, stream_push_pop_atomic) {
+        equeue<int, 8, true> q1;
+
+        q1 << 1 << 2 << 3 << 4 << 5 << 6 << 7 << 8;
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
+
+        q1 << 9;                        // try to insert in full queue
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
+
+        int check_it=1;
+        for (auto it = q1.begin() ; it != q1.end() ; ++it)
+            EXPECT_EQ(*it, check_it++);
+        EXPECT_EQ(9, check_it);         // run through all
+
+        for (int i =1 ; i <= 8 ; ++i) {
+            check_it << q1;
+            EXPECT_EQ(i, check_it);
+        }
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (true, q1.empty());
+        EXPECT_EQ (false, q1.full());
+
+        q1 >> check_it;
+        EXPECT_EQ (int{}, check_it);
+    }
+
+}

test/tests/queue.cpp

@@ -39,12 +39,17 @@ namespace Tqueue {
     TEST(Tqueue, contruct) {
         queue<int, 8> q1;
         queue<int, 8> q2{1, 2, 3, 4, 5, 6, 7, 8};
+        queue<int, 8> q3{1, 2, 3, 4, 5};
 
         EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (0UL, q1.size());
         EXPECT_EQ (8UL, q2.capacity());
+        EXPECT_EQ (8UL, q2.size());
+        EXPECT_EQ (8UL, q3.capacity());
+        EXPECT_EQ (5UL, q3.size());
     }
 
-    // simple push-pop functionality
+    // base class functionality check
     TEST(Tqueue, base_class) {
 
         queue<int, 8> q1;
@@ -55,34 +60,10 @@ namespace Tqueue {
         EXPECT_EQ (true, q1.empty());
         EXPECT_EQ (false, q1.full());
 
-        q1.push_back(7);
+        q1.push(42);
-        EXPECT_EQ (7, q1.front());
-        EXPECT_EQ (7, q1.back());
-        EXPECT_EQ (7, q1.pop_front());
-
-        q1.push_front(42);
         EXPECT_EQ (42, q1.front());
         EXPECT_EQ (42, q1.back());
-        EXPECT_EQ (42, q1.pop_back());
+        EXPECT_EQ (42, q1.pop());
-
-        q1.push_back(1);
-        q1.push_back(2);
-        q1.push_back(3);
-
-        int check_it=1;
-        for (auto it = q1.begin() ; it != q1.end() ; ++it)
-            EXPECT_EQ(*it, check_it++);
-        EXPECT_EQ(4, check_it);         // run through all
-    }
-
-    // push-pop
-    TEST(Tqueue, front_back) {
-        queue<int, 8> q1;
-
-        q1.push(7);
-        EXPECT_EQ (7, q1.front());
-        EXPECT_EQ (7, q1.back());
-        EXPECT_EQ (7, q1.pop());
 
         q1.push(1);
         q1.push(2);
@@ -92,28 +73,116 @@ namespace Tqueue {
         for (auto it = q1.begin() ; it != q1.end() ; ++it)
             EXPECT_EQ(*it, check_it++);
         EXPECT_EQ(4, check_it);         // run through all
-
     }
 
-    // stream operations
+    // stream push-pop
-    TEST(Tqueue, capacity) {
+    TEST(Tqueue, stream_push_pop) {
         queue<int, 8> q1;
 
-        // stream 5 items
+        q1 << 1 << 2 << 3 << 4 << 5 << 6 << 7 << 8;
-        q1 << 1 << 2 << 3 << 4 << 5;
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
+
+        q1 << 9;                        // try to insert in full queue
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (8UL, q1.size());
+        EXPECT_EQ (false, q1.empty());
+        EXPECT_EQ (true, q1.full());
 
         int check_it=1;
         for (auto it = q1.begin() ; it != q1.end() ; ++it)
             EXPECT_EQ(*it, check_it++);
-        EXPECT_EQ (6, check_it);         // run through all
+        EXPECT_EQ(9, check_it);         // run through all
 
-        // get all back
+        for (int i =1 ; i <= 8 ; ++i) {
-        int it;
+            check_it << q1;
-        for (int check_it=1 ; check_it<=5 ; ++check_it) {
+            EXPECT_EQ(i, check_it);
-            q1 >> it;
+        }
-            EXPECT_EQ (check_it, it);
+        EXPECT_EQ (8UL, q1.capacity());
+        EXPECT_EQ (0UL, q1.size());
+        EXPECT_EQ (true, q1.empty());
+        EXPECT_EQ (false, q1.full());
+
+        q1 >> check_it;
+        EXPECT_EQ (int{}, check_it);
     }
 
+
+
+    // Test construction
+     TEST(Tqueue, contruct_atomic) {
+         queue<int, 8, true> q1;
+         queue<int, 8, true> q2{1, 2, 3, 4, 5, 6, 7, 8};
+         queue<int, 8, true> q3{1, 2, 3, 4, 5};
+
+         EXPECT_EQ (8UL, q1.capacity());
+         EXPECT_EQ (0UL, q1.size());
+         EXPECT_EQ (8UL, q2.capacity());
+         EXPECT_EQ (8UL, q2.size());
+         EXPECT_EQ (8UL, q3.capacity());
+         EXPECT_EQ (5UL, q3.size());
+     }
+
+     // base class functionality check
+     TEST(Tqueue, base_class_atomic) {
+
+         queue<int, 8, true> q1;
+
+         // Access of base class functionality
+         EXPECT_EQ (8UL, q1.capacity());
+         EXPECT_EQ (0UL, q1.size());
+         EXPECT_EQ (true, q1.empty());
+         EXPECT_EQ (false, q1.full());
+
+         q1.push(42);
+         EXPECT_EQ (42, q1.front());
+         EXPECT_EQ (42, q1.back());
+         EXPECT_EQ (42, q1.pop());
+
+         q1.push(1);
+         q1.push(2);
+         q1.push(3);
+
+         int check_it=1;
+         for (auto it = q1.begin() ; it != q1.end() ; ++it)
+             EXPECT_EQ(*it, check_it++);
+         EXPECT_EQ(4, check_it);         // run through all
+     }
+
+     // stream push-pop
+     TEST(Tqueue, stream_push_pop_atomic) {
+         queue<int, 8, true> q1;
+
+         q1 << 1 << 2 << 3 << 4 << 5 << 6 << 7 << 8;
+         EXPECT_EQ (8UL, q1.capacity());
+         EXPECT_EQ (8UL, q1.size());
+         EXPECT_EQ (false, q1.empty());
+         EXPECT_EQ (true, q1.full());
+
+         q1 << 9;                        // try to insert in full queue
+         EXPECT_EQ (8UL, q1.capacity());
+         EXPECT_EQ (8UL, q1.size());
+         EXPECT_EQ (false, q1.empty());
+         EXPECT_EQ (true, q1.full());
+
+         int check_it=1;
+         for (auto it = q1.begin() ; it != q1.end() ; ++it)
+             EXPECT_EQ(*it, check_it++);
+         EXPECT_EQ(9, check_it);         // run through all
+
+         for (int i =1 ; i <= 8 ; ++i) {
+             check_it << q1;
+             EXPECT_EQ(i, check_it);
+         }
+         EXPECT_EQ (8UL, q1.capacity());
+         EXPECT_EQ (0UL, q1.size());
+         EXPECT_EQ (true, q1.empty());
+         EXPECT_EQ (false, q1.full());
+
+         q1 >> check_it;
+         EXPECT_EQ (int{}, check_it);
      }
 
 }

test/tests/ring_iterator.cpp

@@ -228,4 +228,197 @@ namespace Tring_iterator {
         EXPECT_EQ (1, (i2 - i1));   // loop
 
     }
+
+    // Test construction atomic
+    TEST(Tring_iterator, construct_atomic) {
+        int A[10];
+
+        //default constructor
+        ring_iterator<int*, 10, true> i1;
+        EXPECT_EQ(nullptr, i1.base());
+        EXPECT_EQ(nullptr, i1.iter());
+        EXPECT_EQ(10UL, i1.size());
+
+        // implementation specific (you can remove it freely)
+        EXPECT_EQ(2*sizeof(int*), sizeof(i1));
+
+        // basic
+        ring_iterator<int*, 10, true> i2(A);
+        EXPECT_EQ(A, i2.base());
+        EXPECT_EQ(A, i2.iter());
+        EXPECT_EQ(10UL, i2.size());
+
+        // basic from assignment
+        ring_iterator<int*, 10, true> i3 = A;
+        EXPECT_EQ(A, i3.base());
+        EXPECT_EQ(A, i3.iter());
+        EXPECT_EQ(10UL, i3.size());
+
+        // basic with offset
+        ring_iterator<int*, 10, true> i4(A, 5);
+        EXPECT_EQ(A, i4.base());
+        EXPECT_EQ(&A[5], i4.iter());
+        EXPECT_EQ(10UL, i4.size());
+
+        // copy (Legacy iterator)
+        auto i5 = i2;
+        EXPECT_EQ(A, i5.base());
+        EXPECT_EQ(A, i5.iter());
+        EXPECT_EQ(10UL, i5.size());
+
+        // arbitrary type
+        struct TT { int a,b,c; };
+        std::array<TT, 10> t;
+        ring_iterator<TT*, 10, true> it(t.data(), 2);
+        EXPECT_EQ(t.begin(), it.base());
+        EXPECT_EQ(&t[2], it.iter());
+        EXPECT_EQ(10UL, it.size());
+    }
+
+    // Legacy iterator atomic
+    TEST(Tring_iterator, LegacyIterator_atomic) {
+
+        EXPECT_EQ(true, (std::is_same<int, typename ring_iterator<int*, 10, true>::value_type>::value));
+        EXPECT_EQ(true, (std::is_same<std::ptrdiff_t, typename ring_iterator<int*, 10, true>::difference_type>::value));
+        EXPECT_EQ(true, (std::is_same<int&, typename ring_iterator<int*, 10, true>::reference>::value));
+        EXPECT_EQ(true, (std::is_same<int*, typename ring_iterator<int*, 10, true>::pointer>::value));
+        EXPECT_EQ(true, (std::is_same<std::random_access_iterator_tag, typename ring_iterator<int*, 10, true>::iterator_category>::value));
+
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10, true> i1(A);
+
+        // copy constructible/assignable
+        auto i2 = i1;
+        EXPECT_EQ(A, i2.base());
+        EXPECT_EQ(A, i2.iter());
+        EXPECT_EQ(10UL, i2.size());
+
+        // dereferenceable - incrementable
+        ring_iterator<int*, 10, true> i3(A);
+        EXPECT_EQ(true, (std::is_reference<decltype(*i3)>::value));
+        EXPECT_EQ(true, (std::is_same<ring_iterator<int*, 10, true>&, decltype(++i3)>::value));
+        EXPECT_EQ(true, (std::is_reference<decltype((*i3++))>::value));
+
+        // more practical
+        ring_iterator<int*, 10, true> i4(A);
+        ring_iterator<int*, 10, true> i5(A, 9);
+        EXPECT_EQ(A[0], *i4);
+        EXPECT_EQ(&A[1], (++i4).iter());
+        // check loop
+        EXPECT_EQ(A[9], *i5);
+        EXPECT_EQ(&A[0], (++i5).iter());
+    }
+
+    // Legacy input iterator atomic
+    TEST(Tring_iterator, LegacyInputIterator_atomic) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10, true> i1(A), i2(A), i3(A, 1);
+
+        struct T { int m; };
+        T B[5] { {0}, {1}, {2}, {3}, {4}};
+        ring_iterator<T*, 5, true> it(B);
+
+        EXPECT_EQ (true, (std::is_same<bool, decltype(i1 == i2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(i1 != i2)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(*i1)>::value));
+        EXPECT_EQ (true, (std::is_same<int, decltype(it->m)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>&, decltype(++i1)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(*i1++)>::value));
+
+        // more practical
+        EXPECT_EQ (true, i1 == i2);
+        EXPECT_EQ (true, i1 != i3);
+        EXPECT_EQ (0, *i1);
+        EXPECT_EQ (0, it->m);
+        EXPECT_EQ (true, (++i1 == i3));
+        EXPECT_EQ (1, *i1++);
+        EXPECT_EQ (2, *i1);
+    }
+
+    // Legacy input iterator atomic
+    TEST(Tring_iterator, LegacyOutputIterator_atomic) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10, true> it(A);
+
+        EXPECT_EQ (true, (std::is_assignable<decltype(*it), int>::value));
+        EXPECT_EQ (true, (std::is_assignable<decltype(*it++), int>::value));
+
+        // more practical
+        *it = 42;
+        EXPECT_EQ (42, A[0]);
+        *it++ = 7;
+        EXPECT_EQ (7, A[0]);
+        EXPECT_EQ (&A[1], it.iter());
+    }
+
+    // Legacy forward iterator atomic
+    TEST(Tring_iterator, LegacyForwardIterator_atomic)
+     {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10, true> it(A);
+
+        EXPECT_EQ (0, *it++);
+        EXPECT_EQ (1, *it);
+    }
+
+    // Legacy bidirectional iterator atomic
+    TEST(Tring_iterator, LegacyBidirectionalIterator_atomic) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10, true> it(A);
+
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>&, decltype(--it)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>, decltype(it--)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(*it--)>::value));
+
+        // more practical
+        ring_iterator<int*, 10, true> i1(A), i2(A, 9);
+        EXPECT_EQ (9, *i2--);   // check loop also
+        EXPECT_EQ (8, *i2);
+        EXPECT_EQ (0, *i1--);   // check loop also
+        EXPECT_EQ (9, *i1);
+    }
+
+    // Legacy random access iterator atomic
+    TEST(Tring_iterator, LegacyRandomAccessIterator_atomic) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10, true> it1(A), it2(A, 7);
+
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>&, decltype(it1 += 7)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>, decltype(it1 + 7)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>, decltype(7 + it1)>::value));
+
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>&, decltype(it1 -= 7)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10, true>, decltype(it1 - 7)>::value));
+
+        EXPECT_EQ (true, (std::is_same<std::ptrdiff_t, decltype(it1 - it2)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(it1[7])>::value));
+
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 < it2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 > it2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 <= it2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 >= it2)>::value));
+
+        // more practical
+        ring_iterator<int*, 10, true> i1(A), i2(A);
+        i1 += 7;
+        EXPECT_EQ (7, *i1);
+        i1 -= 7;
+        EXPECT_EQ (0, *i1);
+        i1 += 11;
+        EXPECT_EQ (1, *i1);
+        i1 -= 2;
+        EXPECT_EQ (9, *i1);
+
+        EXPECT_EQ (7, *(i2+7));
+        EXPECT_EQ (7, *(7+i2));
+        EXPECT_EQ (1, *(i2+11));
+        EXPECT_EQ (1, *(11+i2));
+        EXPECT_EQ (7, *(i1-2));
+        EXPECT_EQ (8, *(i2-2));
+
+        EXPECT_EQ (9, (i1 - i2));
+        EXPECT_EQ (1, (i2 - i1));   // loop
+
+    }
+
 }

test/tests/sequencer.cpp

@@ -26,98 +26,426 @@
  * </dd></dl>
  *
  */
-#include <utils/sequencer.h>
+#include <com/sequencer.h>
 #include <gtest/gtest.h>
 
+#include <type_traits>
+#include <cstring>
+#include <ctime>
 
 namespace test_sequencer {
    using namespace tbx;
 
+   // test settings
+   using data_type        = char;
+   constexpr size_t size  = 64;
+
    // Sequencer implementer mock
-   class Seq : public sequencer_t<Seq, char, 128> {
+   class Seq : public sequencer<Seq, data_type, size> {
-       const char *msg_[10] = {
+       static constexpr int NrCommands =5;
-           "", "", "", "\r\nOK\r\n",
+       static constexpr int NoCommand  =-1;
-           "", "", "+CCLK = \"21/08/26-12:16:30+12\"\r\nOK\r\n"
+
-           "", "", "\r\nERROR\r\n"
+       std::array<const char*, NrCommands> command = {
+           "cmd1",
+           "cmd2\n",
+           "cmd3\r\n",
+           "cmd4\n\r",
+           "cmd5\n",
        };
+       std::array<const char*, NrCommands> reply {
+           "reply1",
+           "reply2\n",
+           "reply3\n text \r text text\n",
+           "reply4\n text\n text \r text\r\n",
+           "reply5\n",
+       };
+       int cmd =NoCommand;
+       clock_t t =0;
+
        public:
            size_t get(char* data) {
-               static int msg =0;
+               static int ans = 0;
-               size_t len = strlen(msg_[msg]);
+               if ((++ans % 3) == 0)
-               strcpy(data, msg_[msg++]);
+                   return 0;
-               if (msg >= 10) msg =0;
+
-               return len;
+               if (cmd == NoCommand) {
+                   std::strcpy(data, "ERROR\n");
+                   return 6;
+               } else {
+                   std::strcpy(data, reply[cmd]);
+                   size_t s = std::strlen(reply[cmd]);
+                   cmd =NoCommand;
+                   return s;
+               }
+           }
+           size_t contents (char* data) {
+               if (cmd == NoCommand) {
+                   std::strcpy(data, "");
+                   return 0;
+               } else {
+                   std::strcpy(data, reply[cmd]);
+                   return std::strlen(reply[cmd]);
+               }
            }
            size_t put (const char* data, size_t n) {
-               (void)*data;
+               for (size_t i =0 ; i<NrCommands ; ++i) {
+                   if (!std::strcmp(data, command[i])) {
+                       cmd =i;
                        return n;
                    }
-           clock_t clock() { static clock_t t=0; return ++t; }
-
-           static status_t my_handler (const char* data, size_t size) {
-               (void)*data;
-               (void)size;
-               return Seq::status_t::OK;
                }
+               cmd =NoCommand;
+               return n;
+           }
+           clock_t clock() { return ++t; }
+           void clear_clock() { t =0; }
    };
 
    /*
-    * Test  sequencer.run()
+    * Test  sequencer object
     */
-   TEST(Tsequencer, run_delay) {
+   TEST (Tsequencer, traits) {
+       EXPECT_EQ ( std::is_default_constructible<Seq>::value, true);
+       EXPECT_EQ ( std::is_nothrow_default_constructible<Seq>::value, true);
+       EXPECT_EQ (!std::is_copy_constructible<Seq>::value, true);
+       EXPECT_EQ (!std::is_copy_assignable<Seq>::value, true);
+
+       EXPECT_EQ ((std::is_same_v<Seq::value_type, data_type>), true);
+       EXPECT_EQ ((std::is_same_v<Seq::pointer_type, data_type*>), true);
+       EXPECT_EQ ((std::is_same_v<Seq::size_type, size_t>), true);
+       EXPECT_EQ ((std::is_same_v<Seq::string_view, std::basic_string_view<data_type>>), true);
+
        Seq s;
-       const std::array<Seq::record_t, 1> script = {{
+       EXPECT_EQ (s.size(), size);
-           /* 0 */{Seq::control_t::NOP,  {"", Seq::match_t::NO, nullptr, Seq::action_t::EXIT_OK, 0}, 1000}
-       }};
-       EXPECT_EQ ((int)Seq::status_t::OK, (int)s.run(script));
    }
 
-   TEST(Tsequencer, run_dummy_output) {
+   TEST (Tsequencer, predicates) {
-       Seq s;
+       EXPECT_EQ ((std::is_invocable_r<bool, decltype(Seq::equals), Seq::string_view, Seq::string_view>::value), true);
-       const std::array<Seq::record_t, 2> script = {{
+       EXPECT_EQ ((std::is_invocable_r<bool, decltype(Seq::starts_with), Seq::string_view, Seq::string_view>::value), true);
-           /* 0 */{Seq::control_t::SEND, {"", Seq::match_t::NO, nullptr, Seq::action_t::NEXT, 0}, 1000},
+       EXPECT_EQ ((std::is_invocable_r<bool, decltype(Seq::ends_with), Seq::string_view, Seq::string_view>::value), true);
-           /* 1 */{Seq::control_t::SEND, {"", Seq::match_t::NO, nullptr, Seq::action_t::EXIT_OK, 0}, 1000}
+       EXPECT_EQ ((std::is_invocable_r<bool, decltype(Seq::contains), Seq::string_view, Seq::string_view>::value), true);
-       }};
+       EXPECT_EQ ((std::is_invocable_r<bool, decltype(Seq::always_true), Seq::string_view, Seq::string_view>::value), true);
-       EXPECT_EQ ((int)Seq::status_t::OK, (int)s.run(script));
+       EXPECT_EQ ((std::is_invocable_r<bool, decltype(Seq::always_false), Seq::string_view, Seq::string_view>::value), true);
+
+       EXPECT_EQ (Seq::nil, nullptr);
    }
 
-   TEST(Tsequencer, run_exits) {
+   TEST (Tsequencer, actions) {
-       Seq s;
+       EXPECT_EQ ( std::is_default_constructible<Seq::action_t>::value, true);
-       const std::array<Seq::record_t, 1> script1 = {{
+       EXPECT_EQ ( std::is_nothrow_default_constructible<Seq::action_t>::value, true);
-           /* 0 */{Seq::control_t::SEND, {"", Seq::match_t::NO, nullptr, Seq::action_t::EXIT_OK, 0}, 1000},
+       EXPECT_EQ ( std::is_copy_constructible<Seq::action_t>::value, true);
-       }};
+       EXPECT_EQ ( std::is_copy_assignable<Seq::action_t>::value, true);
-       EXPECT_EQ ((int)Seq::status_t::OK, (int)s.run(script1));
 
-       const std::array<Seq::record_t, 1> script2 = {{
+       EXPECT_EQ ((std::is_same_v<const Seq::action_t, decltype(Seq::no_action)>), true);
-           /* 0 */{Seq::control_t::SEND, {"", Seq::match_t::NO, nullptr, Seq::action_t::EXIT_ERROR, 0}, 1000},
+       EXPECT_EQ ((std::is_same_v<const Seq::action_t, decltype(Seq::next)>), true);
-       }};
+       EXPECT_EQ ((std::is_same_v<const Seq::action_t, decltype(Seq::exit_ok)>), true);
-       EXPECT_EQ ((int)Seq::status_t::ERROR, (int)s.run(script2));
+       EXPECT_EQ ((std::is_same_v<const Seq::action_t, decltype(Seq::exit_error)>), true);
+
+       EXPECT_EQ ((std::is_same_v<const Seq::action_t, decltype(Seq::go_to<0>)>), true);
+       EXPECT_EQ ((std::is_same_v<const Seq::action_t, decltype(Seq::exit<0>)>), true);
    }
 
-   TEST(Tsequencer, run_sequence) {
+   bool handler_flag = false;
+   const char* text = "abc";
+
+   //static bool check_handle (const str_view_t buffer, const str_view_t token, match_ft match, handler_ft handle)
+   TEST(Tsequencer, check_handle) {
        Seq s;
-       const std::array<Seq::record_t, 8> script = {{
+//       foo (5);
-           /* 0 */{Seq::control_t::NOP,  {"",         Seq::match_t::NO, nullptr, Seq::action_t::GOTO, 1}, 1000},
+//       bar (5);
-           /* 1 */{Seq::control_t::SEND, {"ATE0\r\n", Seq::match_t::NO, nullptr, Seq::action_t::NEXT, 0}, 1000},
+       using str_t = Seq::string_view;
-           /* 2 */{Seq::control_t::EXPECT, {{
+       using val_t = Seq::value_type;
-                       {"OK\r\n", Seq::match_t::ENDS_WITH,   nullptr, Seq::action_t::NEXT, 0},
+
-                       {"ERROR",  Seq::match_t::CONTAINS,    nullptr, Seq::action_t::EXIT_ERROR, 0} }},
+       auto match    = [](const str_t x, const str_t y) ->bool { (void)x; (void)y; return true; };
-                       1000
+       auto no_match = [](const str_t x, const str_t y) ->bool { (void)x; (void)y; return false; };
-           },
+       auto check_match = [] (const str_t x, const str_t y) ->bool {
-           /* 3 */{Seq::control_t::SEND, {"AT+CCLK?", Seq::match_t::NO, nullptr, Seq::action_t::NEXT, 0}, 1000},
+           return x == y;
-           /* 4 */{Seq::control_t::EXPECT, {{
+       };
-                       {"OK\r\n", Seq::match_t::ENDS_WITH,   Seq::my_handler, Seq::action_t::NEXT, 0},
+       auto handler    = [](const val_t* v, size_t s){ (void)*v; (void)s; handler_flag = true; };
-                       {"ERROR",  Seq::match_t::CONTAINS,    nullptr, Seq::action_t::EXIT_ERROR, 0} }},
+       auto set_if_abc = [](const val_t* v, size_t s){
-                       1000
+           (void)*v; (void)s;
-           },
+           handler_flag = (str_t(v, s) == "abc");
-           /* 5 */{Seq::control_t::SEND, {"AT+CT?", Seq::match_t::NO, nullptr, Seq::action_t::NEXT, 0}, 1000},
+       };
-           /* 6 */{Seq::control_t::EXPECT, {{
+
-                       {"OK\r\n", Seq::match_t::ENDS_WITH,   nullptr, Seq::action_t::NEXT, 0},
+       EXPECT_EQ (s.check_handle("", "", nullptr, nullptr), false);
-                       {"ERROR",  Seq::match_t::CONTAINS,    nullptr, Seq::action_t::EXIT_ERROR, 0} }},
+       EXPECT_EQ (s.check_handle("", "", no_match, nullptr), false);
-                       1000
+       EXPECT_EQ (s.check_handle("", "", match, nullptr), false);
-           },
+
-           /* 7 */{Seq::control_t::SEND, {"AT+POWD=0", Seq::match_t::NO, nullptr, Seq::action_t::EXIT_OK, 0}, 1000}
+       handler_flag = false;
+       EXPECT_EQ (s.check_handle("", "", no_match, handler), false);
+       EXPECT_EQ (handler_flag, false);
+
+       handler_flag = false;
+       EXPECT_EQ (s.check_handle("", "", match, handler), true);
+       EXPECT_EQ (handler_flag, true);
+
+       handler_flag = false;
+       EXPECT_EQ (s.check_handle("abcd", "abc", check_match, set_if_abc), false);
+       EXPECT_EQ (handler_flag, false);
+
+       handler_flag = false;
+       EXPECT_EQ (s.check_handle("abc", "abc", check_match, set_if_abc), true);
+       EXPECT_EQ (handler_flag, true);
+
+       handler_flag = false;
+       EXPECT_EQ (s.check_handle("abc", "abcd", check_match, set_if_abc), false);
+       EXPECT_EQ (handler_flag, false);
+
+   }
+
+   TEST(Tsequencer, run_nop_and_exits) {
+       Seq s;
+       const Seq::script_t<1> script1 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::exit_ok, 1000}
        }};
-       EXPECT_EQ ((int)Seq::status_t::ERROR, (int)s.run(script));
+       s.clear_clock();
+       EXPECT_EQ (s.run(script1), Seq::exit_ok.value);
+       EXPECT_GE (s.clock(), (clock_t)1000);
+
+       const Seq::script_t<1> script2 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::exit_error, 1000}
+       }};
+       s.clear_clock();
+       EXPECT_EQ (s.run(script2), Seq::exit_error.value);
+       EXPECT_GE (s.clock(), (clock_t)1000);
+
+       const Seq::script_t<3> script3 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::next, 1000},
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::next, 1000},
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::exit_ok, 1000}
+       }};
+       s.clear_clock();
+       EXPECT_EQ (s.run(script3), Seq::exit_ok.value);
+       EXPECT_GE (s.clock(), (clock_t)3000);
+   }
+
+   TEST(Tsequencer, run_send) {
+       Seq s;
+
+       auto send_wrapper  = [](const data_type* d, size_t s){
+           (void)*d; (void)s; handler_flag = true;
+       };
+       auto send_chk_text = [](const data_type* d, size_t s){
+           handler_flag = (Seq::string_view(d,s) == Seq::string_view(text));
+       };
+
+       const Seq::script_t<2> script1 = {{
+           {Seq::control_t::SEND, "", Seq::nil, Seq::nil,     Seq::next, 0},
+           {Seq::control_t::SEND, "", Seq::nil, send_wrapper, Seq::exit_ok, 0}
+       }};
+       handler_flag =false;
+       EXPECT_EQ (s.run(script1), Seq::exit_ok.value);
+       EXPECT_EQ (handler_flag, true);
+
+
+       const Seq::script_t<1> script2 = {{
+           {Seq::control_t::SEND, "abcd", Seq::nil, send_chk_text, Seq::exit_ok, 0}
+       }};
+       handler_flag =false;
+       EXPECT_EQ (s.run(script2), Seq::exit_ok.value);
+       EXPECT_EQ (handler_flag, false);
+
+       const Seq::script_t<2> script3 = {{
+           {Seq::control_t::SEND, text, Seq::nil, send_chk_text, Seq::exit_ok, 0}
+       }};
+       handler_flag =false;
+       EXPECT_EQ (s.run(script3), Seq::exit_ok.value);
+       EXPECT_EQ (handler_flag, true);
+   }
+
+   TEST(Tsequencer, run_expect) {
+       Seq s;
+
+       const Seq::script_t<7> script = {{
+           {Seq::control_t::EXPECT,    "reply1",   Seq::equals,      Seq::nil,  Seq::exit<1UL>,    1000},
+           {Seq::control_t::OR_EXPECT, "reply2",   Seq::starts_with, Seq::nil,  Seq::exit<2UL>,    0},
+           {Seq::control_t::OR_EXPECT, "reply3",   Seq::starts_with, Seq::nil,  Seq::exit<3UL>,    0},
+           {Seq::control_t::OR_EXPECT, "reply4\n", Seq::starts_with, Seq::nil,  Seq::exit<4UL>,    0},
+           {Seq::control_t::OR_EXPECT, "reply5",   Seq::starts_with, Seq::nil,  Seq::exit<5UL>,    0},
+           {Seq::control_t::OR_EXPECT, "ERROR",    Seq::contains,    Seq::nil,  Seq::exit<6UL>,    0},
+           {Seq::control_t::NOP,       "",         Seq::nil,         Seq::nil,  Seq::exit_error,   1000}
+       }};
+
+       s.clear_clock();
+       s.put("cmd1", std::strlen("cmd1"));
+       EXPECT_EQ (s.run(script), 1UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd2\n", std::strlen("cmd2\n"));
+       EXPECT_EQ (s.run(script), 2UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd3\r\n", std::strlen("cmd3\r\n"));
+       EXPECT_EQ (s.run(script), 3UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd4\n\r", std::strlen("cmd4\n\r"));
+       EXPECT_EQ (s.run(script), 4UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd5\n", std::strlen("cmd5\n"));
+       EXPECT_EQ (s.run(script), 5UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd", std::strlen("cmd"));
+       EXPECT_EQ (s.run(script), 6UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+   }
+
+   TEST(Tsequencer, run_detect) {
+       Seq s;
+
+       const Seq::script_t<7> script = {{
+           {Seq::control_t::DETECT,    "reply1",   Seq::equals,      Seq::nil,  Seq::exit<1UL>,    1000},
+           {Seq::control_t::OR_DETECT, "reply2",   Seq::starts_with, Seq::nil,  Seq::exit<2UL>,    0},
+           {Seq::control_t::OR_DETECT, "reply3",   Seq::starts_with, Seq::nil,  Seq::exit<3UL>,    0},
+           {Seq::control_t::OR_DETECT, "reply4\n", Seq::starts_with, Seq::nil,  Seq::exit<4UL>,    0},
+           {Seq::control_t::OR_DETECT, "reply5",   Seq::starts_with, Seq::nil,  Seq::exit<5UL>,    0},
+           {Seq::control_t::OR_DETECT, "ERROR",    Seq::contains,    Seq::nil,  Seq::exit<6UL>,    0},
+           {Seq::control_t::NOP,       "",         Seq::nil,         Seq::nil,  Seq::exit_ok,      1000}
+       }};
+
+       s.clear_clock();
+       s.put("cmd1", std::strlen("cmd1"));
+       EXPECT_EQ (s.run(script), 1UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd2\n", std::strlen("cmd2\n"));
+       EXPECT_EQ (s.run(script), 2UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd3\r\n", std::strlen("cmd3\r\n"));
+       EXPECT_EQ (s.run(script), 3UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd4\n\r", std::strlen("cmd4\n\r"));
+       EXPECT_EQ (s.run(script), 4UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd5\n", std::strlen("cmd5\n"));
+       EXPECT_EQ (s.run(script), 5UL);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+
+       s.clear_clock();
+       s.put("cmd", std::strlen("cmd"));
+       EXPECT_EQ (s.run(script), Seq::exit_error.value);
+       EXPECT_GT (s.clock(), (clock_t)1000);
+   }
+
+   TEST(Tsequencer, run_script_blocks_n_gotos) {
+       Seq s;
+       const Seq::script_t<15> script = {{
+           /* 0 */{Seq::control_t::NOP,       "",         Seq::nil,         Seq::nil,   Seq::go_to<1>,   1000},
+
+           /* 1 */{Seq::control_t::SEND,      "cmd1",     Seq::nil,         Seq::nil,   Seq::next,       0},
+           /* 2 */{Seq::control_t::EXPECT,    "reply1",   Seq::starts_with, Seq::nil,   Seq::next,       1000},
+           /* 3 */{Seq::control_t::OR_EXPECT, "ERROR",    Seq::contains,    Seq::nil,   Seq::exit_error, 0},
+
+           /* 4 */{Seq::control_t::SEND,      "cmd2\n",   Seq::nil,         Seq::nil,   Seq::next,       0},
+           /* 5 */{Seq::control_t::DETECT,    "ERROR",    Seq::contains,    Seq::nil,   Seq::exit_error, 1000},
+           /* 6 */{Seq::control_t::OR_DETECT, "reply2",   Seq::contains,    Seq::nil,   Seq::go_to<11>,  0},
+
+           /* 7 */{Seq::control_t::SEND,      "cmd3\r\n", Seq::nil,         Seq::nil,  Seq::next,        0},
+           /* 8 */{Seq::control_t::EXPECT,    "ERROR",    Seq::contains,    Seq::nil,  Seq::exit_error,  1000},
+           /* 9 */{Seq::control_t::OR_EXPECT, "lalala",   Seq::starts_with, Seq::nil,  Seq::exit_error,  0},
+           /*10 */{Seq::control_t::OR_EXPECT, "text\n",   Seq::ends_with,   Seq::nil,  Seq::go_to<14>,   0},
+
+           /*11 */{Seq::control_t::SEND,      "cmd4\n\r", Seq::nil,         Seq::nil,  Seq::next,        0},
+           /*12 */{Seq::control_t::EXPECT,    "reply4\n", Seq::starts_with, Seq::nil,  Seq::go_to<7>,    1000},
+           /*13 */{Seq::control_t::OR_EXPECT, "ERROR",    Seq::contains,    Seq::nil,  Seq::exit_error,  0},
+
+           /*14 */{Seq::control_t::NOP,       "",         Seq::nil,         Seq::nil,  Seq::exit_ok,     1000}
+       }};
+       s.clear_clock();
+       EXPECT_EQ (s.run(script), Seq::exit_ok.value);
+       EXPECT_GT (s.clock(), (clock_t)2000);
+   }
+
+   TEST(Tsequencer, run_match_n_handler) {
+       Seq s;
+
+       using str_t = Seq::string_view;
+       using val_t = Seq::value_type;
+
+       auto match    = [](const str_t x, const str_t y) ->bool { (void)x; (void)y; return true; };
+       auto check_match = [] (const str_t x, const str_t y) ->bool {
+           return x == y;
+       };
+       auto handler     = [](const val_t* v, size_t s){ (void)*v; (void)s; handler_flag = true; };
+       auto set_if_rpl2 = [](const val_t* v, size_t s){
+           (void)*v; (void)s;
+           handler_flag = (str_t(v, s) == "reply2\n");
+       };
+
+       const Seq::script_t<4> script1 = {{
+           {Seq::control_t::SEND,      "cmd1",   Seq::nil,        Seq::nil,   Seq::next,       0},
+           {Seq::control_t::EXPECT,    "",       match,           Seq::nil,   Seq::next,       1000},
+           {Seq::control_t::OR_EXPECT, "ERROR",  Seq::contains,   Seq::nil,   Seq::exit_error, 0},
+
+           {Seq::control_t::SEND,      "cmd1",   Seq::nil,        handler,    Seq::exit_ok,    0}
+       }};
+       handler_flag = false;
+       s.clear_clock();
+       EXPECT_EQ (s.run(script1), Seq::exit_ok.value);
+       EXPECT_LT (s.clock(), (clock_t)1000);
+       EXPECT_EQ (handler_flag, true);
+
+       const Seq::script_t<2> script2 = {{
+           {Seq::control_t::SEND,      "cmd1",   Seq::nil,        Seq::nil,    Seq::next,       0},
+           {Seq::control_t::EXPECT,    "reply1", check_match,     set_if_rpl2, Seq::exit_ok,    1000},
+       }};
+       handler_flag = false;
+       EXPECT_EQ (s.run(script2), Seq::exit_ok.value);
+       EXPECT_EQ (handler_flag, false);
+
+       const Seq::script_t<2> script3 = {{
+           {Seq::control_t::SEND,      "cmd2\n",   Seq::nil,      Seq::nil,    Seq::next,       0},
+           {Seq::control_t::EXPECT,    "reply2\n", check_match,   set_if_rpl2, Seq::exit_ok,    1000},
+       }};
+       handler_flag = false;
+       EXPECT_EQ (s.run(script3), Seq::exit_ok.value);
+       EXPECT_EQ (handler_flag, true);
+
+       const Seq::script_t<1> script4 = {{
+           {Seq::control_t::SEND, "cmd1", Seq::nil, handler, Seq::exit_ok, 0}
+       }};
+       handler_flag = false;
+       EXPECT_EQ (s.run(script4), Seq::exit_ok.value);
+       EXPECT_EQ (handler_flag, true);
+   }
+
+   TEST(Tsequencer, run_boundaries) {
+       Seq s;
+
+       const Seq::script_t<1> script1 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::next, 0},
+       }};
+       EXPECT_EQ (s.run(script1), Seq::exit_error.value);
+
+       const Seq::script_t<1> script2 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::go_to<1>, 0},
+       }};
+       EXPECT_EQ (s.run(script2), Seq::exit_error.value);
+
+       const Seq::script_t<1> script3 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::go_to<(size_t)-1>, 0},
+       }};
+       EXPECT_EQ (s.run(script3), Seq::exit_error.value);
+
+       const Seq::script_t<1> script4 = {{
+           {Seq::control_t::EXPECT,  "abc", Seq::nil, Seq::nil, Seq::next, 1000},
+       }};
+       s.clear_clock();
+       EXPECT_EQ (s.run(script4), Seq::exit_error.value);
+       EXPECT_GT (s.clock(), (clock_t)1000);
    }
 }

test/tests/span.cpp

@@ -0,0 +1,274 @@
+/*!
+ * \file span.cpp
+ * \brief
+ *      Unit tests for span
+ *
+ * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ *
+ */
+#include <cont/span.h>
+#include <gtest/gtest.h>
+
+#include <cont/deque.h>
+#include <vector>
+#include <type_traits>
+
+// tests from https://github.com/tcbrindle/span/blob/master/test/test_span.cpp
+
+namespace test_span {
+   using namespace tbx;
+
+   TEST (Tspan, default_constructors) {
+       EXPECT_EQ (true, ( std::is_nothrow_default_constructible<span<int>>::value));
+       EXPECT_EQ (true, ( std::is_nothrow_default_constructible<span<int, 0>>::value));
+       EXPECT_EQ (true, (!std::is_nothrow_default_constructible<span<int, 42>>::value));
+
+       constexpr span<int> s1{};
+
+       EXPECT_EQ (0UL, s1.size());
+       EXPECT_EQ (nullptr, s1.data());
+       EXPECT_EQ (s1.begin(), s1.end());
+
+       constexpr span<int, 0> s2{};
+
+       EXPECT_EQ (0UL, s2.size());
+       EXPECT_EQ (nullptr, s2.data());
+       EXPECT_EQ (s2.begin(), s2.end());
+   }
+
+   TEST (Tspan, pointer_constructors) {
+       // pointer length
+       EXPECT_EQ (true, (std::is_constructible<span<int>, int*, int>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<const int>, int*, int>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<const int>, const int*, int>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<int, 42>, int*, int>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<const int, 42>, int*, int>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<const int, 42>, const int*, int>::value));
+
+       int arr[] = {1, 2, 3};
+
+       // dynamic size
+       span<int> s1(arr, 3);
+       EXPECT_EQ (3UL, s1.size());
+       EXPECT_EQ (arr, s1.data());
+       EXPECT_EQ (std::begin(arr), s1.begin());
+       EXPECT_EQ (std::end(arr), s1.end());
+
+       // fixed size
+       span<int, 3> s2(arr, 3);
+       EXPECT_EQ (3UL, s2.size());
+       EXPECT_EQ (arr, s2.data());
+       EXPECT_EQ (std::begin(arr), s2.begin());
+       EXPECT_EQ (std::end(arr), s2.end());
+
+       // pointer pointer
+       EXPECT_EQ (true, (std::is_constructible<span<int>, int*, int*>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<float>, float*, float*>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<int, 42>, int*, int*>::value));
+       EXPECT_EQ (true, (std::is_constructible<span<float, 42>, float*, float*>::value));
+
+       // dynamic size
+       span<int> s3(arr, arr + 3);
+       EXPECT_EQ (3UL, s3.size());
+       EXPECT_EQ (arr, s3.data());
+       EXPECT_EQ (std::begin(arr), s3.begin());
+       EXPECT_EQ (std::end(arr), s3.end());
+
+       // fixed size
+       span<int, 3> s4(arr, arr + 3);
+       EXPECT_EQ (3UL, s4.size());
+       EXPECT_EQ (arr, s4.data());
+       EXPECT_EQ (std::begin(arr), s4.begin());
+       EXPECT_EQ (std::end(arr), s4.end());
+   }
+
+   TEST (Tspan, C_array_constructors) {
+       using int_array_t = int[3];
+       using float_array_t = float[3];
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<int>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int>, float_array_t>::value));
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int>, int_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int>, float_array_t>::value));
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<int, 3>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 3>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 3>, float_array_t&>::value));
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int, 3>, int_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int, 3>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 3>, float_array_t>::value));
+
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 42>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 42>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 42>, float_array_t&>::value));
+
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 42>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 42>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 42>, float_array_t&>::value));
+
+       int arr[] = {1, 2, 3};
+
+       // non-const dynamic size
+       span<int> s1{arr};
+       EXPECT_EQ (s1.size(), 3UL);
+       EXPECT_EQ (s1.data(), arr);
+       EXPECT_EQ (s1.begin(), std::begin(arr));
+       EXPECT_EQ (s1.end(), std::end(arr));
+
+       // non-const dynamic size
+       span<const int> s2{arr};
+       EXPECT_EQ (s2.size(), 3UL);
+       EXPECT_EQ (s2.data(), arr);
+       EXPECT_EQ (s2.begin(), std::begin(arr));
+       EXPECT_EQ (s2.end(), std::end(arr));
+
+       // non-const fixed size
+       span<int, 3> s3{arr};
+       EXPECT_EQ (s3.size(), 3UL);
+       EXPECT_EQ (s3.data(), arr);
+       EXPECT_EQ (s3.begin(), std::begin(arr));
+       EXPECT_EQ (s3.end(), std::end(arr));
+
+       // non-const fixed size
+       span<const int, 3> s4{arr};
+       EXPECT_EQ (s4.size(), 3UL);
+       EXPECT_EQ (s4.data(), arr);
+       EXPECT_EQ (s4.begin(), std::begin(arr));
+       EXPECT_EQ (s4.end(), std::end(arr));
+   }
+
+   TEST (Tspan, array_constructors) {
+       using int_array_t = std::array<int, 3>;
+       using float_array_t = std::array<float, 3>;
+       using zero_array_t = std::array<int, 0>;
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<int>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int>, float_array_t>::value));
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int>, int_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int>, float_array_t const&>::value));
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<int, 3>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 3>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 3>, float_array_t>::value));
+
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int, 3>, int_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_nothrow_constructible<span<const int, 3>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 3>, float_array_t const&>::value));
+
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 42>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 42>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 42>, float_array_t const&>::value));
+
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 42>, int_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 42>, int_array_t const&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<const int, 42>, float_array_t&>::value));
+
+       EXPECT_EQ (true, ( std::is_constructible<span<int>, zero_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int>, const zero_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_constructible<span<const int>, zero_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_constructible<span<const int>, const zero_array_t&>::value));
+
+       EXPECT_EQ (true, ( std::is_constructible<span<int, 0>, zero_array_t&>::value));
+       EXPECT_EQ (true, (!std::is_constructible<span<int, 0>, const zero_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_constructible<span<const int, 0>, zero_array_t&>::value));
+       EXPECT_EQ (true, ( std::is_constructible<span<const int, 0>, const zero_array_t&>::value));
+
+
+       int_array_t arr = {1, 2, 3};
+
+       // non-const, dynamic size
+       span<int> s1{arr};
+       EXPECT_EQ(s1.size(), 3UL);
+       EXPECT_EQ(s1.data(), arr.data());
+       EXPECT_EQ(s1.begin(), arr.data());
+       EXPECT_EQ(s1.end(), arr.data() + 3);
+
+
+       //const, dynamic size
+       span<int const> s2{arr};
+       EXPECT_EQ(s2.size(), 3UL);
+       EXPECT_EQ(s2.data(), arr.data());
+       EXPECT_EQ(s2.begin(), arr.data());
+       EXPECT_EQ(s2.end(), arr.data() + 3);
+
+
+       // non-const, static size
+       span<int, 3> s3{arr};
+       EXPECT_EQ(s3.size(), 3UL);
+       EXPECT_EQ(s3.data(), arr.data());
+       EXPECT_EQ(s3.begin(), arr.data());
+       EXPECT_EQ(s3.end(), arr.data() + 3);
+
+       // const, dynamic size
+       span<int const, 3> s4{arr};
+       EXPECT_EQ(s4.size(), 3UL);
+       EXPECT_EQ(s4.data(), arr.data());
+       EXPECT_EQ(s4.begin(), arr.data());
+       EXPECT_EQ(s4.end(), arr.data() + 3);
+   }
+
+//   TEST (Tspan, containter_constructors) {
+//       using container_t = tbx::deque<int, 3>;
+//
+//       EXPECT_EQ (true, ( std::is_constructible<span<int>, container_t&>::value));
+//       EXPECT_EQ (true, (!std::is_constructible<span<int>, const container_t&>::value));
+//
+//       EXPECT_EQ (true, ( std::is_constructible<span<const int>, container_t&>::value));
+//       EXPECT_EQ (true, ( std::is_constructible<span<const int>, const container_t&>::value));
+//
+//       EXPECT_EQ (true, (!std::is_constructible<span<int, 3>, container_t&>::value));
+//       EXPECT_EQ (true, (!std::is_constructible<span<int, 3>, const container_t&>::value));
+//
+//       EXPECT_EQ (true, (!std::is_constructible<span<const int, 3>, container_t&>::value));
+//       EXPECT_EQ (true, (!std::is_constructible<span<const int, 3>, const container_t&>::value));
+//
+//       container_t cont = {1, 2, 3};
+//       const container_t ccont = {1, 2, 3};
+//
+//       // non-const, dynamic size
+//       span<int> s1(cont);
+//       EXPECT_EQ(s1.size(), 3UL);
+//       EXPECT_EQ(s1.data(), cont.data());
+//       EXPECT_EQ(s1.begin(), cont.data());
+//       EXPECT_EQ(s1.end(), cont.data() + 3);
+//
+//
+//       //const, dynamic size
+//       span<int const> s2(cont);
+//       EXPECT_EQ(s2.size(), 3UL);
+//       EXPECT_EQ(s2.data(), cont.data());
+//       EXPECT_EQ(s2.begin(), cont.data());
+//       EXPECT_EQ(s2.end(), cont.data() + 3);
+//
+//   }
+
+}