/**
* \file
* \brief Utilities header
*
* \author
* Christos Choutouridis AEM:8997
* <cchoutou@ece.auth.gr>
*/
#ifndef UTILS_HPP_
#define UTILS_HPP_
#include <vector>
#include <iostream>
#include <chrono>
#include <unistd.h>
#include <mpi.h>
#include "config.h"
/*
* MPI_<type> dispatcher mechanism
*/
template <typename T> struct MPI_TypeMapper { };
template <> struct MPI_TypeMapper<char> { static MPI_Datatype getType() { return MPI_CHAR; } };
template <> struct MPI_TypeMapper<short> { static MPI_Datatype getType() { return MPI_SHORT; } };
template <> struct MPI_TypeMapper<int> { static MPI_Datatype getType() { return MPI_INT; } };
template <> struct MPI_TypeMapper<long> { static MPI_Datatype getType() { return MPI_LONG; } };
template <> struct MPI_TypeMapper<long long> { static MPI_Datatype getType() { return MPI_LONG_LONG; } };
template <> struct MPI_TypeMapper<unsigned char> { static MPI_Datatype getType() { return MPI_UNSIGNED_CHAR; } };
template <> struct MPI_TypeMapper<unsigned short>{ static MPI_Datatype getType() { return MPI_UNSIGNED_SHORT; } };
template <> struct MPI_TypeMapper<unsigned int> { static MPI_Datatype getType() { return MPI_UNSIGNED; } };
template <> struct MPI_TypeMapper<unsigned long> { static MPI_Datatype getType() { return MPI_UNSIGNED_LONG; } };
template <> struct MPI_TypeMapper<unsigned long long> { static MPI_Datatype getType() { return MPI_UNSIGNED_LONG_LONG; } };
template <> struct MPI_TypeMapper<float> { static MPI_Datatype getType() { return MPI_FLOAT; } };
template <> struct MPI_TypeMapper<double> { static MPI_Datatype getType() { return MPI_DOUBLE; } };
/*!
* MPI wrapper type to provide MPI functionality and RAII to MPI as a resource
*
* @tparam TID The MPI type for process id [default: int]
*/
template<typename TID = int>
struct MPI_t {
using ID_t = TID; // Export TID type (currently int defined by the standard)
/*!
* Initializes the MPI environment, must called from each process
*
* @param argc [int*] POINTER to main's argc argument
* @param argv [char***] POINTER to main's argv argument
*/
void init(int* argc, char*** argv) {
// Initialize the MPI environment
int err;
if ((err = MPI_Init(argc, argv)) != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Init() - ");
initialized_ = true;
// Get the number of processes
int size_value, rank_value;
if ((err = MPI_Comm_size(MPI_COMM_WORLD, &size_value)) != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Comm_size() - ");
if ((err = MPI_Comm_rank(MPI_COMM_WORLD, &rank_value)) != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Comm_rank() - ");
size_ = static_cast<ID_t>(size_value);
rank_ = static_cast<ID_t>(rank_value);
if (size_ > static_cast<ID_t>(MAX_MPI_SIZE))
throw std::runtime_error(
"(MPI) size - Not supported number of nodes [over " + std::to_string(MAX_MPI_SIZE) + "]\n"
);
// Get the name of the processor
char processor_name[MPI_MAX_PROCESSOR_NAME];
int name_len;
if ((err = MPI_Get_processor_name(processor_name, &name_len)) != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Get_processor_name() - ");
name_ = std::string (processor_name, name_len);
}
/*!
* Initiate a data exchange data with partner using non-blocking Isend-Irecv, as part of the
* sorting network of both bubbletonic or bitonic sorting algorithms.
*
* This function matches a transmit and a receive in order for fully exchanged data between
* current node and partner.
* @note
* This call MUST paired with exchange_wait() for each MPI_t object.
* Calling 2 consecutive exchange_start() for the same MPI_t object is undefined.
*
* @tparam ValueT The underlying value type used in buffers
*
* @param ldata [const ValueT*] Pointer to local data to send
* @param rdata [ValueT*] Pointer to buffer to receive data from partner
* @param count [size_t] The number of data to exchange
* @param partner [mpi_id_t] The partner for the exchange
* @param tag [int] The tag to use for the MPI communication
*/
template<typename ValueT>
void exchange_start(const ValueT* ldata, ValueT* rdata, size_t count, ID_t partner, int tag) {
if (tag < 0)
throw std::runtime_error("(MPI) exchange_data() [tag] - Out of bound");
MPI_Datatype datatype = MPI_TypeMapper<ValueT>::getType();
int err;
err = MPI_Isend(ldata, count, datatype, partner, tag, MPI_COMM_WORLD, &handle_tx);
if (err != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Isend() - ");
err = MPI_Irecv(rdata, count, datatype, partner, tag, MPI_COMM_WORLD, &handle_rx);
if (err != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Irecv() - ");
}
/*!
* Block wait for the completion of the previously called exchange_start()
*
* @note
* This call MUST paired with exchange_start() for each MPI_t object.
* Calling 2 consecutive exchange_wait() for the same MPI_t object is undefined.
*/
void exchange_wait() {
MPI_Status status;
int err;
if ((err = MPI_Wait(&handle_tx, &status)) != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Wait() [send] - ");
if ((err = MPI_Wait(&handle_rx, &status)) != MPI_SUCCESS)
mpi_throw(err, "(MPI) MPI_Wait() [recv] - ");
}
// Accessors
[[nodiscard]] ID_t rank() const noexcept { return rank_; }
[[nodiscard]] ID_t size() const noexcept { return size_; }
[[nodiscard]] const std::string& name() const noexcept { return name_; }
// Mutators
ID_t rank(ID_t rank) noexcept { return rank_ = rank; }
ID_t size(ID_t size) noexcept { return size_ = size; }
std::string& name(const std::string& name) noexcept { return name_ = name; }
/*!
* Finalized the MPI
*/
void finalize() {
// Finalize the MPI environment
initialized_ = false;
MPI_Finalize();
}
//! RAII MPI finalization
~MPI_t() {
// Finalize the MPI environment even on unexpected errors
if (initialized_)
MPI_Finalize();
}
// Local functionality
private:
/*!
* Throw exception helper. It bundles the prefix msg with the MPI error string retrieved by
* MPI API.
*
* @param err The MPI error code
* @param prefixMsg The prefix text for the exception error message
*/
void mpi_throw(int err, const char* prefixMsg) {
char err_msg[MPI_MAX_ERROR_STRING];
int msg_len;
MPI_Error_string(err, err_msg, &msg_len);
throw std::runtime_error(prefixMsg + std::string (err_msg) + '\n');
}
private:
ID_t rank_{}; //!< MPI rank of the process
ID_t size_{}; //!< MPI total size of the execution
std::string name_{}; //!< The name of the local machine
bool initialized_{}; //!< RAII helper flag
MPI_Request handle_tx{}; //!< MPI async exchange handler for Transmission
MPI_Request handle_rx{}; //!< MPI async exchange handler for Receptions
};
/*
* Exported data types
*/
extern MPI_t<> mpi;
using mpi_id_t = MPI_t<>::ID_t;
/*!
* @brief A std::vector wrapper with 2 vectors, an active and a shadow.
*
* This type exposes the standard vector
* functionality of the active vector. The shadow can be used when we need to use the vector as mutable
* data in algorithms that can not support "in-place" editing (like elbow-sort for example)
*
* @tparam Value_t the underlying data type of the vectors
*/
template <typename Value_t>
struct ShadowedVec_t {
// STL requirements
using value_type = Value_t;
using iterator = typename std::vector<Value_t>::iterator;
using const_iterator = typename std::vector<Value_t>::const_iterator;
using size_type = typename std::vector<Value_t>::size_type;
// Default constructor
ShadowedVec_t() = default;
// Constructor from an std::vector
explicit ShadowedVec_t(const std::vector<Value_t>& vec)
: North(vec), South(), active(north) {
South.resize(North.size());
}
explicit ShadowedVec_t(std::vector<Value_t>&& vec)
: North(std::move(vec)), South(), active(north) {
South.resize(North.size());
}
// Copy assignment operator
ShadowedVec_t& operator=(const ShadowedVec_t& other) {
if (this != &other) { // Avoid self-assignment
North = other.North;
South = other.South;
active = other.active;
}
return *this;
}
// Move assignment operator
ShadowedVec_t& operator=(ShadowedVec_t&& other) noexcept {
if (this != &other) { // Avoid self-assignment
North = std::move(other.North);
South = std::move(other.South);
active = other.active;
// There is no need to zero out other since it is valid but in a non-defined state
}
return *this;
}
// Type accessors
std::vector<Value_t>& getActive() { return (active == north) ? North : South; }
std::vector<Value_t>& getShadow() { return (active == north) ? South : North; }
const std::vector<Value_t>& getActive() const { return (active == north) ? North : South; }
const std::vector<Value_t>& getShadow() const { return (active == north) ? South : North; }
// Swap vectors
void switch_active() { active = (active == north) ? south : north; }
// Dispatch vector functionality to active vector
Value_t& operator[](size_type index) { return getActive()[index]; }
const Value_t& operator[](size_type index) const { return getActive()[index]; }
Value_t& at(size_type index) { return getActive().at(index); }
const Value_t& at(size_type index) const { return getActive().at(index); }
void push_back(const Value_t& value) { getActive().push_back(value); }
void push_back(Value_t&& value) { getActive().push_back(std::move(value)); }
void pop_back() { getActive().pop_back(); }
Value_t& front() { return getActive().front(); }
Value_t& back() { return getActive().back(); }
const Value_t& front() const { return getActive().front(); }
const Value_t& back() const { return getActive().back(); }
iterator begin() { return getActive().begin(); }
const_iterator begin() const { return getActive().begin(); }
iterator end() { return getActive().end(); }
const_iterator end() const { return getActive().end(); }
size_type size() const { return getActive().size(); }
void resize(size_t new_size) {
North.resize(new_size);
South.resize(new_size);
}
void reserve(size_t new_capacity) {
North.reserve(new_capacity);
South.reserve(new_capacity);
}
[[nodiscard]] size_t capacity() const { return getActive().capacity(); }
[[nodiscard]] bool empty() const { return getActive().empty(); }
void clear() { getActive().clear(); }
void swap(std::vector<Value_t>& other) { getActive().swap(other); }
// Comparisons
bool operator== (const ShadowedVec_t& other) { return getActive() == other.getActive(); }
bool operator!= (const ShadowedVec_t& other) { return getActive() != other.getActive(); }
bool operator== (const std::vector<value_type>& other) { return getActive() == other; }
bool operator!= (const std::vector<value_type>& other) { return getActive() != other; }
private:
std::vector<Value_t> North{}; //!< Actual buffer to be used either as active or shadow
std::vector<Value_t> South{}; //!< Actual buffer to be used either as active or shadow
enum {
north, south
} active{north}; //!< Flag to select between North and South buffer
};
/*
* Exported data types
*/
using distBuffer_t = ShadowedVec_t<distValue_t>;
extern distBuffer_t Data;
/*!
* A Logger for entire program.
*/
struct Log {
struct Endl {} endl; //!< a tag object to to use it as a new line request.
//! We provide logging via << operator
template<typename T>
Log &operator<<(T &&t) {
if (config.verbose) {
if (line_) {
std::cout << "[Log]: " << t;
line_ = false;
} else
std::cout << t;
}
return *this;
}
// overload for special end line handling
Log &operator<<(Endl e) {
(void) e;
if (config.verbose) {
std::cout << '\n';
line_ = true;
}
return *this;
}
private:
bool line_{true};
};
extern Log logger;
/*!
* A small timing utility based on chrono.
*/
struct Timing {
using Tpoint = std::chrono::steady_clock::time_point;
using Tduration = std::chrono::microseconds;
using microseconds = std::chrono::microseconds;
using milliseconds = std::chrono::milliseconds;
using seconds = std::chrono::seconds;
//! tool to mark the starting point
Tpoint start() noexcept { return mark_ = std::chrono::steady_clock::now(); }
//! tool to mark the ending point
Tpoint stop() noexcept {
Tpoint now = std::chrono::steady_clock::now();
duration_ += dt(now, mark_);
return now;
}
//! A duration calculation utility
static Tduration dt(Tpoint t2, Tpoint t1) noexcept {
return std::chrono::duration_cast<Tduration>(t2 - t1);
}
//! Tool to print the time interval
void print_duration(const char *what, mpi_id_t rank) noexcept {
if (std::chrono::duration_cast<microseconds>(duration_).count() < 10000)
std::cout << "[Timing] (Rank " << rank << ") " << what << ": "
<< std::to_string(std::chrono::duration_cast<microseconds>(duration_).count()) << " [usec]\n";
else if (std::chrono::duration_cast<milliseconds>(duration_).count() < 10000)
std::cout << "[Timing] (Rank " << rank << ") " << what << ": "
<< std::to_string(std::chrono::duration_cast<milliseconds>(duration_).count()) << " [msec]\n";
else {
char stime[26]; // fit ulong
auto sec = std::chrono::duration_cast<seconds>(duration_).count();
auto msec = (std::chrono::duration_cast<milliseconds>(duration_).count() % 1000) / 10; // keep 2 digit
std::sprintf(stime, "%ld.%1ld", sec, msec);
std::cout << "[Timing] (Rank " << rank << ") " << what << ": " << stime << " [sec]\n";
}
}
private:
Tpoint mark_{};
Tduration duration_{};
};
/*!
* Utility "high level function"-like macro to forward a function call
* and accumulate the execution time to the corresponding timing object.
*
* @param Tim The Timing object [Needs to have methods start() and stop()]
* @param Func The function name
* @param ... The arguments to pass to function (the preprocessor way)
*/
#define timeCall(Tim, Func, ...) \
Tim.start(); \
Func(__VA_ARGS__); \
Tim.stop(); \
/*!
* A utility to check if a number is power of two
*
* @tparam Integral The integral type of the number to check
* @param x The number to check
* @return True if it is power of 2, false otherwise
*/
template <typename Integral>
constexpr inline bool isPowerOfTwo(Integral x) noexcept {
return (!(x & (x - 1)) && x);
}
#endif /* UTILS_HPP_ */