HW2: A validator added and small changes

homework_2/src/main.cpp

@@ -43,6 +43,9 @@ bool get_options(int argc, char* argv[]){
                 status = false;
             }
         }
+        else if (arg == "--validation") {
+            session.validation = true;
+        }
         else if (arg == "--ndebug") {
             session.ndebug = true;
         }
@@ -54,14 +57,16 @@ bool get_options(int argc, char* argv[]){
         }
         else if (arg == "-h" || arg == "--help") {
             std::cout << "distbitonic/distbubbletonic - A distributed bitonic sort\n\n";
-            std::cout << "distbitonic -q <> [--ndebug] [-v]\n";
+            std::cout << "distbitonic -q <N> [--validation] [--ndebug] [-v]\n";
             std::cout << "distbitonic -h\n";
-            std::cout << "distbubbletonic -q <> [--ndebug] [-v]\n";
+            std::cout << "distbubbletonic -q <N> [--validation] [--ndebug] [-v]\n";
             std::cout << "distbubbletonic -h\n";
             std::cout << '\n';
             std::cout << "Options:\n\n";
-            std::cout << "   -q | --array-size <size>\n";
-            std::cout << "      Selects the array size according to size = 2^q\n\n";
+            std::cout << "   -q | --array-size <N>\n";
+            std::cout << "      Selects the array size according to size = 2^N\n\n";
+            std::cout << "   --validation\n";
+            std::cout << "      Request a full validation at the end, performed by process rank 0\n\n";
             std::cout << "   --ndebug\n";
             std::cout << "      Skip debug breakpoint when on debug build.\n\n";
             std::cout << "   -t | --timing\n";
@@ -87,6 +92,48 @@ bool get_options(int argc, char* argv[]){
     return status;
 }
 
+/*!
+ * A simple validator for the entire distributed process
+ *
+ * @tparam ShadowedDataT    A Shadowed buffer type with random access iterator.
+ *
+ * @param data          [ShadowedDataT] The local to MPI process
+ * @param Processes     [mpi_id_t]      The total number of MPI processes
+ * @param rank          [mpi_id_t]      The current process id
+ *
+ * @return              [bool]          True if all are sorted and in total ascending order
+ */
+template<typename ShadowedDataT>
+bool validator(ShadowedDataT& data, mpi_id_t Processes, mpi_id_t rank) {
+    using value_t = typename ShadowedDataT::value_type;
+    bool ret = true;    // Have faith!
+
+    // Local results
+    value_t lmin   = data.front();
+    value_t lmax   = data.back();
+    value_t lsort  = static_cast<value_t>(std::is_sorted(data.begin(), data.end()));
+
+    // Gather min/max/sort to rank 0
+    std::vector<value_t> mins(Processes);
+    std::vector<value_t> maxes(Processes);
+    std::vector<value_t> sorts(Processes);
+
+    MPI_Datatype datatype = MPI_TypeMapper<value_t>::getType();
+    MPI_Gather(&lmin,  1, datatype, mins.data(),  1, datatype, 0, MPI_COMM_WORLD);
+    MPI_Gather(&lmax,  1, datatype, maxes.data(), 1, datatype, 0, MPI_COMM_WORLD);
+    MPI_Gather(&lsort, 1, datatype, sorts.data(), 1, datatype, 0, MPI_COMM_WORLD);
+
+    // Check all results
+    if (rank == 0) {
+        for (mpi_id_t r = 1; r < Processes; ++r) {
+            if (sorts[r] == 0)
+                ret = false;
+            if (maxes[r - 1] > mins[r])
+                ret = false;
+        }
+    }
+    return ret;
+}
 
 #if !defined TESTING
 int main(int argc, char* argv[]) try {
@@ -146,7 +193,14 @@ int main(int argc, char* argv[]) try {
     std::string timeMsg = "rank " + std::to_string(mpi.rank());
     timer.print_dt(timeMsg.c_str());
 
-    std::cout << "[Data]: Rank " << mpi.rank() << ": [" << +Data.front() << " .. " << +Data.back() << "]" << std::endl;
+    if (session.validation) {
+        // If requested, we have the chance to fail!
+        if (mpi.rank() == 0)
+            std::cout << "Results validation ...";
+        bool val = validator(Data, mpi.size(), mpi.rank());
+        if (mpi.rank() == 0)
+            std::cout << ((val) ? "\x1B[32m [PASS] \x1B[0m\n" : " \x1B[32m [FAIL] \x1B[0m\n");
+    }
     mpi.finalize();
     return 0;
 }