Add files via upload

Lab04/triad_bench_2.cpp

@@ -0,0 +1,80 @@
+#include <chrono>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <thread>
+#include <vector>
+#include <string>
+#include <cmath>
+
+const int N = pow(2,17) * 9;
+
+std::vector<double> B(N, 1);
+std::vector<double> C(N, 2);
+std::vector<double> D(N, 3);
+
+struct Statistics {
+  double avg_time;
+  double flops;
+};
+
+void ownMethod(std::vector<double>& A, int start, int end) {
+    for (int j = start; j < end; ++j) {
+      A[j] = B[j] + C[j] * D[j];
+    }
+}
+
+void workerThread(std::vector<double>& A, int start, int end, int threadCount, Statistics& stat) {
+  
+  std::chrono::duration<double, std::milli> sumTime;
+  for (int i = 0; i < 20; i++) {
+    auto startTime = std::chrono::system_clock::now();
+    ownMethod(A, start, end);
+    auto endTime = std::chrono::system_clock::now();
+    sumTime += endTime - startTime;
+  }
+  
+  stat.avg_time = sumTime.count() / 20;
+  stat.flops = (2.0 * N) / (stat.avg_time  / 1000);
+}
+
+int main() {
+  
+  std::vector<double> A(N, 0);
+  int range_start = 0;
+  int range_end =  N;
+  int countThreads[] = {1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64};
+  
+  // int num_threads = std::thread::hardware_concurrency(); // use system's core
+  // count
+  for (int j = 0; j < (sizeof(countThreads) / sizeof(int)); j++) {
+    std::vector<Statistics> stats(countThreads[j]);
+
+    std::vector<std::thread> threads;
+
+    for (int i = 0; i < countThreads[j]; ++i) {
+      int start = N / countThreads[j] * i;
+      int end = N / countThreads[j] * (i + 1);
+
+      threads.emplace_back(workerThread, std::ref(A), start, end, countThreads[j], std::ref(stats[j]));
+    }
+
+    for (auto& t : threads) {
+      t.join();
+    }
+
+    std::cout << A[1179647];
+    volatile std::vector<double> dummy(A);
+
+    // std::stringstream fileName;
+    // fileName << "outcomes-" << start << "-" << end << ".csv";
+    // std::ofstream MyFile(fileName.str());
+  
+    // MyFile << "(" << averageTime << "" << flops << ")";
+    // MyFile.close();
+
+    std::cout << "All threads finished.\n";
+  }
+
+  return 0;
+}