From 5df59e937663f478f06c4fb81379f07613039fa5 Mon Sep 17 00:00:00 2001
From: kai <k.penazzi@web.de>
Date: Sat, 26 Apr 2025 13:22:56 +0200
Subject: [PATCH] adjust ...

---
 lab06/MonteCarloPiThreads.cpp    | 41 ++++++++++---------
 lab06/MonteCarloPiThreadsDyn.cpp | 69 ++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 18 deletions(-)
 create mode 100644 lab06/MonteCarloPiThreadsDyn.cpp

diff --git a/lab06/MonteCarloPiThreads.cpp b/lab06/MonteCarloPiThreads.cpp
index 220ce63..92b1ee7 100644
--- a/lab06/MonteCarloPiThreads.cpp
+++ b/lab06/MonteCarloPiThreads.cpp
@@ -1,4 +1,3 @@
-#include "matrix.h"
 #include <chrono>
 #include <cstdint>
 #include <fstream>
@@ -8,19 +7,22 @@
 
 struct bench_result {
   double time;
-  double pi;
+  int threads;
 };
 
 double monteCarloPi(int64_t N) {
   int localCount = 0;
-  std::mt19937 generator(std::random_device{}());
-  std::uniform_real_distribution<double> dist(0.0, 1.0);
-#pragma omp parallel for reduction(+ : localCount)
-  for (int i = 0; i < N; ++i) {
-    double x = dist(generator);
-    double y = dist(generator);
-    if (x * x + y * y <= 1.0) {
-      localCount++;
+#pragma omp parallel
+  {
+    std::mt19937 generator(std::random_device{}() + omp_get_thread_num());
+    std::uniform_real_distribution<double> dist(0.0, 1.0);
+#pragma omp for reduction(+ : localCount)
+    for (int i = 0; i < N; ++i) {
+      double x = dist(generator);
+      double y = dist(generator);
+      if (x * x + y * y <= 1.0) {
+        localCount++;
+      }
     }
   }
 
@@ -32,32 +34,35 @@ bench_result benchmark(int numThreads, int64_t N, double function(int64_t)) {
 
   // start time measurement
   auto start = std::chrono::system_clock::now();
-  auto result = bench_result{0.0, 0.0};
+  auto result = bench_result{0.0, 0};
 
   // perform benchmark
   const int maxNumExec = 10;
   for (int nExec = 0; nExec < maxNumExec; ++nExec) {
-    result.pi = function(N);
+    volatile double pi = function(N);
   }
 
   auto end = std::chrono::system_clock::now();
   std::chrono::duration<double, std::milli> diff = end - start;
   result.time = diff.count() / maxNumExec;
+  result.threads = numThreads;
 
   return result;
 }
 
 int main() {
   const int64_t max_n = 10000000;
-  const int numThreads = 12;
-  std::ofstream fout("multi_monte.csv", std::ios::app);
-  fout << "pi" << ",";
+  const int max_threads = 12;
+  std::ofstream fout("diff_theads.csv", std::ios::app);
+  fout << "threads" << ",";
+  fout << "max_n" << ",";
   fout << "time" << "\n";
 
-  for (int64_t i = 1000; i <= max_n; i += 1000) {
-    const bench_result res = benchmark(numThreads, i, monteCarloPi);
+  for (int i = 1; i <= max_threads; i++) {
+    const bench_result res = benchmark(i, max_n, monteCarloPi);
 
-    fout << res.pi << ",";
+    fout << res.threads << ",";
+    fout << max_n << ",";
     fout << res.time << "\n";
   }
 }
diff --git a/lab06/MonteCarloPiThreadsDyn.cpp b/lab06/MonteCarloPiThreadsDyn.cpp
new file mode 100644
index 0000000..1621041
--- /dev/null
+++ b/lab06/MonteCarloPiThreadsDyn.cpp
@@ -0,0 +1,69 @@
+#include "matrix.h"
+#include <chrono>
+#include <cstdint>
+#include <fstream>
+#include <iostream>
+#include <omp.h>
+#include <random>
+
+struct bench_result {
+  double time;
+  int threads;
+};
+
+double monteCarloPi(int64_t N) {
+  int localCount = 0;
+#pragma omp parallel
+  {
+    std::mt19937 generator(std::random_device{}() + omp_get_thread_num());
+    std::uniform_real_distribution<double> dist(0.0, 1.0);
+#pragma omp for reduction(+ : localCount)
+    for (int i = 0; i < N; ++i) {
+      double x = dist(generator);
+      double y = dist(generator);
+      if (x * x + y * y <= 1.0) {
+        localCount++;
+      }
+    }
+  }
+
+  return 4.0 * localCount / N;
+}
+
+bench_result benchmark(int numThreads, int64_t N, double function(int64_t)) {
+  omp_set_num_threads(numThreads);
+
+  // start time measurement
+  auto start = std::chrono::system_clock::now();
+  auto result = bench_result{0.0, 0};
+
+  // perform benchmark
+  const int maxNumExec = 10;
+  for (int nExec = 0; nExec < maxNumExec; ++nExec) {
+    volatile double pi = function(N);
+  }
+
+  auto end = std::chrono::system_clock::now();
+  std::chrono::duration<double, std::milli> diff = end - start;
+  result.time = diff.count() / maxNumExec;
+  result.threads = numThreads;
+
+  return result;
+}
+
+int main() {
+  const int64_t max_n = 1000000;
+  const int max_threads = 12;
+  std::ofstream fout("dyn_n.csv", std::ios::app);
+  fout << "threads" << ",";
+  fout << "max_n" << ",";
+  fout << "time" << "\n";
+
+  for (int i = 1; i <= max_threads; i++) {
+    const bench_result res = benchmark(i, max_n * i, monteCarloPi);
+
+    fout << res.threads << ",";
+    fout << (max_n * i) << ",";
+    fout << res.time << "\n";
+  }
+}