First Commit

pthread_add.c

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <sys/time.h>
+
+#define ARRAY_SIZE 15000576
+#define NUM_THREADS 8  // Adjust based on your CPU cores
+
+typedef struct {
+    float *a;
+    float *b;
+    float *c;
+    int start;
+    int end;
+} ThreadData;
+
+void *add_arrays(void *arg) {
+    ThreadData *data = (ThreadData *)arg;
+    for (int i = data->start; i < data->end; i++) {
+        data->c[i] = data->a[i] + data->b[i];
+    }
+    return NULL;
+}
+
+double get_time() {
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return tv.tv_sec + tv.tv_usec * 1e-6;
+}
+
+int main() {
+    float *a = (float*)malloc(ARRAY_SIZE * sizeof(float));
+    float *b = (float*)malloc(ARRAY_SIZE * sizeof(float));
+    float *c = (float*)malloc(ARRAY_SIZE * sizeof(float));
+
+    // Initialize arrays
+    for (int i = 0; i < ARRAY_SIZE; i++) {
+        a[i] = i;
+        b[i] = i * 2;
+    }
+
+    // Create threads
+    pthread_t threads[NUM_THREADS];
+    ThreadData thread_data[NUM_THREADS];
+    int chunk_size = ARRAY_SIZE / NUM_THREADS;
+
+    double start = get_time();
+    for (int t = 0; t < NUM_THREADS; t++) {
+        thread_data[t].a = a;
+        thread_data[t].b = b;
+        thread_data[t].c = c;
+        thread_data[t].start = t * chunk_size;
+        thread_data[t].end = (t == NUM_THREADS - 1) ? ARRAY_SIZE : (t + 1) * chunk_size;
+        pthread_create(&threads[t], NULL, add_arrays, &thread_data[t]);
+    }
+
+    // Wait for threads to finish
+    for (int t = 0; t < NUM_THREADS; t++) {
+        pthread_join(threads[t], NULL);
+    }
+    double calc_time = get_time() - start;
+
+    printf("Pthreads calculation time: %.6f ms\n", calc_time * 1000);
+
+    // Print a sample of the result
+    for (int i = 0; i < 10; i++) {
+        printf("c[%d] = %f\n", i, c[i]);
+    }
+
+    free(a);
+    free(b);
+    free(c);
+
+    return 0;
+}