63 lines
1.6 KiB
C
63 lines
1.6 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <pthread.h>
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#include <sys/time.h>
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#include <unistd.h>
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#include <sys/wait.h>
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#define ITERATIONS 10000
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double get_time()
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{
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struct timeval tv;
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gettimeofday(&tv, NULL);
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return tv.tv_sec + tv.tv_usec / 1000000.0;
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}
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void *dummy_thread(void *arg)
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{
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return NULL;
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}
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int main()
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{
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double t_start, t_end;
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double fork_total = 0, pthread_total = 0;
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/* Measure fork() */
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t_start = get_time();
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for (int i = 0; i < ITERATIONS; i++) {
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pid_t pid = fork();
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if (pid == 0) {
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_exit(0);
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} else if (pid > 0) {
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waitpid(pid, NULL, 0);
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}
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}
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t_end = get_time();
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fork_total = t_end - t_start;
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/* Measure pthread_create() */
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t_start = get_time();
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for (int i = 0; i < ITERATIONS; i++) {
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pthread_t tid;
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pthread_create(&tid, NULL, dummy_thread, NULL);
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pthread_join(tid, NULL);
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}
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t_end = get_time();
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pthread_total = t_end - t_start;
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printf("=== Performance Comparison ===\n");
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printf("Iterations: %d\n", ITERATIONS);
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printf("fork() total time: %.6f s (avg: %.3f us)\n",
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fork_total, fork_total / ITERATIONS * 1000000);
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printf("pthread_create() total time: %.6f s (avg: %.3f us)\n",
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pthread_total, pthread_total / ITERATIONS * 1000000);
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printf("Ratio (fork/pthread): %.2fx\n", fork_total / pthread_total);
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printf("\nExplanation: fork() creates a new process with a copy of the\n");
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printf("entire address space, which is much heavier than pthread_create()\n");
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printf("which only creates a new thread sharing the same address space.\n");
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return 0;
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}
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