Wildan M
64 lines
1.3 KiB
C
64 lines
1.3 KiB
C
/// test mutex inside fork
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <pthread.h>
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#include <sys/wait.h>
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#include "test_helpers.h"
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#define NUM_THREADS 4
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#define ITERATIONS 3
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pthread_mutex_t global_lock;
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void* thread_func(void* arg) {
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long tid = (long)arg;
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for (int i = 0; i < ITERATIONS; i++) {
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printf("thread %ld loop %i lock\n", tid, i);
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pthread_mutex_lock(&global_lock);
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pid_t pid = fork();
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if (pid < 0) {
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perror("Fork failed");
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pthread_mutex_unlock(&global_lock);
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pthread_exit(NULL);
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}
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if (pid == 0) {
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_exit(0);
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} else {
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printf("thread %ld unlock\n", tid);
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pthread_mutex_unlock(&global_lock);
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waitpid(pid, NULL, 0);
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}
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usleep(1000);
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}
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return NULL;
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}
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int main() {
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pthread_t threads[NUM_THREADS];
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int status;
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pthread_mutex_init(&global_lock, NULL);
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for (long i = 0; i < NUM_THREADS; i++) {
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status = pthread_create(&threads[i], NULL, thread_func, (void*)i);
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ERROR_IF(pthread_create, status, != 0);
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}
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for (int i = 0; i < NUM_THREADS; i++) {
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pthread_join(threads[i], NULL);
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}
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pthread_mutex_destroy(&global_lock);
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return 0;
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}
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