linux 多线程 原子操作

#include <stdio.h>
#include <pthread.h>
#include <stdatomic.h>

atomic_int counter = ATOMIC_VAR_INIT(0);

void* thread_func(void* arg) {
    for (int i = 0; i < 1000; ++i) {
        atomic_fetch_add(&counter, 1);
    }
    return NULL;
}

int main() {
    pthread_t threads[10];
    for (int i = 0; i < 10; ++i) {
        pthread_create(&threads[i], NULL, thread_func, NULL);
    }
    for (int i = 0; i < 10; ++i) {
        pthread_join(threads[i], NULL);
    }
    printf("Counter: %d\n", atomic_load(&counter));
    return 0;
}

#include <stdio.h>
#include <pthread.h>

int counter = 0;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void* thread_func(void* arg) {
    for (int i = 0; i < 1000; ++i) {
        pthread_mutex_lock(&mutex);
        counter++;
        pthread_mutex_unlock(&mutex);
    }
    return NULL;
}

int main() {
    pthread_t threads[10];
    for (int i = 0; i < 10; ++i) {
        pthread_create(&threads[i], NULL, thread_func, NULL);
    }
    for (int i = 0; i < 10; ++i) {
        pthread_join(threads[i], NULL);
    }
    printf("Counter: %d\n", counter);
    return 0;
}