线程支持

#include <threads.h>
#include <stdio.h>

int thread_func(void *arg)
{
    int num = *(int *)arg;
    printf("Thread %d running\n", num);
    return 0;
}

int main(void)
{
    thrd_t thread;
    int arg = 1;
    
    if (thrd_create(&thread, thread_func, &arg) == thrd_success) {
        thrd_join(thread, NULL);    /* 等待线程结束 */
    }
    
    return 0;
}

#include <threads.h>

static mtx_t mutex;
static int counter = 0;

int increment(void *arg)
{
    for (int i = 0; i < 1000; i++) {
        mtx_lock(&mutex);
        counter++;
        mtx_unlock(&mutex);
    }
    return 0;
}

int main(void)
{
    mtx_init(&mutex, mtx_plain);
    
    thrd_t t1, t2;
    thrd_create(&t1, increment, NULL);
    thrd_create(&t2, increment, NULL);
    
    thrd_join(t1, NULL);
    thrd_join(t2, NULL);
    
    printf("Counter: %d\n", counter);   /* 2000 */
    
    mtx_destroy(&mutex);
    return 0;
}

#include <threads.h>

static mtx_t mutex;
static cnd_t cond;
static int ready = 0;

int worker(void *arg)
{
    mtx_lock(&mutex);
    while (!ready) {
        cnd_wait(&cond, &mutex);    /* 等待条件 */
    }
    printf("Worker proceeding\n");
    mtx_unlock(&mutex);
    return 0;
}

int main(void)
{
    mtx_init(&mutex, mtx_plain);
    cnd_init(&cond);
    
    thrd_t worker_thread;
    thrd_create(&worker_thread, worker, NULL);
    
    /* 模拟工作 */
    thrd_sleep(&(struct timespec){.tv_sec = 1}, NULL);
    
    mtx_lock(&mutex);
    ready = 1;
    cnd_signal(&cond);              /* 通知等待线程 */
    mtx_unlock(&mutex);
    
    thrd_join(worker_thread, NULL);
    
    mtx_destroy(&mutex);
    cnd_destroy(&cond);
    return 0;
}

_Thread_local int thread_local_var;     /* C11 */

/* 或 */
thread_local int tls_var;               /* <threads.h> 宏 */

/* 如果编译器不支持 C11 threads */
#ifdef __STDC_NO_THREADS__
    /* 使用平台特定 API */
    #include <pthread.h>
    /* ... */
#else
    #include <threads.h>
    /* ... */
#endif

mtx_lock(&mutex);
/* 操作 */
if (error())
    return -1;                  /* 错误：未解锁就返回 */
mtx_unlock(&mutex);

/* 正确 */
mtx_lock(&mutex);
/* 操作 */
mtx_unlock(&mutex);
if (error())
    return -1;

/* 错误 */
if (!ready) {                   /* 应该用 while */
    cnd_wait(&cond, &mutex);
}

/* 正确 */
while (!ready) {                /* 防止虚假唤醒 */
    cnd_wait(&cond, &mutex);
}