c – 我需要实现一种睡眠方式,直到它有工作要做

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

static sem_t s_sem;
static int iAlive = 1;

void* thFunc(void *param)
{
    printf("%s : ENTER \n",__FUNCTION__);
    while(iAlive)
    {
        printf("%s : waiting \n",__FUNCTION__);
        sem_wait(&s_sem);

        printf("%s : got a signal - doing something \n",__FUNCTION__);
        sleep(1);
    }

    printf("%s : EXIT \n",__FUNCTION__);
    return 0;
}

int main()
{
    pthread_t thread;
    sem_init(&s_sem,0);

    if(0 != pthread_create(&thread,NULL,thFunc,NULL))
    {
        printf("%s : pthread_create Failed \n",__FUNCTION__);
        return -1;
    }

    while ( getchar() != 'q' )
    {
        printf("%s : sending signal \n",__FUNCTION__);
        sem_post(&s_sem);
    }

    iAlive = 0;
    sem_post(&s_sem);
    pthread_join(thread,NULL);
    sem_destroy(&s_sem);

    return 0;
}

如果需要超时,可以使用sem_timedwait替换sem_wait.