函数pthread_mutex_timedlock当线程试图获取一个已加锁的互斥变量时，pthread_mutex_timedlock互斥量原语允许绑定线程阻塞的时间。pthread_mutex_timedlock函数与pthread_mutex_lock是基本等价的，但是在达到超时时间值时，pthread_mutex_timedlock不会对互斥量进行加锁，而是返回错误码ETIMEDOUT。#include
     
      #include
      
       int pthread_mutex_timedlock(pthread_mutex_t *restrict mutex,const struct timespec *restrict tsptr);超时指定愿意等待的绝对时间（与相对时间对比而言，指定在时间x之前可以阻塞等待，而不是说愿意阻塞Y秒）。这个超时时间是用timespec结构来表示的，它用秒和纳秒来描述时间。
      
     

 

#include"apue.h"#include 
     
      #include
      
       intmain(void){    int err;    struct timespec tout;    struct tm *tmp;    char buf[64];    pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;    pthread_mutex_lock(&lock);    printf("mutex is locked\n");    clock_gettime(CLOCK_REALTIME, &tout);    tmp = localtime(&tout.tv_sec);    strftime(buf, sizeof(buf), "%r", tmp);    printf("current time is %s\n", buf);    pthread_mutex_unlock(&lock);//这个是我自己加的，为了测试这个程序    tout.tv_sec += 10;    /* 10 seconds from now */    /* caution: this could lead to deadlock */    err = pthread_mutex_timedlock(&lock, &tout);    clock_gettime(CLOCK_REALTIME, &tout);    tmp = localtime(&tout.tv_sec);    strftime(buf, sizeof(buf), "%r", tmp);    printf("the time is now %s\n", buf);    if (err == 0)        printf("mutex locked again!\n");    else        printf("can't lock mutex again: %s\n", strerror(err));    exit(0);}