pthread_mutex_t 和 alarm 一起用为什么就无效了？

[社会栋梁]

#include<pthread.h>
#include<signal.h>
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/time.h>

static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

void sig_handler(int signo)
{
         printf("enter mutex before\n");
         pthread_mutex_lock(&mutex);
         unsigned long long  n = 0;
         while(n<10000000000)
         {
        	    if(n%10000 == 0)
        		printf("1");
        	    n++;
         }
          pthread_mutex_unlock(&mutex);
          printf("leave mutex\n");
	  alarm(1);

}

void *pthread_func(void * arg)
{
          alarm(1);
          while(1)
          {
         	pthread_mutex_lock(&mutex);
          	printf("enter mutex thread +++++++\n");
        	unsigned long long  n = 0;
        	while(n<10000000000)
        	{
        		if(n%10000 == 0)
        			printf("0");
        		n++;
        	}
          	pthread_mutex_unlock(&mutex);
          	printf("leave mutex thread ------\n");
          }
          
}
 
int main(int argc, char **argv)
{
          pthread_t tid, tid_1;
          int retval;
 
          signal(SIGALRM, sig_handler);
         
          if((retval = pthread_create(&tid, NULL, pthread_func, NULL)) < 0)
          {
                   perror("pthread_create");
                   exit(-1);
          }
         
          sigset_t sigset;
          sigemptyset(&sigset);
          sigaddset(&sigset, SIGALRM);
          pthread_sigmask(SIG_SETMASK,&sigset,NULL);
 
          while(1)
          {
                   printf("main pthread\n");
                   sleep(10);
          }
          return 0;
}

结果：
main pthread
enter mutex thread +++++++
0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000enter mutex before
main pthread
main pthread
main pthread
。。。

为什么一直没有printf("leave mutex thread ------\n");就中断了呢？

[sundq12]

http://www.cppblog.com/mysileng/archive/2013/01/05/196971.html看看这个文章就知道怎么回事了，要学会google嘛。

[空的]

void *pthread_func(void * arg) 锁了 然后 print 0 1秒过了 触发SIGALRM void sig_handler(int signo) 再请求锁 好了，竞争了就堵死了

[missheaven2011]

引用 1 楼 sundq12 的回复:

http://www.cppblog.com/mysileng/archive/2013/01/05/196971.html看看这个文章就知道怎么回事了，要学会google嘛。

学习了