Linux C语言:开启一个专门用来接收信号的子线程。

以下这个小程序实现这个功能。

上代码：

#include
#include
#include
#include
#include
#include

//程序发生了严重的错误，输出
void error_quit(const char *str)
{
fprintf(stderr, "%s\n", str);
exit(1);
}

//专门用于接收信号的线程函数
static void *sig_thread(void *arg)
{
printf("subthread tid: %u\n", (unsigned int)pthread_self());
sigset_t *set = (sigset_t *) arg;
int res, sig;

while( 1 )
{
//挂起程序，等待信号的到来
res = sigwait(set, &sig);
if( res != 0 )
error_quit("sigwait error");
printf("tid: %u ", (unsigned int)pthread_self());

if( SIGALRM == sig )
{
printf("time out\n");
//循环设置闹钟信号，每5秒响一次
alarm(5);
}
else if( SIGTSTP == sig )
{
printf("catch quit signal\n");
break;
}
else if( SIGINT == sig )
{
printf("quit program\n");
exit(0);
}
}
}

int main(int argc, char *argv[])
{
pthread_t stid;
sigset_t set;
int res;
printf("main pid: %u, tid: %u\n",
(unsigned int)getpid(),
(unsigned int)pthread_self());

//设置要被线程处理的信号集
sigemptyset(&set);
sigaddset(&set, SIGINT);
sigaddset(&set, SIGTSTP);
sigaddset(&set, SIGALRM);
res = pthread_sigmask(SIG_BLOCK, &set, NULL);
if( res != 0 )
error_quit("pthread sigmask error");

alarm(1);
//开启信号处理线程，并让主线程等待其退出后才退出
res = pthread_create(&stid, NULL, &sig_thread, (void *) &set);
if (res != 0)
error_quit("pthread_create error");
pthread_join(stid, NULL);
printf("finish\n");

return 0;
}