我使用struct sigaction做信号量截获,比如SIGHUP,第一次能收到消息并执行回调函数,但是当第二次收到SIGHUP的时候回调函数并没有执行,是我漏掉了什么清理的地方么?
memset(&sa,0,sizeof(struct sigaction)); sa.sa_handler = hup_signal; sigemptyset(&sa.sa_mask); if (sigaction(SIGHUP, &sa, NULL) == -1) { printf("sigaction(%d, SIGHUP) failed", SIGHUP); return 0; }
static void hup_signal(const int sig) { printf("get a hup signal %d\n", sig); }
可能是你系统版本太旧的缘故?
APUE有过说明 One problem with these early versions is that the action for a signal was reset to its default each time the signal occurred.
所以你可以每次调用处理函数后重新安装一下处理函数,比如
void handler(int signal) { //do whatever signal(SIGHUP, handler); }