Linux SIGABRT和abort()函数

void abort(void)         /* POSIX-style abort() function */

{

    sigset_t            mask;

    struct sigaction    action;



    /* Caller can't ignore SIGABRT, if so reset to default */

    sigaction(SIGABRT, NULL, &action);

    if (action.sa_handler == SIG_IGN) {

        action.sa_handler = SIG_DFL;

        sigaction(SIGABRT, &action, NULL);

    }

    if (action.sa_handler == SIG_DFL)

        fflush(NULL);           /* flush all open stdio streams */



    /* Caller can't block SIGABRT; make sure it's unblocked */

    sigfillset(&mask);

    sigdelset(&mask, SIGABRT);  /* mask has only SIGABRT turned off */

    sigprocmask(SIG_SETMASK, &mask, NULL);

    kill(getpid(), SIGABRT);    /* send the signal */



    /* If we're here, process caught SIGABRT and returned */

    fflush(NULL);               /* flush all open stdio streams */ //测试下来并没有flush io

    action.sa_handler = SIG_DFL;

    sigaction(SIGABRT, &action, NULL);  /* reset to default */

    sigprocmask(SIG_SETMASK, &mask, NULL);  /* just in case ... */

    kill(getpid(), SIGABRT);                /* and one more time */

    exit(1);    /* this should never be executed ... */

}

abort(void)实现

1. 它保证该信号不能被忽略，也保证该信号不能被阻塞，
2. 如果有对SIGABRT注册了捕获函数，那么会先执行捕获函数
3. 捕获函数执行后如果依然进程没有退出，那么恢复捕获函数为默认（终止），然后再次发送SIGABRT给进程。

Linux SIGABRT和abort()函数实现