none/tests/pending.c

/* 
   Test pending signals

   1. Signals should remain pending while blocked, and not delivered early
   
   2. When unblocking the signal, the signal should have been delivered
      by the time sigprocmask syscall is complete.
 */
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

static volatile int gotsig = 0;
static volatile int early = 1;

static void handler(int sig)
{
	printf("4: got signal %d\n", sig);

	if (sig != SIGUSR1) {
		fprintf(stderr, "FAILED: got signal %d instead\n", sig);
		exit(1);
	}

	if (early) {
		fprintf(stderr, "FAILED: signal delivered early (in handler)\n");
		exit(1);
	}

	gotsig = 1;
}

int main()
{
	sigset_t all;
	sigset_t sigusr1;
	siginfo_t info;
	
	sigfillset(&all);
	sigemptyset(&sigusr1);
	sigaddset(&sigusr1, SIGUSR1);

	sigprocmask(SIG_BLOCK, &all, NULL);

	signal(SIGUSR1, handler);
	signal(SIGUSR2, handler);

	printf("1: sending signal\n");
	kill(getpid(), SIGUSR1);
	kill(getpid(), SIGUSR2);

	printf("2: sleeping\n");
	sleep(1);

	if (gotsig) {
		fprintf(stderr, "FAILED: signal delivered too early\n");
		return 1;
	}

	printf("3: unblocking\n");
	early = 0;	
	sigprocmask(SIG_UNBLOCK, &sigusr1, NULL);

	printf("5: unblocked...\n");
	if (!gotsig) {
		fprintf(stderr, "FAILED: signal not delivered\n");
		return 1;
	}

	printf("6: checking SIGUSR2 still pending...\n");
	if (sigwaitinfo(&all, &info) == -1) {
		perror("FAILED: sigwaitinfo failed");
		return 1;
	}
	if (info.si_signo != SIGUSR2) {
		fprintf(stderr, "FAILED: SIGUSR2 not still pending; got signal %d\n", 
			info.si_signo);
		return 1;
	}

	printf("OK\n");
	return 0;
}