#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <err.h>
#include <signal.h>

static volatile int	stop;
static pthread_t	td1;
static int		count1;

void *test(void *a)
{
	sigset_t set;

	sigemptyset(&set);
	pthread_sigmask(SIG_SETMASK, &set, NULL);
	int *p = (int *)a;
	while (!stop) {
		++*p;
		getpid();
	}
	return 0;
}

void alarm_handler(int sig)
{
	sigset_t set;

	pthread_sigmask(SIG_SETMASK, NULL, &set);
	if (pthread_self() == td1)
		printf("Caught signal in td1\n");
	else
		printf("Caught signal in main\n");
	printf("Signal mask is 0x%x\n", set.__bits[0]);
	stop = 1;
}

int main()
{
	int err;
	struct sigaction sa; 
	void *rc;

	sa.sa_flags = 0;
	sigfillset(&sa.sa_mask);
	sa.sa_handler = alarm_handler;
	pthread_sigmask(SIG_SETMASK, &sa.sa_mask, NULL);
	sigaction(SIGALRM, &sa, NULL);
	alarm(5);
	printf("Main thread mask is 0x%x\n", sa.sa_mask.__bits[0]);
	err = pthread_create(&td1, NULL, test, &count1);
	if (err)
		errx(1, "pthread_create returns error\n");
	
	pthread_sigmask(SIG_SETMASK, NULL, &sa.sa_mask);
	pthread_join(td1, &rc);
	printf("%d\n", count1/5);
	return 0;
}