#include <pthread.h>
#include <signal.h>

pthread_t td1, td2, td3;

void handler(int sig)
{
	write(1, "sigusr1\n", 8);
}

void *t1(void *a)
{
	int i;

	for (i = 0; i < 10; ++i)
		sleep(1);
	printf("t1 exit...\n");
	return (0);
}

void *t2(void *b)
{
	int ret;

	ret = pthread_join(td1, NULL);
	printf("pthread_join returns: %d\n", ret);
	return (0);
}

int main()
{
	struct sigaction sa;
	int i;


	sa.sa_flags = 0; /* interrupt */
	sa.sa_handler = handler;
	sigemptyset(&sa.sa_mask);
	sigaction(SIGUSR1, &sa, NULL);
	
	pthread_create(&td1, NULL, t1, NULL);
	pthread_create(&td2, NULL, t2, NULL);

	for (i = 0; i < 10; ++i) {
		pthread_kill(td2, SIGUSR1);
		sleep(1);
	}
	pthread_join(td2, NULL);
	return (0);
}