testeintr.c

让你了解Unix进程间的通信是如何实现的

#include	"unpipc.h"

#define	NAME	"testeintr"

static void	sig_alrm(int);

int
main(int argc, char **argv)
{
	sem_t	*sem1, sem2;

		/* 4first test a named semaphore */
	sem_unlink(Px_ipc_name(NAME));
	sem1 = Sem_open(Px_ipc_name(NAME), O_RDWR | O_CREAT | O_EXCL,
					FILE_MODE, 0);

	Signal(SIGALRM, sig_alrm);
	alarm(2);
	if (sem_wait(sem1) == 0)
		printf("sem_wait returned 0?\n");
	else
		err_ret("sem_wait error");
	Sem_close(sem1);

		/* 4now a memory-based semaphore with process scope */
	Sem_init(&sem2, 1, 0);
	alarm(2);
	if (sem_wait(&sem2) == 0)
		printf("sem_wait returned 0?\n");
	else
		err_ret("sem_wait error");
	Sem_destroy(&sem2);

	exit(0);
}

static void
sig_alrm(int signo)
{
	printf("SIGALRM caught\n");
	return;
}