/*
** sigusr.c -- demo sig_atomic_t
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>

volatile sig_atomic_t got_usr1;

void sigusr1_handler(int sig)
{
	got_usr1 = 1;
}

int main(void)
{
	struct sigaction sa;

	got_usr1 = 0;

	sa.sa_handler = sigusr1_handler;
	sa.sa_flags = 0;
	sigemptyset(&sa.sa_mask);

	if (sigaction(SIGUSR1, &sa, NULL) == -1) {
		perror("sigaction");
		exit(1);
	}

	while (!got_usr1) {
		printf("PID %d: working hard...\n", getpid());
		sleep(1);
	}

	printf("Done in by SIGUSR1!\n");

	return 0;
}