#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <signal.h>

/* macro that simplifies handling errors with function calls */
#define ACT_WARN	0
#define ACT_STOP	1
#define CALL(ACT,FUNC,...)        \
do {                              \
    if ( FUNC ( __VA_ARGS__ ) ) { \
        perror ( #FUNC );         \
        if ( ACT == ACT_STOP )    \
			exit (1);             \
    }                             \
} while(0)

static int act[2] = { 0, 0 };

static void alarm_thread ( union sigval val )
{
	printf ( "Timer %d [%d]\n", val.sival_int, ++act[val.sival_int-1] );

	return;
}

int main ()
{
	timer_t timer1, timer2;
	struct sigevent event;
	struct itimerspec period;
	struct timespec t;

	event.sigev_notify = SIGEV_THREAD;
	event.sigev_notify_function = alarm_thread;
	event.sigev_notify_attributes = NULL;

	event.sigev_value.sival_int = 1;
	CALL ( ACT_STOP, timer_create, CLOCK_REALTIME, &event, &timer1 );

	event.sigev_value.sival_int = 2;
	CALL ( ACT_STOP, timer_create, CLOCK_REALTIME, &event, &timer2 );

	period.it_value.tv_sec = period.it_interval.tv_sec = 1;
	period.it_value.tv_nsec = period.it_interval.tv_nsec = 0;
	CALL ( ACT_STOP, timer_settime, timer1, 0, &period, NULL );

	period.it_value.tv_sec = period.it_interval.tv_sec = 2;
	CALL ( ACT_STOP, timer_settime, timer2, 0, &period, NULL );

	t.tv_sec = 10;
	t.tv_nsec = 0;
	nanosleep ( &t, NULL );

	return 0;
}