#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>

static struct {
	const int timer_type;
	const int signal;
	volatile sig_atomic_t count;
} timer_tests[] = {	/* from slowest to fastest */
	{ ITIMER_VIRTUAL,	SIGVTALRM	},
	{ ITIMER_PROF,		SIGPROF		},
	{ ITIMER_REAL,		SIGALRM		},
};

static int count;
static void timer_tick(int sig)
{
	count++;
}

int main()
{
	struct itimerval tv = {
		.it_interval = {
			.tv_sec = 0,
			.tv_usec = 100000
		},
		.it_value = {
			.tv_sec = 0,
			.tv_usec = 100
		},
	};
	int i = 0;
	time_t start;

	if (signal(timer_tests[i].signal, timer_tick) == SIG_ERR)
		exit(1);

	if (setitimer(timer_tests[i].timer_type, &tv, NULL) < 0)
		exit(1);

	start = time(NULL);
	for (;;)
		if (time(NULL) - start > 10)
			break;

	return 0;
}