#include <time.h>
#include <sys/time.h>

int main(int argc, char **argv)
{
	int i, r;
	unsigned long delta;
	struct timeval beg, end;
	struct timespec ts;
	struct timespec rest;
	
	ts.tv_sec  = 0;
	ts.tv_nsec = 900000000;
	
	// > 1 msec
	//
	while (ts.tv_nsec > 1000000)
	{
		r = gettimeofday(&beg, NULL);
		if (r < 0)
			break;
	
		r = nanosleep(&ts, &rest);
		if (r < 0)
			break;

		r = gettimeofday(&end, NULL);
		if (r < 0)
			break;
	
		delta = (end.tv_sec - beg.tv_sec) * 1000 * 1000;
		delta = delta + (end.tv_usec - beg.tv_usec);
		
		printf("requested: %lu us, got: %lu us, diff: %li us\n",
			(ts.tv_nsec / 1000),
			delta,
			delta - (ts.tv_nsec / 1000));
			
		// 1 msec
		//
		ts.tv_nsec -= 1000000;
	}

	printf("ts.tv_nsec: %lu\n", ts.tv_nsec);	

	return 0;
}