Yi-Chao Chen's wiki

Measure Time

#include <sys/time.h>
#define DIFF_T(a,b) \
	(1+ 1000000*(a.tv_sec - b.tv_sec) + (a.tv_usec - b.tv_usec) )
#define TICK(t) \
	{struct timeval x ; \
	gettimeofday(&x, NULL) ; \
	t = x.tv_usec + 1000000* (x.tv_sec & 0xff ) ; \
	}
#define TOCK(t) \
	{ u_long t1 ; TICK(t1) ; \
	  if (t1 < t) t = 256000000 + t1 - t ; \
	  else t = t1 - t ;}
u_long ticks;	/* vars for timekeeping */


TICK(ticks);
/* do something here */
TOCK(ticks);
printf("spend time: %d\n", ticks);