minix/lib/libsys/timing.c

#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/minlib.h>

#define HIGHCOUNT	0
#define LOWCOUNT	1

#define START		0
#define END		1

void util_timer_start(util_timingdata_t *timingdata, char *name)
{
	size_t i;

	if(timingdata->names[0] == '\0') {
		for(i = 0; i < sizeof(timingdata->names) && *name; i++)
			timingdata->names[i] = *name++;
		timingdata->names[sizeof(timingdata->names)-1] = '\0';
	}

	if (timingdata->starttimes[HIGHCOUNT]) {
		panic("restart timer?");
		return;
	}

	read_tsc((u32_t *) &timingdata->starttimes[HIGHCOUNT],
		 (u32_t *) &timingdata->starttimes[LOWCOUNT]);
}

void util_timer_end(util_timingdata_t *timingdata)
{
	unsigned long h, l, d = 0;
	int bin;

	read_tsc((u32_t *) &h, (u32_t *) &l);
	if (!timingdata->starttimes[HIGHCOUNT]) {
		panic("timer stopped but not started");
		return;
	}
	if (timingdata->starttimes[HIGHCOUNT] == h) {
		d = (l - timingdata->starttimes[LOWCOUNT]);
	} else if (timingdata->starttimes[HIGHCOUNT] == h-1 &&
		timingdata->starttimes[LOWCOUNT] > l) {
		d = ((ULONG_MAX - timingdata->starttimes[LOWCOUNT]) + l);
	} else {
		timingdata->misses++;
		return;
	}
	timingdata->starttimes[HIGHCOUNT] = 0;
	if (!timingdata->lock_timings_range[START] ||
		d < timingdata->lock_timings_range[START] ||
		d > timingdata->lock_timings_range[END]) {
		int t;
		if (!timingdata->lock_timings_range[START] ||
			d < timingdata->lock_timings_range[START])
			timingdata->lock_timings_range[START] = d;
		if (!timingdata->lock_timings_range[END] ||
			d > timingdata->lock_timings_range[END])
			timingdata->lock_timings_range[END] = d;
		for(t = 0; t < TIMING_POINTS; t++)
			timingdata->lock_timings[t] = 0;
		timingdata->binsize =
		 (timingdata->lock_timings_range[END] -
		 timingdata->lock_timings_range[START])/(TIMING_POINTS+1);
		if (timingdata->binsize < 1)
		  timingdata->binsize = 1;
		timingdata->resets++;
	}
	bin = (d-timingdata->lock_timings_range[START]) /
		timingdata->binsize;
	if (bin < 0 || bin >= TIMING_POINTS) {
		/* not serious, but can't happen, so shouldn't */
		panic("bin out of range: %d", bin);
	} else {
		timingdata->lock_timings[bin]++;
		timingdata->measurements++;
	}

	return;
}