harvey/sys/src/9/port/watermarks.c

/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

/*
 * high-watermark measurements
 */
#include	"u.h"
#include	"../port/lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"

void
initmark(Watermark *wp, int max, char *name)
{
	memset(wp, 0, sizeof *wp);
	wp->max = max;
	wp->name = name;
}

void
notemark(Watermark *wp, int val)
{
	/* enforce obvious limits */
	if (val < 0)
		val = 0;
	else if (val > wp->max)
		val = wp->max;

	if (val > wp->highwater) {
		wp->highwater = val;
		if (val == wp->max && wp->curr < val)
			wp->hitmax++;
	}
	wp->curr = val;
}

char *
seprintmark(char *buf, char *ebuf, Watermark *wp)
{
	return seprint(buf, ebuf, "%s:\thighwater %d/%d curr %d hitmax %d\n",
		wp->name, wp->highwater, wp->max, wp->curr, wp->hitmax);
}