quota.c 1.97 KB
Newer Older
1
/*
Brian Wellington's avatar
Brian Wellington committed
2
 * Copyright (C) 2000, 2001  Internet Software Consortium.
3
 *
4 5 6
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
7
 *
8 9 10 11 12 13 14 15
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16
 */
17

Brian Wellington's avatar
Brian Wellington committed
18
/* $Id: quota.c,v 1.11 2001/01/09 21:56:21 bwelling Exp $ */
David Lawrence's avatar
David Lawrence committed
19

20
#include <config.h>
21

Brian Wellington's avatar
Brian Wellington committed
22 23
#include <stddef.h>

24 25 26 27 28 29 30 31 32 33 34 35
#include <isc/quota.h>
#include <isc/util.h>

isc_result_t
isc_quota_init(isc_quota_t *quota, int max) {
	quota->max = max;
	quota->used = 0;
	return (isc_mutex_init(&quota->lock));
}

void
isc_quota_destroy(isc_quota_t *quota) {
36
	INSIST(quota->used == 0);
37 38
	quota->max = -1;
	quota->used = -1;
39
	DESTROYLOCK(&quota->lock);
40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
}

isc_result_t
isc_quota_reserve(isc_quota_t *quota) {
	isc_result_t result;
	LOCK(&quota->lock);
	if (quota->used < quota->max) {
		quota->used++;
		result = ISC_R_SUCCESS;
	} else {
		result = ISC_R_QUOTA;
	}
	UNLOCK(&quota->lock);
	return (result);
}

void
isc_quota_release(isc_quota_t *quota) {
	LOCK(&quota->lock);
	INSIST(quota->used > 0);
	quota->used--;
61
	UNLOCK(&quota->lock);
62 63
}

64 65 66 67 68 69 70 71 72 73 74
isc_result_t
isc_quota_attach(isc_quota_t *quota, isc_quota_t **p)
{
	isc_result_t result;
	INSIST(p != NULL && *p == NULL);
	result = isc_quota_reserve(quota);
	if (result != ISC_R_SUCCESS)
		return (result);
	*p = quota;
	return (ISC_R_SUCCESS);
}
75

76 77 78 79 80 81 82
void
isc_quota_detach(isc_quota_t **p)
{
	INSIST(p != NULL && *p != NULL);
	isc_quota_release(*p);
	*p = NULL;
}