1/*	$NetBSD: quota.c,v 1.1.1.1 2009/12/13 16:54:13 kardel Exp $	*/
2
3/*
4 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (C) 2000, 2001  Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17 * PERFORMANCE OF THIS SOFTWARE.
18 */
19
20/* Id: quota.c,v 1.18 2007/06/19 23:47:17 tbox Exp */
21
22/*! \file */
23
24#include <config.h>
25
26#include <stddef.h>
27
28#include <isc/quota.h>
29#include <isc/util.h>
30
31isc_result_t
32isc_quota_init(isc_quota_t *quota, int max) {
33	quota->max = max;
34	quota->used = 0;
35	quota->soft = 0;
36	return (isc_mutex_init(&quota->lock));
37}
38
39void
40isc_quota_destroy(isc_quota_t *quota) {
41	INSIST(quota->used == 0);
42	quota->max = 0;
43	quota->used = 0;
44	quota->soft = 0;
45	DESTROYLOCK(&quota->lock);
46}
47
48void
49isc_quota_soft(isc_quota_t *quota, int soft) {
50	LOCK(&quota->lock);
51	quota->soft = soft;
52	UNLOCK(&quota->lock);
53}
54
55void
56isc_quota_max(isc_quota_t *quota, int max) {
57	LOCK(&quota->lock);
58	quota->max = max;
59	UNLOCK(&quota->lock);
60}
61
62isc_result_t
63isc_quota_reserve(isc_quota_t *quota) {
64	isc_result_t result;
65	LOCK(&quota->lock);
66	if (quota->max == 0 || quota->used < quota->max) {
67		if (quota->soft == 0 || quota->used < quota->soft)
68			result = ISC_R_SUCCESS;
69		else
70			result = ISC_R_SOFTQUOTA;
71		quota->used++;
72	} else
73		result = ISC_R_QUOTA;
74	UNLOCK(&quota->lock);
75	return (result);
76}
77
78void
79isc_quota_release(isc_quota_t *quota) {
80	LOCK(&quota->lock);
81	INSIST(quota->used > 0);
82	quota->used--;
83	UNLOCK(&quota->lock);
84}
85
86isc_result_t
87isc_quota_attach(isc_quota_t *quota, isc_quota_t **p)
88{
89	isc_result_t result;
90	INSIST(p != NULL && *p == NULL);
91	result = isc_quota_reserve(quota);
92	if (result == ISC_R_SUCCESS || result == ISC_R_SOFTQUOTA)
93		*p = quota;
94	return (result);
95}
96
97void
98isc_quota_detach(isc_quota_t **p)
99{
100	INSIST(p != NULL && *p != NULL);
101	isc_quota_release(*p);
102	*p = NULL;
103}
104