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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/*! \file */
#include <config.h>
#include <stddef.h>
#include <isc/atomic.h>
#include <isc/quota.h>
#include <isc/util.h>
void
isc_quota_init(isc_quota_t *quota, unsigned int max) {
atomic_store("a->max, max);
atomic_store("a->used, 0);
atomic_store("a->soft, 0);
}
void
isc_quota_destroy(isc_quota_t *quota) {
INSIST(atomic_load("a->used) == 0);
atomic_store("a->max, 0);
atomic_store("a->used, 0);
atomic_store("a->soft, 0);
}
void
isc_quota_soft(isc_quota_t *quota, unsigned int soft) {
atomic_store("a->soft, soft);
}
void
isc_quota_max(isc_quota_t *quota, unsigned int max) {
atomic_store("a->max, max);
}
unsigned int
isc_quota_getmax(isc_quota_t *quota) {
return (atomic_load_relaxed("a->max));
}
unsigned int
isc_quota_getsoft(isc_quota_t *quota) {
return (atomic_load_relaxed("a->soft));
}
unsigned int
isc_quota_getused(isc_quota_t *quota) {
return (atomic_load_relaxed("a->used));
}
isc_result_t
isc_quota_reserve(isc_quota_t *quota) {
isc_result_t result;
uint32_t max = atomic_load("a->max);
uint32_t soft = atomic_load("a->soft);
uint32_t used = atomic_fetch_add("a->used, 1);
if (max == 0 || used < max) {
if (soft == 0 || used < soft) {
result = ISC_R_SUCCESS;
} else {
result = ISC_R_SOFTQUOTA;
}
} else {
INSIST(atomic_fetch_sub("a->used, 1) > 0);
result = ISC_R_QUOTA;
}
return (result);
}
void
isc_quota_release(isc_quota_t *quota) {
INSIST(atomic_fetch_sub("a->used, 1) > 0);
}
static isc_result_t
doattach(isc_quota_t *quota, isc_quota_t **p, bool force) {
isc_result_t result;
REQUIRE(p != NULL && *p == NULL);
result = isc_quota_reserve(quota);
if (result == ISC_R_SUCCESS || result == ISC_R_SOFTQUOTA) {
*p = quota;
} else if (result == ISC_R_QUOTA && force) {
/* attach anyway */
atomic_fetch_add("a->used, 1);
*p = quota;
result = ISC_R_SUCCESS;
}
return (result);
}
isc_result_t
isc_quota_attach(isc_quota_t *quota, isc_quota_t **p) {
return (doattach(quota, p, false));
}
isc_result_t
isc_quota_force(isc_quota_t *quota, isc_quota_t **p) {
return (doattach(quota, p, true));
}
void
isc_quota_detach(isc_quota_t **p) {
INSIST(p != NULL && *p != NULL);
isc_quota_release(*p);
*p = NULL;
}
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