quota.c revision 9c3531d72aeaad6c5f01efe6a1c82023e1379e4d
/*
* Copyright (C) 2000 Internet Software Consortium.
*
* 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.
*
* 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.
*/
/* $Id: quota.c,v 1.6 2000/06/22 21:57:07 tale Exp $ */
#include <config.h>
#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) {
INSIST(quota->used == 0);
quota->max = -1;
quota->used = -1;
RUNTIME_CHECK(isc_mutex_destroy(&quota->lock) == ISC_R_SUCCESS);
}
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--;
UNLOCK(&quota->lock);
}
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);
}
void
isc_quota_detach(isc_quota_t **p)
{
INSIST(p != NULL && *p != NULL);
isc_quota_release(*p);
*p = NULL;
}