external/bsd/bind/dist/lib/isc/quota.c

   1 /*      $NetBSD: quota.c,v 1.4 2014/12/10 04:37:59 christos 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
  31 isc_result_t
  32 isc_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
  39 void
  40 isc_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
  48 void
  49 isc_quota_soft(isc_quota_t *quota, int soft) {
  50         LOCK(&quota->lock);
  51         quota->soft = soft;
  52         UNLOCK(&quota->lock);
  53 }
  54
  55 void
  56 isc_quota_max(isc_quota_t *quota, int max) {
  57         LOCK(&quota->lock);
  58         quota->max = max;
  59         UNLOCK(&quota->lock);
  60 }
  61
  62 isc_result_t
  63 isc_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
  78 void
  79 isc_quota_release(isc_quota_t *quota) {
  80         LOCK(&quota->lock);
  81         INSIST(quota->used > 0);
  82         quota->used--;
  83         UNLOCK(&quota->lock);
  84 }
  85
  86 isc_result_t
  87 isc_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
  97 void
  98 isc_quota_detach(isc_quota_t **p)
  99 {
 100         INSIST(p != NULL && *p != NULL);
 101         isc_quota_release(*p);
 102         *p = NULL;
 103 }