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-rw-r--r--lib/isc/quota.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/lib/isc/quota.c b/lib/isc/quota.c
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+/*
+ * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 2000, 2001 Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL ISC 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 1.18 2007/06/19 23:47:17 tbox Exp $ */
+
+/*! \file */
+
+#include <config.h>
+
+#include <stddef.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;
+ quota->soft = 0;
+ return (isc_mutex_init(&quota->lock));
+}
+
+void
+isc_quota_destroy(isc_quota_t *quota) {
+ INSIST(quota->used == 0);
+ quota->max = 0;
+ quota->used = 0;
+ quota->soft = 0;
+ DESTROYLOCK(&quota->lock);
+}
+
+void
+isc_quota_soft(isc_quota_t *quota, int soft) {
+ LOCK(&quota->lock);
+ quota->soft = soft;
+ UNLOCK(&quota->lock);
+}
+
+void
+isc_quota_max(isc_quota_t *quota, int max) {
+ LOCK(&quota->lock);
+ quota->max = max;
+ UNLOCK(&quota->lock);
+}
+
+isc_result_t
+isc_quota_reserve(isc_quota_t *quota) {
+ isc_result_t result;
+ LOCK(&quota->lock);
+ if (quota->max == 0 || quota->used < quota->max) {
+ if (quota->soft == 0 || quota->used < quota->soft)
+ result = ISC_R_SUCCESS;
+ else
+ result = ISC_R_SOFTQUOTA;
+ quota->used++;
+ } 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 || result == ISC_R_SOFTQUOTA)
+ *p = quota;
+ return (result);
+}
+
+void
+isc_quota_detach(isc_quota_t **p)
+{
+ INSIST(p != NULL && *p != NULL);
+ isc_quota_release(*p);
+ *p = NULL;
+}