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/*
* Copyright (c) 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "guarded-list.h"
void
guarded_list_init(struct guarded_list *list)
{
ovs_mutex_init(&list->mutex);
list_init(&list->list);
list->n = 0;
}
void
guarded_list_destroy(struct guarded_list *list)
{
ovs_mutex_destroy(&list->mutex);
}
bool
guarded_list_is_empty(const struct guarded_list *list)
{
bool empty;
ovs_mutex_lock(&list->mutex);
empty = list->n == 0;
ovs_mutex_unlock(&list->mutex);
return empty;
}
/* If 'list' has fewer than 'max' elements, adds 'node' at the end of the list
* and returns the number of elements now on the list.
*
* If 'list' already has at least 'max' elements, returns 0 without modifying
* the list. */
size_t
guarded_list_push_back(struct guarded_list *list,
struct ovs_list *node, size_t max)
{
size_t retval = 0;
ovs_mutex_lock(&list->mutex);
if (list->n < max) {
list_push_back(&list->list, node);
retval = ++list->n;
}
ovs_mutex_unlock(&list->mutex);
return retval;
}
struct ovs_list *
guarded_list_pop_front(struct guarded_list *list)
{
struct ovs_list *node = NULL;
ovs_mutex_lock(&list->mutex);
if (list->n) {
node = list_pop_front(&list->list);
list->n--;
}
ovs_mutex_unlock(&list->mutex);
return node;
}
size_t
guarded_list_pop_all(struct guarded_list *list, struct ovs_list *elements)
{
size_t n;
ovs_mutex_lock(&list->mutex);
list_move(elements, &list->list);
n = list->n;
list_init(&list->list);
list->n = 0;
ovs_mutex_unlock(&list->mutex);
return n;
}
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