| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| #ifndef _GUAC_POOL_H |
| #define _GUAC_POOL_H |
| |
| /** |
| * Provides functions and structures for maintaining dynamically allocated and |
| * freed pools of integers. |
| * |
| * @file pool.h |
| */ |
| |
| #include "pool-types.h" |
| |
| #include <pthread.h> |
| |
| struct guac_pool { |
| |
| /** |
| * The minimum number of integers which must have been returned by |
| * guac_pool_next_int before previously-used and freed integers are |
| * allowed to be returned. |
| */ |
| int min_size; |
| |
| /** |
| * The number of integers currently in use. |
| */ |
| int active; |
| |
| /** |
| * The next integer to be released (after no more integers remain in the |
| * pool. |
| */ |
| int __next_value; |
| |
| /** |
| * The first integer in the pool, if any. |
| */ |
| guac_pool_int* __head; |
| |
| /** |
| * The last integer in the pool, if any. |
| */ |
| guac_pool_int* __tail; |
| |
| /** |
| * Lock which is acquired when the pool is being modified or accessed. |
| */ |
| pthread_mutex_t __lock; |
| |
| }; |
| |
| struct guac_pool_int { |
| |
| /** |
| * The integer value of this pool entry. |
| */ |
| int value; |
| |
| /** |
| * The next available (unused) guac_pool_int in the list of |
| * allocated but free'd ints. |
| */ |
| guac_pool_int* __next; |
| |
| }; |
| |
| /** |
| * Allocates a new guac_pool having the given minimum size. |
| * |
| * @param size The minimum number of integers which must have been returned by |
| * guac_pool_next_int before freed integers (previously used |
| * integers) are allowed to be returned. |
| * @return A new, empty guac_pool, having the given minimum size. |
| */ |
| guac_pool* guac_pool_alloc(int size); |
| |
| /** |
| * Frees the given guac_pool. |
| * |
| * @param pool The guac_pool to free. |
| */ |
| void guac_pool_free(guac_pool* pool); |
| |
| /** |
| * Returns the next available integer from the given guac_pool. All integers |
| * returned are non-negative, and are returned in sequences, starting from 0. |
| * This operation is threadsafe. |
| * |
| * @param pool |
| * The guac_pool to retrieve an integer from. |
| * |
| * @return |
| * The next available integer, which may be either an integer not yet |
| * returned by a call to guac_pool_next_int, or an integer which was |
| * previously returned, but has since been freed. |
| */ |
| int guac_pool_next_int(guac_pool* pool); |
| |
| /** |
| * Frees the given integer back into the given guac_pool. The integer given |
| * will be available for future calls to guac_pool_next_int. This operation is |
| * threadsafe. |
| * |
| * @param pool |
| * The guac_pool to free the given integer into. |
| * |
| * @param value |
| * The integer which should be returned to the given pool, such that it can |
| * be received by a future call to guac_pool_next_int. |
| */ |
| void guac_pool_free_int(guac_pool* pool, int value); |
| |
| #endif |
| |