136 lines
3.4 KiB
C
136 lines
3.4 KiB
C
/*
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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#include "config.h"
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#include "guacamole/pool.h"
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#include <stdlib.h>
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guac_pool* guac_pool_alloc(int size) {
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pthread_mutexattr_t lock_attributes;
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guac_pool* pool = malloc(sizeof(guac_pool));
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/* If unable to allocate, just return NULL. */
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if (pool == NULL)
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return NULL;
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/* Initialize empty pool */
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pool->min_size = size;
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pool->active = 0;
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pool->__next_value = 0;
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pool->__head = NULL;
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pool->__tail = NULL;
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/* Init lock */
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pthread_mutexattr_init(&lock_attributes);
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pthread_mutexattr_setpshared(&lock_attributes, PTHREAD_PROCESS_SHARED);
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pthread_mutex_init(&(pool->__lock), &lock_attributes);
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return pool;
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}
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void guac_pool_free(guac_pool* pool) {
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/* Free all ints in pool */
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guac_pool_int* current = pool->__head;
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while (current != NULL) {
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guac_pool_int* old = current;
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current = current->__next;
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free(old);
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}
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/* Destroy lock */
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pthread_mutex_destroy(&(pool->__lock));
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/* Free pool */
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free(pool);
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}
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int guac_pool_next_int(guac_pool* pool) {
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int value;
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/* Acquire exclusive access */
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pthread_mutex_lock(&(pool->__lock));
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pool->active++;
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/* If more integers are needed, return a new one. */
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if (pool->__head == NULL || pool->__next_value < pool->min_size) {
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value = pool->__next_value++;
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pthread_mutex_unlock(&(pool->__lock));
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return value;
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}
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/* Otherwise, remove first integer. */
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value = pool->__head->value;
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/* If only one element exists, reset pool to empty. */
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if (pool->__tail == pool->__head) {
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free(pool->__head);
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pool->__head = NULL;
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pool->__tail = NULL;
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}
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/* Otherwise, advance head. */
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else {
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guac_pool_int* old_head = pool->__head;
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pool->__head = old_head->__next;
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free(old_head);
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}
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/* Return retrieved value. */
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pthread_mutex_unlock(&(pool->__lock));
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return value;
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}
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void guac_pool_free_int(guac_pool* pool, int value) {
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/* Allocate and initialize new returned value */
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guac_pool_int* pool_int = malloc(sizeof(guac_pool_int));
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pool_int->value = value;
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pool_int->__next = NULL;
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/* Acquire exclusive access */
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pthread_mutex_lock(&(pool->__lock));
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pool->active--;
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/* If pool empty, store as sole entry. */
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if (pool->__tail == NULL)
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pool->__head = pool->__tail = pool_int;
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/* Otherwise, append to end of pool. */
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else {
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pool->__tail->__next = pool_int;
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pool->__tail = pool_int;
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}
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/* Value has been freed */
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pthread_mutex_unlock(&(pool->__lock));
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}
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