Edit File: apr_reslist.h
/* 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 APR_RESLIST_H #define APR_RESLIST_H /** * @file apr_reslist.h * @brief APR-UTIL Resource List Routines */ #include "apr.h" #include "apu.h" #include "apr_pools.h" #include "apr_errno.h" #include "apr_time.h" /** * @defgroup APR_Util_RL Resource List Routines * @ingroup APR_Util * @{ */ #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /** Opaque resource list object */ typedef struct apr_reslist_t apr_reslist_t; /* Generic constructor called by resource list when it needs to create a * resource. * @param resource opaque resource * @param params flags * @param pool Pool */ typedef apr_status_t (*apr_reslist_constructor)(void **resource, void *params, apr_pool_t *pool); /* Generic destructor called by resource list when it needs to destroy a * resource. * @param resource opaque resource * @param params flags * @param pool Pool */ typedef apr_status_t (*apr_reslist_destructor)(void *resource, void *params, apr_pool_t *pool); /* Cleanup order modes */ #define APR_RESLIST_CLEANUP_DEFAULT 0 /**< default pool cleanup */ #define APR_RESLIST_CLEANUP_FIRST 1 /**< use pool pre cleanup */ /** * Create a new resource list with the following parameters: * @param reslist An address where the pointer to the new resource * list will be stored. * @param min Allowed minimum number of available resources. Zero * creates new resources only when needed. * @param smax Resources will be destroyed during reslist maintenance to * meet this maximum restriction as they expire (reach their ttl). * @param hmax Absolute maximum limit on the number of total resources. * @param ttl If non-zero, sets the maximum amount of time in microseconds an * unused resource is valid. Any resource which has exceeded this * time will be destroyed, either when encountered by * apr_reslist_acquire() or during reslist maintenance. * @param con Constructor routine that is called to create a new resource. * @param de Destructor routine that is called to destroy an expired resource. * @param params Passed to constructor and deconstructor * @param pool The pool from which to create this resource list. Also the * same pool that is passed to the constructor and destructor * routines. * @remark If APR has been compiled without thread support, hmax will be * automatically set to 1 and values of min and smax will be forced to * 1 for any non-zero value. */ APU_DECLARE(apr_status_t) apr_reslist_create(apr_reslist_t **reslist, int min, int smax, int hmax, apr_interval_time_t ttl, apr_reslist_constructor con, apr_reslist_destructor de, void *params, apr_pool_t *pool); /** * Destroy the given resource list and all resources controlled by * this list. * FIXME: Should this block until all resources become available, * or maybe just destroy all the free ones, or maybe destroy * them even though they might be in use by something else? * Currently it will abort if there are resources that haven't * been released, so there is an assumption that all resources * have been released to the list before calling this function. * @param reslist The reslist to destroy */ APU_DECLARE(apr_status_t) apr_reslist_destroy(apr_reslist_t *reslist); /** * Retrieve a resource from the list, creating a new one if necessary. * If we have met our maximum number of resources, we will block * until one becomes available. * @param reslist The resource list. * @param resource An address where the pointer to the resource * will be stored. */ APU_DECLARE(apr_status_t) apr_reslist_acquire(apr_reslist_t *reslist, void **resource); /** * Return a resource back to the list of available resources. * @param reslist The resource list. * @param resource The resource to return to the list. */ APU_DECLARE(apr_status_t) apr_reslist_release(apr_reslist_t *reslist, void *resource); /** * Set the timeout the acquire will wait for a free resource * when the maximum number of resources is exceeded. * @param reslist The resource list. * @param timeout Timeout to wait. The zero waits forever. */ APU_DECLARE(void) apr_reslist_timeout_set(apr_reslist_t *reslist, apr_interval_time_t timeout); /** * Return the number of outstanding resources. * @param reslist The resource list. */ APU_DECLARE(apr_uint32_t) apr_reslist_acquired_count(apr_reslist_t *reslist); /** * Invalidate a resource in the pool - e.g. a database connection * that returns a "lost connection" error and can't be restored. * Use this instead of apr_reslist_release if the resource is bad. * @param reslist The resource list. * @param resource The resource to invalidate. */ APU_DECLARE(apr_status_t) apr_reslist_invalidate(apr_reslist_t *reslist, void *resource); /** * Perform routine maintenance on the resource list. This call * may instantiate new resources or expire old resources. * @param reslist The resource list. */ APU_DECLARE(apr_status_t) apr_reslist_maintain(apr_reslist_t *reslist); /** * Set reslist cleanup order. * @param reslist The resource list. * @param mode Cleanup order mode * <PRE> * APR_RESLIST_CLEANUP_DEFAULT default pool cleanup order * APR_RESLIST_CLEANUP_FIRST use pool pre cleanup * </PRE> * @remark If APR_RESLIST_CLEANUP_FIRST is used the destructors will * be called before child pools of the pool used to create the reslist * are destroyed. This allows to explicitly destroy the child pools * inside reslist destructors. */ APU_DECLARE(void) apr_reslist_cleanup_order_set(apr_reslist_t *reslist, apr_uint32_t mode); #ifdef __cplusplus } #endif /** @} */ #endif /* ! APR_RESLIST_H */
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