| /* 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" |
| |
| #if APR_HAS_THREADS |
| |
| /** |
| * @defgroup APR_Util_RL Resource List Routines |
| * @ingroup APR_Util |
| * @{ |
| * @warning |
| * <strong><em>Resource list data types and routines are only available when |
| * threads are enabled (i.e. APR_HAS_THREADS is not zero).</em></strong> |
| */ |
| |
| #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 param 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 param flags |
| * @param pool Pool |
| */ |
| typedef apr_status_t (*apr_reslist_destructor)(void *resource, void *params, |
| apr_pool_t *pool); |
| |
| /** |
| * 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 to meet this maximum |
| * restriction as they expire. |
| * @param hmax Absolute maximum limit on the number of total resources. |
| * @param ttl If non-zero, sets the maximum amount of time a resource |
| * may be available while exceeding the soft limit. |
| * @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 resoure list. Also the |
| * same pool that is passed to the constructor and destructor |
| * routines. |
| * @warning If you're creating a sub-pool of the pool passed into this |
| * function in your constructor, you will need to follow some rules |
| * when it comes to destruction of that sub-pool, as calling |
| * apr_pool_destroy() outright on it in your destructor may create |
| * double free situations. That is because by the time destructor is |
| * called, the sub-pool may have already been destroyed. This also |
| * means that in the destructor, memory from the sub-pool should be |
| * treated as invalid. For examples of how to do this correctly, see |
| * mod_dbd of Apache 2.2 and memcache support in APR Util 1.3. |
| */ |
| 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. |
| */ |
| APU_DECLARE(apr_status_t) apr_reslist_acquire(apr_reslist_t *reslist, |
| void **resource); |
| |
| /** |
| * Return a resource back to the list of available resources. |
| */ |
| 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 forewer. |
| */ |
| 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. |
| */ |
| APU_DECLARE(apr_status_t) apr_reslist_invalidate(apr_reslist_t *reslist, |
| void *resource); |
| |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| /** @} */ |
| |
| #endif /* APR_HAS_THREADS */ |
| |
| #endif /* ! APR_RESLIST_H */ |