| /* 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_THREAD_MUTEX_H |
| #define APR_THREAD_MUTEX_H |
| |
| /** |
| * @file apr_thread_mutex.h |
| * @brief APR Thread Mutex Routines |
| */ |
| |
| #include "apr.h" |
| #include "apr_errno.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif /* __cplusplus */ |
| |
| #if APR_HAS_THREADS || defined(DOXYGEN) |
| |
| /** |
| * @defgroup apr_thread_mutex Thread Mutex Routines |
| * @ingroup APR |
| * @{ |
| */ |
| |
| /** Opaque thread-local mutex structure */ |
| typedef struct apr_thread_mutex_t apr_thread_mutex_t; |
| |
| #define APR_THREAD_MUTEX_DEFAULT 0x0 /**< platform-optimal lock behavior */ |
| #define APR_THREAD_MUTEX_NESTED 0x1 /**< enable nested (recursive) locks */ |
| #define APR_THREAD_MUTEX_UNNESTED 0x2 /**< disable nested locks */ |
| #define APR_THREAD_MUTEX_TIMED 0x4 /**< enable timed locks */ |
| |
| /* Delayed the include to avoid a circular reference */ |
| #include "apr_pools.h" |
| #include "apr_time.h" |
| |
| /** |
| * Create and initialize a mutex that can be used to synchronize threads. |
| * @param mutex the memory address where the newly created mutex will be |
| * stored. |
| * @param flags Or'ed value of: |
| * <PRE> |
| * APR_THREAD_MUTEX_DEFAULT platform-optimal lock behavior. |
| * APR_THREAD_MUTEX_NESTED enable nested (recursive) locks. |
| * APR_THREAD_MUTEX_UNNESTED disable nested locks (non-recursive). |
| * </PRE> |
| * @param pool the pool from which to allocate the mutex. |
| * @warning Be cautious in using APR_THREAD_MUTEX_DEFAULT. While this is the |
| * most optimal mutex based on a given platform's performance characteristics, |
| * it will behave as either a nested or an unnested lock. |
| */ |
| APR_DECLARE(apr_status_t) apr_thread_mutex_create(apr_thread_mutex_t **mutex, |
| unsigned int flags, |
| apr_pool_t *pool); |
| /** |
| * Acquire the lock for the given mutex. If the mutex is already locked, |
| * the current thread will be put to sleep until the lock becomes available. |
| * @param mutex the mutex on which to acquire the lock. |
| */ |
| APR_DECLARE(apr_status_t) apr_thread_mutex_lock(apr_thread_mutex_t *mutex); |
| |
| /** |
| * Attempt to acquire the lock for the given mutex. If the mutex has already |
| * been acquired, the call returns immediately with APR_EBUSY. Note: it |
| * is important that the APR_STATUS_IS_EBUSY(s) macro be used to determine |
| * if the return value was APR_EBUSY, for portability reasons. |
| * @param mutex the mutex on which to attempt the lock acquiring. |
| */ |
| APR_DECLARE(apr_status_t) apr_thread_mutex_trylock(apr_thread_mutex_t *mutex); |
| |
| /** |
| * Attempt to acquire the lock for the given mutex until timeout expires. |
| * If the acquisition time outs, the call returns with APR_TIMEUP. |
| * @param mutex the mutex on which to attempt the lock acquiring. |
| * @param timeout the relative timeout (microseconds). |
| * @note A timeout negative or nul means immediate attempt, returning |
| * APR_TIMEUP without blocking if it the lock is already acquired. |
| */ |
| APR_DECLARE(apr_status_t) apr_thread_mutex_timedlock(apr_thread_mutex_t *mutex, |
| apr_interval_time_t timeout); |
| |
| /** |
| * Release the lock for the given mutex. |
| * @param mutex the mutex from which to release the lock. |
| */ |
| APR_DECLARE(apr_status_t) apr_thread_mutex_unlock(apr_thread_mutex_t *mutex); |
| |
| /** |
| * Destroy the mutex and free the memory associated with the lock. |
| * @param mutex the mutex to destroy. |
| */ |
| APR_DECLARE(apr_status_t) apr_thread_mutex_destroy(apr_thread_mutex_t *mutex); |
| |
| /** |
| * Get the pool used by this thread_mutex. |
| * @return apr_pool_t the pool |
| */ |
| APR_POOL_DECLARE_ACCESSOR(thread_mutex); |
| |
| #endif /* APR_HAS_THREADS */ |
| |
| /** @} */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* ! APR_THREAD_MUTEX_H */ |