github.com/krum110487/go-htaccess@v0.0.0-20240316004156-60641c8e7598/tests/data/apache_2_2_34/include/apr_thread_mutex.h (about)

     1  /* Licensed to the Apache Software Foundation (ASF) under one or more
     2   * contributor license agreements.  See the NOTICE file distributed with
     3   * this work for additional information regarding copyright ownership.
     4   * The ASF licenses this file to You under the Apache License, Version 2.0
     5   * (the "License"); you may not use this file except in compliance with
     6   * the License.  You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  #ifndef APR_THREAD_MUTEX_H
    18  #define APR_THREAD_MUTEX_H
    19  
    20  /**
    21   * @file apr_thread_mutex.h
    22   * @brief APR Thread Mutex Routines
    23   */
    24  
    25  #include "apr.h"
    26  #include "apr_errno.h"
    27  
    28  #ifdef __cplusplus
    29  extern "C" {
    30  #endif /* __cplusplus */
    31  
    32  #if APR_HAS_THREADS || defined(DOXYGEN)
    33  
    34  /**
    35   * @defgroup apr_thread_mutex Thread Mutex Routines
    36   * @ingroup APR 
    37   * @{
    38   */
    39  
    40  /** Opaque thread-local mutex structure */
    41  typedef struct apr_thread_mutex_t apr_thread_mutex_t;
    42  
    43  #define APR_THREAD_MUTEX_DEFAULT  0x0   /**< platform-optimal lock behavior */
    44  #define APR_THREAD_MUTEX_NESTED   0x1   /**< enable nested (recursive) locks */
    45  #define APR_THREAD_MUTEX_UNNESTED 0x2   /**< disable nested locks */
    46  
    47  /* Delayed the include to avoid a circular reference */
    48  #include "apr_pools.h"
    49  
    50  /**
    51   * Create and initialize a mutex that can be used to synchronize threads.
    52   * @param mutex the memory address where the newly created mutex will be
    53   *        stored.
    54   * @param flags Or'ed value of:
    55   * <PRE>
    56   *           APR_THREAD_MUTEX_DEFAULT   platform-optimal lock behavior.
    57   *           APR_THREAD_MUTEX_NESTED    enable nested (recursive) locks.
    58   *           APR_THREAD_MUTEX_UNNESTED  disable nested locks (non-recursive).
    59   * </PRE>
    60   * @param pool the pool from which to allocate the mutex.
    61   * @warning Be cautious in using APR_THREAD_MUTEX_DEFAULT.  While this is the
    62   * most optimal mutex based on a given platform's performance characteristics,
    63   * it will behave as either a nested or an unnested lock.
    64   */
    65  APR_DECLARE(apr_status_t) apr_thread_mutex_create(apr_thread_mutex_t **mutex,
    66                                                    unsigned int flags,
    67                                                    apr_pool_t *pool);
    68  /**
    69   * Acquire the lock for the given mutex. If the mutex is already locked,
    70   * the current thread will be put to sleep until the lock becomes available.
    71   * @param mutex the mutex on which to acquire the lock.
    72   */
    73  APR_DECLARE(apr_status_t) apr_thread_mutex_lock(apr_thread_mutex_t *mutex);
    74  
    75  /**
    76   * Attempt to acquire the lock for the given mutex. If the mutex has already
    77   * been acquired, the call returns immediately with APR_EBUSY. Note: it
    78   * is important that the APR_STATUS_IS_EBUSY(s) macro be used to determine
    79   * if the return value was APR_EBUSY, for portability reasons.
    80   * @param mutex the mutex on which to attempt the lock acquiring.
    81   */
    82  APR_DECLARE(apr_status_t) apr_thread_mutex_trylock(apr_thread_mutex_t *mutex);
    83  
    84  /**
    85   * Release the lock for the given mutex.
    86   * @param mutex the mutex from which to release the lock.
    87   */
    88  APR_DECLARE(apr_status_t) apr_thread_mutex_unlock(apr_thread_mutex_t *mutex);
    89  
    90  /**
    91   * Destroy the mutex and free the memory associated with the lock.
    92   * @param mutex the mutex to destroy.
    93   */
    94  APR_DECLARE(apr_status_t) apr_thread_mutex_destroy(apr_thread_mutex_t *mutex);
    95  
    96  /**
    97   * Get the pool used by this thread_mutex.
    98   * @return apr_pool_t the pool
    99   */
   100  APR_POOL_DECLARE_ACCESSOR(thread_mutex);
   101  
   102  #endif /* APR_HAS_THREADS */
   103  
   104  /** @} */
   105  
   106  #ifdef __cplusplus
   107  }
   108  #endif
   109  
   110  #endif  /* ! APR_THREAD_MUTEX_H */