github.com/krum110487/go-htaccess@v0.0.0-20240316004156-60641c8e7598/tests/data/apache_2_4_58/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  #define APR_THREAD_MUTEX_TIMED    0x4   /**< enable timed locks */
    47  
    48  /* Delayed the include to avoid a circular reference */
    49  #include "apr_pools.h"
    50  #include "apr_time.h"
    51  
    52  /**
    53   * Create and initialize a mutex that can be used to synchronize threads.
    54   * @param mutex the memory address where the newly created mutex will be
    55   *        stored.
    56   * @param flags Or'ed value of:
    57   * <PRE>
    58   *           APR_THREAD_MUTEX_DEFAULT   platform-optimal lock behavior.
    59   *           APR_THREAD_MUTEX_NESTED    enable nested (recursive) locks.
    60   *           APR_THREAD_MUTEX_UNNESTED  disable nested locks (non-recursive).
    61   * </PRE>
    62   * @param pool the pool from which to allocate the mutex.
    63   * @warning Be cautious in using APR_THREAD_MUTEX_DEFAULT.  While this is the
    64   * most optimal mutex based on a given platform's performance characteristics,
    65   * it will behave as either a nested or an unnested lock.
    66   */
    67  APR_DECLARE(apr_status_t) apr_thread_mutex_create(apr_thread_mutex_t **mutex,
    68                                                    unsigned int flags,
    69                                                    apr_pool_t *pool);
    70  /**
    71   * Acquire the lock for the given mutex. If the mutex is already locked,
    72   * the current thread will be put to sleep until the lock becomes available.
    73   * @param mutex the mutex on which to acquire the lock.
    74   */
    75  APR_DECLARE(apr_status_t) apr_thread_mutex_lock(apr_thread_mutex_t *mutex);
    76  
    77  /**
    78   * Attempt to acquire the lock for the given mutex. If the mutex has already
    79   * been acquired, the call returns immediately with APR_EBUSY. Note: it
    80   * is important that the APR_STATUS_IS_EBUSY(s) macro be used to determine
    81   * if the return value was APR_EBUSY, for portability reasons.
    82   * @param mutex the mutex on which to attempt the lock acquiring.
    83   */
    84  APR_DECLARE(apr_status_t) apr_thread_mutex_trylock(apr_thread_mutex_t *mutex);
    85  
    86  /**
    87   * Attempt to acquire the lock for the given mutex until timeout expires.
    88   * If the acquisition time outs, the call returns with APR_TIMEUP.
    89   * @param mutex the mutex on which to attempt the lock acquiring.
    90   * @param timeout the relative timeout (microseconds).
    91   * @note A timeout negative or nul means immediate attempt, returning
    92   *       APR_TIMEUP without blocking if it the lock is already acquired.
    93   */
    94  APR_DECLARE(apr_status_t) apr_thread_mutex_timedlock(apr_thread_mutex_t *mutex,
    95                                                   apr_interval_time_t timeout);
    96  
    97  /**
    98   * Release the lock for the given mutex.
    99   * @param mutex the mutex from which to release the lock.
   100   */
   101  APR_DECLARE(apr_status_t) apr_thread_mutex_unlock(apr_thread_mutex_t *mutex);
   102  
   103  /**
   104   * Destroy the mutex and free the memory associated with the lock.
   105   * @param mutex the mutex to destroy.
   106   */
   107  APR_DECLARE(apr_status_t) apr_thread_mutex_destroy(apr_thread_mutex_t *mutex);
   108  
   109  /**
   110   * Get the pool used by this thread_mutex.
   111   * @return apr_pool_t the pool
   112   */
   113  APR_POOL_DECLARE_ACCESSOR(thread_mutex);
   114  
   115  #endif /* APR_HAS_THREADS */
   116  
   117  /** @} */
   118  
   119  #ifdef __cplusplus
   120  }
   121  #endif
   122  
   123  #endif  /* ! APR_THREAD_MUTEX_H */