/usr/include/apr-1.0/apr_proc_mutex.h is in libapr1-dev 1.4.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | /* 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_PROC_MUTEX_H
#define APR_PROC_MUTEX_H
/**
* @file apr_proc_mutex.h
* @brief APR Process Locking Routines
*/
#include "apr.h"
#include "apr_pools.h"
#include "apr_errno.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @defgroup apr_proc_mutex Process Locking Routines
* @ingroup APR
* @{
*/
/**
* Enumerated potential types for APR process locking methods
* @warning Check APR_HAS_foo_SERIALIZE defines to see if the platform supports
* APR_LOCK_foo. Only APR_LOCK_DEFAULT is portable.
*/
typedef enum {
APR_LOCK_FCNTL, /**< fcntl() */
APR_LOCK_FLOCK, /**< flock() */
APR_LOCK_SYSVSEM, /**< System V Semaphores */
APR_LOCK_PROC_PTHREAD, /**< POSIX pthread process-based locking */
APR_LOCK_POSIXSEM, /**< POSIX semaphore process-based locking */
APR_LOCK_DEFAULT /**< Use the default process lock */
} apr_lockmech_e;
/** Opaque structure representing a process mutex. */
typedef struct apr_proc_mutex_t apr_proc_mutex_t;
/* Function definitions */
/**
* Create and initialize a mutex that can be used to synchronize processes.
* @param mutex the memory address where the newly created mutex will be
* stored.
* @param fname A file name to use if the lock mechanism requires one. This
* argument should always be provided. The lock code itself will
* determine if it should be used.
* @param mech The mechanism to use for the interprocess lock, if any; one of
* <PRE>
* APR_LOCK_FCNTL
* APR_LOCK_FLOCK
* APR_LOCK_SYSVSEM
* APR_LOCK_POSIXSEM
* APR_LOCK_PROC_PTHREAD
* APR_LOCK_DEFAULT pick the default mechanism for the platform
* </PRE>
* @param pool the pool from which to allocate the mutex.
* @see apr_lockmech_e
* @warning Check APR_HAS_foo_SERIALIZE defines to see if the platform supports
* APR_LOCK_foo. Only APR_LOCK_DEFAULT is portable.
*/
APR_DECLARE(apr_status_t) apr_proc_mutex_create(apr_proc_mutex_t **mutex,
const char *fname,
apr_lockmech_e mech,
apr_pool_t *pool);
/**
* Re-open a mutex in a child process.
* @param mutex The newly re-opened mutex structure.
* @param fname A file name to use if the mutex mechanism requires one. This
* argument should always be provided. The mutex code itself will
* determine if it should be used. This filename should be the
* same one that was passed to apr_proc_mutex_create().
* @param pool The pool to operate on.
* @remark This function must be called to maintain portability, even
* if the underlying lock mechanism does not require it.
*/
APR_DECLARE(apr_status_t) apr_proc_mutex_child_init(apr_proc_mutex_t **mutex,
const char *fname,
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_proc_mutex_lock(apr_proc_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_proc_mutex_trylock(apr_proc_mutex_t *mutex);
/**
* Release the lock for the given mutex.
* @param mutex the mutex from which to release the lock.
*/
APR_DECLARE(apr_status_t) apr_proc_mutex_unlock(apr_proc_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_proc_mutex_destroy(apr_proc_mutex_t *mutex);
/**
* Destroy the mutex and free the memory associated with the lock.
* @param mutex the mutex to destroy.
* @note This function is generally used to kill a cleanup on an already
* created mutex
*/
APR_DECLARE(apr_status_t) apr_proc_mutex_cleanup(void *mutex);
/**
* Return the name of the lockfile for the mutex, or NULL
* if the mutex doesn't use a lock file
*/
APR_DECLARE(const char *) apr_proc_mutex_lockfile(apr_proc_mutex_t *mutex);
/**
* Display the name of the mutex, as it relates to the actual method used.
* This matches the valid options for Apache's AcceptMutex directive
* @param mutex the name of the mutex
*/
APR_DECLARE(const char *) apr_proc_mutex_name(apr_proc_mutex_t *mutex);
/**
* Display the name of the default mutex: APR_LOCK_DEFAULT
*/
APR_DECLARE(const char *) apr_proc_mutex_defname(void);
/**
* Get the pool used by this proc_mutex.
* @return apr_pool_t the pool
*/
APR_POOL_DECLARE_ACCESSOR(proc_mutex);
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* ! APR_PROC_MUTEX_H */
|