/* 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.
*/
/**
* @file util_mutex.h
* @brief Apache Mutex support library
*
* @defgroup APACHE_CORE_MUTEX Mutex Library
* @ingroup APACHE_CORE
* @{
*/
#ifndef UTIL_MUTEX_H
#define UTIL_MUTEX_H
#include "httpd.h"
#include "http_config.h"
#include "apr_global_mutex.h"
#if APR_HAS_FLOCK_SERIALIZE
# define AP_LIST_FLOCK_SERIALIZE ", 'flock:/path/to/file'"
#else
# define AP_LIST_FLOCK_SERIALIZE
#endif
#if APR_HAS_FCNTL_SERIALIZE
# define AP_LIST_FCNTL_SERIALIZE ", 'fcntl:/path/to/file'"
#else
# define AP_LIST_FCNTL_SERIALIZE
#endif
#if APR_HAS_SYSVSEM_SERIALIZE
# define AP_LIST_SYSVSEM_SERIALIZE ", 'sysvsem'"
#else
# define AP_LIST_SYSVSEM_SERIALIZE
#endif
#if APR_HAS_POSIXSEM_SERIALIZE
# define AP_LIST_POSIXSEM_SERIALIZE ", 'posixsem'"
#else
# define AP_LIST_POSIXSEM_SERIALIZE
#endif
#if APR_HAS_PROC_PTHREAD_SERIALIZE
# define AP_LIST_PTHREAD_SERIALIZE ", 'pthread'"
#else
# define AP_LIST_PTHREAD_SERIALIZE
#endif
#if APR_HAS_FLOCK_SERIALIZE || APR_HAS_FCNTL_SERIALIZE
# define AP_LIST_FILE_SERIALIZE ", 'file:/path/to/file'"
#else
# define AP_LIST_FILE_SERIALIZE
#endif
#if APR_HAS_SYSVSEM_SERIALIZE || APR_HAS_POSIXSEM_SERIALIZE
# define AP_LIST_SEM_SERIALIZE ", 'sem'"
#else
# define AP_LIST_SEM_SERIALIZE
#endif
#define AP_ALL_AVAILABLE_MUTEXES_STRING \
"Mutex mechanisms are: 'none', 'default'" \
AP_LIST_FLOCK_SERIALIZE AP_LIST_FCNTL_SERIALIZE \
AP_LIST_FILE_SERIALIZE AP_LIST_PTHREAD_SERIALIZE \
AP_LIST_SYSVSEM_SERIALIZE AP_LIST_POSIXSEM_SERIALIZE \
AP_LIST_SEM_SERIALIZE
#define AP_AVAILABLE_MUTEXES_STRING \
"Mutex mechanisms are: 'default'" \
AP_LIST_FLOCK_SERIALIZE AP_LIST_FCNTL_SERIALIZE \
AP_LIST_FILE_SERIALIZE AP_LIST_PTHREAD_SERIALIZE \
AP_LIST_SYSVSEM_SERIALIZE AP_LIST_POSIXSEM_SERIALIZE \
AP_LIST_SEM_SERIALIZE
#ifdef __cplusplus
extern "C" {
#endif
/**
* Get Mutex config data and parse it
* @param arg The mutex config string
* @param pool The allocation pool
* @param mutexmech The APR mutex locking mechanism
* @param mutexfile The lockfile to use as required
* @return APR status code
* @fn apr_status_t ap_parse_mutex(const char *arg, apr_pool_t *pool,
apr_lockmech_e *mutexmech,
const char **mutexfile)
*/
AP_DECLARE(apr_status_t) ap_parse_mutex(const char *arg, apr_pool_t *pool,
apr_lockmech_e *mutexmech,
const char **mutexfile);
/* private function to process the Mutex directive */
AP_DECLARE_NONSTD(const char *) ap_set_mutex(cmd_parms *cmd, void *dummy,
const char *arg);
/* private function to initialize Mutex infrastructure */
AP_DECLARE_NONSTD(void) ap_mutex_init(apr_pool_t *p);
/**
* option flags for ap_mutex_register(), ap_global_mutex_create(), and
* ap_proc_mutex_create()
*/
#define AP_MUTEX_ALLOW_NONE 1 /* allow "none" as mutex implementation;
* respected only on ap_mutex_register()
*/
#define AP_MUTEX_DEFAULT_NONE 2 /* default to "none" for this mutex;
* respected only on ap_mutex_register()
*/
/**
* Register a module's mutex type with core to allow configuration
* with the Mutex directive. This must be called in the pre_config
* hook; otherwise, configuration directives referencing this mutex
* type will be rejected.
*
* The default_dir and default_mech parameters allow a module to set
* defaults for the lock file directory and mechanism. These could
* be based on compile-time settings. These aren't required except
* in special circumstances.
*
* The order of precedence for the choice of mechanism and lock file
* directory is:
*
* 1. Mutex directive specifically for this mutex
* e.g., Mutex mpm-default flock:/tmp/mpmlocks
* 2. Mutex directive for global default
* e.g., Mutex default flock:/tmp/httpdlocks
* 3. Defaults for this mutex provided on the ap_mutex_register()
* 4. Built-in defaults for all mutexes, which are
* APR_LOCK_DEFAULT and DEFAULT_REL_RUNTIMEDIR.
*
* @param pconf The pconf pool
* @param type The type name of the mutex, used as the basename of the
* file associated with the mutex, if any. This must be unique among
* all mutex types (mutex creation accommodates multi-instance mutex
* types); mod_foo might have mutex types "foo-pipe" and "foo-shm"
* @param default_dir Default dir for any lock file required for this
* lock, to override built-in defaults; should be NULL for most
* modules, to respect built-in defaults
* @param default_mech Default mechanism for this lock, to override
* built-in defaults; should be APR_LOCK_DEFAULT for most modules, to
* respect built-in defaults
* or NULL if there are no defaults for this mutex.
* @param options combination of AP_MUTEX_* constants, or 0 for defaults
*/
AP_DECLARE(apr_status_t) ap_mutex_register(apr_pool_t *pconf,
const char *type,
const char *default_dir,
apr_lockmech_e default_mech,
apr_int32_t options);
/**
* Create an APR global mutex that has been registered previously with
* ap_mutex_register(). Mutex files, permissions, and error logging will
* be handled internally.
* @param mutex The memory address where the newly created mutex will be
* stored. If this mutex is disabled, mutex will be set to NULL on
* output. (That is allowed only if the AP_MUTEX_ALLOW_NONE flag is
* passed to ap_mutex_register().)
* @param name The generated filename of the created mutex, or NULL if
* no file was created. Pass NULL if this result is not needed.
* @param type The type name of the mutex, matching the type name passed
* to ap_mutex_register().
* @param instance_id A unique string to be used in the lock filename IFF
* this mutex type is multi-instance, NULL otherwise.
* @param server server_rec of main server
* @param pool pool lifetime of the mutex
* @param options combination of AP_MUTEX_* constants, or 0 for defaults
* (currently none are defined for this function)
*/
AP_DECLARE(apr_status_t) ap_global_mutex_create(apr_global_mutex_t **mutex,
const char **name,
const char *type,
const char *instance_id,
server_rec *server,
apr_pool_t *pool,
apr_int32_t options);
/**
* Create an APR proc mutex that has been registered previously with
* ap_mutex_register(). Mutex files, permissions, and error logging will
* be handled internally.
* @param mutex The memory address where the newly created mutex will be
* stored. If this mutex is disabled, mutex will be set to NULL on
* output. (That is allowed only if the AP_MUTEX_ALLOW_NONE flag is
* passed to ap_mutex_register().)
* @param name The generated filename of the created mutex, or NULL if
* no file was created. Pass NULL if this result is not needed.
* @param type The type name of the mutex, matching the type name passed
* to ap_mutex_register().
* @param instance_id A unique string to be used in the lock filename IFF
* this mutex type is multi-instance, NULL otherwise.
* @param server server_rec of main server
* @param pool pool lifetime of the mutex
* @param options combination of AP_MUTEX_* constants, or 0 for defaults
* (currently none are defined for this function)
*/
AP_DECLARE(apr_status_t) ap_proc_mutex_create(apr_proc_mutex_t **mutex,
const char **name,
const char *type,
const char *instance_id,
server_rec *server,
apr_pool_t *pool,
apr_int32_t options);
AP_CORE_DECLARE(void) ap_dump_mutexes(apr_pool_t *p, server_rec *s, apr_file_t *out);
#ifdef __cplusplus
}
#endif
#endif /* UTIL_MUTEX_H */
/** @} */
