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apr_thread_mutex.h
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5  * (the "License"); you may not use this file except in compliance with
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7  *
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9  *
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13  * See the License for the specific language governing permissions and
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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 */
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  */
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  */
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  */
83 
84 /**
85  * Release the lock for the given mutex.
86  * @param mutex the mutex from which to release the lock.
87  */
89 
90 /**
91  * Destroy the mutex and free the memory associated with the lock.
92  * @param mutex the mutex to destroy.
93  */
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 */
apr_status_t apr_thread_mutex_lock(apr_thread_mutex_t *mutex)
struct apr_thread_mutex_t apr_thread_mutex_t
Definition: apr_thread_mutex.h:41
#define APR_DECLARE(type)
Definition: apr.h:479
apr_status_t apr_thread_mutex_create(apr_thread_mutex_t **mutex, unsigned int flags, apr_pool_t *pool)
APR memory allocation.
apr_status_t apr_thread_mutex_destroy(apr_thread_mutex_t *mutex)
APR Error Codes.
apr_status_t apr_thread_mutex_unlock(apr_thread_mutex_t *mutex)
APR Platform Definitions.
apr_status_t apr_thread_mutex_trylock(apr_thread_mutex_t *mutex)
struct apr_pool_t apr_pool_t
Definition: apr_pools.h:60
int apr_status_t
Definition: apr_errno.h:44
#define APR_POOL_DECLARE_ACCESSOR(type)
Definition: apr_pools.h:81