Apache Portable Runtime
apr_thread_mutex.h
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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 #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  */
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  */
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  */
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 absolute time or relative timeout (microseconds)
91  * @param absolute whether the timeout given is absolute (!0) or relative (0)
92  */
94  apr_time_t timeout,
95  int absolute);
96 
97 /**
98  * Release the lock for the given mutex.
99  * @param mutex the mutex from which to release the lock.
100  */
102 
103 /**
104  * Destroy the mutex and free the memory associated with the lock.
105  * @param mutex the mutex to destroy.
106  */
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 */
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
apr_status_t apr_thread_mutex_create(apr_thread_mutex_t **mutex, unsigned int flags, apr_pool_t *pool)
apr_int64_t apr_time_t
Definition: apr_time.h:45
APR memory allocation.
apr_status_t apr_thread_mutex_destroy(apr_thread_mutex_t *mutex)
APR Error Codes.
#define APR_DECLARE(type)
Definition: apr.h:500
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
APR Time Library.
apr_status_t apr_thread_mutex_timedlock(apr_thread_mutex_t *mutex, apr_time_t timeout, int absolute)
#define APR_POOL_DECLARE_ACCESSOR(type)
Definition: apr_pools.h:81