Thread Mutex Routines

Defines
#define	APR_THREAD_MUTEX_DEFAULT   0x0
#define	APR_THREAD_MUTEX_NESTED   0x1
#define	APR_THREAD_MUTEX_UNNESTED   0x2
Typedefs
typedef struct apr_thread_mutex_t	apr_thread_mutex_t
Functions
apr_status_t	apr_thread_mutex_create (apr_thread_mutex_t **mutex, unsigned int flags, apr_pool_t *pool)
apr_status_t	apr_thread_mutex_lock (apr_thread_mutex_t *mutex)
apr_status_t	apr_thread_mutex_trylock (apr_thread_mutex_t *mutex)
apr_status_t	apr_thread_mutex_unlock (apr_thread_mutex_t *mutex)
apr_status_t	apr_thread_mutex_destroy (apr_thread_mutex_t *mutex)
apr_pool_t *	apr_thread_mutex_pool_get (const apr_thread_mutex_t *thethread_mutex)

---

Define Documentation

#define APR_THREAD_MUTEX_DEFAULT   0x0

platform-optimal lock behavior

#define APR_THREAD_MUTEX_NESTED   0x1

enable nested (recursive) locks

#define APR_THREAD_MUTEX_UNNESTED   0x2

disable nested locks

---

Typedef Documentation

typedef struct apr_thread_mutex_t apr_thread_mutex_t

Opaque thread-local mutex structure

---

Function Documentation

apr_status_t apr_thread_mutex_create	(	apr_thread_mutex_t **	mutex,
		unsigned int	flags,
		apr_pool_t *	pool
	)

Create and initialize a mutex that can be used to synchronize threads.

Parameters:

mutex	the memory address where the newly created mutex will be stored.
flags	Or'ed value of: APR_THREAD_MUTEX_DEFAULT platform-optimal lock behavior. APR_THREAD_MUTEX_NESTED enable nested (recursive) locks. APR_THREAD_MUTEX_UNNESTED disable nested locks (non-recursive).
pool	the pool from which to allocate the mutex.

Warning:

Be cautious in using APR_THREAD_MUTEX_DEFAULT. While this is the most optimial mutex based on a given platform's performance charateristics, it will behave as either a nested or an unnested lock.

apr_status_t apr_thread_mutex_destroy

(

apr_thread_mutex_t *

mutex

)

Destroy the mutex and free the memory associated with the lock.

Parameters:

mutex

the mutex to destroy.

apr_status_t apr_thread_mutex_lock

(

apr_thread_mutex_t *

mutex

)

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.

Parameters:

mutex

the mutex on which to acquire the lock.

apr_pool_t* apr_thread_mutex_pool_get

(

const apr_thread_mutex_t *

thethread_mutex

)

Get the pool used by this thread_mutex.

Returns:

apr_pool_t the pool

apr_status_t apr_thread_mutex_trylock

(

apr_thread_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.

Parameters:

mutex

the mutex on which to attempt the lock acquiring.

apr_status_t apr_thread_mutex_unlock

(

apr_thread_mutex_t *

mutex

)

Release the lock for the given mutex.

Parameters:

mutex

the mutex from which to release the lock.