pthread_mutex_init(3C)													    pthread_mutex_init(3C)

NAME

       pthread_mutex_init, pthread_mutex_destroy - initialize or destroy a mutex

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       int pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr);

       int pthread_mutex_destroy(pthread_mutex_t *mutex);
       pthread_mutex_t mutex= PTHREAD_MUTEX_INITIALIZER

       The  pthread_mutex_init()  function  initializes  the  mutex  referenced  by mutex with attributes specified by attr. If attr is  NULL, the
       default mutex attributes are used; the effect is the same as passing the address of a default mutex attributes object. Upon successful ini-
       tialization, the state of the mutex becomes initialized and unlocked.

       Attempting to initialize an already initialized mutex results in undefined behavior.

       The  pthread_mutex_destroy()  function destroys the mutex object referenced by mutex; the mutex object becomes, in effect, uninitialized. A
       destroyed mutex object can be re-initialized using pthread_mutex_init(); the results of otherwise referencing the object after it has  been
       destroyed are undefined.

       It is safe to destroy an initialized mutex that is unlocked. Attempting to destroy a locked mutex results in undefined behavior.

       In  cases  where  default  mutex attributes are appropriate, the macro PTHREAD_MUTEX_INITIALIZER can be used to initialize mutexes that are
       statically allocated. The effect is equivalent to dynamic initialization by a call to pthread_mutex_init() with parameter attr specified as
       NULL, except that no error checks are performed.

       If successful, the pthread_mutex_init() and pthread_mutex_destroy() functions return  0. Otherwise, an error number is returned to indicate
       the error.

       The pthread_mutex_init() function will fail if:

       EAGAIN	       The system lacked the necessary resources (other than memory) to initialize another mutex.

       EBUSY	       An attempt was detected to  re-initialize the object referenced by mutex,  a robust mutex previously  initialized  but  not
		       yet destroyed.

       EINVAL	       The value specified by attr has not been initialized using pthread_mutexattr_init(3C).

       EINVAL	       An attempt was made to initialize mutex to be robust and not PTHREAD_PRIO_INHERIT.

       EINVAL	       An  attempt  was made to initalize mutex to be PTHREAD_PRIO_INHERIT or PTHREAD_PRIO_PROTECT and the type of the mutex to be
		       PTHREAD_MUTEX_ERRORCHECK or PTHREAD_MUTEX_RECURSIVE.

       EINVAL	       An attpemt was made to initalize mutex to be PTHREAD_PROCESS_SHARED and the type of the mutex  to  be  PTHREAD_MUTEX_RECUR-
		       SIVE.

       EINVAL	       The process-shared attribute associated with attr is invalid.

       ENOMEM	       Insufficient memory exists to initialize the mutex.

       EPERM	       The caller does not have the privilege to perform the operation.

       The pthread_mutex_init() function may fail if:

       EBUSY	       An  attempt  was  detected  to  re-initialize  the  object  referenced by mutex, a mutex previously initialized but not yet
		       destroyed.

       EINVAL	       The value specified by attr or mutex is invalid.

       The pthread_mutex_destroy() function may fail if:

       EBUSY	       An attempt was detected to destroy the object referenced by mutex while it is locked  or  referenced  (for  example,  while
		       being used in a pthread_cond_wait(3C) or pthread_cond_timedwait(3C)) by another thread.

       EINVAL	       The value specified by mutex is invalid.

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

       pthread_cond_timedwait(3C),   pthread_cond_wait(3C),  pthread_mutex_getprioceiling(3C),	pthread_mutex_lock(3C),  pthread_mutex_unlock(3C),
       pthread_mutex_setprioceiling(3C), pthread_mutex_trylock(3C), pthread_mutexattr_init(3C),  pthread_mutexattr_getpshared(3C),  pthread_mutex-
       attr_setpshared(3C) attributes(5), mutex(5), standards(5)

								    23 Mar 2005 					    pthread_mutex_init(3C)