pthread_mutex_init(3C)					   Standard C Library Functions 				    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;

DESCRIPTION

       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.

       Except for robust mutexes, 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.

RETURN VALUES

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

ERRORS

       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 a robust mutex  previously  initialized  but  not  yet  destroyed.  See  pthread_mutex-
		 attr_setrobust(3C).

       EINVAL	 An  attempt  was  detected  to  re-initialize	a  robust  mutex  previously  initialized  with a different set of attributes. See
		 pthread_mutexattr_setrobust(3C).

       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.

ATTRIBUTES

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

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

SEE ALSO

       pthread_cond_wait(3C),	pthread_mutex_lock(3C),  pthread_mutexattr_setprioceiling(3C),	pthread_mutexattr_setprotocol(3C),  pthread_mutex-
       attr_setpshared(3C), pthread_mutexattr_setrobust(3C), pthread_mutexattr_settype(3C), attributes(5), mutex(5), standards(5)

SunOS 5.11							    11 Nov 2008 					    pthread_mutex_init(3C)