pthread_mutexattr_setpshared(3P)	      pthread_mutexattr_setpshared(3P)

NAME    [Toc]    [Back]

     pthread_mutexattr_setpshared, pthread_mutexattr_getpshared	- set and get
     mutex process-shared attribute

C SYNOPSIS    [Toc]    [Back]

     #include <pthread.h>

     int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
	  int pshared);

     int pthread_mutexattr_getpshared(const pthread_mutexattr_t	*attr,
	  int *opshared);

DESCRIPTION    [Toc]    [Back]

     The pthread_mutexattr_getpshared()	function obtains the value of the
     process-shared attribute from the attributes object referenced by attr.
     The pthread_mutexattr_setpshared()	function is used to set	the process-
     shared attribute in an initialized	attributes object referenced by	attr.

     The process-shared	attribute is set to PTHREAD_PROCESS_SHARED to permit a
     mutex to be operated upon by any thread that has access to	the memory
     where the mutex is	allocated, even	if the mutex is	allocated in memory
     that is shared by multiple	processes.  If the process-shared attribute is
     PTHREAD_PROCESS_PRIVATE, the mutex	will only be operated upon by threads
     created within the	same process as	the thread that	initialized the	mutex;
     if	threads	of differing processes attempt to operate on such a mutex, the
     behavior is undefined.  The default value of the attribute	is
     PTHREAD_PROCESS_PRIVATE.

     Note that the process-shared attribute cannot be set to
     PTHREAD_PROCESS_SHARED if the attributes specify the priority inheritance
     protocol (see pthread_mutexattr_setprotocol(3P)).

DIAGNOSTICS    [Toc]    [Back]

     Upon successful completion, pthread_mutexattr_setpshared()	returns	zero.
     Otherwise,	an error number	is returned to indicate	the error.

     Upon successful completion, pthread_mutexattr_getpshared()	returns	zero
     and returns the value of the process-shared attribute of attr via the
     opshared parameter.  Otherwise, an	error number is	returned to indicate
     the error.

     [EINVAL]	    The	new value specified for	the attribute is outside the
		    range of legal values for that attribute.

     [EINVAL]	    The	value of pshared is PTHREAD_PROCESS_SHARED and the
		    protocol for the mutex attribute object has	the value
		    PTHREAD_PRIO_INHERIT.

     These functions will not return an	error code of [EINTR].





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pthread_mutexattr_setpshared(3P)	      pthread_mutexattr_setpshared(3P)

SEE ALSO    [Toc]    [Back]

     pthread_create(3P), pthread_mutex_init(3P), pthread_mutex_lock(3P),
     pthread_mutexattr_init(3P), pthread_cond_init(3P).


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