PTHREAD_MUTEXATTR_GETPSHARED(3P)                    POSIX Programmer's Manual                   PTHREAD_MUTEXATTR_GETPSHARED(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get and set the process-shared attribute

SYNOPSIS
       #include <pthread.h>

       int pthread_mutexattr_getpshared(const pthread_mutexattr_t *
              restrict attr, int *restrict pshared);
       int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
              int pshared);


DESCRIPTION
       The  pthread_mutexattr_getpshared()  function  shall obtain the value of the process-shared attribute from the attributes
       object referenced by attr. The pthread_mutexattr_setpshared() function shall set the process-shared attribute in an  ini-
       tialized 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  multi-
       ple  processes.  If  the  process-shared  attribute  is PTHREAD_PROCESS_PRIVATE, the mutex shall 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 shall be
       PTHREAD_PROCESS_PRIVATE.

RETURN VALUE
       Upon successful completion, pthread_mutexattr_setpshared() shall  return  zero;  otherwise,  an  error  number  shall  be
       returned to indicate the error.

       Upon  successful  completion,  pthread_mutexattr_getpshared() shall return zero and store the value of the process-shared
       attribute of attr into the object referenced by the pshared parameter. Otherwise, an error number shall  be  returned  to
       indicate the error.

ERRORS
       The pthread_mutexattr_getpshared() and pthread_mutexattr_setpshared() functions may fail if:

       EINVAL The value specified by attr is invalid.


       The pthread_mutexattr_setpshared() function may fail if:

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


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

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       pthread_cond_destroy(), pthread_create(), pthread_mutex_destroy(), pthread_mutexattr_destroy(), the Base Definitions vol-
       ume of IEEE Std 1003.1-2001, <pthread.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                              PTHREAD_MUTEXATTR_GETPSHARED(3P)