PTHREAD_MUTEXATTR_GETPSHAREPOSIX Programmer's MPTHREAD_MUTEXATTR_GETPSHARED(P)



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  pro-
       cess-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 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   volume   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, Copyright (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.opengroup.org/unix/online.html .



IEEE/The Open Group                  2003      PTHREAD_MUTEXATTR_GETPSHARED(P)