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
       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 .