NAME

       pthread_rwlockattr_getpshared,  pthread_rwlockattr_setpshared  - get and set the process-shared attribute
       of the read-write lock attributes object

SYNOPSIS

       #include <pthread.h>

       int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *
              restrict attr, int *restrict pshared);
       int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr,
              int pshared);

DESCRIPTION

       The pthread_rwlockattr_getpshared() function shall obtain the value of the process-shared attribute  from
       the  initialized attributes object referenced by attr. The pthread_rwlockattr_setpshared() function shall
       set the process-shared attribute in an initialized attributes object referenced by attr.

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

       Additional  attributes,  their  default  values, and the names of the associated functions to get and set
       those attribute values are implementation-defined.

RETURN VALUE

       Upon successful completion, the pthread_rwlockattr_getpshared() function 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.

       If successful, the pthread_rwlockattr_setpshared() function shall return zero; otherwise, an error number
       shall be returned to indicate the error.

ERRORS

       The pthread_rwlockattr_getpshared() and pthread_rwlockattr_setpshared() functions may fail if:

       EINVAL The value specified by attr is invalid.

       The pthread_rwlockattr_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_rwlock_destroy()  ,  pthread_rwlockattr_destroy()  ,   pthread_rwlockattr_init()   ,   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_RWLOCKATTR_GETPSHARED(P)