PROLOG

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

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.  See  Section  2.9.9,
       Synchronization Object Copies and Alternative Mappings for further requirements. 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.

       The behavior is undefined if the value specified by the attr argument to  pthread_rwlockattr_getpshared()
       or pthread_rwlockattr_setpshared() does not refer to an initialized read-write lock attributes object.

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_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()

       The Base Definitions volume of POSIX.1‐2017, <pthread.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                 PTHREAD_RWLOCKATTR_GETPSHARED(3POSIX)