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_destroy,   pthread_rwlockattr_init  —  destroy  and  initialize  the  read-write  lock
       attributes object

SYNOPSIS

       #include <pthread.h>

       int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr);
       int pthread_rwlockattr_init(pthread_rwlockattr_t *attr);

DESCRIPTION

       The pthread_rwlockattr_destroy() function shall destroy a read-write lock attributes object. A  destroyed
       attr  attributes  object  can  be reinitialized using pthread_rwlockattr_init(); the results of otherwise
       referencing the  object  after  it  has  been  destroyed  are  undefined.  An  implementation  may  cause
       pthread_rwlockattr_destroy() to set the object referenced by attr to an invalid value.

       The pthread_rwlockattr_init() function shall initialize a read-write lock attributes object attr with the
       default value for all of the attributes defined by the implementation.

       Results are undefined if pthread_rwlockattr_init() is  called  specifying  an  already  initialized  attr
       attributes object.

       After  a  read-write lock attributes object has been used to initialize one or more read-write locks, any
       function affecting the  attributes  object  (including  destruction)  shall  not  affect  any  previously
       initialized read-write locks.

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

RETURN VALUE

       If successful, the pthread_rwlockattr_destroy()  and  pthread_rwlockattr_init()  functions  shall  return
       zero; otherwise, an error number shall be returned to indicate the error.

ERRORS

       The pthread_rwlockattr_init() function shall fail if:

       ENOMEM Insufficient memory exists to initialize the read-write lock attributes object.

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

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       If    an    implementation    detects    that   the   value   specified   by   the   attr   argument   to
       pthread_rwlockattr_destroy() does not refer to an initialized read-write lock attributes  object,  it  is
       recommended that the function should fail and report an [EINVAL] error.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_rwlock_destroy(), pthread_rwlockattr_getpshared()

       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 .