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 .