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_mutex_consistent — mark state protected by robust mutex as consistent

SYNOPSIS

       #include <pthread.h>

       int pthread_mutex_consistent(pthread_mutex_t *mutex);

DESCRIPTION

       If  mutex  is  a  robust  mutex  in  an inconsistent state, the pthread_mutex_consistent()
       function can be used to mark the state protected by  the  mutex  referenced  by  mutex  as
       consistent again.

       If  an  owner  of  a  robust  mutex  terminates while holding the mutex, the mutex becomes
       inconsistent and the next thread that acquires the mutex lock shall  be  notified  of  the
       state  by the return value [EOWNERDEAD].  In this case, the mutex does not become normally
       usable again until the state is marked consistent.

       If the thread which acquired the mutex lock with the return value [EOWNERDEAD]  terminates
       before  calling  either  pthread_mutex_consistent()  or  pthread_mutex_unlock(),  the next
       thread that acquires the mutex lock shall be notified about the state of the mutex by  the
       return value [EOWNERDEAD].

       The   behavior   is   undefined   if   the  value  specified  by  the  mutex  argument  to
       pthread_mutex_consistent() does not refer to an initialized mutex.

RETURN VALUE

       Upon successful completion, the pthread_mutex_consistent()  function  shall  return  zero.
       Otherwise, an error value shall be returned to indicate the error.

ERRORS

       The pthread_mutex_consistent() function shall fail if:

       EINVAL The  mutex  object  referenced  by  mutex  is  not  robust  or  does not protect an
              inconsistent state.

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

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The  pthread_mutex_consistent()  function  is   only   responsible   for   notifying   the
       implementation  that  the  state protected by the mutex has been recovered and that normal
       operations with the mutex can be resumed. It is the responsibility of the  application  to
       recover  the  state  so  it  can  be reused. If the application is not able to perform the
       recovery, it can notify the implementation that the situation is unrecoverable by  a  call
       to  pthread_mutex_unlock()  without  a  prior call to pthread_mutex_consistent(), in which
       case subsequent threads that attempt to lock the mutex will fail to acquire the  lock  and
       be returned [ENOTRECOVERABLE].

RATIONALE

       If  an  implementation  detects  that  the  value  specified  by  the  mutex  argument  to
       pthread_mutex_consistent() does not refer to an initialized mutex, it is recommended  that
       the function should fail and report an [EINVAL] error.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_mutex_lock(), pthread_mutexattr_getrobust()

       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 .