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_condattr_getclock, pthread_condattr_setclock — get and set the clock selection condition variable
       attribute

SYNOPSIS

       #include <pthread.h>

       int pthread_condattr_getclock(const pthread_condattr_t *restrict attr,
           clockid_t *restrict clock_id);
       int pthread_condattr_setclock(pthread_condattr_t *attr,
           clockid_t clock_id);

DESCRIPTION

       The  pthread_condattr_getclock()  function  shall  obtain  the  value  of  the  clock  attribute from the
       attributes object referenced by attr.

       The pthread_condattr_setclock() function shall set the  clock  attribute  in  an  initialized  attributes
       object referenced by attr.  If pthread_condattr_setclock() is called with a clock_id argument that refers
       to a CPU-time clock, the call shall fail.

       The  clock  attribute  is  the clock ID of the clock that shall be used to measure the timeout service of
       pthread_cond_timedwait().  The default value of the clock attribute shall refer to the system clock.

       The behavior is undefined if the value specified by the attr argument to  pthread_condattr_getclock()  or
       pthread_condattr_setclock() does not refer to an initialized condition variable attributes object.

RETURN VALUE

       If  successful,  the  pthread_condattr_getclock()  function  shall return zero and store the value of the
       clock attribute of attr into the object referenced by the clock_id argument. Otherwise, an  error  number
       shall be returned to indicate the error.

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

ERRORS

       The pthread_condattr_setclock() function may fail if:

       EINVAL The value specified by clock_id does not refer to a known clock, or is a CPU-time clock.

       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_condattr_getclock()
       or pthread_condattr_setclock() does not refer to an initialized condition variable attributes object,  it
       is recommended that the function should fail and report an [EINVAL] error.

FUTURE DIRECTIONS

       None.

SEE ALSO

       pthread_cond_destroy(), pthread_cond_timedwait(), pthread_condattr_destroy(),
       pthread_condattr_getpshared(), pthread_create(), pthread_mutex_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_CONDATTR_GETCLOCK(3POSIX)