PTHREAD_CONDATTR_GETCLOCK(3POSIX Programmer's ManPTHREAD_CONDATTR_GETCLOCK(3P)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.
pthread_condattr_getclock, pthread_condattr_setclock — get and set the
clock selection condition variable attribute
int pthread_condattr_getclock(const pthread_condattr_t *restrict attr,
clockid_t *restrict clock_id);
int pthread_condattr_setclock(pthread_condattr_t *attr,
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.
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
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.
If an implementation detects that the value specified by the attr argu‐
ment 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.
SEE ALSOpthread_cond_destroy(), pthread_cond_timedwait(), pthread_con‐
dattr_destroy(), pthread_condattr_getpshared(), pthread_create(),
The Base Definitions volume of POSIX.1‐2008, <pthread.h>
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
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POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
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