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From: "Dean_Jenkins at mentor dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug nptl/14717] Allow choice of clock source for calls to sem_timedwait() and pthread_mutex_timedwait().
Date: Thu, 23 Oct 2014 09:18:00 -0000	[thread overview]
Message-ID: <bug-14717-131-KMUvUf3Ynb@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-14717-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=14717

Dean Jenkins <Dean_Jenkins at mentor dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Dean_Jenkins at mentor dot com

--- Comment #4 from Dean Jenkins <Dean_Jenkins at mentor dot com> ---
Is there any news on allowing CLOCK_MONOTONIC to be used with sem_timedwait() ?

The issue we are facing on an embedded ARM project is that sem_timedwait() can
misbehave when the system clock aka CLOCK_REALTIME is modified such as by a GPS
timebase. Typically the system does not have a real RTC and starts at the EPOCH
of 1970 and then sometime after boot the system clock gets adjusted to the
present day time. This causes a misbehaviour of sem_timedwait() because an
absolute timespec is used such as a time in 1970.

I think a lack of a monotonic clock for functions such as sem_timedwait() is a
serious limitation in embedded systems.

I read reports on the Internet about sem_timedwait() not having a monotonic
clock but no solutions or workarounds appear to be written in the reports. Does
anyone have a workaround because this seems to be a long-standing
issue/limitation ?

Thanks.

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  parent reply	other threads:[~2014-10-23  9:18 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-14 11:58 [Bug nptl/14717] New: " grotlek at hotmail dot com
2012-10-14 11:59 ` [Bug nptl/14717] " grotlek at hotmail dot com
2012-10-15  3:46 ` bugdal at aerifal dot cx
2012-10-16 13:31 ` grotlek at hotmail dot com
2013-05-09 19:29 ` ondra at iuuk dot mff.cuni.cz
2013-05-21  8:20 ` ondra at iuuk dot mff.cuni.cz
2014-06-14 12:52 ` fweimer at redhat dot com
2014-10-23  9:18 ` Dean_Jenkins at mentor dot com [this message]
2015-10-07  8:54 ` sourceware.org at hovland dot cx
2021-08-11 16:05 ` sourceware-bugzilla at mac dot mcrowe.com
2021-08-11 16:19 ` sourceware.org at hovland dot cx
2021-08-11 20:13 ` adhemerval.zanella at linaro dot org

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