From: Alexander Terekhov <TEREKHOV@de.ibm.com>
To: Ross Johnson <rpj@callisto.canberra.edu.au>
Cc: Pthreads-Win32 list <pthreads-win32@sources.redhat.com>
Subject: Re: starvation in pthread_once?
Date: Tue, 08 Mar 2005 09:49:00 -0000 [thread overview]
Message-ID: <OF60172FE4.0D25A226-ONC1256FBE.00337955-C1256FBE.0035CF09@de.ibm.com> (raw)
In-Reply-To: <1110262256.6900.118.camel@desk.home>
[... pthread_once() and cancelation ...]
> Should one or more waiting threads get woken up and made to
> re-compete to run the init routine?
Yes. As for the rest, what you need here is DCSI-TLS or DCSI-MBR
(acquire/release memory barriers are needed on both Itanic and
XBOX NEXT... and, apart from hardware memory model, compiler
shall respect acquire/release semantics on IA-32 as well). For
serialization simply use a named mutex associated with address
of control variable and process id (to minimize contention).
DCSI-TLS: (__declspec(thread) for control variable; DLL issues
aside for a moment)
if (!once_control) {
named_mutex::guard guard(&once_control);
if (!once_control) {
<init>
once_control = true;
}
}
DCSI-MBR: (atomic<> for control variable)
if (!once_control.load(msync::acq)) {
named_mutex::guard guard(&once_control);
if (!once_control.load(msync::none)) {
<init>
once_control.store(true, msync::rel);
}
}
regards,
alexander.
next prev parent reply other threads:[~2005-03-08 9:49 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-03 9:32 Gottlob Frege
2005-03-04 23:18 ` Ross Johnson
2005-03-08 2:22 ` Ross Johnson
2005-03-08 3:00 ` Gottlob Frege
2005-03-08 6:11 ` Ross Johnson
2005-03-08 9:49 ` Alexander Terekhov [this message]
2005-03-08 9:56 ` Alexander Terekhov
2005-03-08 9:58 ` Alexander Terekhov
2005-03-08 16:11 ` Gottlob Frege
2005-03-08 17:14 ` Alexander Terekhov
2005-03-08 18:28 ` Gottlob Frege
2005-03-14 2:47 ` Ross Johnson
[not found] ` <97ffb310503140832401faa2b@mail.gmail.com>
[not found] ` <1110842168.21321.78.camel@desk.home>
[not found] ` <97ffb3105031415473a3ee169@mail.gmail.com>
[not found] ` <1110855601.21321.203.camel@desk.home>
[not found] ` <97ffb31050321080747aa5a7c@mail.gmail.com>
[not found] ` <1111464847.8363.91.camel@desk.home>
[not found] ` <97ffb3105032209269b0f44e@mail.gmail.com>
2009-09-16 15:38 ` Gottlob Frege
2009-09-17 1:28 ` Ross Johnson
2005-03-08 16:05 ` Gottlob Frege
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