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From: "dan at censornet dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug nptl/12683] Race conditions in pthread cancellation
Date: Thu, 15 Jan 2015 14:01:00 -0000	[thread overview]
Message-ID: <bug-12683-131-qA4wvs5Egr@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-12683-131@http.sourceware.org/bugzilla/>

https://sourceware.org/bugzilla/show_bug.cgi?id=12683

--- Comment #27 from Dan Searle <dan at censornet dot com> ---
(In reply to Rich Felker from comment #26)
> I don't think this is the bug you're seeing. If it were, use of async
> cancellation would only make it worse. But the symptoms you'd see from this
> bug would be things like side effects of a function having happened despite
> it getting cancelled.
> 
> If you're seeing 100% cpu load from threads in recv, the most likely
> explanation is that the socket you're reading from is in EOF status (remote
> sending end closed), so that recv immediately returns zero. Repeatedly
> attempting to read in this situation would be an application bug, not
> anything related to glibc.

Thanks Rich, your suggestion made me think to look through the code paths again
and you are quite right, there was an infinite loop in there, not obvious but I
found it.

In light of the current problems with cancellable threads and syscalls, I'm
going to disable cancelation during the main job execution (where all the
recv() can poll()) call are, just in case this bug is causing problems I'm
unaware of.

Many thanks, you saved me a lot of hair pulling :)

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  parent reply	other threads:[~2015-01-15 14:01 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-18 22:28 [Bug nptl/12683] New: " bugdal at aerifal dot cx
2011-04-18 22:35 ` [Bug nptl/12683] " bugdal at aerifal dot cx
2011-09-21 18:30 ` bugdal at aerifal dot cx
2012-04-29  2:56 ` bugdal at aerifal dot cx
2012-04-29  2:57 ` bugdal at aerifal dot cx
2012-09-22 23:13 ` bugdal at aerifal dot cx
2013-08-16 15:32 ` carlos at redhat dot com
2013-08-16 15:34 ` carlos at redhat dot com
2013-08-16 15:34 ` carlos at redhat dot com
2013-08-16 16:22 ` bugdal at aerifal dot cx
2013-08-16 16:59 ` carlos at redhat dot com
2013-08-16 17:14 ` bugdal at aerifal dot cx
2013-08-16 18:09 ` carlos at redhat dot com
2014-01-10 20:25 ` carlos at redhat dot com
2014-01-10 21:31 ` carlos at redhat dot com
2014-01-10 22:37 ` bugdal at aerifal dot cx
2014-01-12 18:31 ` carlos at redhat dot com
2014-01-12 23:55 ` bugdal at aerifal dot cx
2014-01-13  1:52 ` carlos at redhat dot com
2014-01-13  4:37 ` bugdal at aerifal dot cx
2014-01-14 14:51 ` carlos at redhat dot com
2014-02-16 19:42 ` jackie.rosen at hushmail dot com
2014-05-28 19:47 ` schwab at sourceware dot org
2014-05-28 19:47 ` schwab at sourceware dot org
2014-06-27 13:35 ` fweimer at redhat dot com
2014-07-19 18:44 ` sstewartgallus00 at mylangara dot bc.ca
2014-07-19 18:54 ` bugdal at aerifal dot cx
2014-07-20 18:15 ` sstewartgallus00 at mylangara dot bc.ca
2014-07-20 18:41 ` bugdal at aerifal dot cx
2014-08-19 14:08 ` azanella at linux dot vnet.ibm.com
2014-08-28 15:02 ` carlos at redhat dot com
2015-01-15 13:20 ` dan at censornet dot com
2015-01-15 13:31 ` bugdal at aerifal dot cx
2015-01-15 14:01 ` dan at censornet dot com [this message]
2020-06-08 14:04 ` fweimer at redhat dot com

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