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From: "Hans dot Boehm at hp dot com" <gcc-bugzilla@gcc.gnu.org>
To: java-prs@gcc.gnu.org
Subject: [Bug libgcj/16662] IllegalMonitorStateException in EventQueue.getNextEvent(): possible hash synchronization bug?
Date: Thu, 05 Aug 2004 00:56:00 -0000	[thread overview]
Message-ID: <20040805005648.16015.qmail@sourceware.org> (raw)
In-Reply-To: <20040721214713.16662.mckinlay@redhat.com>


------- Additional Comments From Hans dot Boehm at hp dot com  2004-08-05 00:56 -------
I'm looking at this, and trying to remember the intricacies of this code.

It appears that the faulting thread successfully acquired the heavyweight lock 
on an object (presumably because the lightweight entry was used for another 
object) and then another thread later acquired the lightweight lock on the same 
object.  This should of course be impossible.

Looking at the code, I noticed that _Jv_ObjectCheckMonitor appears broken.  If 
the address in the lightweight lock is zero, we may still hold a heavyweight 
lock on the object.  This can happen since the lightweight lock slots are 
shared between objects.  Thus it may have been in use when we first tried to 
acquire the lock.  But I don't know what relies on _Jv_ObjectCheckMonitor.  I 
would guess it has nothing to do with this problem.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |Hans dot Boehm at hp dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16662


  parent reply	other threads:[~2004-08-05  0:56 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-07-21 21:47 [Bug libgcj/16662] New: " mckinlay at redhat dot com
2004-07-26 18:57 ` [Bug libgcj/16662] " mckinlay at redhat dot com
2004-08-05  0:56 ` Hans dot Boehm at hp dot com [this message]
2004-08-07  0:43 ` Hans dot Boehm at hp dot com
2004-08-10  0:44 ` Hans dot Boehm at hp dot com
2004-08-10 18:02 ` mckinlay at redhat dot com
2004-08-10 18:30 ` Hans dot Boehm at hp dot com
2004-08-12 17:56 ` cvs-commit at gcc dot gnu dot org
2004-08-12 18:38 ` pinskia at gcc dot gnu dot org
2004-09-07 21:15 ` cvs-commit at gcc dot gnu dot org
2004-10-06 22:47 ` cvs-commit at gcc dot gnu dot org
2004-12-01  0:32 ` cvs-commit at gcc dot gnu dot org
     [not found] <bug-16662-6651@http.gcc.gnu.org/bugzilla/>
2007-05-15  9:46 ` rob1weld at aol dot com

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