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Date: Thu, 10 Mar 2011 14:58:21 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: [Qemu-devel] Re: [PATCH 2/2] vnc: don't mess up with iohandlers in
	the vnc thread
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To: Corentin Chary <corentin.chary@gmail.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, kvm@vger.kernel.org, Jan Kiszka <jan.kiszka@siemens.com>, qemu-devel <qemu-devel@nongnu.org>, Anthony Liguori <aliguori@linux.vnet.ibm.com>, Peter Lieven <pl@dlh.net>

On 03/10/2011 02:54 PM, Corentin Chary wrote:
> > >  You can use a bottom half for this instead of a special socket. Signaling
> > >  a bottom half is async-signal- and thread-safe.
> >
> >  Bottom halves are thread safe?
> >
> >  I don't think so.
>
> The bottom halves API is not thread safe, but calling
> qemu_bh_schedule_idle()

Not _idle please.

> in another thread *seems* to be safe (here, it
> would be protected from qemu_bh_delete() by vnc_lock_output()).

If it weren't protected against qemu_bh_delete, you would have already 
the same race between writing to the socket and closing it in another 
thread.

Paolo