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Date: Wed, 01 Jul 2009 21:41:26 +0200
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Subject: Re: [Qemu-devel] [PATCH 0/2] Tunnel character device data over VNC
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To: Anthony Liguori <anthony@codemonkey.ws>
Cc: qemu-devel@nongnu.org

On 07/01/09 20:51, Anthony Liguori wrote:
> Allowing multiple readers/writers for character devices is much more
> complex to get right though. The current chardev API does not have good
> semantics for just handling one client that connects and disconnects. It
> certainly wouldn't gracefully handle multiple client states at once.
>
> You could do something like a mirrored mode but things get really ugly
> when dealing with multiple read-write clients.

I'm thinking about mirrored mode of course.  Everything else doesn't 
make sense for guest devices.  And you have that issue with Dan's 
current code already: -serial unix:, then connect via socket and via 
vnc.  Voila, two read-write clients.

> Think of how that would
> behave with the monitor for instance.

> I agree that for something like -monitor tcp::1025,server,nowait, you
> want to be able to connect multiple times and get multiple monitor
> sessions.

Monitor is a special case.  Multiple connections to the same session are 
not very useful there.  Multiple sessions are a different (albeit 
related) problem.

cheers,
   Gerd