[Twisted-Python] Callback blocked in event loop

[Jean-Paul Calderone]

On Fri, 10 Nov 2006 15:24:51 +0000 (GMT), Matt P <twisted-list at zorinholdings.com> wrote:
>
>Hello
>
>I've got a bit of an issue that someone may recognise and bea ble to set me 
>straight!
>
> [snip]
>
>Events may be raised in the server, as a twisted.pb call to fireEvent on the 
>server and also come in on a separate thread (from a JMS message queue) and 
>get posted onto the DefferedQueue for events.
>
>If events are raised in the server, remote listeners get their 
>pb.Referenceable callback immediately. It works as I would like.
>
> [snip]
>
>So, only in the case where teh DeferredQueue.put(...) is called from another 
>thread do I have the problem. I can't see why the blocking. Does this 
>behaviour make sense to anyone!?

DeferredQueue isn't threadsafe.  Instead of calling put() directly from a
non-reactor thread, call it with reactor.callFromThread:


    reactor.callFromThread(q.put, value)

Jean-Paul