[python-win32] COM server with events and multiple threads

[Thomas Heller]

Mark Hammond schrieb:
> The problem is that the connection server is getting an interface object on
> one thread (the main thread as part of the Advise call) - but the new
> threads you create are using these objects without marshalling the objects.
> 
> ie, your new threads are referencing objects "owned" by another thread.
> This is why the calls are being delivered to VB on the wrong thread.  If you
> marshalled the objects to the new thread, that marshalling would ensure VB
> received the call on the correct thread.
> 
> You marshall the COM object by using CoMarshalInterThreadInterfaceInStream
> and CoGetInterfaceAndReleaseStream.
> 
> win32com.server.connect wasn't really designed for this case -
> 'self.connections' can only be used directly or indirectly by thead the
> Advise call was made on.  Each thread must have its own copy of the
> interfaces in self.connections, passed to it via
> CoMarshalInterThreadInterfaceInStream.  This will be tricky to work with new
> connections established after the thread has started.  One option may be a
> queue - the "main" thread could queue CoMarshalInterThreadInterfaceInStream
> wrapped objects, and the worker thread could dequeue the objects and call
> CoGetInterfaceAndReleaseStream before attempting to use the object.
> 
> If you could make sensible modifications to win32com.server.connect to
> support that scenario, I'd be happy to integrate them.  You may find it
> easier to "fork" that class for your own purposes though.
> 

Another (easier, imo) option would be to use the Global Interface Table.
Once that is wrapped in win32com.

Thomas