[Twisted-Python] win32com client in a twisted thread

[Andrew Bennetts]

Don Dwiggins wrote:
> I'm running a Windows service with Twisted (xmlrpc), and I've run into 
> an odd case.
> 
> In a recently implemented method, I create a COM object with 
> win32com.client.Dispatch (using a COM DLL that's part of the overall 
> application) and make a couple of calls on it, getting a return value. 
> This works well, except that the COM object calls a web service, which 
> can take a few seconds, so I wanted to defer it.
> 
> When I isolate it into a function, and call that with deferToThread, the 
> thread appears to die.  I tried putting the Dispatch call in the 
> mainline, then passing it to the function -- this kills Python (not too 
> surprising really).

My memory of this stuff is *very* hazy, but IIRC, if you want to use
win32com stuff from a non-main thread you need to call
pythoncom.CoInitialize() in that thread.

-Andrew.