serial ports, threads and windows

[Tom Brown]

Hey people,

I've written a python app that r/w eight serial ports to control eight devices 
using eight threads. This all works very nicely in Linux. I even put a GUI on 
it using PyQt4. Still works nicely. 

Then I put the app on on a virtual Windows machine running inside of vmware on 
the same Linux box.  Vmware only lets me have four serial ports so I run the 
app against four serial ports using four threads. The app did not respond 
quick enough to data from the serial ports and eventually hung.

So, I tried one serial port and the app still did not respond quick enough to 
the single serial port. It eventually hangs.

When the app hung, in each case, it was not hogging the cpu nor reading any 
data off the serial ports. The task manager didn't show it was doing anything 
at all.

When it runs on Windows, could it be:

1) Just struggling to run inside of VMware?

2) Using threads with Qt on Windows is a problem?

3) Threads in python on Windows is a problem?

Any ideas?

Thanks,
Tom