python threads on multi-CPU machines

Paul McGuire ptmcg at
Tue Aug 19 07:51:35 CEST 2003

Just one general caveat, based on some multi-thread code I worked on about a
year ago: if you want to support your users running your multithread code on
multi-CPU machines, you *must, must, must* stress test on multi-CPU

We had a very nasty intermittent bug (collision with threads in Tcl
interpreter) that I could *not* reproduce on my single-processor development
box, but which showed up in the field on the customer's quad-processor
Finally, after about a day and a half, I moved over to our dual processor
test machine, and the bug showed up after about 20 minutes of stress
testing.  It turned out that the 3rd party thread library we were using was
built to be compatible with the Win98 (!) thread API - once I rebuilt to run
using the WinNT thread API, the window was closed, and the app ran great on
the multiCPU servers.

I'm sorry if this is off-topic, and I am fairly new in this newsgroup, but I
know we were very eager to push multiCPU machines on our customers, and we
did not realize what risk we were taking on.

-- Paul McGuire
Austin, TX

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