Beginner Threaded file reading access
Cameron Laird
claird at lairds.com
Sat Mar 27 07:16:51 EST 2004
In article <c4393i$gbr$1 at news.service.uci.edu>,
Josiah Carlson <jcarlson at nospam.uci.edu> wrote:
>> Multithreading will not help this sequence unless (A) you have multiple
>> processors, or (B) the processing in bar() needs to wait for something. If
>> bar() is CPU bound, you would get the same performance by just executing
>> sequentially.
>
>It is even worse than that. In windows, Python is really a single
>process, and no amount of threading is going to let one instance of
>Python use more than 100% of a single CPU. I'm not sure if this is also
>the case with linux or OS X.
>
> - Josiah
Go through this with me. I agree with your conclusion, and I
don't keep up with Windows engineering. Moreover, I think it's
important that we educate the masses that multithreading in-
herently *slows* operations on a single CPU. However, I was
sure that Windows *does* include the ability to distribute
intraprocess native threads across SMP. Am I misreading you?
Are you making the point that Python's use of Windows threads
only provides for concurrency between, in practice, one I/O
and one computational operation?
--
Cameron Laird <claird at phaseit.net>
Business: http://www.Phaseit.net
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