[Python-Dev] threading (GilState) question

[Michael Hudson]

James Y Knight <foom at fuhm.net> writes:

> On Apr 10, 2005, at 11:22 AM, Michael Hudson wrote:
>
>> Bob Ippolito <bob at redivi.com> writes:
>>
>>> Is there a good reason to *not* call PyEval_InitThreads when using a
>>> threaded Python?
>>
>> Well, it depends how expensive ones OS's locking primitives are, I
>> think.  There were some numbers posted to the twisted list recently
>> that showed it didn't make a whole lot of difference on some platform
>> or other... I don't have the knowledge or the courage to make that
>> call.
>>
>>> Sounds like it would just be easier to implicitly call it during
>>> Py_Initialize some day.
>>
>> That might indeed be simpler.
>
> Here's the numbers. It looks like something changed between python 2.2
> and 2.3 that made calling PyEval_InitThreads a lot less expensive. So,
> it doesn't seem to make a whole lot of difference on recent versions
> of Python.

Thanks.  I see similar results for 2.3 and 2.4 on OS X (don't have 2.2
here).

It's very much a guess, but could this patch:

[ 525532 ] Add support for POSIX semaphores

be the one to thank?

Cheers,
mwh

-- 
  Now this is what I don't get.  Nobody said absolutely anything
  bad about anything.  Yet it is always possible to just pull
  random flames out of ones ass.
         -- http://www.advogato.org/person/vicious/diary.html?start=60