Re: Solving the problem of mutual recursion

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From	Ian Kelly <ian.g.kelly@gmail.com>
Date	2013-05-27 00:19 -0600
Subject	Re: Solving the problem of mutual recursion
Newsgroups	comp.lang.python
Message-ID	<mailman.2236.1369635613.3114.python-list@python.org> (permalink)

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On Sun, May 26, 2013 at 4:16 PM, Chris Angelico <rosuav@gmail.com> wrote:
> On Mon, May 27, 2013 at 5:35 AM, Ian Kelly <ian.g.kelly@gmail.com> wrote:
>> I'm pretty sure that CPython uses the GIL regardless of platform.  And
>> yes you can have multiple OS-level threads, but because of the GIL
>> only one will actually be running at a time.  Other possibilities
>> include:
>
> 6) It's spinning in a function that has released the GIL. Python
> threads can certainly execute concurrently; they just can't be
> manipulating Python objects. Most of the I/O functions will release
> the GIL before doing a potentially-blocking operation, and some
> CPU-heavy functions can do the same (I'm given to understand that
> numpy does this) - just depends on having a long job that involves no
> refcounted objects.

7) Since the program being tested does basically nothing except start
and exit threads, the extra 40% probably represents the overhead of
all that starting and stopping, which would be done outside the GIL.

Thread

Solving the problem of mutual recursion Peter Brooks <peter.h.m.brooks@gmail.com> - 2013-05-26 04:49 -0700
  Re: Solving the problem of mutual recursion Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-05-26 18:09 +0300
    Re: Solving the problem of mutual recursion Roy Smith <roy@panix.com> - 2013-05-26 11:23 -0400
    Re: Solving the problem of mutual recursion Peter Brooks <peter.h.m.brooks@gmail.com> - 2013-05-26 10:21 -0700
      RE: Solving the problem of mutual recursion Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-05-26 21:09 +0300
        Re: Solving the problem of mutual recursion Peter Brooks <peter.h.m.brooks@gmail.com> - 2013-05-26 11:13 -0700
          RE: Solving the problem of mutual recursion Carlos Nepomuceno <carlosnepomuceno@outlook.com> - 2013-05-26 21:22 +0300
            Re: Solving the problem of mutual recursion Peter Brooks <peter.h.m.brooks@gmail.com> - 2013-05-26 12:05 -0700
          Re: Solving the problem of mutual recursion Ian Kelly <ian.g.kelly@gmail.com> - 2013-05-26 13:35 -0600
          Re: Solving the problem of mutual recursion Chris Angelico <rosuav@gmail.com> - 2013-05-27 08:16 +1000
            Re: Solving the problem of mutual recursion Peter Brooks <peter.h.m.brooks@gmail.com> - 2013-05-26 21:36 -0700
              Re: Solving the problem of mutual recursion Ian Kelly <ian.g.kelly@gmail.com> - 2013-05-27 00:07 -0600
              Re: Solving the problem of mutual recursion Chris Angelico <rosuav@gmail.com> - 2013-05-27 17:37 +1000
          Re: Solving the problem of mutual recursion Ian Kelly <ian.g.kelly@gmail.com> - 2013-05-27 00:19 -0600
          Re: Solving the problem of mutual recursion Ian Kelly <ian.g.kelly@gmail.com> - 2013-05-27 01:04 -0600

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