[pypy-dev] FAQ entry

[William ML Leslie]

On 8 April 2015 at 04:54, Yuriy Taraday <yorik.sar at gmail.com> wrote:

> Did you miss mailing list intentionally?
>

​Ach no!  I always seem to do this on pypy-dev.  Thanks for pointing that
out.​



>
> On Tue, Apr 7, 2015 at 5:59 PM William ML Leslie <
> william.leslie.ttg at gmail.com> wrote:
>
>> On 8 April 2015 at 00:00, Yuriy Taraday <yorik.sar at gmail.com> wrote:
>>
>>> GC introduces concurrency to user code anyway: call to some __del__
>>> method can happen in any time in user code, so it might be called in a
>>> separate thread just as well
>>>
>> ​
>> ​Obligatory: ​http://wingolog.org/archives/201
>> ​​
>> 2/02/16/unexpected-concurrency
>>
>
> Yes, that's how I see it: one can't bet on where and when finalizers are
> run, so they appear to the rest of the program as if they're run in some
> special thread that wake ups in some scary moments. So a separate thread is
> just as good for them.
>

Except that, up until now, you can expect that __del__ is run ​in /one/ of
the threads you've started.  If you only have one thread, you know exactly
which thread your __del__ will be run in.  So you could make assumptions
about thread-local state when you write such a method.

​Not that I have an opinion here.  __del__ is problematic, and entirely to
be avoided in new code, afaiac.​

-- 
William Leslie

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