[Python-ideas] Async API

[Yury Selivanov]

On 2012-10-24, at 8:00 PM, Yury Selivanov <yselivanov.ml at gmail.com> wrote:

> On 2012-10-24, at 7:43 PM, Guido van Rossum <guido at python.org> wrote:
>> On Wed, Oct 24, 2012 at 4:26 PM, Yury Selivanov <yselivanov.ml at gmail.com> wrote:
>>> On 2012-10-24, at 7:12 PM, Guido van Rossum <guido at python.org> wrote:
>>>> Ok, I can understand. But still, this is a problem with timeouts in
>>>> general, not just with timeouts in a yield-based environment. How does
>>>> e.g. Twisted deal with this?
>> 
>>> I don't know, I hope someone with an expertise in Twisted can tell us.
>>> 
>>> But I would imagine that they don't have this particular problem, as it
>>> should be related only to coroutines and schedulers that run them.  I.e.
>>> it's a problem when you run some code and may interrupt it.  And you can't
>>> interrupt a plain python code that uses callbacks without yields and
>>> greenlets.
>> 
>> Well, but in the Twisted world, if a cleanup callback requires more
>> blocking calls, it has to spawn more deferred callbacks. So I think
>> they *do* have the problem, unless they don't have a way at all to
>> constrain the total running time of an action involving cascading
>> callbacks. Also, they have inlineCallbacks which does use yield.
> 
> Right.
> 
> I was under impression that you don't just use 'finally' stmt but rather
> setup a Deferred with a cleanup callback.  Anyways, I'm now curious enough
> so I'll take a look...

Well, that wasn't too hard to find:

Timeouts:
http://stackoverflow.com/questions/221745/is-it-possible-to-set-a-timeout-on-a-socket-in-twisted

-
Yury