Re: Question about asyncio and blocking operations

Path	csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From	"Frank Millman" <frank@chagford.com>
Newsgroups	comp.lang.python
Subject	Re: Question about asyncio and blocking operations
Date	Thu, 28 Jan 2016 11:13:53 +0200
Lines	25
Message-ID	<mailman.45.1453972447.2338.python-list@python.org> (permalink)
References	<n8038j$575$1@ger.gmane.org> <n8818q$35e$1@ger.gmane.org> <CALwzidk-RBkB-vi6CgcEeoFHQrsoTFvqX9MqzDD=rnY5bOCRUg@mail.gmail.com> <n8aln3$fah$1@ger.gmane.org> <CALwzidn6TvN9W-2qnn2JYvJu8NHzn499nPtfjn9OHjdDcebVbA@mail.gmail.com> <CALwzidmmUeL3Sq9o6ZgKYM3-V22HCshG03wQqsXvhh6xy1otgQ@mail.gmail.com> <CALwzidkr-fT6S6wH2caNaxyQvUdAw=x7XDqkqOfNRrwzwnjvOQ@mail.gmail.com>
Mime-Version	1.0
Content-Type	text/plain; format=flowed; charset="iso-8859-1"; reply-type=original
Content-Transfer-Encoding	7bit
X-Trace	news.uni-berlin.de JtJRtU/xWE825Od6Fye6ogNkvGVH7p21GvKxBH6w0B0A==
Return-Path	<python-python-list@m.gmane.org>
X-Original-To	python-list@python.org
Delivered-To	python-list@mail.python.org
X-Spam-Status	OK 0.000
X-Spam-Evidence	'H': 1.00; 'S': 0.00; 'handler': 0.04; 'none,': 0.05; 'subject:Question': 0.05; 'bug.': 0.07; 'handler.': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'assume': 0.11; 'jan': 0.11; 'exception': 0.13; 'wed,': 0.15; '2016': 0.16; 'received:80.91.229.3': 0.16; 'received:io': 0.16; 'received:plane.gmane.org': 0.16; 'received:psf.io': 0.16; 'skip:n 70': 0.16; 'swallows': 0.16; 'think?': 0.16; 'thread.': 0.16; 'wrote:': 0.16; 'am,': 0.23; 'seems': 0.23; 'wrote': 0.23; 'header :In-Reply-To:1': 0.24; 'discussion': 0.24; 'url:bugs': 0.24; 'requests': 0.25; "doesn't": 0.26; 'header:X-Complaints-To:1': 0.26; 'separate': 0.27; 'that.': 0.30; 'work.': 0.30; 'run': 0.33; 'url:python': 0.33; 'url:org': 0.36; 'to:addr:python-list': 0.36; 'subject:: ': 0.37; 'thanks': 0.37; 'received:org': 0.37; 'test': 0.39; 'skip:e 20': 0.39; 'to:addr:python.org': 0.40; 'skip:u 10': 0.61; 'back': 0.62; 'between': 0.65; 'results': 0.66; 'frank': 0.72; 'present.': 0.72; 'fascinating': 0.91
X-Injected-Via-Gmane	http://gmane.org/
X-Gmane-NNTP-Posting-Host	197.89.169.53
In-Reply-To	<CALwzidkr-fT6S6wH2caNaxyQvUdAw=x7XDqkqOfNRrwzwnjvOQ@mail.gmail.com>
X-MSMail-Priority	Normal
Importance	Normal
X-Newsreader	Microsoft Windows Live Mail 15.4.3502.922
X-MimeOLE	Produced By Microsoft MimeOLE V15.4.3502.922
X-BeenThere	python-list@python.org
X-Mailman-Version	2.1.20+
Precedence	list
List-Id	General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe	<https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive	<http://mail.python.org/pipermail/python-list/>
List-Post	<mailto:python-list@python.org>
List-Help	<mailto:python-list-request@python.org?subject=help>
List-Subscribe	<https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Xref	csiph.com comp.lang.python:102176

Show key headers only | View raw

"Ian Kelly"  wrote in message 
news:CALwzidkr-fT6S6wH2caNaxyQvUdAw=x7XDqkqOfNRrwzwnjvOQ@mail.gmail.com...
>
> On Wed, Jan 27, 2016 at 10:14 AM, Ian Kelly <ian.g.kelly@gmail.com> wrote:
> > Unfortunately this doesn't actually work at present.
> > EventLoop.run_in_executor swallows the StopIteration exception and
> > just returns None, which I assume is a bug.
>
> http://bugs.python.org/issue26221
>

Thanks for that. Fascinating discussion between you and GvR.

Reading it gave me an idea.

Run the database handler in a separate thread. Use a queue.Queue to send 
requests to the handler. Use an asyncio.Queue to send results back to the 
caller, which can call 'await q.get()'.

I ran a quick test and it seems to work. What do you think?

Frank

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread

Thread

Re: Question about asyncio and blocking operations "Frank Millman" <frank@chagford.com> - 2016-01-28 11:13 +0200

csiph-web