Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.mixmin.net!weretis.net!feeder1.news.weretis.net!feeder.erje.net!eu.feeder.erje.net!newsfeed.xs4all.nl!newsfeed4.news.xs4all.nl!xs4all!newsgate.cistron.nl!newsgate.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.029 X-Spam-Evidence: '*H*': 0.94; '*S*': 0.00; 'suggestions,': 0.07; 'imply': 0.09; 'thread,': 0.09; 'timeout': 0.09; 'thread': 0.11; 'passed.': 0.16; 'query.': 0.16; 'subject:threads': 0.16; 'threads': 0.16; 'timeout,': 0.16; 'trying': 0.21; 'programming': 0.23; 'minutes.': 0.23; 'specified': 0.23; "i've": 0.23; 'seems': 0.23; 'header:User-Agent:1': 0.26; 'thanks!': 0.26; "doesn't": 0.28; 'actual': 0.28; 'servers.': 0.29; 'case,': 0.29; 'starts': 0.29; 'checks': 0.30; 'query': 0.30; 'code': 0.31; 'implement': 0.32; 'cancel': 0.33; 'like:': 0.33; 'to:addr:python-list': 0.33; 'know.': 0.33; 'languages': 0.33; 'another': 0.33; 'server': 0.35; 'so,': 0.35; 'expected': 0.35; 'sometimes': 0.35; 'something': 0.35; 'really': 0.36; 'but': 0.36; 'generation': 0.36; 'should': 0.36; 'charset:us-ascii': 0.36; 'turn': 0.36; 'hours.': 0.37; 'to:addr:python.org': 0.39; 'takes': 0.39; 'received:192': 0.39; 'where': 0.40; 'received:192.168': 0.40; 'end': 0.40; 'content- disposition:inline': 0.60; 'within': 0.64; 'canceling': 0.84; 'killing': 0.84; 'outside.': 0.84; 'received:72.249': 0.84; 'received:83.103': 0.84 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=lavabit; d=nerdshack.com; b=45fr+iNkBjHoDFE7eQTJ8fJkav35MjUWykiwJMPjeqReyQvxDPZV29qmywJ0B1uIWzOgOzWK0za8m3bTrnf+PVM6VWlLr6JbjRG3FpF1zeaPnFbmHAxJ7LoCXuvq+EEovrx+LJ5S4YyGtU+TB9dKVUi8i1vST/jDTGu6M26qtwc=; h=Date:From:To:Subject:Message-ID:MIME-Version:Content-Type:Content-Disposition:User-Agent; Date: Sat, 26 Jan 2013 15:14:08 +0200 From: hyperboreean To: python-list@python.org Subject: Cancel threads after timeout MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 30 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1359207608 news.xs4all.nl 6879 [2001:888:2000:d::a6]:49848 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:37720 Here's the use case I want to implement - I have to generate a report from multiple database servers. This report should be generated every 2 hours. Sometimes it happens that a query on one of the database servers takes longer than expected and impedes the generation of this report (that's right, the queries are ran sequential). What I am trying to achieve is to parallelize the queries on each database server and to be able to cancel one of them if it takes longer than X minutes. threading.Thread doesn't support this and seems that in general programming languages don't implement a way to cancel threads from the outside. Now, I've read all the stackoverflow threads about killing a thread, canceling a thread after a timeout, but all of them imply that you are able to check from within the thread if you should end the computation or not - that's not really my case, where the computation is a SQL query. So, what I have in mind is something like: the main loop starts a threading.Thread which in turn is responsible for starting another thread in which the actual computation happens (could be a threading.Thread or a multiprocessing.Process) *and* checks if the specified timeout has passed. If the time is up, it exits, letting the main loop know. Lots of words, no code - let me know if you have any suggestions, ideas to this rant. Thanks!