Path: csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed3.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 0.002 X-Spam-Evidence: '*H*': 1.00; '*S*': 0.00; 'from:addr:yahoo.co.uk': 0.04; '__name__': 0.09; 'friday,': 0.09; 'lawrence': 0.09; 'prevents': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'snippet': 0.09; 'subject:process': 0.09; 'tismer': 0.09; 'python': 0.11; 'def': 0.12; '#this': 0.16; "'__main__':": 0.16; 'inputs': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'spacing': 0.16; 'subject:skip:m 10': 0.16; 'sys.exit(0)': 0.16; 'tried:': 0.16; 'try?': 0.16; 'language': 0.16; 'wrote:': 0.18; 'module': 0.19; 'solution.': 0.20; 'programming': 0.22; 'import': 0.22; 'print': 0.22; 'header :User-Agent:1': 0.23; 'url:moin': 0.24; 'second': 0.26; 'header:X -Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'code': 0.31; 'url:wiki': 0.31; 'prints': 0.31; 'url:python': 0.33; 'could': 0.34; 'basic': 0.35; 'problem.': 0.35; 'objects': 0.35; 'but': 0.35; 'there': 0.35; 'thanks': 0.36; 'url:org': 0.36; 'detail': 0.37; 'christian': 0.38; 'thank': 0.38; 'url:library': 0.38; 'to:addr:python-list': 0.38; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'read': 0.60; 'above,': 0.60; 'solve': 0.60; 'url:3': 0.61; 'world.': 0.61; 'further': 0.61; 'email addr:gmail.com': 0.63; 'provide': 0.64; 'more': 0.64; 'different': 0.65; 'between': 0.67; 'hang': 0.67; 'answer.': 0.68; 'evaluate': 0.72; 'exchanging': 0.91; 'subject:answer': 0.95; '2013': 0.98 X-Injected-Via-Gmane: http://gmane.org/ To: python-list@python.org From: Mark Lawrence Subject: Re: multiprocessing: child process race to answer Date: Sun, 03 Nov 2013 10:24:54 +0000 References: <0e33c77e-3489-44ac-ba5c-2507adc5e827@googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Gmane-NNTP-Posting-Host: host-78-147-179-131.as13285.net User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 In-Reply-To: <0e33c77e-3489-44ac-ba5c-2507adc5e827@googlegroups.com> 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: 65 NNTP-Posting-Host: 2001:888:2000:d::a6 X-Trace: 1383474301 news.xs4all.nl 15997 [2001:888:2000:d::a6]:49385 X-Complaints-To: abuse@xs4all.nl Xref: csiph.com comp.lang.python:58386 On 03/11/2013 10:10, cappleman@gmail.com wrote: > On Friday, November 1, 2013 10:35:47 PM UTC-4, smhall05 wrote: >> I am using a basic multiprocessing snippet I found: >> >> >> >> #----------------------------------------------------- >> >> from multiprocessing import Pool >> >> >> >> def f(x): >> >> return x*x >> >> >> >> if __name__ == '__main__': >> >> pool = Pool(processes=4) # start 4 worker processes >> >> result = pool.apply_async(f, [10]) # evaluate "f(10)" asynchronously >> >> print result.get(timeout=1) >> >> print pool.map(f, range(10)) # prints "[0, 1, 4,..., 81]" >> >> #--------------------------------------------------------- >> >> >> >> I am using this code to have each process go off and solve the same problem, just with different inputs to the problem. I need to be able to kill all processes once 1 of n processes has come up with the solution. There will only be one answer. >> >> >> >> I have tried: >> >> >> >> sys.exit(0) #this causes the program to hang >> >> pool.close() >> >> pool.terminate >> >> >> >> These still allow further processing before the program terminates. What else can I try? I am not able to share the exact code at this time. I can provide more detail if I am unclear. Thank you > > You could take a look at the Mutiprocessing module capabilities for exchanging objects between processes: > > http://docs.python.org/3.3/library/multiprocessing.html#exchanging-objects-between-processes > Would you please read and action this as it prevents the double line spacing that you can observe above, thanks https://wiki.python.org/moin/GoogleGroupsPython -- Python is the second best programming language in the world. But the best has yet to be invented. Christian Tismer Mark Lawrence