Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!eternal-september.org!feeder.eternal-september.org!.POSTED!not-for-mail From: markspace <-@.> Newsgroups: comp.lang.java.programmer Subject: Re: Thread question Date: Wed, 30 Nov 2011 06:04:14 -0800 Organization: A noiseless patient Spider Lines: 29 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Wed, 30 Nov 2011 14:04:15 +0000 (UTC) Injection-Info: mx04.eternal-september.org; posting-host="XjIWM99mD7Ijfdu600oVPA"; logging-data="2692"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+ZjvwNfQgjOAOqjtQ0I1Cx7ugkUN7+4vk=" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20111105 Thunderbird/8.0 In-Reply-To: Cancel-Lock: sha1:iodcQ8wjWMIc/DUtf8QBzqVtwJU= Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:10360 On 11/30/2011 5:50 AM, markspace wrote: > On 11/30/2011 1:31 AM, Roedy Green wrote: > >> 1. some sort of throttle on releasing them that I don't swamp the JVM. > > I wouldn't bother. It's actually well known that for fast efficient IO > you should start as many threads as possible. 21 threads aren't going to > swamp anything. > > If you start to have in excess of say 100 to 1000 threads, then maybe > you can think about a throttle. Until there's a chance of that many > threads, you're just gold-plating your software. > > > Reading the docs carefully, it looks like Executors::newFixedThreadPool might only allocate new threads as it needs them, up to a maximum. Rather than say allocate the maximum number of specified threads immediately. If it does, this would be ideal for throttling your tasks. Even if it doesn't, a relatively small number of threads, say "newFixedThreadPool(50)" is probably much much easier than trying to invent some throttling mechanism yourself.