From owner-svn-src-all@FreeBSD.ORG Thu Mar 27 08:37:38 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 26C1B2D7; Thu, 27 Mar 2014 08:37:38 +0000 (UTC) Received: from mail-wi0-x231.google.com (mail-wi0-x231.google.com [IPv6:2a00:1450:400c:c05::231]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 236D0F73; Thu, 27 Mar 2014 08:37:36 +0000 (UTC) Received: by mail-wi0-f177.google.com with SMTP id cc10so2862209wib.10 for ; Thu, 27 Mar 2014 01:37:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=bEnc+uWDtge/cTZWGqxVz8encmFwq7Y25N20+zY0ons=; b=eXzCu1tPQZmdxz6K0r8FinBtnj0DutIbVH0G00TLCvZgUP16Sjh668rW+9W7xLLHf5 vMncjlHB8B0TJCYkpmQNF9Qh7KfxazlYq3NNUonW9FlL/FnmIXtftnko7TKRF1qyQnEt 1Miz38HePP/ZdtZCS5m1CMNlESpNSmUmtqoWk8blJkn0LtMOySYM+fvf5+sz09TED/jR 97Ic/S2vLS+47rFCcFa2JO5j2C4Pt1QYRR7ZjZs49g3XyPXvu96i+pdgwfwCz3MFPBWs CDbD+Ub91zxNosk8d05lluapFDcz7QZ5f+YoZRRK05a5yafF0hV+oQ/79G+/7G28WWZM 664w== X-Received: by 10.180.7.227 with SMTP id m3mr2850095wia.59.1395909455470; Thu, 27 Mar 2014 01:37:35 -0700 (PDT) Received: from dft-labs.eu (n1x0n-1-pt.tunnel.tserv5.lon1.ipv6.he.net. [2001:470:1f08:1f7::2]) by mx.google.com with ESMTPSA id fb6sm10192375wib.2.2014.03.27.01.37.32 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 27 Mar 2014 01:37:33 -0700 (PDT) Date: Thu, 27 Mar 2014 09:37:30 +0100 From: Mateusz Guzik To: David Xu Subject: Re: svn commit: r263755 - head/sys/kern Message-ID: <20140327083730.GA22942@dft-labs.eu> References: <201403252330.s2PNUaei052956@svn.freebsd.org> <5333D70D.7050306@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <5333D70D.7050306@freebsd.org> User-Agent: Mutt/1.5.21 (2010-09-15) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Mateusz Guzik X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Mar 2014 08:37:38 -0000 On Thu, Mar 27, 2014 at 03:45:17PM +0800, David Xu wrote: > I think the async process pointer can be cleared when a process exits > by registering an event handler. please see attached patch. > Sure, but I'm not very fond of this solution. This is a rather obscure bug you wont hit unless you explicitly try, and even then you need root privs by default. As such writing a callback function which will be executed for all exiting processes seems unjustified for me. Ideally we would get some mechanism which would allow to register callbacks for events related to given entity. Then it could be used to provide a "call this function when process p exits", amongst other things. -- Mateusz Guzik