From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: GC and stack marking Date: Mon, 19 May 2014 22:14:38 +0300 Message-ID: <83vbt1bmxt.fsf@gnu.org> References: <83a9add91p.fsf@gnu.org> <537A51C0.50008@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1400526896 3149 80.91.229.3 (19 May 2014 19:14:56 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 19 May 2014 19:14:56 +0000 (UTC) Cc: fabrice.popineau@gmail.com, emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon May 19 21:14:50 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WmT1L-00017H-U0 for ged-emacs-devel@m.gmane.org; Mon, 19 May 2014 21:14:48 +0200 Original-Received: from localhost ([::1]:49818 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmT1L-0003bg-AR for ged-emacs-devel@m.gmane.org; Mon, 19 May 2014 15:14:47 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:35244) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmT1D-0003Uv-OJ for emacs-devel@gnu.org; Mon, 19 May 2014 15:14:44 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WmT18-0002HC-JN for emacs-devel@gnu.org; Mon, 19 May 2014 15:14:39 -0400 Original-Received: from mtaout22.012.net.il ([80.179.55.172]:64446) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WmT18-0002Gw-BP for emacs-devel@gnu.org; Mon, 19 May 2014 15:14:34 -0400 Original-Received: from conversion-daemon.a-mtaout22.012.net.il by a-mtaout22.012.net.il (HyperSendmail v2007.08) id <0N5U0090051TPF00@a-mtaout22.012.net.il> for emacs-devel@gnu.org; Mon, 19 May 2014 22:14:32 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout22.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0N5U009KX5G8K340@a-mtaout22.012.net.il>; Mon, 19 May 2014 22:14:32 +0300 (IDT) In-reply-to: <537A51C0.50008@cs.ucla.edu> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 X-Received-From: 80.179.55.172 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:171937 Archived-At: > Date: Mon, 19 May 2014 11:47:28 -0700 > From: Paul Eggert > CC: Fabrice Popineau > > On 05/19/2014 09:31 AM, Eli Zaretskii wrote: > > is it possible that a Lisp object which is no longer referenced by anything won't be GC'ed because it is marked by mark_stack due to some kind of coincidence? > > Yes. Normally Emacs uses a conservative approach, which means it > occasionally does not collect something that is in fact garbage. See, > for example, > . Thanks for confirming. I couldn't explain what I saw in the debugger except as such a coincidence. > > how can we make sure this hash-table indeed gets GC'd before we dump Emacs? > > > > We could have the garbage collector treat purify-flag specially, I suppose. I'm not sure I understand the suggestion. Can you elaborate?