From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Conservative GC isn't safe Date: Mon, 28 Nov 2016 17:55:55 +0200 Message-ID: <83h96rzjhw.fsf@gnu.org> References: <66485157-00cd-4704-a421-cbfe84299cae@cs.ucla.edu> <805F5A19-BFAF-4CA4-AAD6-497C6D554830@raeburn.org> <837f7p0w5b.fsf@gnu.org> <16D21C8B-B91E-497D-BA1A-B5A3FC9D1B13@raeburn.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Trace: blaine.gmane.org 1480349043 1237 195.159.176.226 (28 Nov 2016 16:04:03 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 28 Nov 2016 16:04:03 +0000 (UTC) Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org To: Ken Raeburn Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Nov 28 17:03:51 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cBOPG-0007N7-NC for ged-emacs-devel@m.gmane.org; Mon, 28 Nov 2016 17:03:50 +0100 Original-Received: from localhost ([::1]:59667 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBOPK-0000MR-G5 for ged-emacs-devel@m.gmane.org; Mon, 28 Nov 2016 11:03:54 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46428) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBOHf-0002uF-9E for emacs-devel@gnu.org; Mon, 28 Nov 2016 10:56:00 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cBOHc-000166-7G for emacs-devel@gnu.org; Mon, 28 Nov 2016 10:55:59 -0500 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:43843) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBOHc-00015z-3j; Mon, 28 Nov 2016 10:55:56 -0500 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:2904 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1cBOHb-00083H-7O; Mon, 28 Nov 2016 10:55:55 -0500 In-reply-to: <16D21C8B-B91E-497D-BA1A-B5A3FC9D1B13@raeburn.org> (message from Ken Raeburn on Mon, 28 Nov 2016 04:50:56 -0500) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.devel:209651 Archived-At: > From: Ken Raeburn > Date: Mon, 28 Nov 2016 04:50:56 -0500 > Cc: monnier@iro.umontreal.ca, > emacs-devel@gnu.org > > But if the caller never refers to the object again, it’s certainly possible that it wouldn’t keep around any copies of the Lisp_Object value, even in other registers, once it’s set up the arguments for the one function call that uses the object. If the caller also created the object, there may not be any other references left. One of the callers should still hold the reference.