From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Andy Wingo Newsgroups: gmane.lisp.guile.user Subject: Re: smob mark functions in 2.0 Date: Thu, 24 Nov 2011 11:56:21 +0100 Message-ID: <8739ddeqlm.fsf@pobox.com> References: <87aa7mmt76.fsf@pobox.com> <874nxumo1m.fsf@gnu.org> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1322132207 12112 80.91.229.12 (24 Nov 2011 10:56:47 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 24 Nov 2011 10:56:47 +0000 (UTC) Cc: guile-user@gnu.org To: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=) Original-X-From: guile-user-bounces+guile-user=m.gmane.org@gnu.org Thu Nov 24 11:56:39 2011 Return-path: Envelope-to: guile-user@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RTWys-0001vU-Bk for guile-user@m.gmane.org; Thu, 24 Nov 2011 11:56:38 +0100 Original-Received: from localhost ([::1]:33565 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RTWyp-0003oL-LJ for guile-user@m.gmane.org; Thu, 24 Nov 2011 05:56:35 -0500 Original-Received: from eggs.gnu.org ([140.186.70.92]:52020) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RTWym-0003oG-1u for guile-user@gnu.org; Thu, 24 Nov 2011 05:56:32 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RTWyg-0000eb-9z for guile-user@gnu.org; Thu, 24 Nov 2011 05:56:31 -0500 Original-Received: from a-pb-sasl-sd.pobox.com ([74.115.168.62]:41396 helo=sasl.smtp.pobox.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RTWyg-0000eS-5w; Thu, 24 Nov 2011 05:56:26 -0500 Original-Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 782E677E3; Thu, 24 Nov 2011 05:56:25 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; s=sasl; bh=DeP3r8A71HR7 o3UUS6jFBXtKGq8=; b=tBOxedUwfeniCFN+ftw/07hMOjg4d7waY39dqGFciGlS +MuftLtCIseGsWFqEcb15YbNiXX1/winbs6fUbGgSTrVurrbCtRIohTWZRPkDoSu jaGMg3aHNK5gksbZQWAvyRF2ZO2BX7t3ZKTKrCzeH7BVtVtKHReE5Y2cgnDyiUw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type:content-transfer-encoding; q=dns; s=sasl; b=KbqbTg WNdThSu2XUslMbUx58U2CG8G4XBTnAWd/3REU73dI74rXsL4zTaq4PRYAQuxVB/+ ck+kJQDYaZG9woODBceHzY1cgyoMRmBmzPQCdIHFIj3GSiJlHVYvPcwlBreh57Sn Zj7efbsOv9NcHwdd3wx2KVQGs3kX3ZHp4nZ3U= Original-Received: from a-pb-sasl-sd.pobox.com (unknown [127.0.0.1]) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTP id 71C0F77E2; Thu, 24 Nov 2011 05:56:25 -0500 (EST) Original-Received: from badger (unknown [91.117.99.155]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by a-pb-sasl-sd.pobox.com (Postfix) with ESMTPSA id DC36977E1; Thu, 24 Nov 2011 05:56:24 -0500 (EST) In-Reply-To: <874nxumo1m.fsf@gnu.org> ("Ludovic =?utf-8?Q?Court=C3=A8s=22'?= =?utf-8?Q?s?= message of "Thu, 24 Nov 2011 00:12:05 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) X-Pobox-Relay-ID: F3DAADB4-168A-11E1-B7E9-65B1DE995924-02397024!a-pb-sasl-sd.pobox.com X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 74.115.168.62 X-BeenThere: guile-user@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: General Guile related discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-user-bounces+guile-user=m.gmane.org@gnu.org Original-Sender: guile-user-bounces+guile-user=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.user:8997 Archived-At: On Thu 24 Nov 2011 00:12, ludo@gnu.org (Ludovic Court=C3=A8s) writes: >> So, your mark function might see freed objects. This is terrible, but >> it is the way that it is. The key is that, if you touch a Scheme object >> in your mark function, to first do a check on that object, to see that >> it is valid. You can check the TC bits of the first word, or otherwise >> check that other words are non-NULL. > > What about making that check in libguile before invoking the user=E2=80= =99s mark > function? Yes, we do that. I think you wrote that code! The problem was in a mark function, accessing *other* Scheme objects. Andy --=20 http://wingolog.org/