From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30474 invoked by alias); 10 Sep 2012 05:09:43 -0000 Received: (qmail 30459 invoked by uid 22791); 10 Sep 2012 05:09:42 -0000 X-SWARE-Spam-Status: No, hits=-4.3 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 10 Sep 2012 05:09:29 +0000 From: "bkoz at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/54172] [4.7 Regression] __cxa_guard_acquire thread-safety issue Date: Mon, 10 Sep 2012 05:09:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: major X-Bugzilla-Who: bkoz at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.2 X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-09/txt/msg00746.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54172 --- Comment #14 from Benjamin Kosnik 2012-09-10 05:08:15 UTC --- Author: bkoz Date: Mon Sep 10 05:08:07 2012 New Revision: 191125 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=191125 Log: 2012-09-09 Thiago Macieira PR libstdc++/54172 * libsupc++/guard.cc (__cxa_guard_acquire): Exit the loop earlier if we detect that another thread has had success. Don't compare_exchange from a finished state back to a waiting state. Comment. Modified: branches/gcc-4_7-branch/libstdc++-v3/ChangeLog branches/gcc-4_7-branch/libstdc++-v3/libsupc++/guard.cc