From owner-freebsd-threads@freebsd.org Wed May 4 16:56:31 2016 Return-Path: Delivered-To: freebsd-threads@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0CE7FB2C1A7 for ; Wed, 4 May 2016 16:56:31 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id F1B301A76 for ; Wed, 4 May 2016 16:56:30 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u44GuUeu068314 for ; Wed, 4 May 2016 16:56:30 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-threads@FreeBSD.org Subject: [Bug 209233] [patch] pthread_suspend_all_np races with check_suspend Date: Wed, 04 May 2016 16:56:31 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: threads X-Bugzilla-Version: 11.0-CURRENT X-Bugzilla-Keywords: patch X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: le277@cam.ac.uk X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-threads@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 May 2016 16:56:31 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D209233 --- Comment #5 from Lawrence Esswood --- (In reply to Konstantin Belousov from comment #3) I had a very wonky test that very unreliably failed, now I know why it happ= ens I can probably create a much better one to attach. Your suggestion I think would work. You would also have to change the break condition on the check_suspend loop otherwise if the thread is woken for any reason it will break too early. One question however, what happens if the thread in check_suspend has its NEED_SUSPEND flag set and is signalled somewhere between the loop exit and = the _thr_signal_unblock? I think it won't do another check_suspend / check_defe= rred until it next hits a _thr_ast which might be never. We could maybe extend t= he thread lock to include the _thr_signal_unblock, or have the end of check_suspend make a recursive call. I will try knock up a test case. --=20 You are receiving this mail because: You are the assignee for the bug.=