From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 118863 invoked by alias); 25 Jan 2016 10:43:25 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 118850 invoked by uid 89); 25 Jan 2016 10:43:24 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 25 Jan 2016 10:43:23 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id 60AAE7AE89; Mon, 25 Jan 2016 10:43:22 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u0PAhLxE019185; Mon, 25 Jan 2016 05:43:21 -0500 Message-ID: <56A5FC48.70608@redhat.com> Date: Mon, 25 Jan 2016 10:43:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Yao Qi CC: gdb-patches@sourceware.org Subject: Re: [PATCH] Fix fail in gdb.base/interrupt-noterm.exp References: <1453480183-5131-1-git-send-email-yao.qi@linaro.org> <56A25D13.2080608@redhat.com> <86twm5r0yp.fsf@gmail.com> <56A26849.9070206@redhat.com> <86powqqa57.fsf@gmail.com> In-Reply-To: <86powqqa57.fsf@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2016-01/txt/msg00612.txt.bz2 On 01/25/2016 09:30 AM, Yao Qi wrote: > Pedro Alves writes: > >> If 1. is followed by 3., then the \\003 is always read by gdb > > s/ready by/sent by/ ? I meant, s/by gdb/by gdbserver/. >> >> It still seems to me like a gdbserver bug. >> >> I think that after calling enable_async_io, we need to check whether >> input is already pending from GDB, and if so, process it immediately -- we >> know the only input coming from GDB at this point is a \\003. IOW, I think >> we need to call input_interrupt after calling enable_async_io. input_interrupt >> already uses select before reading, so it handles the case of there >> being no input available without blocking. >> >> However, we need to be careful, because a SIGIO can race with calling >> input_interrupt from mainline code... > > What you mean here is that we can call input_interrupt after calling > enable_async_io, but meanwhile, \\0003 arrives, and input_interrupt is > invoked as a SIGIO handler, so there is a race. Is it correct? That's correct. > > I agree your next email about the approach of block/unblock SIGIO is > better. I'll give a fix that way. > Great, thanks! -- Pedro Alves