From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27505 invoked by alias); 26 Nov 2015 16:23:23 -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 27491 invoked by uid 89); 26 Nov 2015 16:23:22 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 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; Thu, 26 Nov 2015 16:23:22 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 1CCBD8EFE6; Thu, 26 Nov 2015 16:23:21 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tAQGNJAr026381; Thu, 26 Nov 2015 11:23:20 -0500 Message-ID: <565731F7.3010203@redhat.com> Date: Thu, 26 Nov 2015 16:23:00 -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 03/18] attach + target always in non-stop mode: stop all threads References: <1444836486-25679-1-git-send-email-palves@redhat.com> <1444836486-25679-4-git-send-email-palves@redhat.com> <86r3ki0vzy.fsf@gmail.com> <565357B1.4070805@redhat.com> <86oaegwxhk.fsf@gmail.com> In-Reply-To: <86oaegwxhk.fsf@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-11/txt/msg00571.txt.bz2 On 11/26/2015 04:12 PM, Yao Qi wrote: > Pedro Alves writes: > >> It actually ends up being the same, and bit more generic to go with >> lowest, because target_attach should always adds the main thread first. >> Otherwise, there's no such concept of "main" thread in the common code. >> "The thread with pid == lwpid" holds true for NTPL/Linux, but not everywhere, >> and even then the leader thread may have exited already. I'll update >> the comment. > > Yes, there is no such concept of "main" thread. My real concern on > "choosing lowest one" is about pid recycling. Our intention is to pick up > main thread, but the lowest one may not be the main thread if pid > recycling is considered. But this the GDB thread id. If a new thread recycles an old pid/tid, it'll still get a new GDB thread id. (And if GDB thread ids wrap around we have bigger problems elsewhere, which I think we'd likely sort by simply making gdb thread ids 64-bit instead). Thanks, Pedro Alves