From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19070 invoked by alias); 14 Mar 2005 07:16:23 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 18906 invoked from network); 14 Mar 2005 07:16:16 -0000 Received: from unknown (HELO lon-del-01.spheriq.net) (195.46.50.97) by sourceware.org with SMTP; 14 Mar 2005 07:16:16 -0000 Received: from lon-out-03.spheriq.net ([195.46.50.131]) by lon-del-01.spheriq.net with ESMTP id j2E7GGdJ006193 for ; Mon, 14 Mar 2005 07:16:16 GMT Received: from lon-cus-02.spheriq.net (lon-cus-02.spheriq.net [195.46.50.38]) by lon-out-03.spheriq.net with ESMTP id j2E7GE8Y024146 for ; Mon, 14 Mar 2005 07:16:15 GMT Received: from beta.dmz-us.st.com (beta.dmz-us.st.com [167.4.1.35]) by lon-cus-02.spheriq.net with ESMTP id j2E7GCc2019999 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=OK); Mon, 14 Mar 2005 07:16:14 GMT Received: from zeta.dmz-us.st.com (ns4.st.com [167.4.80.115]) by beta.dmz-us.st.com (STMicroelectronics) with ESMTP id 4F8ABDA41; Mon, 14 Mar 2005 07:16:08 +0000 (GMT) Received: by zeta.dmz-us.st.com (STMicroelectronics, from userid 60012) id A99334F6FD; Mon, 14 Mar 2005 07:16:06 +0000 (GMT) Received: from zeta.dmz-us.st.com (localhost [127.0.0.1]) by zeta.dmz-us.st.com (STMicroelectronics) with ESMTP id 6DABD69; Mon, 14 Mar 2005 07:16:06 +0000 (UTC) Received: from mail1.snj.st.com (mail1.snj.st.com [167.4.202.26]) by zeta.dmz-us.st.com (STMicroelectronics) with ESMTP id 638A64F6FB; Mon, 14 Mar 2005 07:16:05 +0000 (GMT) Received: from st.com (lugpc0041.mno.st.com [164.129.156.41]) by mail1.snj.st.com (MOS 3.4.4-GR) with ESMTP id AYO01763 (AUTH "pete huerter"); Sun, 13 Mar 2005 23:16:02 -0800 (PST) Message-ID: <42353A2F.7070300@st.com> Date: Mon, 14 Mar 2005 07:16:00 -0000 From: Peter D HUERTER User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20020830 MIME-Version: 1.0 To: Eli Zaretskii Cc: Nick Roberts , drow@false.org, dave.korn@artimi.com, kostik@ispras.ru, gdb@sources.redhat.com Subject: Re: MI output command error References: <16946.1979.617105.196894@farnswood.snap.net.nz> <20050311213042.GA14428@nevyn.them.org> <16946.4725.343793.980977@farnswood.snap.net.nz> <01c526ed$Blat.v2.4$2b933720@zahav.net.il> <16948.2374.864364.458035@farnswood.snap.net.nz> <01c52804$Blat.v2.4$4a0be180@zahav.net.il> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-O-General-Status: No X-O-Spam1-Status: Not Scanned X-O-Spam2-Status: Not Scanned X-O-URL-Status: Not Scanned X-O-Virus1-Status: No X-O-Virus2-Status: Not Scanned X-O-Virus3-Status: No X-O-Virus4-Status: No X-O-Virus5-Status: Not Scanned X-O-Image-Status: Not Scanned X-O-Attach-Status: No X-SpheriQ-Ver: 2.1.0 X-SW-Source: 2005-03/txt/msg00152.txt.bz2 Eli Zaretskii wrote: >>From: Nick Roberts >>Date: Sun, 13 Mar 2005 22:35:02 +1300 >>Cc: drow@false.org, dave.korn@artimi.com, kostik@ispras.ru, >> gdb@sources.redhat.com >> >> > I'm all for documenting this in some useful way, but I fail to see how >> > could this be done. Describing the async operation itself is already >> > a big challenge, as the details are extremely confusing, unless you've >> > read the code several times and have a good understanding of the >> > underlying system calls (like `poll' and `select'). Differences >> > between interpreters add another dimension of complexity to this. >> >>Well for someone to be able to code it must mean that it can be documented. >>But if you mean that those who did the coding are no longer available to >>do the documenting, then I can see this would be a difficult task. >> >> > >People who code are generally never available for documenting (present >company excluded), that's why gdbint.texinfo is in such poor shape ;-) > >But what I meant was that, knowing what I do about the event loop, I >don't know how to document it in a useful way, because talking about >async operation is generally hard. Of course, I will applaud anyone >who tries, and will try to help such an effort ion any way I can. > > > >>Actually if the asynchronous operation was working, I'm not sure what I would >>do with it. When I debug, I'm used to waiting for execution to stop. >> >> > >Precisely. That is one reason why async CLI operation was never fully >implemented: the event loop is ready for it, but the CLI layer simply >waits until some event comes in. > > Asynchronous mode allows for a "halt" command to be used to stop a program (instead of ^C for example). This is important for debugging thread-parallel and process-parallel programs. E.g. when debugging an MPI-CH program that runs into deadlock, using ^C is not an option because it kills the background listener processes which may not be under the control of the debugger. In the context of parallel debugging, ptools.org describes asynchronous command mode. The old HPDF (High Performance Debugging Forum) initiative. Pete.