From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3848 invoked by alias); 9 Dec 2005 14:34:56 -0000 Received: (qmail 3825 invoked by uid 22791); 9 Dec 2005 14:34:56 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Fri, 09 Dec 2005 14:34:55 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1EkjKm-00038V-Er; Fri, 09 Dec 2005 09:34:52 -0500 Date: Fri, 09 Dec 2005 20:52:00 -0000 From: Daniel Jacobowitz To: gdb-patches@sourceware.org, gdb-patches@sources.redhat.com Subject: Re: [linux] Always ignore restart/cancellation signals Message-ID: <20051209143451.GA11917@nevyn.them.org> Mail-Followup-To: gdb-patches@sourceware.org, gdb-patches@sources.redhat.com References: <20051208142420.GA21882@nevyn.them.org> <200512081950.jB8Jo9im029464@elgar.sibelius.xs4all.nl> <20051208133824.24b4c680@ironwood.lan> <20051208204301.GA29490@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2005-12/txt/msg00174.txt.bz2 On Fri, Dec 09, 2005 at 01:47:50PM +0200, Eli Zaretskii wrote: > There's no need to, IMHO. I think Jim was wrong: symbols starting > with __ are indeed reserved for the implementation, but the meaning of > that reservation is that user code should not _define_ such symbols, > not that it must not use them. In effect, this rule sets up a > namespace that the library implementation can use without risking that > it steps on the feet of user code. But if we don't define any symbols > that begin with __, we are safe accessing them, I think. OK. > I have no idea why the above comment from bits/signum.h was written. > I think it is wrong and the glibc maintainers should be asked to > either remove it or explain why they think these symbols should not be > used at user level. The comment is actually correct - for the vast majority of users of the header. I've long ago accepted that it's GDB's business to poke around in the implementation :-) The problem is that an application may want to register handlers for "a few" realtime signals. It seems common to count up from SIGRTMIN, so SIGRTMIN is made a runtime constant that skips those signals belonging to the implementation. If you use the constant in the header for anything, the implementation reserves the right to kick you when you're down. -- Daniel Jacobowitz CodeSourcery, LLC From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3839 invoked by alias); 9 Dec 2005 14:34:56 -0000 Received: (qmail 3824 invoked by uid 22791); 9 Dec 2005 14:34:55 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Fri, 09 Dec 2005 14:34:54 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1EkjKm-00038V-Er; Fri, 09 Dec 2005 09:34:52 -0500 Date: Fri, 09 Dec 2005 20:49:00 -0000 From: Daniel Jacobowitz To: gdb-patches@sourceware.org, gdb-patches@sources.redhat.com Subject: Re: [linux] Always ignore restart/cancellation signals Message-ID: <20051209143451.GA11917@nevyn.them.org> Mail-Followup-To: gdb-patches@sourceware.org, gdb-patches@sources.redhat.com References: <20051208142420.GA21882@nevyn.them.org> <200512081950.jB8Jo9im029464@elgar.sibelius.xs4all.nl> <20051208133824.24b4c680@ironwood.lan> <20051208204301.GA29490@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2005-12/txt/msg00173.txt.bz2 Message-ID: <20051209204900.ZdxWBqWZNJPoz63HM9NvLsGYzsvdy89QN9EypYKBCEg@z> On Fri, Dec 09, 2005 at 01:47:50PM +0200, Eli Zaretskii wrote: > There's no need to, IMHO. I think Jim was wrong: symbols starting > with __ are indeed reserved for the implementation, but the meaning of > that reservation is that user code should not _define_ such symbols, > not that it must not use them. In effect, this rule sets up a > namespace that the library implementation can use without risking that > it steps on the feet of user code. But if we don't define any symbols > that begin with __, we are safe accessing them, I think. OK. > I have no idea why the above comment from bits/signum.h was written. > I think it is wrong and the glibc maintainers should be asked to > either remove it or explain why they think these symbols should not be > used at user level. The comment is actually correct - for the vast majority of users of the header. I've long ago accepted that it's GDB's business to poke around in the implementation :-) The problem is that an application may want to register handlers for "a few" realtime signals. It seems common to count up from SIGRTMIN, so SIGRTMIN is made a runtime constant that skips those signals belonging to the implementation. If you use the constant in the header for anything, the implementation reserves the right to kick you when you're down. -- Daniel Jacobowitz CodeSourcery, LLC