From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25097 invoked by alias); 27 Feb 2014 14:47:11 -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 25085 invoked by uid 89); 27 Feb 2014 14:47:10 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_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 ESMTP; Thu, 27 Feb 2014 14:47:09 +0000 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s1REl6OE009505 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 27 Feb 2014 09:47:06 -0500 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s1REl4de012596; Thu, 27 Feb 2014 09:47:05 -0500 Message-ID: <530F4FE8.1010006@redhat.com> Date: Thu, 27 Feb 2014 14:47:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: gdb-patches@sourceware.org CC: teawater@gmail.com, luis_gustavo@mentor.com Subject: Re: [PATCH 3/5] Linux waitpid/__WALL emulation wrapper: If WNOHANG is set, don't touch sigprocmask. References: <52E12075.3040601@redhat.com> <1390486209-8167-1-git-send-email-palves@redhat.com> <1390486209-8167-3-git-send-email-palves@redhat.com> In-Reply-To: <1390486209-8167-3-git-send-email-palves@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2014-02/txt/msg00831.txt.bz2 On 01/23/2014 02:10 PM, Pedro Alves wrote: > So the caller can use waitpid WNOHANG+sigsuspend. Otherwise, > my_waitpid lets the SIGCHLD handler run by mistake. Sorry, that rationale was bogus. I've pushed this in, but as an optimization. --- [PATCH] Linux waitpid/__WALL emulation wrapper: If WNOHANG is set, don't touch sigprocmask. Just a small optimization. No need to block/unblock signals if we're not going to call sigsuspend. gdb/ 2014-02-27 Pedro Alves * nat/linux-waitpid.c (my_waitpid): Only block signals if WNOHANG isn't set. --- gdb/ChangeLog | 5 +++++ gdb/nat/linux-waitpid.c | 21 +++++++++++++-------- 2 files changed, 18 insertions(+), 8 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index bb5f5aa..6cfb9c5 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,10 @@ 2014-02-27 Pedro Alves + * nat/linux-waitpid.c (my_waitpid): Only block signals if WNOHANG + isn't set. + +2014-02-27 Pedro Alves + PR 12702 * linux-nat.c (status_to_str): Moved to nat/linux-waitpid.c. * nat/linux-waitpid.c: Include string.h. diff --git a/gdb/nat/linux-waitpid.c b/gdb/nat/linux-waitpid.c index e9e69db..4693120 100644 --- a/gdb/nat/linux-waitpid.c +++ b/gdb/nat/linux-waitpid.c @@ -92,15 +92,19 @@ my_waitpid (int pid, int *status, int flags) wnohang = (flags & WNOHANG) != 0; flags &= ~(__WALL | __WCLONE); - flags |= WNOHANG; - /* Block all signals while here. This avoids knowing about - LinuxThread's signals. */ - sigfillset (&block_mask); - sigprocmask (SIG_BLOCK, &block_mask, &org_mask); + if (!wnohang) + { + flags |= WNOHANG; + + /* Block all signals while here. This avoids knowing about + LinuxThread's signals. */ + sigfillset (&block_mask); + sigprocmask (SIG_BLOCK, &block_mask, &org_mask); - /* ... except during the sigsuspend below. */ - sigemptyset (&wake_mask); + /* ... except during the sigsuspend below. */ + sigemptyset (&wake_mask); + } while (1) { @@ -129,7 +133,8 @@ my_waitpid (int pid, int *status, int flags) flags ^= __WCLONE; } - sigprocmask (SIG_SETMASK, &org_mask, NULL); + if (!wnohang) + sigprocmask (SIG_SETMASK, &org_mask, NULL); } else { -- 1.7.11.7