From owner-freebsd-threads@FreeBSD.ORG Wed Aug 18 10:04:10 2010 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E91861065670; Wed, 18 Aug 2010 10:04:10 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from mail.zoral.com.ua (mx0.zoral.com.ua [91.193.166.200]) by mx1.freebsd.org (Postfix) with ESMTP id 61C998FC12; Wed, 18 Aug 2010 10:04:09 +0000 (UTC) Received: from deviant.kiev.zoral.com.ua (root@deviant.kiev.zoral.com.ua [10.1.1.148]) by mail.zoral.com.ua (8.14.2/8.14.2) with ESMTP id o7IA45UF017313 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 18 Aug 2010 13:04:05 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: from deviant.kiev.zoral.com.ua (kostik@localhost [127.0.0.1]) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4) with ESMTP id o7IA456d013710; Wed, 18 Aug 2010 13:04:05 +0300 (EEST) (envelope-from kostikbel@gmail.com) Received: (from kostik@localhost) by deviant.kiev.zoral.com.ua (8.14.4/8.14.4/Submit) id o7IA45Ca013709; Wed, 18 Aug 2010 13:04:05 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: deviant.kiev.zoral.com.ua: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 18 Aug 2010 13:04:03 +0300 From: Kostik Belousov To: David Xu Message-ID: <20100818100403.GS2396@deviant.kiev.zoral.com.ua> References: <4C650F27.1000305@freebsd.org> <20100813141402.GW2396@deviant.kiev.zoral.com.ua> <4C65E0FE.2030803@freebsd.org> <20100814144715.GB2396@deviant.kiev.zoral.com.ua> <4C6926D0.2020909@freebsd.org> <20100816082022.GO2396@deviant.kiev.zoral.com.ua> <4C696A96.7020709@freebsd.org> <20100816104303.GP2396@deviant.kiev.zoral.com.ua> <4C6AA092.40708@freebsd.org> <4C6BE0F7.10207@freebsd.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="viPXr9xSpacAnv0s" Content-Disposition: inline In-Reply-To: <4C6BE0F7.10207@freebsd.org> User-Agent: Mutt/1.4.2.3i X-Virus-Scanned: clamav-milter 0.95.2 at skuns.kiev.zoral.com.ua X-Virus-Status: Clean X-Spam-Status: No, score=-2.3 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_40, DNS_FROM_OPENWHOIS autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on skuns.kiev.zoral.com.ua Cc: freebsd-threads@freebsd.org Subject: Re: PTHREAD_CANCEL_DEFERRED X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Aug 2010 10:04:11 -0000 --viPXr9xSpacAnv0s Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 18, 2010 at 01:32:39PM +0000, David Xu wrote: > David Xu wrote: > >My idea is to always let close() syscall run, until it will be > >blocked by lower layer, e.g tty or socket layer, as manual of close() > >said it always release the file descriptor despite whether > >it returns EINTR or EWOULDBLOCK, when it is going to sleep, > >a flag will cause it to abort the sleep. > >if the thread does not found the flag at that time, > >a latter signal SIGCANCEL sent by pthread_cancel will unblock it, > >this is how signal works. > > >=20 > I have worked out a patch: > http://people.freebsd.org/~davidxu/patch/thread_cancel.patch >=20 Ok, the patch is definitely better then my proposal. But it has several details that seems to need correction. First, if TDP_WAKEUP-marked thread receives any non-cancellation signal, then a syscall returns with EINTR. This breaks SA_RESTART. Also, I think that a condition to perform cancellation in thr_syscalls.c should be not (ret =3D=3D -1), but (ret =3D=3D -1 && errno =3D=3D EINTR). --viPXr9xSpacAnv0s Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (FreeBSD) iEYEARECAAYFAkxrsBMACgkQC3+MBN1Mb4jHJACgzVVP9f6BqiiU8kp38JWlA2mn pJ0AoLfssacTaKIHw254auwDhMP6Tt9i =E/yl -----END PGP SIGNATURE----- --viPXr9xSpacAnv0s--