From owner-freebsd-current Wed May 9 6:40:42 2001 Delivered-To: freebsd-current@freebsd.org Received: from rina.r.dl.itc.u-tokyo.ac.jp (cvsup2.r.dl.itc.u-tokyo.ac.jp [133.11.199.247]) by hub.freebsd.org (Postfix) with ESMTP id 1B1F037B422; Wed, 9 May 2001 06:40:38 -0700 (PDT) (envelope-from tanimura@r.dl.itc.u-tokyo.ac.jp) Received: from rina.r.dl.itc.u-tokyo.ac.jp (localhost [127.0.0.1]) by rina.r.dl.itc.u-tokyo.ac.jp (8.11.3+3.4W/3.7W-rina.r-20010412) with ESMTP id f49AUYP07219 ; Wed, 9 May 2001 19:30:35 +0900 (JST) Message-Id: <200105091030.f49AUYP07219@rina.r.dl.itc.u-tokyo.ac.jp> Date: Wed, 09 May 2001 19:30:34 +0900 From: Seigo Tanimura To: jhb@FreeBSD.org Cc: tanimura@r.dl.itc.u-tokyo.ac.jp, current@FreeBSD.org Subject: RE: select(2) converted to use a condition variable, and optimis In-Reply-To: In your message of "Wed, 09 May 2001 19:20:07 +0900" <200105091020.f49AK7P05497@rina.r.dl.itc.u-tokyo.ac.jp> References: <200105081026.f48AQgP75260@rina.r.dl.itc.u-tokyo.ac.jp> <200105091020.f49AK7P05497@rina.r.dl.itc.u-tokyo.ac.jp> User-Agent: Wanderlust/1.1.1 (Purple Rain) SEMI/1.13.7 (Awazu) FLIM/1.13.2 (Kasanui) MULE XEmacs/21.1 (patch 14) (Cuyahoga Valley) (i386--freebsd) Organization: Digital Library Research Division, Information Techinology Centre, The University of Tokyo MIME-Version: 1.0 (generated by SEMI 1.13.7 - "Awazu") Content-Type: text/plain; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 09 May 2001 19:20:07 +0900, Seigo Tanimura said: Seigo> That does not, however, necessarily imply that we can scan file Seigo> descriptors with holding a process lock. Another process can release a Seigo> reference to a file descriptor via closef() during polling the Seigo> descriptor by calling its fo_poll. In this case, fdrop() subsequent to Seigo> the call of fo_poll may result the reference count of the descriptor Seigo> to be zero. Hang on, the process that owns a file descriptor should be fhold()ing the descriptor. Since we never call closef() during waiting for an event, that problem described above is no more than absurd fear. -- Seigo Tanimura To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message