From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Timer scheduling and cancel-timer Date: Sun, 20 Jan 2013 11:22:03 -0800 Organization: UCLA Computer Science Department Message-ID: <50FC43DB.6070505@cs.ucla.edu> References: <20130121005802.c7383f4994ead287e738f96f@cx4a.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1358709740 6659 80.91.229.3 (20 Jan 2013 19:22:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 20 Jan 2013 19:22:20 +0000 (UTC) Cc: emacs-devel@gnu.org To: Tomohiro Matsuyama Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Jan 20 20:22:39 2013 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Tx0TW-000301-UO for ged-emacs-devel@m.gmane.org; Sun, 20 Jan 2013 20:22:39 +0100 Original-Received: from localhost ([::1]:59008 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tx0TG-0007st-0U for ged-emacs-devel@m.gmane.org; Sun, 20 Jan 2013 14:22:22 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:60409) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tx0TC-0007jp-9Y for emacs-devel@gnu.org; Sun, 20 Jan 2013 14:22:19 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tx0TA-0006fq-EK for emacs-devel@gnu.org; Sun, 20 Jan 2013 14:22:18 -0500 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:49687) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tx0TA-0006f4-9r for emacs-devel@gnu.org; Sun, 20 Jan 2013 14:22:16 -0500 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id 7D6DD39E8109; Sun, 20 Jan 2013 11:22:08 -0800 (PST) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lE6MEAziGtIe; Sun, 20 Jan 2013 11:22:08 -0800 (PST) Original-Received: from [192.168.1.9] (pool-71-189-154-249.lsanca.fios.verizon.net [71.189.154.249]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 2F03839E8108; Sun, 20 Jan 2013 11:22:08 -0800 (PST) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 In-Reply-To: <20130121005802.c7383f4994ead287e738f96f@cx4a.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:156502 Archived-At: On 01/20/2013 07:58 AM, Tomohiro Matsuyama wrote: > (setq my-timer > (run-with-timer > nil 0.1 > (lambda () > (when my-timer > (cancel-timer my-timer) > (setq my-timer nil) > (sit-for 0.3))))) > > After evaluating this code several times, you may see "zombie" timers > in timer-list, though the code intends to keep at most one timer. Hmm, isn't that due to a race in the above code? A timer can fire when a timer action is running. Do you get zombie timers with the following? It should avoid the race. (setq my-timer (run-with-timer nil 0.1 (lambda () (let ((m my-timer)) (when m (cancel-timer m) (setq my-timer nil) (sit-for 0.3))))))