From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9962 invoked by alias); 25 Apr 2014 15:53:19 -0000 Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Workers List List-Post: List-Help: X-Seq: 32583 Received: (qmail 10468 invoked from network); 25 Apr 2014 15:53:13 -0000 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 From: Bart Schaefer Message-id: <140425085311.ZM12268@torch.brasslantern.com> Date: Fri, 25 Apr 2014 08:53:11 -0700 In-reply-to: <20140425093525.3754a495@pwslap01u.europe.root.pri> Comments: In reply to Peter Stephenson "Re: zsh got stuck without any message because of history lock file" (Apr 25, 9:35am) References: <53594068.4040503@googlemail.com> <140424100228.ZM10689@torch.brasslantern.com> <140424220232.ZM11424@torch.brasslantern.com> <20140425093525.3754a495@pwslap01u.europe.root.pri> X-Mailer: OpenZMail Classic (0.9.2 24April2005) To: zsh-workers@zsh.org Subject: Re: zsh got stuck without any message because of history lock file MIME-version: 1.0 Content-type: text/plain; charset=us-ascii On Apr 25, 9:35am, Peter Stephenson wrote: } } It's hard to construct an argument where locking a single file with } multiple different mechanisms is the right answer. The argument goes something like this: Consider a .zhistory on a shared filesystem (NFS or Samba). Mutliple hosts access this file system. Some of the operating systems involved support fcntl(), some do not. In this situation the only correct thing is to use the .LOCK file, but that might be expensive for some of the hosts that have fcntl(). Posit that these are the busiest hosts, most likely to have lock contention. In this circumstance it may be beneficial to "fail faster" by attempting fcntl() [which blocks out all the other zsh that support it], then only create the .LOCK file [to block out the rest] after fcntl() succeeds. I don't claim this scenario is likely or that we have to account for it, but prior to 32580 zsh *has* supported it.