Date: Mon, 07 Jul 2008 07:51:12 +0000 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Sergey Babkin <babkin@verizon.net> Cc: arch@freebsd.org Subject: Re: Proposal: a revoke() system call Message-ID: <4219.1215417072@critter.freebsd.dk> In-Reply-To: Your message of "Sun, 06 Jul 2008 18:34:14 -0400." <48714866.906912CC@verizon.net>
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In message <48714866.906912CC@verizon.net>, Sergey Babkin writes: >Hi all, > >I want to propose a system call with the following functionality: > >Syntax: > > int revoke(int fd, int flags) We already have a revoke(2) system call, so the name will have to be something different. >Rationale: > >In the multithreaded programs often multiple threads work with the >same file descriptor. A particularly typical situation is a reader >thread and a writer thread. The reader thread calls read(), gets >blocked until it gets more data, then processes the data and >continues the loop. Another example of a "reader thread" would be >the main thread of a daemon that accepts the incoming connections >and starts new per-connection threads. Have you tried to implement the functionality you're asking for ? You'll have to hunt down into all sorts of protocols, drivers and other code to find the threads sleeping on your fd so you can wake them. It may be quite a piece of work. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
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