From owner-freebsd-hackers@FreeBSD.ORG  Sun Mar 29 17:22:09 2015
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 452CA424
 for <freebsd-hackers@FreeBSD.org>; Sun, 29 Mar 2015 17:22:09 +0000 (UTC)
Received: from mx1.stack.nl (relay04.stack.nl [IPv6:2001:610:1108:5010::107])
 (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits))
 (Client CN "mailhost.stack.nl",
 Issuer "CA Cert Signing Authority" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 05E2FDD1
 for <freebsd-hackers@FreeBSD.org>; Sun, 29 Mar 2015 17:22:09 +0000 (UTC)
Received: from snail.stack.nl (snail.stack.nl [IPv6:2001:610:1108:5010::131])
 by mx1.stack.nl (Postfix) with ESMTP id 6241BB8058;
 Sun, 29 Mar 2015 19:22:07 +0200 (CEST)
Received: by snail.stack.nl (Postfix, from userid 1677)
 id 4CEFC28494; Sun, 29 Mar 2015 19:22:07 +0200 (CEST)
Date: Sun, 29 Mar 2015 19:22:07 +0200
From: Jilles Tjoelker <jilles@stack.nl>
To: Konstantin Belousov <kostikbel@gmail.com>
Subject: Re: kevent behavior
Message-ID: <20150329172207.GC95224@stack.nl>
References: <550A6DA2.1070004@gmail.com> <20150324221541.GA67584@stack.nl>
 <20150325090041.GY2379@kib.kiev.ua>
 <20150325223530.GA79065@stack.nl>
 <20150326214551.GG2379@kib.kiev.ua>
 <20150326225826.GA97319@stack.nl>
 <20150327132654.GJ2379@kib.kiev.ua>
 <20150329150316.GB95224@stack.nl>
 <20150329160338.GZ2379@kib.kiev.ua>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20150329160338.GZ2379@kib.kiev.ua>
User-Agent: Mutt/1.5.21 (2010-09-15)
Cc: freebsd-hackers@FreeBSD.org, Ivan Radovanovic <radovanovic@gmail.com>
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 29 Mar 2015 17:22:09 -0000

On Sun, Mar 29, 2015 at 07:03:38PM +0300, Konstantin Belousov wrote:
> On Sun, Mar 29, 2015 at 05:03:16PM +0200, Jilles Tjoelker wrote:
> > On Fri, Mar 27, 2015 at 03:26:54PM +0200, Konstantin Belousov wrote:
> > > +Otherwise, i.e. if
> > > +.Fa nevents
> > > +is zero, the call is not cancellable.
> > 
> > > +Cancellation can only occur when the call was blocked and no changes
> > > +to the queue were requested.
> > 
> > This is not how the code works, but I think the code is correct. The
> > code also allows cancellation before anything happens. As such, if
> > cancellation occurs at kevent(2), the kqueue's state is unchanged (from
> > that call).
> Below is only a new diff for the man pages changes.  I found our list
> of the cancellation points in the pthread_testcancel(3), but did not
> checked it for correctness.

Given that the special case for fcntl() is mentioned in
pthread_testcancel(3) (only a cancellation point if cmd is F_SETLKW),
the same should be done for kevent().

Looks good to me otherwise.

-- 
Jilles Tjoelker