From owner-freebsd-threads@FreeBSD.ORG  Thu Sep  9 06:29:28 2010
Return-Path: <owner-freebsd-threads@FreeBSD.ORG>
Delivered-To: freebsd-threads@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 8455A10656BF
	for <freebsd-threads@freebsd.org>; Thu,  9 Sep 2010 06:29:28 +0000 (UTC)
	(envelope-from davidxu@freebsd.org)
Received: from freefall.freebsd.org (freefall.freebsd.org
	[IPv6:2001:4f8:fff6::28])
	by mx1.freebsd.org (Postfix) with ESMTP id 5A15A8FC19;
	Thu,  9 Sep 2010 06:29:28 +0000 (UTC)
Received: from [127.0.0.1] (localhost [127.0.0.1])
	by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id o896TQPI081896;
	Thu, 9 Sep 2010 06:29:27 GMT (envelope-from davidxu@freebsd.org)
Message-ID: <4C88EF47.4010906@freebsd.org>
Date: Thu, 09 Sep 2010 14:29:27 +0000
From: David Xu <davidxu@freebsd.org>
User-Agent: Thunderbird 2.0.0.24 (X11/20100630)
MIME-Version: 1.0
To: Jilles Tjoelker <jilles@stack.nl>
References: <20100906220041.GA4729@stack.nl> <4C86787E.6070908@freebsd.org>
	<20100908175609.GA30144@stack.nl>
In-Reply-To: <20100908175609.GA30144@stack.nl>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: freebsd-threads@freebsd.org
Subject: Re: sigwait() cancellation point
X-BeenThere: freebsd-threads@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Threading on FreeBSD <freebsd-threads.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>, 
	<mailto:freebsd-threads-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-threads>
List-Post: <mailto:freebsd-threads@freebsd.org>
List-Help: <mailto:freebsd-threads-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-threads>,
	<mailto:freebsd-threads-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 09 Sep 2010 06:29:28 -0000

Jilles Tjoelker wrote:
> On Tue, Sep 07, 2010 at 05:38:06PM +0000, David Xu wrote:
>> Jilles Tjoelker wrote:
>>> Our sigwait() implementation may not be POSIX-compliant as it returns
>>> EINTR when it is interrupted by a caught signal. (Unfortunately I can
>>> only find this in SUSv4 in the Rationale, B.2.3 Error Numbers,
>>> Disallowing Return of the [EINTR] Error Code; the sigwait() page in XSH
>>> does not list an [EINTR] error condition, but does not prohibit one
>>> either like pthread_mutex_lock() and various others do.)
> 
>> A system call can not return EINTR is not flexible, I think why don't
>> we fix it in libc and libthr, but let kernel returns EINTR?
> 
>> I have worked out a patch:
> 
>> http://people.freebsd.org/~davidxu/patch/sigwait.diff
> 
> The idea and patch seem sensible. Some man page changes seem in order
> though: sigwaitinfo.2 should mention this difference between sigwait()
> and sigwaitinfo() more explicitly.
> 
problem is I still want to know which OS does not return EINTR ?
it seems I can not find one on net, so is it an accident of the
specification group?