DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=tfdefqBZC+fKrZEy1h2wBEg8xUio09vSTQE5fNuEvky/RpKx56j9Z
	cFlogT4A7j4dLfUNsBLCViDfiUw/L1gD7hgpRx0kCZ/O13V66cdxvh7cZxiwOfSi
	iO9QSqyuaI9cRs32qTbdCS9WsJd1SQz/4fHKSIUrVFI2xkx32xwfTc=
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
Date: Tue, 29 Oct 2013 13:22:05 -0400
From: Christopher Faylor <cgf-use-the-mailinglist-please@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: SIGKILL and TerminateProcess
Message-ID: <20131029172205.GA1433@ednor.casa.cgf.cx>
Reply-To: cygwin@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
References: <5F8AAC04F9616747BC4CC0E803D5907D0C40AFEB@MLBXv04.nih.gov>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <5F8AAC04F9616747BC4CC0E803D5907D0C40AFEB@MLBXv04.nih.gov>
User-Agent: Mutt/1.5.20 (2009-06-14)

On Tue, Oct 29, 2013 at 03:47:47PM +0000, Lavrentiev, Anton (NIH/NLM/NCBI) [C] wrote:
>Hello List,
>
>I have a question, as to why CYGWIN does not use the TerminateProcess approach when
>dealing with SIGKILL sent to a process (in the manner the CYGWIN's own kill utility
>does when invoked with -f)?  Usually SIGKILL is expected to reliably terminate
>its victim (let alone it can't be intercepted, hence, does not need any "handling"
>provisions).  Yet under CYGWIN, if the point of execution is found as "unsafe" in the
>target process, the signal cannot be delivered quickly.  Such as when the process is busy dealing with a time-consuming Windows API (the dumbest example is Sleep() ;-),
>then the process will not get killed even with SIGKILL.  Could CYGWIN please consider
>special-casing SIGKILL to perform something similar to the force-killing of the
>command-line utility?

Sorry but we aren't going to redesign the signal delivery mechanism for
your use case.

Cygwin does not guarantee delivery of signals to processes which are
calling Windows API functions directly.  If you do that you should be
prepared to deal with problems.

If you are finding that SIGKILL does not reliably kill a blocking UNIX
function, however, that is a bug.

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple