From owner-freebsd-hackers@FreeBSD.ORG Fri Jan 22 15:56:02 2010 Return-Path: <owner-freebsd-hackers@FreeBSD.ORG> Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 02ED5106566B; Fri, 22 Jan 2010 15:56:02 +0000 (UTC) (envelope-from rrs@lakerest.net) Received: from lakerest.net (unknown [IPv6:2001:240:585:2:213:d4ff:fef3:2d8d]) by mx1.freebsd.org (Postfix) with ESMTP id 7A64D8FC15; Fri, 22 Jan 2010 15:56:01 +0000 (UTC) Received: from [32.177.153.43] ([32.177.153.43]) (authenticated bits=0) by lakerest.net (8.14.3/8.14.3) with ESMTP id o0MFtsjC094006 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Fri, 22 Jan 2010 10:55:59 -0500 (EST) (envelope-from rrs@lakerest.net) Message-Id: <905EFCFB-7362-4F54-B9E7-69C0B4699A37@lakerest.net> From: Randall Stewart <rrs@lakerest.net> To: Ivan Voras <ivoras@freebsd.org> In-Reply-To: <hjcgfv$100$1@ger.gmane.org> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v936) Date: Fri, 22 Jan 2010 07:55:47 -0800 References: <AD99639C-0DC6-4C4C-B945-A8BD23D6DF8E@lakerest.net> <9bbcef731001220527u5bbec479n59143b6631c6e2d8@mail.gmail.com> <20100122151035.GX77705@hoeg.nl> <hjcgfv$100$1@ger.gmane.org> X-Mailer: Apple Mail (2.936) Cc: freebsd-hackers@freebsd.org Subject: Re: Greetings... a patch I would like your comments on... X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD <freebsd-hackers.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/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: Fri, 22 Jan 2010 15:56:02 -0000 Ivan: A couple of comments... On Jan 22, 2010, at 7:33 AM, Ivan Voras wrote: > On 01/22/10 16:10, Ed Schouten wrote: >> * Ivan Voras<ivoras@freebsd.org> wrote: >>> This is a good and useful addition! I think Windows has >>> implemented a >>> generalization of this (called "wait objects" or something like >>> that), >>> which effectively allows a select()- (or in this case kqueue())-like >>> syscall to wait on both file descriptors and condvars (as well as >>> probably other MS-style objects). It's useful for multiplexing >>> events >>> for dissimilar sources. >> >> NtWaitForSingleObject(), NtWaitForMultipleObjects(), etc. :-) >> > > Yes, I was thinking about WaitForMultipleObjects() - I sometimes > wished I had it in FreeBSD :) > > I think the hackers@ side of the thread is missing the original link > to the patch file offered for review, so here it is: > > http://people.freebsd.org/~rrs/kque_umtx.patch > > My kqueue-fu level is too low to be really useful here but from what > I've read it looks like a logical and even reasonably clean way of > doing it. thanks it made sense to me ;-) > > If I read the comment at filt_umtxattach() correctly, in the best > case you would need an extension to the kevent structure to add more > fields like data & udata (for passing values back and forth between > userland and kernel). I agree with this - it would be very > convenient for some future purposes (like file modification > notification) if the kernel filter could both accept and return a > struct of data from/to the userland. Yeah, more arguments inside the kevent would allow me to add the COND_CV_WAIT* where a lock and condition are passed in as well... But I was hesitant to add more than was already there since doing so would cause ABI ripples that I did not want to face. I plan on committing this to head if I don't get strong "you idiot you did it wrong" comments ;-) R > > > > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org > " > ------------------------------ Randall Stewart 803-317-4952 (cell) 803-345-0391(direct)