Git Mailing List Archive on lore.kernel.org
 help / color / Atom feed
From: Jeff King <peff@peff.net>
To: Junio C Hamano <gitster@pobox.com>
Cc: Denton Liu <liu.denton@gmail.com>,
	Git Mailing List <git@vger.kernel.org>,
	Force Charlie <charlieio@outlook.com>,
	Jonathan Tan <jonathantanmy@google.com>,
	Jonathan Nieder <jrnieder@gmail.com>
Subject: Re: [PATCH 6/6] remote-curl: ensure last packet is a flush
Date: Mon, 18 May 2020 12:52:06 -0400
Message-ID: <20200518165206.GE42240@coredump.intra.peff.net> (raw)
In-Reply-To: <xmqqeerh5hi5.fsf@gitster.c.googlers.com>

On Mon, May 18, 2020 at 09:34:42AM -0700, Junio C Hamano wrote:

> Jeff King <peff@peff.net> writes:
> 
> > On Fri, May 15, 2020 at 05:02:45PM -0400, Denton Liu wrote:
> >
> >> On Wed, May 13, 2020 at 02:04:58PM -0400, Denton Liu wrote:
> >> > This is not a complete solution to the problem, however. It is possible
> >> > that a flush packet could be sent in the middle of a message and the
> >> > connection could die immediately after. Then, remote-curl would not
> >> > error out and fetch-pack would still be in the middle of a transaction
> >> > and they would enter deadlock. A complete solution would involve
> >> > reframing the stateless-connect protocol, possibly by introducing
> >> > another control packet ("0002"?) as a stateless request separator
> >> > packet which is always sent at the end of post_rpc().
> >> > ...
> > I do kind of like the idea of a stateless separator packet, if I
> > understand your meaning correctly. I'll wait to see what the patches
> > look like. :)
> 
> I vaguely recall talking with somebody (perhaps it was Shawn Pearce)
> about my long-time complaint on the on-the-wire protocol, in that
> the protocol sometimes uses flush to merely mean "I've finished
> speaking one section of my speech" and sometimes "I've done talking
> for now and it's your turn to speak to me" (the receiving end needs
> to know which one a particular flush means without knowing the
> context in which it is issued---which makes it impossible to write a
> protocol agnostic proxy.  
> 
> If the above proposal means that we'll have an explicit way to say
> "Not just I am done with one section of my speech, but it is your
> turn to speak and I am going to listen", that would be wonderful.

I think we already have that now in v2 because of the "0001" delim
packet. All of the flushes are (I think) really "this is the end of my
speech", and any inner "my list is ending, but I have more to say"
delimiters are "0001".

-Peff

  reply index

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-13 18:04 [PATCH 0/6] remote-curl: partial fix for a deadlock with stateless rpc Denton Liu
2020-05-13 18:04 ` [PATCH 1/6] remote-curl: fix typo Denton Liu
2020-05-13 18:04 ` [PATCH 2/6] remote-curl: remove label indentation Denton Liu
2020-05-13 18:04 ` [PATCH 3/6] transport: combine common cases with a fallthrough Denton Liu
2020-05-13 23:14   ` Eric Sunshine
2020-05-18  9:18     ` Denton Liu
2020-05-18 17:43       ` Eric Sunshine
2020-05-13 18:04 ` [PATCH 4/6] pkt-line: extern packet_length() Denton Liu
2020-05-13 23:23   ` Eric Sunshine
2020-05-15 20:56   ` Jeff King
2020-05-15 20:57     ` Jeff King
2020-05-13 18:04 ` [PATCH 5/6] remote-curl: error on incomplete packet Denton Liu
2020-05-15 21:38   ` Jeff King
2020-05-18  9:08     ` Denton Liu
2020-05-18 15:49       ` Jeff King
2020-05-13 18:04 ` [PATCH 6/6] remote-curl: ensure last packet is a flush Denton Liu
2020-05-15 21:02   ` Denton Liu
2020-05-15 21:41     ` Jeff King
2020-05-18 16:34       ` Junio C Hamano
2020-05-18 16:52         ` Jeff King [this message]
2020-05-18 21:00           ` Jeff King
2020-05-18 15:47 ` [PATCH v2 0/7] remote-curl: fix deadlocks when remote server disconnects Denton Liu
2020-05-18 15:47   ` [PATCH v2 1/7] remote-curl: fix typo Denton Liu
2020-05-18 15:47   ` [PATCH v2 2/7] remote-curl: remove label indentation Denton Liu
2020-05-18 18:37     ` Junio C Hamano
2020-05-18 15:47   ` [PATCH v2 3/7] transport: extract common fetch_pack() call Denton Liu
2020-05-18 18:40     ` Junio C Hamano
2020-05-18 15:47   ` [PATCH v2 4/7] pkt-line: extern packet_length() Denton Liu
2020-05-18 16:04     ` Jeff King
2020-05-18 17:50       ` Eric Sunshine
2020-05-18 20:08         ` Jeff King
2020-05-18 18:44       ` Junio C Hamano
2020-05-18 15:47   ` [PATCH v2 5/7] remote-curl: error on incomplete packet Denton Liu
2020-05-18 16:22     ` Jeff King
2020-05-18 16:51       ` Denton Liu
2020-05-18 15:47   ` [PATCH v2 6/7] pkt-line: PACKET_READ_RESPONSE_END Denton Liu
2020-05-18 15:47   ` [PATCH v2 7/7] stateless-connect: send response end packet Denton Liu
2020-05-18 16:43     ` Jeff King
2020-05-18 17:12       ` Denton Liu
2020-05-18 17:26         ` Jeff King
2020-05-18 16:50   ` [PATCH v2 0/7] remote-curl: fix deadlocks when remote server disconnects Jeff King
2020-05-18 17:36     ` Denton Liu
2020-05-18 20:58       ` Jeff King
2020-05-18 22:52         ` Junio C Hamano
2020-05-19  2:38           ` Jeff King
2020-05-18 19:36     ` Junio C Hamano
2020-05-19 10:53   ` [PATCH v3 " Denton Liu
2020-05-19 10:53     ` [PATCH v3 1/7] remote-curl: fix typo Denton Liu
2020-05-19 10:53     ` [PATCH v3 2/7] remote-curl: remove label indentation Denton Liu
2020-05-19 10:53     ` [PATCH v3 3/7] transport: extract common fetch_pack() call Denton Liu
2020-05-19 10:53     ` [PATCH v3 4/7] pkt-line: extern packet_length() Denton Liu
2020-05-19 16:23       ` Eric Sunshine
2020-05-19 10:53     ` [PATCH v3 5/7] remote-curl: error on incomplete packet Denton Liu
2020-05-19 10:53     ` [PATCH v3 6/7] pkt-line: define PACKET_READ_RESPONSE_END Denton Liu
2020-05-19 10:54     ` [PATCH v3 7/7] stateless-connect: send response end packet Denton Liu
2020-05-19 18:40     ` [PATCH v3 0/7] remote-curl: fix deadlocks when remote server disconnects Jeff King
2020-05-19 21:14       ` Denton Liu
2020-05-19 20:51     ` [PATCH v3 8/7] fixup! pkt-line: extern packet_length() Denton Liu
2020-05-22 13:33     ` [PATCH v3 9/9] fixup! remote-curl: error on incomplete packet Denton Liu
2020-05-22 15:54       ` Jeff King
2020-05-22 16:05         ` Denton Liu
2020-05-22 16:31           ` Jeff King

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200518165206.GE42240@coredump.intra.peff.net \
    --to=peff@peff.net \
    --cc=charlieio@outlook.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=jonathantanmy@google.com \
    --cc=jrnieder@gmail.com \
    --cc=liu.denton@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Git Mailing List Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/git/0 git/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 git git/ https://lore.kernel.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.git


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git