From: Jonathan Tan <jonathantanmy@google.com>
To: Jonathan Nieder <jrnieder@gmail.com>
Cc: git@vger.kernel.org, gitster@pobox.com, bmwill@google.com
Subject: Re: [PATCH 2/6] fetch-pack: truly stop negotiation upon ACK ready
Date: Tue, 5 Jun 2018 17:38:18 -0700 [thread overview]
Message-ID: <20180605173818.4d56cf328d81b29a2878c1f6@google.com> (raw)
In-Reply-To: <20180605231634.GD9266@aiede.svl.corp.google.com>
On Tue, 5 Jun 2018 16:16:34 -0700
Jonathan Nieder <jrnieder@gmail.com> wrote:
> Hi,
>
> Jonathan Tan wrote:
>
> > When "ACK %s ready" is received, find_common() clears rev_list in an
> > attempt to stop further "have" lines from being sent [1]. This appears
> > to work, despite the invocation to mark_common() in the "while" loop.
>
> Does "appears to work" mean "works" or "doesn't work but does an okay
> job of faking"?
"Appears to work" means I think that it works, but I don't think I can
conclusively prove it.
> > Though it is possible for mark_common() to invoke rev_list_push() (thus
> > making rev_list non-empty once more), it is more likely that the commits
>
> nit: s/more likely/most likely/
> or s/it is more likely that/usually/
>
> > in rev_list that have un-SEEN parents are also unparsed, meaning that
> > mark_common() is not invoked on them.
> >
> > To avoid all this uncertainty, it is better to explicitly end the loop
> > when "ACK %s ready" is received instead of clearing rev_list. Remove the
> > clearing of rev_list and write "if (got_ready) break;" instead.
>
> I'm still a little curious about whether this can happen in practice
> or whether it's just about readability (or whether you didn't figure
> out which, which is perfectly fine), but either way it's a good
> change.
I tried to figure out which, but concluded that I can't.
I think that in v2's commit message, I'll start with describing the
readability aspect.
> > @@ -1281,7 +1281,6 @@ static int process_acks(struct packet_reader *reader, struct oidset *common)
> > }
> >
> > if (!strcmp(reader->line, "ready")) {
> > - clear_prio_queue(&rev_list);
> > received_ready = 1;
> > continue;
>
> I'm curious about the lifetime of &rev_list. Does the priority queue
> get freed eventually?
No (which potentially causes a problem in the case that fetch-pack is
invoked twice), but I fix that in patch 4/6, so I didn't bother
addressing it here. I'll add a note about the lifetime of this priority
queue in v2.
next prev parent reply other threads:[~2018-06-06 0:38 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-04 17:29 [PATCH 0/6] Refactor fetch negotiation into its own API Jonathan Tan
2018-06-04 17:29 ` [PATCH 1/6] fetch-pack: clear marks before everything_local() Jonathan Tan
2018-06-05 23:08 ` Jonathan Nieder
2018-06-06 0:32 ` Jonathan Tan
2018-06-04 17:29 ` [PATCH 2/6] fetch-pack: truly stop negotiation upon ACK ready Jonathan Tan
2018-06-05 23:16 ` Jonathan Nieder
2018-06-05 23:18 ` Jonathan Nieder
2018-06-06 0:38 ` Jonathan Tan [this message]
2018-06-04 17:29 ` [PATCH 3/6] fetch-pack: in protocol v2, enqueue commons first Jonathan Tan
2018-06-05 23:30 ` Jonathan Nieder
2018-06-06 2:10 ` Jonathan Tan
2018-06-04 17:29 ` [PATCH 4/6] fetch-pack: make negotiation-related vars local Jonathan Tan
2018-06-05 23:35 ` Jonathan Nieder
2018-06-06 2:12 ` Jonathan Tan
2018-06-04 17:29 ` [PATCH 5/6] fetch-pack: move common check and marking together Jonathan Tan
2018-06-06 0:01 ` Jonathan Nieder
2018-06-06 2:12 ` Jonathan Tan
2018-06-04 17:29 ` [PATCH 6/6] fetch-pack: introduce negotiator API Jonathan Tan
2018-06-06 0:37 ` Jonathan Nieder
2018-06-06 2:17 ` Jonathan Tan
2018-06-06 20:47 ` [PATCH v2 0/8] Refactor fetch negotiation into its own API Jonathan Tan
2018-06-06 20:47 ` [PATCH v2 1/8] fetch-pack: split up everything_local() Jonathan Tan
2018-06-14 17:26 ` Brandon Williams
2018-06-06 20:47 ` [PATCH v2 2/8] fetch-pack: clear marks before re-marking Jonathan Tan
2018-06-06 20:47 ` [PATCH v2 3/8] fetch-pack: directly end negotiation if ACK ready Jonathan Tan
2018-06-14 17:29 ` Brandon Williams
2018-06-14 17:34 ` Brandon Williams
2018-06-06 20:47 ` [PATCH v2 4/8] fetch-pack: use ref adv. to prune "have" sent Jonathan Tan
2018-06-14 17:32 ` Brandon Williams
2018-06-14 19:52 ` Junio C Hamano
2018-06-06 20:47 ` [PATCH v2 5/8] fetch-pack: make negotiation-related vars local Jonathan Tan
2018-06-14 17:38 ` Brandon Williams
2018-06-14 19:36 ` Junio C Hamano
2018-06-06 20:47 ` [PATCH v2 6/8] fetch-pack: move common check and marking together Jonathan Tan
2018-06-06 20:47 ` [PATCH v2 7/8] fetch-pack: introduce negotiator API Jonathan Tan
2018-06-06 20:47 ` [PATCH v2 8/8] negotiator/default: use better style in comments Jonathan Tan
2018-06-14 17:39 ` Brandon Williams
2018-06-14 22:54 ` [PATCH v3 0/7] Refactor fetch negotiation into its own API Jonathan Tan
2018-06-14 22:54 ` [PATCH v3 1/7] fetch-pack: split up everything_local() Jonathan Tan
2018-06-14 22:54 ` [PATCH v3 2/7] fetch-pack: clear marks before re-marking Jonathan Tan
2018-06-14 22:54 ` [PATCH v3 3/7] fetch-pack: directly end negotiation if ACK ready Jonathan Tan
2018-06-15 16:04 ` Junio C Hamano
2018-06-14 22:54 ` [PATCH v3 4/7] fetch-pack: use ref adv. to prune "have" sent Jonathan Tan
2018-06-14 22:54 ` [PATCH v3 5/7] fetch-pack: make negotiation-related vars local Jonathan Tan
2018-06-14 22:54 ` [PATCH v3 6/7] fetch-pack: move common check and marking together Jonathan Tan
2018-06-14 22:54 ` [PATCH v3 7/7] fetch-pack: introduce negotiator API Jonathan Tan
2018-06-25 18:24 ` [PATCH v3 0/7] Refactor fetch negotiation into its own API Brandon Williams
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=20180605173818.4d56cf328d81b29a2878c1f6@google.com \
--to=jonathantanmy@google.com \
--cc=bmwill@google.com \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=jrnieder@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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).