Mercurial > hg
view tests/test-merge-halt.t @ 37631:2f626233859b
wireproto: implement batching on peer executor interface
This is a bit more complicated than non-batch requests because we
need to buffer sends until the last request arrives *and* we need
to support resolving futures as data arrives from the remote.
In a classical concurrent.futures executor model, the future
"starts" as soon as it is submitted. However, we have nothing to
start until the last command is submitted.
If we did nothing, calling result() would deadlock, since the future
hasn't "started." So in the case where we queue the command, we return
a special future type whose result() will trigger sendcommands().
This eliminates the deadlock potential. It also serves as a check
against callers who may be calling result() prematurely, as it will
prevent any subsequent callcommands() from working. This behavior
is slightly annoying and a bit restrictive. But it's the world
that half duplex connections forces on us.
In order to support streaming responses, we were previously using
a generator. But with a futures-based API, we're using futures
and not generators. So in order to get streaming, we need a
background thread to read data from the server.
The approach taken in this patch is to leverage the ThreadPoolExecutor
from concurrent.futures for managing a background thread. We create
an executor and future that resolves when all response data is
processed (or an error occurs). When exiting the context manager,
we wait on that background reading before returning.
I was hoping we could manually spin up a threading.Thread and this
would be simple. But I ran into a few deadlocks when implementing.
After looking at the source code to concurrent.futures, I figured
it would just be easier to use a ThreadPoolExecutor than implement
all the code needed to manually manage a thread.
To prove this works, a use of the batch API in discovery has been
updated.
Differential Revision: https://phab.mercurial-scm.org/D3269
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 13 Apr 2018 11:02:34 -0700 |
parents | 05535d0dea68 |
children | dc5e5577af39 |
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$ cat >> $HGRCPATH <<EOF > [extensions] > rebase= > [phases] > publish=False > [merge] > EOF $ hg init repo $ cd repo $ echo a > a $ echo b > b $ hg commit -qAm ab $ echo c >> a $ echo c >> b $ hg commit -qAm c $ hg up -q ".^" $ echo d >> a $ echo d >> b $ hg commit -qAm d Testing on-failure=continue $ echo on-failure=continue >> $HGRCPATH $ hg rebase -s 1 -d 2 --tool false rebasing 1:1f28a51c3c9b "c" merging a merging b merging a failed! merging b failed! unresolved conflicts (see hg resolve, then hg rebase --continue) [1] $ hg resolve --list U a U b $ hg rebase --abort rebase aborted Testing on-failure=halt $ echo on-failure=halt >> $HGRCPATH $ hg rebase -s 1 -d 2 --tool false rebasing 1:1f28a51c3c9b "c" merging a merging b merging a failed! merge halted after failed merge (see hg resolve) [1] $ hg resolve --list U a U b $ hg rebase --abort rebase aborted Testing on-failure=prompt $ cat <<EOS >> $HGRCPATH > [merge] > on-failure=prompt > [ui] > interactive=1 > EOS $ cat <<EOS | hg rebase -s 1 -d 2 --tool false > y > n > EOS rebasing 1:1f28a51c3c9b "c" merging a merging b merging a failed! continue merge operation (yn)? y merging b failed! continue merge operation (yn)? n merge halted after failed merge (see hg resolve) [1] $ hg resolve --list U a U b $ hg rebase --abort rebase aborted Check that successful tool with failed post-check halts the merge $ cat <<EOS >> $HGRCPATH > [merge-tools] > true.check=changed > EOS $ cat <<EOS | hg rebase -s 1 -d 2 --tool true > y > n > n > EOS rebasing 1:1f28a51c3c9b "c" merging a merging b output file a appears unchanged was merge successful (yn)? y output file b appears unchanged was merge successful (yn)? n merging b failed! continue merge operation (yn)? n merge halted after failed merge (see hg resolve) [1] $ hg resolve --list R a U b $ hg rebase --abort rebase aborted Check that conflicts with conflict check also halts the merge $ cat <<EOS >> $HGRCPATH > [merge-tools] > true.check=conflicts > true.premerge=keep > [merge] > on-failure=halt > EOS $ hg rebase -s 1 -d 2 --tool true rebasing 1:1f28a51c3c9b "c" merging a merging b merging a failed! merge halted after failed merge (see hg resolve) [1] $ hg resolve --list U a U b $ hg rebase --abort rebase aborted Check that always-prompt also can halt the merge $ cat <<EOS | hg rebase -s 1 -d 2 --tool true --config merge-tools.true.check=prompt > y > n > EOS rebasing 1:1f28a51c3c9b "c" merging a merging b was merge of 'a' successful (yn)? y was merge of 'b' successful (yn)? n merging b failed! merge halted after failed merge (see hg resolve) [1] $ hg resolve --list R a U b $ hg rebase --abort rebase aborted Check that successful tool otherwise allows the merge to continue $ hg rebase -s 1 -d 2 --tool echo --keep --config merge-tools.echo.premerge=keep rebasing 1:1f28a51c3c9b "c" merging a merging b $TESTTMP/repo/a *a~base* *a~other* (glob) $TESTTMP/repo/b *b~base* *b~other* (glob)