Mercurial > hg
view tests/test-exchange-obsmarkers-case-A6.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 | b11e8c67fb0f |
children | 34a46d48d24e |
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============================================ Testing obsolescence markers push: Cases A.6 ============================================ Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of all changesets that requested to be "in sync" after the push (even if they are already on both side). This test belongs to a series of tests checking such set is properly computed and applied. This does not tests "obsmarkers" discovery capabilities. Category A: simple cases TestCase 6: new markers between changesets already known on both side Variants: # a: explicit push # b: bare push A.6 new markers between changesets already known on both side ============================================================== .. {{{ .. A ◕⇠● B .. |/ .. ● O .. }}} .. .. Marker exist from: .. .. * `A◕⇠● B` .. .. Command runs: .. .. * hg push -r B .. * hg push .. .. Expected exchange: .. .. * `A◕⇠● B` Setup ----- $ . $TESTDIR/testlib/exchange-obsmarker-util.sh initial $ setuprepos A.6 creating test repo for test case A.6 - pulldest - main - pushdest cd into `main` and proceed with env setup $ cd main $ mkcommit A0 $ hg update -q 0 $ mkcommit A1 created new head make both changeset known in remote $ hg push -qf ../pushdest $ hg push -qf ../pulldest create a marker after this $ hg debugobsolete `getid 'desc(A0)'` `getid 'desc(A1)'` obsoleted 1 changesets $ hg log -G --hidden @ e5ea8f9c7314 (draft): A1 | | x 28b51eb45704 (draft): A0 |/ o a9bdc8b26820 (public): O $ inspect_obsmarkers obsstore content ================ 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} $ cd .. $ cd .. $ cp -R A.6 A.6.a $ cp -R A.6 A.6.b Actual Test (explicit push version) ----------------------------------- $ dotest A.6.a A1 ## Running testcase A.6.a # testing echange of "A1" (e5ea8f9c7314) ## initial state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest # obstore: pulldest ## pushing "A1" from main to pushdest pushing to pushdest searching for changes no changes found remote: 1 new obsolescence markers remote: obsoleted 1 changesets ## post push state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest ## pulling "e5ea8f9c7314" from main into pulldest pulling from main no changes found 1 new obsolescence markers obsoleted 1 changesets ## post pull state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} Actual Test (bare push version) ------------------------------- $ dotest A.6.b ## Running testcase A.6.b ## initial state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest # obstore: pulldest ## pushing from main to pushdest pushing to pushdest searching for changes no changes found remote: 1 new obsolescence markers remote: obsoleted 1 changesets ## post push state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest ## pulling from main into pulldest pulling from main searching for changes no changes found 1 new obsolescence markers obsoleted 1 changesets ## post pull state # obstore: main 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pushdest 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'} # obstore: pulldest 28b51eb45704506b5c603decd6bf7ac5e0f6a52f e5ea8f9c73143125d36658e90ef70c6d2027a5b7 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}