commands: make commit acquire locks before processing (issue4368) Before this patch, "hg commit" (process A) executes steps below: 1. get current branch heads via 'repo.branchheads()' - cache 'repo.changelog' 2. invoke 'repo.commit()' 3. acquire wlock - invalidate 'repo.dirstate' 4. access 'repo.dirstate' - re-read '.hg/dirstate' - check validity of parent revisions with 'repo.changelog' 5. invoke 'repo.commitctx()' 6. acquire store lock (slock) - invalidate 'repo.changelog' 7. do committing 8. release slock 9. release wlock 10. check new branch head (via 'cmdutil.commitstatus()') If acquisition of wlock at (3) above waits for another "hg commit" (process B) or so running parallelly to release wlock, process A causes creating orphan revision, because: - '.hg/dirstate' refers the revision, which is newly added by process B, as its parent - but already cached 'repo.changelog' doesn't contain such revision - therefore, validating parents of '.hg/dirstate' at (4) above replaces such revision with 'nullid' Then, process A creates "orphan" revision, of which parent is "null" revision. In addition to it, "created new head" may be shown at the end of process A unintentionally, if store is updated parallelly, because both getting branch heads (1) and checking new branch head (10) are executed outside slock scope. To avoid this issue, this patch makes "hg commit" acquire wlock and slock before processing. This patch resolves the issue between "hg commit" processes, but not one between "hg commit" and other commands. Subsequent patches resolve the latter. Even after this patch, there are still corner case problems below: - filecache may overlook changes of '.hg/dirstate', and it causes similar issue (see below for detail) https://bz.mercurial-scm.org/show_bug.cgi?id=4368#c10 - 3rd party extension may cause similar issue, if it directly uses 'repo.commit()' without acquisition of wlock and slock This can be fixed by acquisition of slock at the beginning of 'repo.commit()', but it seems suitable for "default" branch In fact, acquisition of slock itself is already introduced at "default" branch by 4414d500604f, but acquisition is not at the beginning of 'repo.commit()'. This patch also changes some tests: - test-fncache.t needs this tricky wrapping, to release (= forced failure of) wlock certainly - order of "hg commit" output is changed by widening scope of locks, because some hooks are fired after releasing wlock

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#require killdaemons

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Test wire protocol unbundle with hashed heads (capability: unbundlehash)

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  $ cat << EOF >> $HGRCPATH

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  > [experimental]

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  > # This tests is intended for bundle1 only.

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  > # bundle2 carries the head information inside the bundle itself and

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  > # always uses 'force' as the heads value.

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  > bundle2-exp = False

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  > EOF

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Create a remote repository.

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  $ hg init remote

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  $ hg serve -R remote --config web.push_ssl=False --config web.allow_push=* -p $HGPORT -d --pid-file=hg1.pid -E error.log -A access.log

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  $ cat hg1.pid >> $DAEMON_PIDS

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Clone the repository and push a change.

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  $ hg clone http://localhost:$HGPORT/ local

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  no changes found

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  updating to branch default

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  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

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  $ touch local/README

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  $ hg ci -R local -A -m hoge

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  adding README

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  $ hg push -R local

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  pushing to http://localhost:$HGPORT/

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  searching for changes

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  remote: adding changesets

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  remote: adding manifests

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  remote: adding file changes

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  remote: added 1 changesets with 1 changes to 1 files

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Ensure hashed heads format is used.

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The hash here is always the same since the remote repository only has the null head.

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  $ cat access.log | grep unbundle

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  * - - [*] "POST /?cmd=unbundle HTTP/1.1" 200 - x-hgarg-1:heads=686173686564+6768033e216468247bd031a0a2d9876d79818f8f (glob)

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Explicitly kill daemons to let the test exit on Windows

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  $ killdaemons.py

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