tests/test-racy-mutations.t
author Pierre-Yves David <pierre-yves.david@octobus.net>
Tue, 09 Apr 2024 02:54:12 +0200
changeset 51577 b5d494f7d28a
parent 51181 dcaa2df1f688
permissions -rw-r--r--
push: rework the computation of fallbackheads to be correct The previous computation tried to be smart but ended up being wrong. This was caught by phase movement test while reworking the phase discovery logic to be faster. The previous logic was failing to catch case where the pushed set was not based on a common heads (i.e. when the discovery seemed to have "over discovered" content, outside the pushed set) In the following graph, `e` is a common head and we `hg push -r f`. We need to detect `c` as a fallback heads and we previous failed to do so:: e | d f |/ c | b | a The performance impact of the change seems minimal. On the most impacted repository at hand (mozilla-try), the slowdown seems mostly mixed in the overall noise `hg push` but seems to be in the hundred of milliseconds order of magnitude. When using rust, we seems to be a bit faster, probably because we leverage more accelaratd internals. I added a couple of performance related common for further investigation later on.

#testcases skip-detection fail-if-detected

Test situations that "should" only be reproducible:
- on networked filesystems, or
- user using `hg debuglocks` to eliminate the lock file, or
- something (that doesn't respect the lock file) writing to the .hg directory
while we're running


Initial setup
-------------

  $ hg init base-repo
  $ cd base-repo

  $ cat > "$TESTTMP_FORWARD_SLASH/waitlock_editor.sh" <<EOF
  >     [ -n "\${WAITLOCK_ANNOUNCE:-}" ] && touch "\${WAITLOCK_ANNOUNCE}"
  >     f="\${WAITLOCK_FILE}"
  >     start=\`date +%s\`
  >     timeout=5
  >     "$RUNTESTDIR_FORWARD_SLASH/testlib/wait-on-file" "\$timeout" "\$f"
  >     if [ \$# -gt 1 ]; then
  >         cat "\$@"
  >     fi
  > EOF

Things behave differently if we don't already have a 00changelog.i file when
this all starts, so let's make one.

  $ echo r0 > r0
  $ hg commit -qAm 'r0'

  $ cd ..
  $ cp -R base-repo main-client
  $ cp -R base-repo racing-client

  $ mkdir sync
  $ EDITOR_STARTED="$TESTTMP_FORWARD_SLASH/sync/.editor_started"
  $ MISCHIEF_MANAGED="$TESTTMP_FORWARD_SLASH/sync/.mischief_managed"
  $ JOBS_FINISHED="$TESTTMP_FORWARD_SLASH/sync/.jobs_finished"

Actual test
-----------

Start an hg commit that will take a while

  $ cd main-client

#if fail-if-detected
  $ cat >> $HGRCPATH << EOF
  > [debug]
  > revlog.verifyposition.changelog = fail
  > EOF
#endif

  $ echo foo > foo
  $ (
  >    unset HGEDITOR;
  >    WAITLOCK_ANNOUNCE="${EDITOR_STARTED}" \
  >    WAITLOCK_FILE="${MISCHIEF_MANAGED}" \
  >    hg commit -qAm 'r1 (foo)' --edit foo \
  >    --config ui.editor="sh $TESTTMP_FORWARD_SLASH/waitlock_editor.sh" \
  >    > .foo_commit_out 2>&1 ;\
  >    touch "${JOBS_FINISHED}"
  > ) &

Wait for the "editor" to actually start
  $ sh "$RUNTESTDIR_FORWARD_SLASH/testlib/wait-on-file" 5 "${EDITOR_STARTED}"


Do a concurrent edition
  $ cd ../racing-client
  $ touch ../pre-race
  $ sleep 1
  $ echo bar > bar
  $ hg --repository ../racing-client commit -qAm 'r2 (bar)' bar
  $ hg --repository ../racing-client debugrevlogindex -c
     rev linkrev nodeid       p1           p2
       0       0 222799e2f90b 000000000000 000000000000
       1       1 6f124f6007a0 222799e2f90b 000000000000

We simulate an network FS race by overwriting raced repo content with the new
content of the files changed in the racing repository

  $ for x in `find . -type f -newer ../pre-race`; do
  >    cp $x ../main-client/$x
  > done
  $ cd ../main-client

Awaken the editor from that first commit
  $ touch "${MISCHIEF_MANAGED}"
And wait for it to finish
  $ WAITLOCK_FILE="${JOBS_FINISHED}" sh "$TESTTMP_FORWARD_SLASH/waitlock_editor.sh"

#if skip-detection
(Ensure there was no output)
  $ cat .foo_commit_out
And observe a corrupted repository -- rev 2's linkrev is 1, which should never
happen for the changelog (the linkrev should always refer to itself).
  $ hg debugrevlogindex -c
     rev linkrev nodeid       p1           p2
       0       0 222799e2f90b 000000000000 000000000000
       1       1 6f124f6007a0 222799e2f90b 000000000000
       2       1 ac80e6205bb2 222799e2f90b 000000000000
#endif

#if fail-if-detected
  $ cat .foo_commit_out
  note: commit message saved in .hg/last-message.txt
  note: use 'hg commit --logfile .hg/last-message.txt --edit' to reuse it
  transaction abort!
  rollback completed
  abort: 00changelog.i: file cursor at position 128, expected 64
And no corruption in the changelog.
  $ hg debugrevlogindex -c
     rev linkrev nodeid       p1           p2
       0       0 222799e2f90b 000000000000 000000000000
       1       1 6f124f6007a0 222799e2f90b 000000000000 (missing-correct-output !)
And, because of transactions, there's none in the manifestlog either.
  $ hg debugrevlogindex -m
     rev linkrev nodeid       p1           p2
       0       0 7b7020262a56 000000000000 000000000000
       1       1 ad3fe36d86d9 7b7020262a56 000000000000
#endif