tests/test-racy-mutations.t
author Pierre-Yves David <pierre-yves.david@octobus.net>
Thu, 07 Mar 2024 10:55:22 +0100
changeset 51531 f85f23f1479b
parent 51181 dcaa2df1f688
permissions -rw-r--r--
branchcache: skip entries that are topological heads in the on disk file In the majority of cases, topological heads are also branch heads. We have efficient way to get the topological heads and efficient way to retrieve their branch information. So there is little value in putting them in the branch cache file explicitly. On the contrary, writing them explicitly tend to create very large cache file that are inefficient to read and update. So the branch cache v3 format is no longer including them. This changeset focus on the format aspect and have no focus on the performance aspect. We will cover that later.

#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