view tests/test-dirstate-race2.t @ 49275:c6a3243567b6

chg: replace mercurial.util.recvfds() by simpler pure Python implementation On Python 3, we have socket.socket.recvmsg(). This makes it possible to receive FDs in pure Python code. The new code behaves like the previous implementations, except that it’s more strict about the format of the ancillary data. This works because we know in which format the FDs are passed. Because the code is (and always has been) specific to chg (payload is 1 byte, number of passed FDs is limited) and we now have only one implementation and the code is very short, I decided to stop exposing a function in mercurial.util. Note on terminology: The SCM_RIGHTS mechanism is used to share open file descriptions to another process over a socket. The sending side passes an array of file descriptors and the receiving side receives an array of file descriptors. The file descriptors are different in general on both sides but refer to the same open file descriptions. The two terms are often conflated, even in the official documentation. That’s why I used “FD” above, which could mean both “file descriptor” and “file description”.
author Manuel Jacob <me@manueljacob.de>
date Thu, 02 Jun 2022 23:57:56 +0200
parents e845537f6adb
children
line wrap: on
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#testcases dirstate-v1 dirstate-v2

#if dirstate-v2
  $ cat >> $HGRCPATH << EOF
  > [format]
  > use-dirstate-v2=1
  > [storage]
  > dirstate-v2.slow-path=allow
  > EOF
#endif

Checking the size/permissions/file-type of files stored in the
dirstate after an update where the files are changed concurrently
outside of hg's control.

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg commit -qAm _
  $ echo aa > a
  $ hg commit -m _
# this sleep is there to ensure current time has -at-least- one second away
# from the current time. It ensure the mtime is not ambiguous. If the test
# "sleep" longer this will be fine.
# It is not used to synchronise parallele operation so it is "fine" to use it.
  $ sleep 1
  $ hg status

  $ hg debugdirstate --no-dates
  n 644          3 (set  |unset)               a (re)

  $ cat >> $TESTTMP/dirstaterace.py << EOF
  > import time
  > from mercurial import (
  >     commit,
  >     extensions,
  >     merge,
  > )
  > def extsetup(ui):
  >     extensions.wrapfunction(merge, 'applyupdates', wrap(0))
  >     extensions.wrapfunction(commit, 'commitctx', wrap(1))
  > def wrap(duration):
  >     def new(orig, *args, **kwargs):
  >         res = orig(*args, **kwargs)
  >         with open("a", "w"):
  >             pass # just truncate the file
  >         time.sleep(duration)
  >         return res
  >     return new
  > EOF

Do an update where file 'a' is changed between hg writing it to disk
and hg writing the dirstate. The dirstate is correct nonetheless, and
so hg status correctly shows a as clean.

  $ hg up -r 0 --config extensions.race=$TESTTMP/dirstaterace.py
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugdirstate --no-dates
  n 644          2 (set  |unset)               a (re)
  $ echo a > a; hg status; hg diff

Do a commit where file 'a' is changed between hg committing its new
revision into the repository, and the writing of the dirstate.

This used to results in a corrupted dirstate (size did not match committed size).

  $ echo aaa > a; hg commit -qm _
  $ hg merge -qr 1; hg resolve -m; rm a.orig
  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
  (no more unresolved files)
  $ cat a
  <<<<<<< working copy: be46f74ce38d - test: _
  aaa
  =======
  aa
  >>>>>>> merge rev:    eb3fc6c17aa3 - test: _
  $ hg debugdirstate --no-dates
  m   0         -2 (set  |unset)               a (re)
  $ hg commit -m _ --config extensions.race=$TESTTMP/dirstaterace.py
  $ hg debugdirstate --no-dates
  n   0         -1 unset               a
  $ cat a | wc -c
   *0 (re)
  $ hg cat -r . a | wc -c
   *105 (re)
  $ hg status; hg diff --stat
  M a
   a |  5 -----
   1 files changed, 0 insertions(+), 5 deletions(-)