contrib/lock-checker.py

merge: change priority / ordering of merge actions

The ordering of actions matters. Normal file system semantics is that files
have to be removed before a directory with the same name can be created.

Before the first ordering key was to have 'r' and 'f' actions come first,
secondary key was the filename.

Because of future refactorings we want to consistently have all action types
(with a sensible priority) as separate first keys. Grouped by action type, we
sort by filename.

Not processing in strict filename order could give worse performance,
especially on spinning disks. That is however primarily an issue in the cases
where "all" actions are of the same kind and will be grouped together anyway.

"""Extension to verify locks are obtained in the required places.

This works by wrapping functions that should be surrounded by a lock
and asserting the lock is held. Missing locks are called out with a
traceback printed to stderr.

This currently only checks store locks, not working copy locks.
"""
import os
from mercurial import util

def _checklock(repo):
    l = repo._lockref and repo._lockref()
    if l is None or not l.held:
        util.debugstacktrace('missing lock', skip=1)

def reposetup(ui, repo):
    orig = repo.__class__
    class lockcheckrepo(repo.__class__):
        def _writejournal(self, *args, **kwargs):
            _checklock(self)
            return orig._writejournal(self, *args, **kwargs)

        def transaction(self, *args, **kwargs):
            _checklock(self)
            return orig.transaction(self, *args, **kwargs)

        # TODO(durin42): kiilerix had a commented-out lock check in
        # _writebranchcache and _writerequirements

        def _tag(self, *args, **kwargs):
            _checklock(self)
            return orig._tag(self, *args, **kwargs)

        def write(self, *args, **kwargs):
            assert os.path.lexists(self._join('.hg/wlock'))
            return orig.write(self, *args, **kwargs)

    repo.__class__ = lockcheckrepo