view contrib/lock-checker.py @ 18091:f7f8159caad3

ancestor: add lazy membership testing to lazyancestors

This also makes the perfancestorset command use lazy membership testing. In a
linear repository with over 400,000 commits, without this patch, hg
perfancestorset takes 0.80 seconds no matter how far behind we're looking.
With this patch, hg perfancestorset -- X takes:

    Rev X       Time
       -1      0.00s
    -4000      0.01s
   -20000      0.04s
   -80000      0.17s
  -200000      0.43s
  -300000      0.69s
        0      0.88s

Thus, for revisions close to tip, we're up to several orders of magnitude
faster. At 0 we're around 10% slower.

"""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
import traceback

def _warnstack(ui, msg, skip=1):
    '''issue warning with the message and the current stack, skipping the
    skip last entries'''
    ui.warn('%s at:\n' % msg)
    entries = traceback.extract_stack()[:-skip]
    fnmax = max(len(entry[0]) for entry in entries)
    for fn, ln, func, _text in entries:
        ui.warn(' %*s:%-4s in %s\n' % (fnmax, fn, ln, func))

def _checklock(repo):
    l = repo._lockref and repo._lockref()
    if l is None or not l.held:
        _warnstack(repo.ui, 'missing lock', skip=2)

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