view contrib/lock-checker.py @ 20244:47d0843647d1

util: introduce util.debugstacktrace for showing a stack trace without crashing

This is often very handy when hacking/debugging.

Calling util.debugstacktrace('hey') from a place in hg will give something like:
  hey at:
   ./hg:38                                     in <module>
   /home/user/hgsrc/mercurial/dispatch.py:28   in run
   /home/user/hgsrc/mercurial/dispatch.py:65   in dispatch
   /home/user/hgsrc/mercurial/dispatch.py:88   in _runcatch
   /home/user/hgsrc/mercurial/dispatch.py:740  in _dispatch
   /home/user/hgsrc/mercurial/dispatch.py:514  in runcommand
   /home/user/hgsrc/mercurial/dispatch.py:830  in _runcommand
   /home/user/hgsrc/mercurial/dispatch.py:801  in checkargs
   /home/user/hgsrc/mercurial/dispatch.py:737  in <lambda>
   /home/user/hgsrc/mercurial/util.py:472      in check
...

"""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