index: embed nodetree in index object to avoid reference cycle
Since the index has a reference to a nodetree and the nodetree has a
reference back to the index, there is a reference cycle, so the index
(and its nodetree) can never be freed. This patch fixes that by making
"nodetree" a plan C struct that the index can embed, and also
introduces a new "nodetreeObject" that is a Python type wrapping the
nodetree struct.
Thanks to Yuya for noticing this and for suggesting the solution.
All tests passed on the first attempt once it compiled (I guess C is
like Haskell in this regard?).
Differential Revision: https://phab.mercurial-scm.org/D4372
# Dummy extension that adds a delay after acquiring a lock.
#
# This extension can be used to test race conditions between lock acquisition.
from __future__ import absolute_import
import os
import time
def reposetup(ui, repo):
class delayedlockrepo(repo.__class__):
def lock(self):
delay = float(os.environ.get('HGPRELOCKDELAY', '0.0'))
if delay:
time.sleep(delay)
res = super(delayedlockrepo, self).lock()
delay = float(os.environ.get('HGPOSTLOCKDELAY', '0.0'))
if delay:
time.sleep(delay)
return res
repo.__class__ = delayedlockrepo