changelog: specify checkambig=True to revlog.__init__, to avoid ambiguity
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to 00changelog.i (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to 00changelog.i again
Therefore, cache validation doesn't work after (3) as expected.
To avoid such file stat ambiguity around truncation, this patch
specifies checkambig=True to revlog.__init__(). This makes revlog
write changes out with checkambig=True.
Even though changes of 00changelog.i themselves are written out at
changelog._finalize(), this checkambig=True is needed, because
revlog.checkinlinesize(), which is invoked at the end of
changelog._finalize(), might replace already changed 00changelog.i by
converted one.
Even after this patch, avoiding file stat ambiguity of 00changelog.i
around truncation isn't yet completed, because truncation side isn't
aware of this issue.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
from __future__ import absolute_import
import copy
import os
import silenttestrunner
import tempfile
import types
import unittest
from mercurial import (
error,
lock,
scmutil,
)
testlockname = 'testlock'
# work around http://bugs.python.org/issue1515
if types.MethodType not in copy._deepcopy_dispatch:
def _deepcopy_method(x, memo):
return type(x)(x.im_func, copy.deepcopy(x.im_self, memo), x.im_class)
copy._deepcopy_dispatch[types.MethodType] = _deepcopy_method
class lockwrapper(lock.lock):
def __init__(self, pidoffset, *args, **kwargs):
# lock.lock.__init__() calls lock(), so the pidoffset assignment needs
# to be earlier
self._pidoffset = pidoffset
super(lockwrapper, self).__init__(*args, **kwargs)
def _getpid(self):
return super(lockwrapper, self)._getpid() + self._pidoffset
class teststate(object):
def __init__(self, testcase, dir, pidoffset=0):
self._testcase = testcase
self._acquirecalled = False
self._releasecalled = False
self._postreleasecalled = False
self.vfs = scmutil.vfs(dir, audit=False)
self._pidoffset = pidoffset
def makelock(self, *args, **kwargs):
l = lockwrapper(self._pidoffset, self.vfs, testlockname,
releasefn=self.releasefn, acquirefn=self.acquirefn,
*args, **kwargs)
l.postrelease.append(self.postreleasefn)
return l
def acquirefn(self):
self._acquirecalled = True
def releasefn(self):
self._releasecalled = True
def postreleasefn(self):
self._postreleasecalled = True
def assertacquirecalled(self, called):
self._testcase.assertEqual(
self._acquirecalled, called,
'expected acquire to be %s but was actually %s' % (
self._tocalled(called),
self._tocalled(self._acquirecalled),
))
def resetacquirefn(self):
self._acquirecalled = False
def assertreleasecalled(self, called):
self._testcase.assertEqual(
self._releasecalled, called,
'expected release to be %s but was actually %s' % (
self._tocalled(called),
self._tocalled(self._releasecalled),
))
def assertpostreleasecalled(self, called):
self._testcase.assertEqual(
self._postreleasecalled, called,
'expected postrelease to be %s but was actually %s' % (
self._tocalled(called),
self._tocalled(self._postreleasecalled),
))
def assertlockexists(self, exists):
actual = self.vfs.lexists(testlockname)
self._testcase.assertEqual(
actual, exists,
'expected lock to %s but actually did %s' % (
self._toexists(exists),
self._toexists(actual),
))
def _tocalled(self, called):
if called:
return 'called'
else:
return 'not called'
def _toexists(self, exists):
if exists:
return 'exist'
else:
return 'not exist'
class testlock(unittest.TestCase):
def testlock(self):
state = teststate(self, tempfile.mkdtemp(dir=os.getcwd()))
lock = state.makelock()
state.assertacquirecalled(True)
lock.release()
state.assertreleasecalled(True)
state.assertpostreleasecalled(True)
state.assertlockexists(False)
def testrecursivelock(self):
state = teststate(self, tempfile.mkdtemp(dir=os.getcwd()))
lock = state.makelock()
state.assertacquirecalled(True)
state.resetacquirefn()
lock.lock()
# recursive lock should not call acquirefn again
state.assertacquirecalled(False)
lock.release() # brings lock refcount down from 2 to 1
state.assertreleasecalled(False)
state.assertpostreleasecalled(False)
state.assertlockexists(True)
lock.release() # releases the lock
state.assertreleasecalled(True)
state.assertpostreleasecalled(True)
state.assertlockexists(False)
def testlockfork(self):
state = teststate(self, tempfile.mkdtemp(dir=os.getcwd()))
lock = state.makelock()
state.assertacquirecalled(True)
# fake a fork
forklock = copy.deepcopy(lock)
forklock._pidoffset = 1
forklock.release()
state.assertreleasecalled(False)
state.assertpostreleasecalled(False)
state.assertlockexists(True)
# release the actual lock
lock.release()
state.assertreleasecalled(True)
state.assertpostreleasecalled(True)
state.assertlockexists(False)
def testinheritlock(self):
d = tempfile.mkdtemp(dir=os.getcwd())
parentstate = teststate(self, d)
parentlock = parentstate.makelock()
parentstate.assertacquirecalled(True)
# set up lock inheritance
with parentlock.inherit() as lockname:
parentstate.assertreleasecalled(True)
parentstate.assertpostreleasecalled(False)
parentstate.assertlockexists(True)
childstate = teststate(self, d, pidoffset=1)
childlock = childstate.makelock(parentlock=lockname)
childstate.assertacquirecalled(True)
childlock.release()
childstate.assertreleasecalled(True)
childstate.assertpostreleasecalled(False)
childstate.assertlockexists(True)
parentstate.resetacquirefn()
parentstate.assertacquirecalled(True)
parentlock.release()
parentstate.assertreleasecalled(True)
parentstate.assertpostreleasecalled(True)
parentstate.assertlockexists(False)
def testmultilock(self):
d = tempfile.mkdtemp(dir=os.getcwd())
state0 = teststate(self, d)
lock0 = state0.makelock()
state0.assertacquirecalled(True)
with lock0.inherit() as lock0name:
state0.assertreleasecalled(True)
state0.assertpostreleasecalled(False)
state0.assertlockexists(True)
state1 = teststate(self, d, pidoffset=1)
lock1 = state1.makelock(parentlock=lock0name)
state1.assertacquirecalled(True)
# from within lock1, acquire another lock
with lock1.inherit() as lock1name:
# since the file on disk is lock0's this should have the same
# name
self.assertEqual(lock0name, lock1name)
state2 = teststate(self, d, pidoffset=2)
lock2 = state2.makelock(parentlock=lock1name)
state2.assertacquirecalled(True)
lock2.release()
state2.assertreleasecalled(True)
state2.assertpostreleasecalled(False)
state2.assertlockexists(True)
state1.resetacquirefn()
state1.assertacquirecalled(True)
lock1.release()
state1.assertreleasecalled(True)
state1.assertpostreleasecalled(False)
state1.assertlockexists(True)
lock0.release()
def testinheritlockfork(self):
d = tempfile.mkdtemp(dir=os.getcwd())
parentstate = teststate(self, d)
parentlock = parentstate.makelock()
parentstate.assertacquirecalled(True)
# set up lock inheritance
with parentlock.inherit() as lockname:
childstate = teststate(self, d, pidoffset=1)
childlock = childstate.makelock(parentlock=lockname)
childstate.assertacquirecalled(True)
# fork the child lock
forkchildlock = copy.deepcopy(childlock)
forkchildlock._pidoffset += 1
forkchildlock.release()
childstate.assertreleasecalled(False)
childstate.assertpostreleasecalled(False)
childstate.assertlockexists(True)
# release the child lock
childlock.release()
childstate.assertreleasecalled(True)
childstate.assertpostreleasecalled(False)
childstate.assertlockexists(True)
parentlock.release()
def testinheritcheck(self):
d = tempfile.mkdtemp(dir=os.getcwd())
state = teststate(self, d)
def check():
raise error.LockInheritanceContractViolation('check failed')
lock = state.makelock(inheritchecker=check)
state.assertacquirecalled(True)
def tryinherit():
with lock.inherit():
pass
self.assertRaises(error.LockInheritanceContractViolation, tryinherit)
lock.release()
if __name__ == '__main__':
silenttestrunner.main(__name__)