tests/test-lock.py

debug: add a method to check the state of, and built an SSL cert chain

This is only useful on Windows, and avoids the need to use Internet Explorer to
build the certificate chain.  I can see this being extended in the future to
print information about the certificate(s) to help debug issues on any platform.
Maybe even perform some of the python checks listed on the secure connections
wiki page.  But for now, all I need is 1) a command that can be invoked in a
setup script to ensure the certificate is installed, and 2) a command that the
user can run if/when a certificate changes in the future.

It would have been nice to leverage the sslutil library to pick up host specific
settings, but attempting to use sslutil.wrapsocket() failed the
'not sslsocket.cipher()' check in it and aborted.

The output is a little more chatty than some commands, but I've seen the update
take 10+ seconds, and this is only a debug command.

from __future__ import absolute_import

import copy
import errno
import os
import silenttestrunner
import tempfile
import types
import unittest

from mercurial import (
    error,
    lock,
    vfs as vfsmod,
)

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 = vfsmod.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)

        with self.assertRaises(error.LockInheritanceContractViolation):
            with lock.inherit():
                pass

        lock.release()

    def testfrequentlockunlock(self):
        """This tests whether lock acquisition fails as expected, even if
        (1) lock can't be acquired (makelock fails by EEXIST), and
        (2) locker info can't be read in (readlock fails by ENOENT) while
        retrying 5 times.
        """

        d = tempfile.mkdtemp(dir=os.getcwd())
        state = teststate(self, d)

        def emulatefrequentlock(*args):
            raise OSError(errno.EEXIST, "File exists")
        def emulatefrequentunlock(*args):
            raise OSError(errno.ENOENT, "No such file or directory")

        state.vfs.makelock = emulatefrequentlock
        state.vfs.readlock = emulatefrequentunlock

        try:
            state.makelock(timeout=0)
            self.fail("unexpected lock acquisition")
        except error.LockHeld as why:
            self.assertTrue(why.errno == errno.ETIMEDOUT)
            self.assertTrue(why.locker == "")
            state.assertlockexists(False)

if __name__ == '__main__':
    silenttestrunner.main(__name__)