test-lock.py: add a lock wrapper that allows faking the PID

This will be used in upcoming patches to create locks that appear as if they're
being created by child processes.

tests/test-lock.py

@@ -1,136 +1,145
 from __future__ import absolute_import
 
 import os
 import silenttestrunner
 import tempfile
 import unittest
 
 from mercurial import (
     lock,
     scmutil,
 )
 
 testlockname = 'testlock'
 
+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 os.getpid() + self._pidoffset
+
 class teststate(object):
     def __init__(self, testcase, dir):
         self._testcase = testcase
         self._acquirecalled = False
         self._releasecalled = False
         self._postreleasecalled = False
         self.vfs = scmutil.vfs(dir, audit=False)
 
     def makelock(self, *args, **kwargs):
         l = lock.lock(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)
         lock.lock()
         # fake a fork
         lock.pid += 1
         lock.release()
         state.assertreleasecalled(False)
         state.assertpostreleasecalled(False)
         state.assertlockexists(True)
 
         # release the actual lock
         lock.pid -= 1
         lock.release()
         state.assertreleasecalled(True)
         state.assertpostreleasecalled(True)
         state.assertlockexists(False)
 
 if __name__ == '__main__':
     silenttestrunner.main(__name__)