def setUp(self):
self.manager = DefaultLockManager()
self.lockfunc = lambda x: None
def test():
from pysqlite2.lock_manager import DefaultLockManager, set_lock_manager
set_lock_manager(DefaultLockManager())
runner = unittest.TextTestRunner()
runner.run(suite())
class LockManagerTests(unittest.TestCase):
def setUp(self):
self.manager = DefaultLockManager()
self.lockfunc = lambda x: None
def tearDown(self):
self.manager = None
def _print(self, message):
# print fmt
pass
def CheckDisabledByDefault(self):
"""The lock manager is disabled by default."""
self.assertEqual(get_lock_manager(), None)
def CheckSharedLocks(self):
"""Check that we can acquire many shared locks concurrently."""
for client in range(10):
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, client)
self._print(self.manager)
for client in range(10):
self.manager.unlock("filename", LOCK_NONE, client)
self._print(self.manager)
self.assertTrue(self.manager.is_idle())
def CheckDetectDeadlock(self):
"""Checks that shared can not be raised to a higher level if a reserved lock exists."""
self.manager.lock(self.lockfunc, "filename", LOCK_RESERVED, "first")
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, "second")
self.assertRaises(DeadlockError, self.manager.lock, self.lockfunc, "filename", LOCK_RESERVED, "second")
self.assertRaises(DeadlockError, self.manager.lock, self.lockfunc, "filename", LOCK_EXCLUSIVE, "second")
def CheckUnlockWithoutLock(self):
"""Checks that unlock without first locking is harmless (SQLite seems to do it sometimes)."""
self.manager.unlock("filename", LOCK_NONE, "client")
def CheckRaiseLower(self):
"""Checks that the lock level can go up and down all the way."""
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, "client")
self.manager.lock(self.lockfunc, "filename", LOCK_RESERVED, "client")
self.manager.lock(self.lockfunc, "filename", LOCK_EXCLUSIVE, "client")
self.manager.unlock("filename", LOCK_RESERVED, "client")
self.manager.unlock("filename", LOCK_SHARED, "client")
self.manager.unlock("filename", LOCK_NONE, "client")
self.assertTrue(self.manager.is_idle())
def CheckExclusiveBlocksShared(self):
"""Check that a shared lock must wait while an exclusive lock is set."""
self.manager.lock(self.lockfunc, "filename", LOCK_EXCLUSIVE, "exclusive")
def shared_locker():
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, "shared")
t = threading.Thread(target=shared_locker)
t.start()
t.join(0.1)
self._print(self.manager)
self.assertTrue(t.is_alive())
self.manager.unlock("filename", LOCK_NONE, "exclusive")
t.join()
self._print(self.manager)
self.assertFalse(self.manager.is_idle())
def CheckPendingBlocksShared(self):
"""Check that a pending lock blocks further shared locks."""
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, "shared_1")
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, "shared_2")
def exclusive_locker():
self.manager.lock(self.lockfunc, "filename", LOCK_EXCLUSIVE, "exclusive")
def shared_locker():
self.manager.lock(self.lockfunc, "filename", LOCK_SHARED, "shared_blocked")
self._print("An exclusive lock will block now (going to PENDING first)")
t_exclusive = threading.Thread(target=exclusive_locker)
t_exclusive.start()
t_exclusive.join(0.1)
self._print(self.manager)
self.assertTrue(t_exclusive.is_alive())
self.assertEqual(self.manager._filelocks["filename"]._lock_holders["exclusive"], LOCK_PENDING)
self._print("A shared lock will be added to the end of the queue")
t_shared = threading.Thread(target=shared_locker)
t_shared.start()
t_shared.join(0.1)
self._print(self.manager)
self.assertTrue(t_shared.is_alive())
self.assertTrue("shared_blocked" not in self.manager._filelocks["filename"]._lock_holders)
self._print("Unblocking the exclusive locker")
self.manager.unlock("filename", LOCK_NONE, "shared_1")
self.manager.unlock("filename", LOCK_NONE, "shared_2")
t_exclusive.join()
self._print(self.manager)
# Shared lock must still be blocked
t_shared.join(0.1)
self.assertTrue(t_shared.is_alive())
self.assertTrue("shared_blocked" not in self.manager._filelocks["filename"]._lock_holders)
self._print("Unblocking the shared locker")
self.manager.unlock("filename", LOCK_NONE, "exclusive")
t_shared.join()
self._print(self.manager)
self.assertFalse(self.manager.is_idle())
self.manager.unlock("filename", LOCK_NONE, "shared_blocked")
self.assertTrue(self.manager.is_idle())
def CheckMutualExclusion(self):
"""Checks that RESERVED or higher locks are mutually exclusive."""
def locker_thread(clientname):
try:
for level in lock_sequence:
self.manager.lock(self.lockfunc, "filename", level, clientname)
time.sleep(0.05)
active_threads.add(threading.current_thread())
# In case the mutual exclusion does not work, this gives other threads
# the chance to take over.
time.sleep(0.1)
concurrent_threads.append(set(active_threads))
active_threads.discard(threading.current_thread())
self.manager.unlock("filename", LOCK_NONE, clientname)
except Exception, e:
traceback.print_exc()
exceptions.append(e)
for lock_sequence in [LOCK_RESERVED, LOCK_EXCLUSIVE], [LOCK_RESERVED], [LOCK_EXCLUSIVE]:
active_threads = set()
concurrent_threads = []
exceptions = []
threads = [threading.Thread(target=locker_thread, args=(name,), name=name)
for name in ("Locker Thread #{0}".format(i) for i in range(5))]
for thread in threads:
thread.start()
for thread in threads:
thread.join()
self.assertFalse(exceptions, "Exceptions in threads for lock sequence {0!r}: {1!r}.".format(lock_sequence, exceptions))
for entry in concurrent_threads:
self.assertTrue(len(entry) == 1, "Concurrent threads detected via lock sequence {0!r}: {1!r}".format(lock_sequence, entry))