Fix several random failures in tests that didn't wait for transaction to be unlocked

NEOCluster.tic() gets a new 'slave' parameter that must be True when a client
node is in 'master' mode (i.e. setPoll(True)). In this case, tic() will wait
that all nodes finish their work and the client polls with a non-zero timeout.

Here, tic(slave=1) is used to wait for the storage to process
NotifyUnlockInformation notification from the master.

Traceback (most recent call last):
  File "neo/tests/threaded/test.py", line 80, in testBasicStore
    self.assertEqual(data_info, cluster.storage.getDataLockInfo())
  File "neo/tests/__init__.py", line 170, in assertEqual
    return super(NeoTestBase, self).assertEqual(first, second, msg=msg)
failureException: {('\x0b\xee\xc7\xb5\xea?\x0f\xdb\xc9]\r\xd4\x7f<[\xc2u\xda\x8a3', 0): 0} != {('\x0b\xee\xc7\xb5\xea?\x0f\xdb\xc9]\r\xd4\x7f<[\xc2u\xda\x8a3', 0): 1}

neo/tests/threaded/__init__.py

@@ -72,6 +72,7 @@ class Serialized(object):
         cls._lock_list = deque() # FIFO of Semaphore
         cls._lock_lock = threading.Lock()
         cls._pdb = False
+        cls.blocking = threading.Event()
         cls.pending = 0
 
     @classmethod
@@ -172,9 +173,16 @@ class SerializedEventManager(EventManager):
             Serialized.tic(self._lock)
             if blocking != 0:
                 blocking = self._blocking
-                if blocking != 0 and Serialized.pending == 1:
+                if blocking != 0:
+                    if Serialized.pending == 1:
                         Serialized.pending = blocking = 0
+                    else:
+                        Serialized.blocking.set()
+        try:
             EventManager._poll(self, blocking)
+        finally:
+            if blocking:
+                Serialized.blocking.clear()
 
     def addReader(self, conn):
         EventManager.addReader(self, conn)
@@ -716,13 +724,14 @@ class NEOCluster(object):
         self._unpatch()
 
     @staticmethod
-    def tic(force=False):
-        # XXX: Should we automatically switch client in slave mode if it isn't ?
+    def tic(force=False, slave=False):
         f = sys._getframe(1)
         try:
             logging.info('tic (%s:%u) ...', f.f_code.co_filename, f.f_lineno)
         finally:
             del f
+        if slave:
+            return Serialized.blocking.wait()
         if force:
             Serialized.tic()
             logging.info('forced tic')

neo/tests/threaded/test.py

@@ -77,6 +77,7 @@ class Test(NEOThreadedTest):
                 self.assertEqual(data_info, cluster.storage.getDataLockInfo())
                 serial = storage.tpc_finish(txn)
                 data_info[key] = 0
+                cluster.tic(slave=1)
                 self.assertEqual(data_info, cluster.storage.getDataLockInfo())
                 self.assertEqual((data, serial), storage.load(oid, ''))
                 storage._cache.clear()
@@ -183,6 +184,7 @@ class Test(NEOThreadedTest):
             self.assertEqual(data_info, cluster.storage.getDataLockInfo())
 
             tid1 = storage.tpc_finish(txn[2])
+            cluster.tic(slave=1)
             data_info[key] -= 1
             self.assertEqual(data_info, cluster.storage.getDataLockInfo())
 
@@ -401,6 +403,7 @@ class Test(NEOThreadedTest):
             t, c = cluster.getTransaction()
             c.root()[0] = 'ok'
             t.commit()
+            cluster.tic(slave=1)
             data_info = cluster.storage.getDataLockInfo()
             self.assertEqual(data_info.values(), [0, 0])
             # (obj|trans) become t(obj|trans)