Fix test failures in test_sync_noflush_novote, take 2

The doTicks approach did not work well because it isn't very accurate and doesn't take into account the time spent outside of the actual ticking.
So this replaces it with a direct loop which compares against the current time to ensure that exactly the right amount of time has elapsed since the creation of the SyncObj.

This test may break again if the time spent inside SyncObj increases greatly; for example, if __init__ takes very long, the start time would not match the corresponding values inside the objects. Each individual tick may also not take too long.

Author: JustAnotherArchivist

test_syncobj.py

@@ -379,6 +379,14 @@ def sync_noflush_novote(journalFile2Enabled):
 	# Specifically, o2 is expected to ignore the messages until 1.1 * timeout, i.e. including the one sent by o1 after 2.5 seconds, except for updating its term.
 	# Note that o1 has flushing enabled but o2 doesn't!
 
+	def tick(o1, o2, startTime, totalTickTime, sleepTime):
+		# Tick o1 and o2 until totalTickTime has elapsed since startTime
+		assert time.time() < startTime + totalTickTime # Make sure that we tick at least once
+		while time.time() < start + totalTickTime:
+			o1.doTick()
+			o2.doTick()
+			time.sleep(sleepTime)
+
 	random.seed(42)
 
 	a = [getNextAddr(), getNextAddr()]
@@ -397,14 +405,15 @@ def sync_noflush_novote(journalFile2Enabled):
 
 	states = defaultdict(list)
 
+	start = time.time()
 	o1 = TestObj(a[0], [a[1]], TEST_TYPE.NOFLUSH_NOVOTE_1, journalFile = journalFiles[0], onStateChanged=lambda old, new: states[a[0]].append(new))
 	o2 = TestObj(a[1], [a[0]], TEST_TYPE.NOFLUSH_NOVOTE_2, journalFile = journalFiles[1] if journalFile2Enabled else None, onStateChanged=lambda old, new: states[a[1]].append(new))
 	objs = [o1, o2]
 
 	assert not o1._isReady()
 	assert not o2._isReady()
 
-	doTicks(objs, 2.25)
+	tick(o1, o2, start, 2.25, 0.01)
 
 	# Here, o1 has called several elections, but o2 never granted its vote.
 
@@ -413,20 +422,30 @@ def sync_noflush_novote(journalFile2Enabled):
 	assert _RAFT_STATE.LEADER not in states[a[0]]
 	assert states[a[1]] == [] # Never had a state change, i.e. it's still the default follower
 
-	doTicks(objs, 0.3) # 2.55 total
+	tick(o1, o2, start, 2.45, 0.01)
 
-	# We have now surpassed o2's timeout, but the last vote request from o1 was at 2.5, i.e. *before* o2's 1.1 * timeout (= 2.64) has expired.
+	# We have now surpassed o2's timeout, but the last vote request from o1 was at 2.0, i.e. *before* o2's 1.1 * timeout (= 2.64) has expired.
 	# o2 is expected to have called for an election at 2.4, but o1 would never vote for o2 due to the missing log entry.
-	# Due to the bigger term in o2's vote request message, o1 should now be a follower.
+	# o1 converted to a follower due to o2's bigger term.
 
 	assert o1._SyncObj__raftState == _RAFT_STATE.FOLLOWER
 	assert o2._SyncObj__raftState == _RAFT_STATE.CANDIDATE
 	assert _RAFT_STATE.LEADER not in states[a[0]]
 	assert _RAFT_STATE.LEADER not in states[a[1]]
 
-	doTicks(objs, 0.6) # 3.15 total
+	tick(o1, o2, start, 2.55, 0.01)
+
+	# While o1 converted to a follower at 2.4 due to o2's vote request, it still called for an election at 2.5 since the term change doesn't affect the election timeout.
+	# Therefore, o2 converted to a follower again at 2.5 due to the bigger term. However, o2 still didn't grant its vote to o1 since 1.1 * timeout (= 2.64) hasn't elapsed yet.
+
+	assert o1._SyncObj__raftState == _RAFT_STATE.CANDIDATE
+	assert o2._SyncObj__raftState == _RAFT_STATE.FOLLOWER
+	assert _RAFT_STATE.LEADER not in states[a[0]]
+	assert _RAFT_STATE.LEADER not in states[a[1]]
+
+	tick(o1, o2, start, 3.15, 0.01)
 
-	# o1 called for another election at 2.9 (it reset its timeout on o2's vote request at 2.4), i.e. after o2's vote block timeout, so it should now be elected.
+	# o1 called for another election at 3.0, i.e. after o2's vote block timeout, so it should now be elected.
 	assert o1._SyncObj__raftState == _RAFT_STATE.LEADER
 	assert o2._SyncObj__raftState == _RAFT_STATE.FOLLOWER
 	assert _RAFT_STATE.LEADER not in states[a[1]]