public void No_deadlock_and_no_race_condition_on_resources_using_sessions()
{
var mgr = new LockManager();
var watch = new Stopwatch();
watch.Start();
int iterations = 10_000;
Parallel.For(0, iterations, i =>
{
Parallel.Invoke(
() =>
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, false, "a", "b", "c");
ReadAbc();
mgr.CloseSession(session);
},
() =>
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, false, "a");
ReadA();
mgr.CloseSession(session);
},
() =>
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, true, "a", "b", "c");
WriteAbc();
mgr.CloseSession(session);
},
() =>
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, true, "a");
WriteA();
mgr.CloseSession(session);
});
});
watch.Stop();
Console.WriteLine($"{iterations} iterations took {watch.ElapsedMilliseconds} ms");
Console.WriteLine($"retries = {mgr.Retries}");
Console.WriteLine($"a = {_resourceA.Count} b = {_resourceB.Count} c = {_resourceC.Count}");
int locks = mgr.GetCurrentlyHoldLocks();
Assert.AreEqual(0, locks);
}
public void Consistent_read_sessions()
{
ILockManager lockManager = new LockManager(null);
var session = Guid.NewGuid();
lockManager.AcquireLock(session, false, "x", "y", "z");
bool success = lockManager.CheckLock(session, false, "x");
Assert.IsTrue(success);
// try with a new session (should not work)
success = lockManager.CheckLock(Guid.NewGuid(), false, "x");
Assert.IsFalse(success);
// read-only lock so it should not work
success = lockManager.CheckLock(session, true, "x");
Assert.IsFalse(success);
// different resource so it should not work
success = lockManager.CheckLock(session, true, "nope");
Assert.IsFalse(success);
// trying to close an inactive session throws an exception
Assert.Throws <NotSupportedException>(() => lockManager.CloseSession(Guid.NewGuid()));
}
public void Managing_pending_locks()
{
var log = A.Fake <IEventsLog>();
ILockManager lockManager = new LockManager(log);
var sessionId = Guid.NewGuid();
lockManager.AcquireLock(sessionId, false, "x", "y", "z");
Assert.AreEqual(3, lockManager.GetCurrentlyHoldLocks());
Assert.IsTrue(lockManager.CheckLock(sessionId, false, "x", "y", "z"));
// false because it is a read-only lock
Assert.False(lockManager.CheckLock(sessionId, true, "x", "y", "z"));
lockManager.CloseSession(sessionId);
Assert.AreEqual(0, lockManager.GetCurrentlyHoldLocks());
// session no longer active
Assert.IsFalse(lockManager.CheckLock(sessionId, false, "x", "y", "z"));
lockManager.AcquireLock(sessionId, true, "tony", "tara");
Assert.AreEqual(2, lockManager.GetCurrentlyHoldLocks());
Thread.Sleep(500);
Assert.AreEqual(2, lockManager.GetCurrentlyHoldLocks(100));
var locks = lockManager.ForceRemoveAllLocks(100);
A.CallTo(() => log.LogEvent(EventType.LockRemoved, null, 0)).MustHaveHappened();
Assert.AreEqual(2, locks);
Assert.AreEqual(0, lockManager.GetCurrentlyHoldLocks());
}
public void Mixed_use_of_sessions_and_simple_accesses_simulating_both_transactional_and_non_transactional_clients()
{
var mgr = new LockManager();
var watch = new Stopwatch();
watch.Start();
int iterations = 100;
Parallel.For(0, iterations, i =>
{
Parallel.Invoke(
() =>
{
for (int i = 0; i < iterations; i++)
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, false, "a", "b", "c");
ReadAbc();
mgr.CloseSession(session);
}
},
() =>
{
for (int i = 0; i < iterations; i++)
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, false, "a");
ReadA();
mgr.CloseSession(session);
}
},
() =>
{
for (int i = 0; i < iterations; i++)
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, true, "a", "b", "c");
WriteAbc();
mgr.CloseSession(session);
}
},
() =>
{
for (int i = 0; i < iterations; i++)
{
var session = Guid.NewGuid();
mgr.AcquireLock(session, true, "a");
WriteA();
mgr.CloseSession(session);
}
},
() =>
{
for (int i = 0; i < 100; i++)
{
mgr.DoWithReadLock(ReadAbc, "a", "b", "c");
}
},
() =>
{
for (int i = 0; i < 100; i++)
{
mgr.DoWithReadLock(ReadA, "a");
}
},
() =>
{
for (int i = 0; i < 100; i++)
{
mgr.DoWithWriteLock(WriteAbc, "a", "b", "c");
}
},
() =>
{
for (int i = 0; i < 100; i++)
{
mgr.DoWithWriteLock(WriteA, "a");
}
});
});
watch.Stop();
Console.WriteLine($"{iterations} iterations took {watch.ElapsedMilliseconds} ms");
Console.WriteLine($"retries = {mgr.Retries}");
Console.WriteLine($"a = {_resourceA.Count} b = {_resourceB.Count} c = {_resourceC.Count}");
int locks = mgr.GetCurrentlyHoldLocks();
Assert.AreEqual(0, locks);
}