public async Task LockManager_BasicTest()
{
LockManager <int, int> lockManager = new LockManager <int, int>();
await lockManager.AcquireLock(1, 1, LockMode.Update);
await lockManager.AcquireLock(1, 2, LockMode.Update);
await lockManager.AcquireLock(1, 3, LockMode.Update);
Task[] tasks = new Task[]
{
lockManager.AcquireLock(2, 1, LockMode.Update),
lockManager.AcquireLock(3, 2, LockMode.Update),
lockManager.AcquireLock(4, 3, LockMode.Update),
};
lockManager.ReleaseLocks(1);
Task.WaitAll(tasks);
lockManager.ReleaseLocks(2);
lockManager.ReleaseLocks(3);
await lockManager.AcquireLock(5, 1, LockMode.Default);
await lockManager.AcquireLock(5, 2, LockMode.Default);
await Assert.ThrowsExceptionAsync <TimeoutException>(
async() =>
{
await lockManager.AcquireLock(5, 3, LockMode.Default, timeout: TimeSpan.FromMilliseconds(10));
}
);
}
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 ChangeRequestTask GetChangeRequestTaskByIdForEdit(int id, string currentUser)
{
using (var transaction = _appDataContext.Database.BeginTransaction(System.Data.IsolationLevel.Serializable))
{
try
{
LockManager lockManager = new LockManager(_appDataContext);
lockManager.AcquireLock(id, "ChangeRequestTask", currentUser);
ChangeRequestTask crt = _appDataContext.ChangeRequestTasks.Where(c => c.ID == id).SingleOrDefault();
if (crt != null)
{
transaction.Commit();
}
else
{
throw new ConcurrencyException(
"Entity not found. Entity man have been deleted by another user.");
}
return(crt);
}
catch (ConcurrencyException ex)
{
transaction.Rollback();
string newMessage = ex.Message.Replace("Entity", "Change Request Task " + id.ToString("D5"));
throw new ConcurrencyException(newMessage);
}
catch (Exception)
{
transaction.Rollback();
throw;
}
}
}
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 LockTest_PathPipLockNotMutallyExclusive()
{
Setup();
var lockManager = new LockManager();
var process = CreateProcess(new[] { CreateSourceFile() }, new[] { CreateOutputFileArtifact() });
// Test pip locks and path locks are NOT mutually exclusive
TestMutuallyExclusive(
() => lockManager.AcquirePathAccessLock(process),
() => lockManager.AcquireLock(new PipId(30)),
assertExclusive: false);
}
public void LockTest_CommonPipLockMutallyExclusive()
{
Setup();
var lockManager = new LockManager();
// Single pip contention
TestMutuallyExclusive(() => lockManager.AcquireLock(new PipId(20)), () => lockManager.AcquireLock(new PipId(20)));
// Single pip contention with one pair pip lock
TestMutuallyExclusive(() => lockManager.AcquireLocks(new PipId(20), new PipId(21)), () => lockManager.AcquireLock(new PipId(20)));
// Pair pip contention reverse order
TestMutuallyExclusive(() => lockManager.AcquireLocks(new PipId(20), new PipId(21)), () => lockManager.AcquireLocks(new PipId(21), new PipId(20)));
}
public MsrLockResponse Lock(MsrLockRequest request)
{
ThrowIf.Null(request, "request");
NetTracer.Information(string.Format("The Msr lock request received: {0}", request.DeviceName));
IRamblerStripeReader device;
MsrLockResponse result = new MsrLockResponse();
result.Token = LockManager.AcquireLock <IRamblerStripeReader>(Microsoft.Dynamics.Commerce.HardwareStation.HostHelpers.HostContext.GetCurrentUser(this.Request), request, out device);
NetTracer.Information(string.Format("The Msr device is locked: {0}", result.Token));
return(result);
}
public void LockTest_GlobalLock_PipLockMutallyExclusive()
{
Setup();
var lockManager = new LockManager();
// Global lock and pip lock are mutually exclusive
TestMutuallyExclusive(() => lockManager.AcquireGlobalExclusiveLock(), () => lockManager.AcquireLock(new PipId(20)));
}
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);
}
/// <summary>
/// Acquires an update lock
/// </summary>
/// <returns>False if lock is already set</returns>
public bool AcquireUpdateLock()
{
return(lockManager.AcquireLock(LockManager.UpdateFlag));
}