public void UnlockWriteTest()
{
MyLM target = new MyLM();
Transaction context = new Transaction();
Transaction context2 = new Transaction();
Lockable resource = new RID(RID.Type.CAR, "test");
target.LockForWrite(context, resource);
target.UnlockWrite(context, resource);
target.LockForWrite(context2, resource);
}
public void LM_UpgradeReadLockToWriteLock5()
{
MyLM lm = new MyLM();
RID res1 = new RID();
Transaction t1 = new Transaction();
lm.LockForRead(t1, res1);
lm.LockForWrite(t1, res1);
lm.LockForWrite(t1, res1); // This should be a noop since the transaction already has a write lock on the resource.
}
public void LM_GetWritelockOnResLockedWithWriteLock()
{
MyLM lm = new MyLM();
RID res1 = new RID();
Transaction t1 = new Transaction();
Transaction t2 = new Transaction();
lm.setDeadlockTimeout(500); // Shorten deadlock timeout to speed up unit test
lm.LockForWrite(t1, res1);
lm.LockForWrite(t2, res1);
}
public void LM_UpgradeReadLockToWriteLock4()
{
MyLM lm = new MyLM();
RID res1 = new RID();
Transaction t1 = new Transaction();
Transaction t2 = new Transaction();
lm.setDeadlockTimeout(500); // Shorten deadlock timeout to speed up unit test
lm.LockForWrite(t2, res1);
lm.LockForWrite(t1, res1);
}
public void LockForWriteTest()
{
MyLM target = new MyLM();
target.setDeadlockTimeout(1000);
Transaction context = new Transaction();
Transaction context2 = new Transaction();
Lockable resource = new RID(RID.Type.CAR, "test");
target.setDeadlockTimeout(10);
target.LockForWrite(context, resource);
target.LockForWrite(context2, resource);
}
public void LockConversionTest3()
{
MyLM target = new MyLM();
target.setDeadlockTimeout(1000);
Transaction context = new Transaction();
Transaction context2 = new Transaction();
Lockable resource = new RID(RID.Type.CAR, "test");
target.LockForUpdate(context, resource);
target.LockForRead(context2, resource);
ManualResetEvent e = new ManualResetEvent(false);
ThreadPool.QueueUserWorkItem((obj) =>
{
Thread.Sleep(200);
target.UnlockRead(context2, resource);
e.Set();
});
target.LockForWrite(context, resource);
if (!e.WaitOne(2000))
{
Assert.Fail("Failed");
}
}
public void LM_DowngradeWriteLockToReadLock()
{
MyLM lm = new MyLM();
RID res1 = new RID();
Transaction t1 = new Transaction();
lm.LockForWrite(t1, res1);
lm.LockForRead(t1, res1);
}
public void LockConversionTest2()
{
MyLM target = new MyLM();
target.setDeadlockTimeout(1000);
Transaction context = new Transaction();
Transaction context2 = new Transaction();
Lockable resource = new RID(RID.Type.CAR, "test");
target.setDeadlockTimeout(10);
target.LockForUpdate(context, resource);
target.LockForRead(context2, resource);
target.LockForWrite(context, resource);
Assert.Fail("shall not reach this line");
}
public void LM_UpgradeReadLockToWriteLock2()
{
MyLM lm = new MyLM();
RID res1 = new RID();
Transaction t1 = new Transaction();
LM_Rid_Bundle param = new LM_Rid_Bundle(lm, res1);
Thread thread = new Thread(AttemptWriteLockOnResource);
lm.setDeadlockTimeout(3000); // Shorten deadlock timeout to 3 seconds speed up unit test
lm.LockForRead(t1, res1);
thread.Start(param);
Thread.Sleep(1000);
lm.LockForWrite(t1, res1);
thread.Join();
// Make sure that the second thread failed with deadlock exception.
// This should happen because the first thread is still holding either the read lock or write lock
// when the second thread trys to acquire a write lock. The second thread won't be able to steal the
// lock from the first thread because two phase locking was used when the LM upgrades the read lock
// to a write lock.
Assert.AreEqual(param.status, 1);
}