public void Locksmith_WhenWriteLockIsDowngraded_AllowsNewReadersToEnter()
{
const int successValue = 25;
const int initialValue = 10;
int readResult = initialValue;
ManualResetEvent readerFinishedEvent = new ManualResetEvent(false);
Locksmith.EnterWriteLock(ref lockState, writeLockTestObject);
Locksmith.Downgrade(ref lockState, readLockTestObject);
{
StartNewThreadThatRuns(SetReadResultToFailureValue);
readerFinishedEvent.WaitOne();
Assert.That(readResult, Is.EqualTo(successValue));
}
Locksmith.ExitReadLock(ref lockState, readLockTestObject, writeLockTestObject);
return;
void SetReadResultToFailureValue()
{
Locksmith.EnterReadLock(ref lockState, readLockTestObject);
{
readResult = successValue;
}
Locksmith.ExitReadLock(ref lockState, readLockTestObject, writeLockTestObject);
readerFinishedEvent.Set();
}
}
public void Locksmith_WhenWriteLockIsDowngraded_ThrowsIfExitWriteLockIsCalled()
{
Locksmith.EnterWriteLock(ref lockState, writeLockTestObject);
Locksmith.Downgrade(ref lockState, readLockTestObject);
Assert.Throws <SynchronizationLockException>(TryToCallExitWriteLock);
Locksmith.ExitReadLock(ref lockState, readLockTestObject, writeLockTestObject);
return;
void TryToCallExitWriteLock() =>
Locksmith.ExitWriteLock(ref lockState, readLockTestObject, writeLockTestObject);
}