public IAsyncResult BeginWrite(ReaderWriterGateCallback callback, Object state,
AsyncCallback asyncCallback, Object asyncState) {
AsyncResult<Object> ar = new AsyncResult<Object>(asyncCallback, asyncState);
ReaderWriterGateReleaser releaser = new ReaderWriterGateReleaser(callback, this, false, state, ar);
m_syncLock.Enter(true);
switch (m_state) {
case ReaderWriterGateStates.Free: // If Free "RFW -> OBW, invoke, return
case ReaderWriterGateStates.ReservedForWriter:
m_state = ReaderWriterGateStates.OwnedByWriter;
ThreadPool.QueueUserWorkItem(releaser.Invoke);
break;
case ReaderWriterGateStates.OwnedByReaders: // If OBR | OBRAWP -> OBRAWP, queue, return
case ReaderWriterGateStates.OwnedByReadersAndWriterPending:
m_state = ReaderWriterGateStates.OwnedByReadersAndWriterPending;
m_qWriteRequests.Enqueue(releaser);
break;
case ReaderWriterGateStates.OwnedByWriter: // If OBW, queue, return
m_qWriteRequests.Enqueue(releaser);
break;
}
m_syncLock.Leave();
return ar;
}
public IAsyncResult BeginWrite(ReaderWriterGateCallback callback, Object state,
AsyncCallback asyncCallback, Object asyncState)
{
AsyncResult <Object> ar = new AsyncResult <Object>(asyncCallback, asyncState);
ReaderWriterGateReleaser releaser = new ReaderWriterGateReleaser(callback, this, false, state, ar);
m_syncLock.Enter(true);
switch (m_state)
{
case ReaderWriterGateStates.Free: // If Free "RFW -> OBW, invoke, return
case ReaderWriterGateStates.ReservedForWriter:
m_state = ReaderWriterGateStates.OwnedByWriter;
ThreadPool.QueueUserWorkItem(releaser.Invoke);
break;
case ReaderWriterGateStates.OwnedByReaders: // If OBR | OBRAWP -> OBRAWP, queue, return
case ReaderWriterGateStates.OwnedByReadersAndWriterPending:
m_state = ReaderWriterGateStates.OwnedByReadersAndWriterPending;
m_qWriteRequests.Enqueue(releaser);
break;
case ReaderWriterGateStates.OwnedByWriter: // If OBW, queue, return
m_qWriteRequests.Enqueue(releaser);
break;
}
m_syncLock.Leave();
return(ar);
}
internal void Release(Boolean reader)
{
m_syncLock.Enter(true);
// If writer or last reader, the lock is being freed
Boolean freeing = reader ? (--m_numReaders == 0) : true;
if (freeing)
{
// Wake up a writer, or all readers, or set to free
if (m_qWriteRequests.Count > 0)
{
// A writer is queued, invoke it
m_state = ReaderWriterGateStates.OwnedByWriter;
ThreadPool.QueueUserWorkItem(m_qWriteRequests.Dequeue().Invoke);
}
else if (m_qReadRequests.Count > 0)
{
// Reader(s) are queued, invoke all of them
m_state = ReaderWriterGateStates.OwnedByReaders;
m_numReaders = m_qReadRequests.Count;
while (m_qReadRequests.Count > 0)
{
ThreadPool.QueueUserWorkItem(m_qReadRequests.Dequeue().Invoke);
}
}
else
{
// No writers or readers, free the gate
m_state = ReaderWriterGateStates.Free;
}
}
m_syncLock.Leave();
}
public ReaderWriterGate(Boolean blockReadersUntilFirstWriteCompletes) {
m_state = blockReadersUntilFirstWriteCompletes ? ReaderWriterGateStates.ReservedForWriter : ReaderWriterGateStates.Free;
}
internal void Release(Boolean reader) {
m_syncLock.Enter(true);
// If writer or last reader, the lock is being freed
Boolean freeing = reader ? (--m_numReaders == 0) : true;
if (freeing) {
// Wake up a writer, or all readers, or set to free
if (m_qWriteRequests.Count > 0) {
// A writer is queued, invoke it
m_state = ReaderWriterGateStates.OwnedByWriter;
ThreadPool.QueueUserWorkItem(m_qWriteRequests.Dequeue().Invoke);
} else if (m_qReadRequests.Count > 0) {
// Reader(s) are queued, invoke all of them
m_state = ReaderWriterGateStates.OwnedByReaders;
m_numReaders = m_qReadRequests.Count;
while (m_qReadRequests.Count > 0) {
ThreadPool.QueueUserWorkItem(m_qReadRequests.Dequeue().Invoke);
}
} else {
// No writers or readers, free the gate
m_state = ReaderWriterGateStates.Free;
}
}
m_syncLock.Leave();
}
public ReaderWriterGate(Boolean blockReadersUntilFirstWriteCompletes)
{
m_state = blockReadersUntilFirstWriteCompletes ? ReaderWriterGateStates.ReservedForWriter : ReaderWriterGateStates.Free;
}
