/// <summary>
/// If possible, this method dequeues a read from the read queue and starts it.
/// This is only possible if all of the following are true:
/// 1) any previous read has completed
/// 2) there's a read in the queue
/// 3) and the stream is ready.
///
/// This method is thread safe.
/// </summary>
private void MaybeDequeueRead(object ignore)
{
lock (lockObj)
{
if ((flags & kClosed) > 0)
{
readQueue.Clear();
return;
}
if ((currentRead == null) && (stream != null))
{
if((flags & kPauseReads) > 0)
{
// Don't do any reads yet.
// We're waiting for TLS negotiation to start and/or finish.
}
else if(readQueue.Count > 0)
{
// Get the next object in the read queue
Object nextRead = readQueue.Dequeue();
if (nextRead is AsyncSpecialPacket)
{
// Next read packet is a special instruction packet.
// Right now this can only mean a StartTLS instruction.
AsyncSpecialPacket specialRead = (AsyncSpecialPacket)nextRead;
// Update flags - this flag will be unset when TLS finishes
flags |= kPauseReads;
// And attempt to start TLS
// This method won't do anything unless both kPauseReads and kPauseWrites are set.
MaybeStartTLS();
}
else
{
// Get the new current read AsyncReadPacket
currentRead = (AsyncReadPacket)nextRead;
// Start time-out timer
if (currentRead.timeout >= 0)
{
readTimer = new System.Threading.Timer(new TimerCallback(stream_DidNotRead),
currentRead,
currentRead.timeout,
Timeout.Infinite);
}
// Do we have any overflow data that we've already read from the stream?
if (readOverflow != null)
{
// Start reading from the overflow
DoReadOverflow();
}
else
{
// Start reading from the stream
DoStartRead();
}
}
}
else if((flags & kCloseAfterReads) > 0)
{
if ((flags & kCloseAfterWrites) > 0)
{
if ((writeQueue.Count == 0) && (currentWrite == null))
{
Close(null);
}
}
else
{
Close(null);
}
}
}
}
}
/// <summary>
/// Ends the current read by disposing and nullifying the read timer,
/// and then nullifying the current read.
/// </summary>
private void EndCurrentRead()
{
if (readTimer != null)
{
readTimer.Dispose();
readTimer = null;
}
currentRead = null;
}