public void QueueSend(UInt32 payloadID, Byte[] datagram, UInt32 length)
{
if (queue.Length <= queueCount)
{
CdpBufferPoolDatagram[] newQueue = new CdpBufferPoolDatagram[queue.Length + extendLength];
Array.Copy(queue, newQueue, queue.Length);
queue = newQueue;
}
if (queueCount <= 0)
{
queue[0].datagram = datagram;
queue[0].length = length;
queueCount = 1;
firstPayloadIDInQueue = payloadID;
}
else
{
if (payloadID != firstPayloadIDInQueue + queueCount)
{
throw new InvalidOperationException(
String.Format("You queued datagram with payload ID '{0}' but the queue has {1} datagram(s) and the first payload id in the queue is {2}",
payloadID, queueCount, firstPayloadIDInQueue));
}
queue[queueCount].datagram = datagram;
queue[queueCount].length = length;
queueCount++;
}
}
public void ControllerSendPayloadWithAck(UInt32 offsetLimit, ICdpTimeout timeout)
{
// 1. Check for acks/resends/halts
Byte[] bufferToSend = GetRequestedBuffer(offsetLimit);
try
{
// Cdp Header
UInt32 payloadID = nextPayloadID++;
bufferToSend[0] = (Byte)(((Byte)CdpFlagValue.PayloadWithAck << 4) |
(0x0F & (payloadID >> 8)));
bufferToSend[1] = (Byte)payloadID;
//
// Send the datagram
//
connectedDatagramTransmitter.Send(bufferToSend, 0, offsetLimit);
Int64 stopwatchTicksAfterSend = Stopwatch.GetTimestamp();
Int32 timeoutMillis = timeout.WaitForAckInitialRetryTimeout(averageLatency);
if (timeoutMillis < 0)
{
throw new InvalidOperationException(String.Format(
"The ICdpTimeout class '{0}' returned negative ({1}) when calling WaitForAckInitialTimeout({2})",
timeout.GetType().Name, timeoutMillis, averageLatency));
}
Int32 retries = 0;
// Keep resending the datagram until a header is recevied or timeout is reached
while (true)
{
Console.WriteLine("Send Retry {0}", retries);
Int32 bytesRead = connectedDatagramTransmitter.ReceiveBlocking(headerBuffer, 0, 2, timeoutMillis);
if (bytesRead < 0)
{
Int32 elapsedMillis = (Stopwatch.GetTimestamp() - stopwatchTicksAfterSend).StopwatchTicksAsInt32Milliseconds();
timeoutMillis = timeout.WaitForAckRetryOrTimeout(retries, averageLatency, elapsedMillis, timeoutMillis);
if (timeoutMillis <= 0)
{
throw new TimeoutException(String.Format("Timed out waiting for ack: {0} retries {1} milliseconds elapsed", retries, elapsedMillis));
}
// Retry sending the packet
connectedDatagramTransmitter.Send(bufferToSend, 0, offsetLimit);
retries++;
continue;
}
//
// Check the datagram
//
if (bytesRead == 0)
{
// It's just a heart beat packet
}
else
{
Byte receivedFlagValue = (Byte)(headerBuffer[0] >> 4);
UInt32 receivedPayloadID = (UInt32)((0xF00 & (headerBuffer[0] << 8)) | (0xFF & headerBuffer[1]));
if (receivedFlagValue == (Byte)CdpFlagValue.Ack)
{
if (receivedPayloadID == payloadID)
{
Console.WriteLine("[CdpDebug] Received ACK for payload id {0}", payloadID);
break;
}
Console.WriteLine("[CdpDebug] Got an ack for an old payload id {0}?", receivedPayloadID);
}
else if (receivedFlagValue == (Byte)CdpFlagValue.Halt)
{
throw new CdpBadHaltException();
}
else if (receivedFlagValue == (Byte)CdpFlagValue.Resend)
{
if (receivedPayloadID <= payloadID)
{
UInt32 index = datagramQueue.PayloadIDToIndex(receivedPayloadID);
if (index >= 0)
{
if (receivedPayloadID < payloadID)
{
do
{
Console.WriteLine("[Debug] Queue Index {0} Payload ID {1}", index, receivedPayloadID + index);
CdpBufferPoolDatagram datagram = datagramQueue.queue[index];
connectedDatagramTransmitter.Send(datagram.datagram, 0, datagram.length);
index++;
} while (receivedPayloadID + index < payloadID);
}
connectedDatagramTransmitter.Send(bufferToSend, 0, offsetLimit);
}
}
}
else
{
Console.WriteLine("Unknown flag value {0} from '{1}' (Maybe I should throw an exception? TBD)",
receivedFlagValue, connectedDatagramTransmitter.RemoteEndPoint);
}
}
//
// Get next timeout
//
{
Int32 elapsedMillis = (Stopwatch.GetTimestamp() - stopwatchTicksAfterSend).StopwatchTicksAsInt32Milliseconds();
timeoutMillis = timeout.WaitForAckRetryOrTimeout(retries, averageLatency, elapsedMillis, timeoutMillis);
if (timeoutMillis <= 0)
{
throw new TimeoutException(String.Format("Timed out waiting for ack: {0} retries {1} milliseconds elapsed", retries, elapsedMillis));
}
}
}
datagramQueue.EmptyAndFree(); // free the queue because everything has been acked
}
finally
{
Cdp.BufferPool.FreeBuffer(bufferToSend);
}
}
