/// <summary>
/// create a receiver with a valid {@link UDTSession}
/// </summary>
/// <param name="session"></param>
/// <param name="endpoint"></param>
public UDTReceiver(UDTSession session, UDPEndPoint endpoint)
{
this.roundTripTimeVar = roundTripTime / 2;
this.endpoint = endpoint;
this.session = session;
//( System.DateTime.UtcNow.Ticks - new DateTime(1970, 1, 1, 0, 0, 0).Ticks)/10000;
//如果要得到Java中 System.currentTimeMillis() 一样的结果，就可以写成 上面那样，也可以这样写：
// TimeSpan ts=new TimeSpan( System.DateTime.UtcNow.Ticks - new DateTime(1970, 1, 1, 0, 0, 0).Ticks);
//(long)ts.TotalMilliseconds;
this.sessionUpSince = (long)ts.TotalMilliseconds;
this.statistics = session.getStatistics();
if (!session.isReady())
{
Log.Write(this.ToString(), "UDTSession is not ready.");
}
ackHistoryWindow = new AckHistoryWindow(16);
packetHistoryWindow = new PacketHistoryWindow(16);
receiverLossList = new ReceiverLossList();
packetPairWindow = new PacketPairWindow(16);
largestReceivedSeqNumber = (int)session.getInitialSequenceNumber() - 1;
bufferSize = session.getReceiveBufferSize();
handoffQueue = new Queue <UDTPacket>(4 * session.getFlowWindowSize());
storeStatistics = false; //Boolean.getBoolean("udt.receiver.storeStatistics");
initMetrics();
start();
}
/* (non-Javadoc)
* @see udt.CongestionControl#onACK(long)
*/
public void onACK(long ackSeqno)
{
//increase window during slow start
if (slowStartPhase)
{
congestionWindowSize += ackSeqno - lastAckSeqNumber;
lastAckSeqNumber = ackSeqno;
//but not beyond a maximum size
if (congestionWindowSize > session.getFlowWindowSize())
{
slowStartPhase = false;
if (packetArrivalRate > 0)
{
packetSendingPeriod = 1000000.0 / packetArrivalRate;
}
else
{
packetSendingPeriod = (double)congestionWindowSize / (roundTripTime + Util.getSYNTimeD());
}
}
}
else
{
//1.if it is not in slow start phase,set the congestion window size
//to the product of packet arrival rate and(rtt +SYN)
double A = packetArrivalRate / 1000000.0 * (roundTripTime + Util.getSYNTimeD());
congestionWindowSize = (long)A + 16;
Log.Write(this.ToString(), "receive rate " + packetArrivalRate + " rtt " + roundTripTime + " set to window size: " + (A + 16));
}
//no rate increase during slow start
if (slowStartPhase)
{
return;
}
//no rate increase "immediately" after a NAK
if (loss)
{
loss = false;
return;
}
//4. compute the increase in sent packets for the next SYN period
double numOfIncreasingPacket = computeNumOfIncreasingPacket();
//5. update the send period
double factor = Util.getSYNTimeD() / (packetSendingPeriod * numOfIncreasingPacket + Util.getSYNTimeD());
packetSendingPeriod = factor * packetSendingPeriod;
//packetSendingPeriod=0.995*packetSendingPeriod;
statistics.setSendPeriod(packetSendingPeriod);
}
public UDTSender(UDTSession session, UDPEndPoint endpoint)
{
if (!session.isReady())
{
Log.Write(this.ToString(), "UDTSession is not ready.");
}
this.endpoint = endpoint;
this.session = session;
statistics = session.getStatistics();
senderLossList = new SenderLossList();
sendBuffer = new Dictionary <long, DataPacket>(session.getFlowWindowSize());
sendQueue = new Queue <DataPacket>(1000);
lastAckSequenceNumber = (int)session.getInitialSequenceNumber();
currentSequenceNumber = (int)session.getInitialSequenceNumber() - 1;
waitForAckLatch.Set(new CountDownLatch(1));
waitForSeqAckLatch.Set(new CountDownLatch(1));
storeStatistics = false; //Boolean.getBoolean("udt.sender.storeStatistics");
initMetrics();
doStart();
}