/// <summary>
/// Used when "resending" or sending queued "ACKs"
/// </summary>
internal List <SACKSlot> PrepareACKList()
{
List <SACKSlot> list = new List <SACKSlot>();
lock (this)
{
//---- Add all the slots, except the first one
for (int index = 1; index < _slots.Count; index++)
{
SACKSlot slot = _slots[index];
if (slot.ACKsCount > 0)
{
slot.ACKsCount = 0;
list.Add(slot.Clone());
}
}
//---- Add the first slot
// Useful when some ACKs are loosed
if (_slots[0].StartPacketId > -1)
{
if (list.Count > 1 || _slots[0].ACKsCount > 0)
{
_slots[0].ACKsCount = 0;
list.Insert(0, _slots[0].Clone());
}
}
Interlocked.Exchange(ref _acksCount, 0);
}
CheckACKCount();
return(list);
}
internal SACKWindow()
{
SACKSlot slot = new SACKSlot(-1, -1);
slot.ACKsCount = 0;
_slots.Add(slot);
}
/// <summary>
/// Used when sending a packet.
/// </summary>
internal void GetSLACKSlots(out SACKSlot slot1, out SACKSlot slot2, out SACKSlot slot3, out SACKSlot slot4)
{
slot1 = null;
slot2 = null;
slot3 = null;
slot4 = null;
lock (this)
{
if (_slots[0].StartPacketId < 0)
{
return;
}
//---- Useful when some ACKs are loosed
slot1 = _slots[0].Clone();
_slots[0].ACKsCount = 0;
Interlocked.Exchange(ref _acksCount, _acksCount - slot1.ACKsCount);
CheckACKCount();
//---- Add all the slots
for (int index = 1; index < _slots.Count; index++)
{
SACKSlot slot = _slots[index];
if (slot.ACKsCount > 0)
{
Interlocked.Exchange(ref _acksCount, _acksCount - slot.ACKsCount);
slot.ACKsCount = 0;
CheckACKCount();
if (slot2 == null)
{
slot2 = slot.Clone();
}
else if (slot3 == null)
{
slot3 = slot.Clone();
}
else if (slot4 == null)
{
slot4 = slot.Clone();
return;
}
}
}
}
}
internal void OnReceivePacket(int packetId)
{
RUDPStack.Trace("SACK OnReceivePacket:" + packetId);
Monitor.Enter(this);
try
{
SACKSlot slot;
SACKSlot newSlot;
for (int index = 0; index < _slots.Count; index++)
{
slot = _slots[index];
//-- Already in the slot
if (packetId >= slot.StartPacketId && packetId <= slot.EndPacketId)
{
slot.ACKsCount++;
return;
}
//-- Grow the slot
if (slot.EndPacketId + 1 == packetId)
{
slot.EndPacketId++;
slot.ACKsCount++;
// First packet
if (slot.StartPacketId < 0)
{
slot.StartPacketId = 0;
}
// Merge with next
if ((index + 1) < _slots.Count && (slot.EndPacketId + 1) == _slots[index + 1].StartPacketId)
{
index++;
slot.EndPacketId = _slots[index].EndPacketId;
slot.ACKsCount += _slots[index].ACKsCount;
_slots.RemoveAt(index);
}
return;
}
//-- Before this slot (and then after previous one !)
if (packetId < slot.StartPacketId)
{
if (packetId == slot.StartPacketId - 1)
{
slot.StartPacketId--;
slot.ACKsCount++;
}
else
{
newSlot = new SACKSlot(packetId, packetId);
_slots.Insert(index, newSlot);
}
return;
}
}
//-- New slot at the end
newSlot = new SACKSlot(packetId, packetId);
_slots.Add(newSlot);
}
finally
{
Interlocked.Increment(ref _acksCount);
Monitor.Exit(this);
CheckACKCount();
}
}
/// <summary>
/// Handle the bytes received from a socket.
/// </summary>
private static void HandlePayload(PhysicalSocket physical, byte[] payload, int length, IPEndPoint sender,
out RUDPPacketChannel channel,
out int packetId,
out int advertisedWindowSize,
out SACKSlot slot1,
out SACKSlot slot2,
out SACKSlot slot3,
out SACKSlot slot4,
out byte[] packetPayload)
{
int offset = 0;
//-- Protocol version
byte version = payload[offset];
offset++;
//-- Header information
byte sacksSlotCount = payload[offset];
offset++;
//-- Channel
byte channelByte = payload[offset];
offset++;
switch (channelByte)
{
case 0:
channel = RUDPPacketChannel.Undefined;
break;
case 10:
channel = RUDPPacketChannel.Ping;
break;
case 20:
channel = RUDPPacketChannel.PingRendezVous;
break;
case 30:
channel = RUDPPacketChannel.TearDown;
break;
case 40:
channel = RUDPPacketChannel.UserPacket;
break;
case 50:
channel = RUDPPacketChannel.ACK;
break;
case 70:
channel = RUDPPacketChannel.OutOfOrder;
break;
case 100:
channel = RUDPPacketChannel.KeepAlive;
break;
case 120:
channel = RUDPPacketChannel.MTUTuning;
break;
case 121:
channel = RUDPPacketChannel.MTUTuningACK;
break;
case 150:
channel = RUDPPacketChannel.Bandwidth01;
break;
case 151:
channel = RUDPPacketChannel.BandwidthResponse01;
break;
case 155:
channel = RUDPPacketChannel.Bandwidth02;
break;
case 156:
channel = RUDPPacketChannel.BandwidthResponse02;
break;
default:
throw new Exception("Unsupported channel type");
}
//-- Packet Id
packetId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
//-- Control information : Advertised window
advertisedWindowSize = BinaryHelper.ReadInt(payload, offset);
offset += 4;
//-- Payload length
int payloadLength = BinaryHelper.ReadInt(payload, offset);
offset += 4;
//---- SACK Slots
slot1 = null;
slot2 = null;
slot3 = null;
slot4 = null;
int startPacketId;
int endPacketId;
if (sacksSlotCount > 0)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot1 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
if (sacksSlotCount > 1)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot2 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
if (sacksSlotCount > 2)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot3 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
if (sacksSlotCount > 3)
{
startPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
endPacketId = BinaryHelper.ReadInt(payload, offset);
offset += 4;
slot4 = new SACKSlot(startPacketId, endPacketId);
}
else offset += 8;
//-- Payload
packetPayload = new byte[payloadLength];
if (payloadLength > 0)
Buffer.BlockCopy(payload, offset, packetPayload, 0, payloadLength);
}
/// <summary>
/// Create the RUDP packet : HEADER + payload
/// </summary>
internal static byte[] MakePacketPayload(RUDPSocket rudp,
int packetId,
RUDPPacketChannel channel,
SACKSlot slot1, SACKSlot slot2, SACKSlot slot3, SACKSlot slot4,
byte[] payload,
int offset,
int payloadLength)
{
//---- Here we make the payload while we will send:
/**
* We create a header
* The format is:
* --------------
* - 1 byte : protocol version
* - 1 byte : header information
* - 1 byte : channel
* - 4 bytes : message ID
* - 4 bytes : advertized congestion window size
* - 4 bytes : payloadLength
* - 4 X (4 + 4) : 32 bytes for 4 SACK slots
* - the payload bytes
*/
int headerOffset = 0;
byte[] packetPayload = PayloadManager.Allocate(channel, RUDPHeaderLength + payloadLength);
//---- Protocol version
packetPayload[headerOffset] = (byte)1;
headerOffset++;
//---- Header information
// 3 bits : number of ACK slots
// sack slot (3 bits)
byte sacksSlotCount = 0;
if (slot1 != null)
sacksSlotCount++;
if (slot2 != null)
sacksSlotCount++;
if (slot3 != null)
sacksSlotCount++;
if (slot4 != null)
sacksSlotCount++;
packetPayload[headerOffset] = 0; // Reset (Because buffer reused)
packetPayload[headerOffset] |= sacksSlotCount;
headerOffset++;
//---- Channel
packetPayload[headerOffset] = (byte)channel;
headerOffset++;
//---- Message Id
BinaryHelper.WriteInt(packetId, packetPayload, headerOffset);
headerOffset += 4;
//---- Control information : Advertised window
if (rudp == null)
BinaryHelper.WriteInt(-1, packetPayload, headerOffset);
else
BinaryHelper.WriteInt((int)rudp._controlWindow.AdvertisedWindow, packetPayload, headerOffset);
headerOffset += 4;
//---- Payload length
BinaryHelper.WriteInt(payloadLength, packetPayload, headerOffset);
headerOffset += 4;
//---- SACK Slots
if (slot1 != null)
{
BinaryHelper.WriteInt(slot1.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot1.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else
{
// Reset (Because buffer reused)
Buffer.BlockCopy(Clean8Bytes, 0, packetPayload, headerOffset, 8);
headerOffset += 8;
}
if (slot2 != null)
{
BinaryHelper.WriteInt(slot2.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot2.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else
{
// Reset (Because buffer reused)
Buffer.BlockCopy(Clean8Bytes, 0, packetPayload, headerOffset, 8);
headerOffset += 8;
}
if (slot3 != null)
{
BinaryHelper.WriteInt(slot3.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot3.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else
{
// Reset (Because buffer reused)
Buffer.BlockCopy(Clean8Bytes, 0, packetPayload, headerOffset, 8);
headerOffset += 8;
}
if (slot4 != null)
{
BinaryHelper.WriteInt(slot4.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot4.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else
{
// Reset (Because buffer reused)
Buffer.BlockCopy(Clean8Bytes, 0, packetPayload, headerOffset, 8);
headerOffset += 8;
}
if (payload == null)
return packetPayload;
//---- Payload
Buffer.BlockCopy(payload, offset, packetPayload, headerOffset, payloadLength);
return packetPayload;
}
static private void UpdatePacketPayload(byte[] packetPayload, SACKSlot slot1, SACKSlot slot2, SACKSlot slot3, SACKSlot slot4)
{
//---- Update header
byte sacksSlotCount = 0;
if (slot1 != null)
sacksSlotCount++;
if (slot2 != null)
sacksSlotCount++;
if (slot3 != null)
sacksSlotCount++;
if (slot4 != null)
sacksSlotCount++;
packetPayload[1] = sacksSlotCount;
//---- Update slots
int headerOffset = 15;
if (slot1 != null)
{
BinaryHelper.WriteInt(slot1.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot1.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else headerOffset += 8;
if (slot2 != null)
{
BinaryHelper.WriteInt(slot2.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot2.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else headerOffset += 8;
if (slot3 != null)
{
BinaryHelper.WriteInt(slot3.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot3.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
else headerOffset += 8;
if (slot4 != null)
{
BinaryHelper.WriteInt(slot4.StartPacketId, packetPayload, headerOffset);
headerOffset += 4;
BinaryHelper.WriteInt(slot4.EndPacketId, packetPayload, headerOffset);
headerOffset += 4;
}
//else headerOffset += 8;
}
private static void HandleACKs(RUDPSocket rudp,
SACKSlot slot1,
SACKSlot slot2,
SACKSlot slot3,
SACKSlot slot4)
{
// No ack
if (slot1 == null)
return;
int maxId = slot1.EndPacketId;
if (slot4 != null)
maxId = slot4.EndPacketId;
else if (slot3 != null)
maxId = slot3.EndPacketId;
else if (slot2 != null)
maxId = slot2.EndPacketId;
#if CONSOLE_TRACE
if (slot1 != null)
Trace("Handle ACK[1](" + rudp.Handle + "): " + slot1.StartPacketId + " <-> " + slot1.EndPacketId);
if (slot2 != null)
Trace("Handle ACK[2](" + rudp.Handle + "): " + slot2.StartPacketId + " <-> " + slot2.EndPacketId);
if (slot3 != null)
Trace("Handle ACK[3](" + rudp.Handle + "): " + slot3.StartPacketId + " <-> " + slot3.EndPacketId);
if (slot4 != null)
Trace("Handle ACK[4](" + rudp.Handle + "): " + slot4.StartPacketId + " <-> " + slot4.EndPacketId);
#endif
//---- Prepare the list of packets
List<RUDPOutgoingPacket> toACKPackets = new List<RUDPOutgoingPacket>();
RUDPOutgoingPacket lastPacket = null;
double currentRTT = Double.MaxValue;
rudp._outgoingPacketsLock.EnterReadLock();
try
{
for (int index = 0; index < rudp._outgoingPackets.Count; index++)
{
RUDPOutgoingPacket packet = rudp._outgoingPackets[index];
if (packet.PacketId > maxId)
break;
if (packet.IsACKed)
continue;
if (slot4 != null)
if (packet.PacketId >= slot4.StartPacketId && packet.PacketId <= slot4.EndPacketId)
{
if (packet.Retransmission < 1)
{
lastPacket = packet;
currentRTT = Math.Min(currentRTT, HiResTimer.MicroSeconds - lastPacket.TSFirstSend);
}
toACKPackets.Add(packet);
continue;
}
if (slot3 != null)
if (packet.PacketId >= slot3.StartPacketId && packet.PacketId <= slot3.EndPacketId)
{
if (packet.Retransmission < 1)
{
lastPacket = packet;
currentRTT = Math.Min(currentRTT, HiResTimer.MicroSeconds - lastPacket.TSFirstSend);
}
toACKPackets.Add(packet);
continue;
}
if (slot2 != null)
if (packet.PacketId >= slot2.StartPacketId && packet.PacketId <= slot2.EndPacketId)
{
if (packet.Retransmission < 1)
{
lastPacket = packet;
currentRTT = Math.Min(currentRTT, HiResTimer.MicroSeconds - lastPacket.TSFirstSend);
}
toACKPackets.Add(packet);
continue;
}
if (packet.PacketId >= slot1.StartPacketId && packet.PacketId <= slot1.EndPacketId)
{
if (packet.Retransmission < 1)
{
lastPacket = packet;
currentRTT = Math.Min(currentRTT, HiResTimer.MicroSeconds - lastPacket.TSFirstSend);
}
toACKPackets.Add(packet);
}
}
}
finally
{
rudp._outgoingPacketsLock.ExitReadLock();
}
//---- If no good packet, use current RTT
if (lastPacket == null)
currentRTT = rudp.RTT;
if (currentRTT < 1)
currentRTT = 1;
//---- Set the ACK for all the packets
for (int index = 0; index < toACKPackets.Count; index++)
{
RUDPOutgoingPacket packet = toACKPackets[index];
SetPacketACKed(rudp, packet, currentRTT);
}
}
private static void HandlePacket(PhysicalSocket physical,
IPEndPoint sender,
RUDPPacketChannel channel,
int packetId,
int advertisedWindowSize,
SACKSlot slot1, SACKSlot slot2, SACKSlot slot3, SACKSlot slot4,
byte[] payload)
{
RUDPSocket rudp = null;
//---- PING
if (channel == RUDPPacketChannel.Ping || channel == RUDPPacketChannel.PingRendezVous)
{
rudp = HandlePing(physical, sender, packetId, channel);
// Do not handle this message
if (rudp == null)
return;
}
//---- Search the socket
if (rudp == null)
{
physical._connectedRDUPsLock.EnterReadLock();
physical._connectedRDUPs.TryGetValue(sender, out rudp);
physical._connectedRDUPsLock.ExitReadLock();
}
//---- Direct send of ACK, because socket can be shutdowned and removed
if (channel == RUDPPacketChannel.TearDown)
{
byte[] packetPayload = MakePacketPayload(rudp, -1, RUDPPacketChannel.ACK, new SACKSlot(packetId, packetId), null, null, null, null, 0, 0);
SocketSendACK(rudp, physical, sender, packetPayload);
PayloadManager.Deallocate(RUDPPacketChannel.ACK, packetPayload);
}
//---- Released socket
if (rudp == null)
return;
#if CONSOLE_TRACE
if (packetId > -1)
Trace("Handle packet (" + rudp.Handle + ")(" + channel + "):" + packetId);
#endif
//---- Advertised window
rudp._controlWindow.OnReceiveAdvertisedWindow(advertisedWindowSize);
//---- Handle ACKs
HandleACKs(rudp, slot1, slot2, slot3, slot4);
if (channel == RUDPPacketChannel.ACK)
return;
//---- Non reliable messages
if (packetId < 0)
{
//-- Bandwidth
if (channel == RUDPPacketChannel.Bandwidth01)
{
PushPacketToSend(rudp, false, RUDPPacketChannel.BandwidthResponse01, null, 0, 0);
return;
}
else if (channel == RUDPPacketChannel.Bandwidth02)
{
PushPacketToSend(rudp, false, RUDPPacketChannel.BandwidthResponse02, payload, 0, 8);
return;
}
else if (channel == RUDPPacketChannel.BandwidthResponse01)
{
rudp._bandwidthResponse01TS = HiResTimer.MicroSeconds;
}
else if (channel == RUDPPacketChannel.BandwidthResponse02)
{
//---- Calculate bandwidth
// Bdw (Bytes / milli-sec)
long now = HiResTimer.MicroSeconds;
double delay = (now - rudp._bandwidthResponse01TS) / 1000;
if (delay < 0.001)
delay = 0.001;
// Arrival Speed
double arrivalSpeed = (RUDPHeaderLength + UDPHeaderLength) / delay;
// RTT
double currentRtt = (now - BinaryHelper.ReadInt(payload, 0)) / 1000;
if (currentRtt < 0.001)
currentRtt = 0.001;
// BDP = Bandwidth(Byte / Ms) * RTT;
double bandwidth = (long)(arrivalSpeed * currentRtt);
rudp._bandwidth = (long)(rudp._bandwidth * 0.875f + bandwidth * 0.125f);
}
//-- MTU Tuning
else if (channel == RUDPPacketChannel.MTUTuning)
{
rudp._pmtuDiscovery.OnReceiveProbe(payload.Length);
return;
}
else if (channel == RUDPPacketChannel.MTUTuningACK)
{
rudp._pmtuDiscovery.OnReceiveProbeACK(payload);
return;
}
//if ((rudp._incomingNonReliablePackets.Count * rudp._mtu) >= rudp._receiveSize)
//return;
RUDPIngoingPacket nonReliablePacket = new RUDPIngoingPacket(rudp, packetId, payload, channel, HiResTimer.MicroSeconds);
rudp._incomingPackets.AddPacket(nonReliablePacket);
rudp.HandleNextUserPacket(false);
return;
}
//---- Do not process a duplicated packets
bool isDuplicatedPacket;
isDuplicatedPacket = (packetId <= rudp._incomingPackets.CurrentPacketId);
if (!isDuplicatedPacket)
isDuplicatedPacket = rudp._incomingPackets.ContainsPacket(packetId);
//---- Can I receive the packet now ?
bool canReceive = rudp._controlWindow.CanReceive(packetId, payload.Length);
//---- Send the ACK
if (channel != RUDPPacketChannel.Ping && channel != RUDPPacketChannel.PingRendezVous)
if (canReceive || // Can receive, then we send ACK
(!canReceive && isDuplicatedPacket)) // Is duplicated, then already in the list -> send another ACK
rudp._sackWindow.OnReceivePacket(packetId);
//---- Check if we can handle this message
if (!canReceive || isDuplicatedPacket)
return;
//---- If we are not connected, we cannot hanlde messages ! We need a connection before.
if (rudp._status != RUDPSocketStatus.Connected && channel == RUDPPacketChannel.UserPacket)
return;
//---- Check for Out of order packets
if (rudp._incomingPackets.Count > 0)
{
int greaterPacketId = rudp._incomingPackets.LastPacketId;
if (packetId != greaterPacketId + 1)
{
byte[] oooPayload = new byte[8];
// start packet
BinaryHelper.WriteInt(greaterPacketId + 1, oooPayload, 0);
// end packet
BinaryHelper.WriteInt(packetId - 1, oooPayload, 4);
PushPacketToSend(rudp, false, RUDPPacketChannel.OutOfOrder, oooPayload, 0, 8);
}
}
//---- Receive Out of order notification
if (channel == RUDPPacketChannel.OutOfOrder)
{
rudp._controlWindow.OnOutOfOrder(BinaryHelper.ReadInt(payload, 0), BinaryHelper.ReadInt(payload, 4));
}
//---- TEAR DOWN
if (channel == RUDPPacketChannel.TearDown)
{
// Initiate the close process
if (rudp._status == RUDPSocketStatus.Connected)
{
// Notify control window
rudp._controlWindow.OnReceive(null);
// Start shutdown
AsyncShutdown(rudp);
}
return;
}
//---- Add the packet to incoming list
RUDPIngoingPacket packet = new RUDPIngoingPacket(rudp, packetId, payload, channel, HiResTimer.MicroSeconds);
// Notify control window
rudp._controlWindow.OnReceive(packet);
rudp._incomingPackets.AddPacket(packet);
//------ Handle the ordered ingoing packets
rudp.HandleNextUserPacket(false);
}
internal void OnReceivePacket(int packetId)
{
RUDPStack.Trace("SACK OnReceivePacket:" + packetId);
Monitor.Enter(this);
try
{
SACKSlot slot;
SACKSlot newSlot;
for (int index = 0; index < _slots.Count; index++)
{
slot = _slots[index];
//-- Already in the slot
if (packetId >= slot.StartPacketId && packetId <= slot.EndPacketId)
{
slot.ACKsCount++;
return;
}
//-- Grow the slot
if (slot.EndPacketId + 1 == packetId)
{
slot.EndPacketId++;
slot.ACKsCount++;
// First packet
if (slot.StartPacketId < 0)
slot.StartPacketId = 0;
// Merge with next
if ((index + 1) < _slots.Count && (slot.EndPacketId + 1) == _slots[index + 1].StartPacketId)
{
index++;
slot.EndPacketId = _slots[index].EndPacketId;
slot.ACKsCount += _slots[index].ACKsCount;
_slots.RemoveAt(index);
}
return;
}
//-- Before this slot (and then after previous one !)
if (packetId < slot.StartPacketId)
{
if (packetId == slot.StartPacketId - 1)
{
slot.StartPacketId--;
slot.ACKsCount++;
}
else
{
newSlot = new SACKSlot(packetId, packetId);
_slots.Insert(index, newSlot);
}
return;
}
}
//-- New slot at the end
newSlot = new SACKSlot(packetId, packetId);
_slots.Add(newSlot);
}
finally
{
Interlocked.Increment(ref _acksCount);
Monitor.Exit(this);
CheckACKCount();
}
}
internal SACKWindow()
{
SACKSlot slot = new SACKSlot(-1, -1);
slot.ACKsCount = 0;
_slots.Add(slot);
}
/// <summary>
/// Used when sending a packet.
/// </summary>
internal void GetSLACKSlots(out SACKSlot slot1, out SACKSlot slot2, out SACKSlot slot3, out SACKSlot slot4)
{
slot1 = null;
slot2 = null;
slot3 = null;
slot4 = null;
lock (this)
{
if (_slots[0].StartPacketId < 0)
return;
//---- Useful when some ACKs are loosed
slot1 = _slots[0].Clone();
_slots[0].ACKsCount = 0;
Interlocked.Exchange(ref _acksCount, _acksCount - slot1.ACKsCount);
CheckACKCount();
//---- Add all the slots
for (int index = 1; index < _slots.Count; index++)
{
SACKSlot slot = _slots[index];
if (slot.ACKsCount > 0)
{
Interlocked.Exchange(ref _acksCount, _acksCount - slot.ACKsCount);
slot.ACKsCount = 0;
CheckACKCount();
if (slot2 == null)
slot2 = slot.Clone();
else if (slot3 == null)
slot3 = slot.Clone();
else if (slot4 == null)
{
slot4 = slot.Clone();
return;
}
}
}
}
}