internal virtual void Post(TcpFlags flags, uint ackno, uint seqno, uint length = 0, int retransmission = 0, bool timeout = false)
{
SegmentsContext segments = null;
lock (this)
{
lock (this.SegmentsContexts)
{
segments = new SegmentsContext()
{
AcknowledgeNo = ackno,
SequenceNo = seqno,
Flags = flags,
Length = length,
Stopwatch = new Stopwatch(),
Retransmission = retransmission,
Pcb = this,
Timeout = timeout,
};
if (retransmission > 0)
{
long nackNo = segments.SequenceNo + segments.Length;
if (this.SegmentsContexts.TryAdd(nackNo, segments))
{
segments.Stopwatch.Start();
}
}
}
}
TcpFrame frame = segments.CreateFrame(this);
this.Locator.Tcp.Output(frame);
}
public override bool Send(BufferSegment payload)
{
if (payload == null || payload.Length <= 0)
{
return(false);
}
bool sendto(BufferSegment buffer)
{
if (buffer == null || buffer.Length <= 0)
{
return(false);
}
SegmentsContext segments = null;
lock (this)
{
lock (this.SegmentsContexts)
{
segments = new SegmentsContext()
{
AcknowledgeNo = this.SequenceNo,
SequenceNo = this.AcknowledgeNo,
Flags = TcpFlags.TCP_PSH | TcpFlags.TCP_ACK,
Length = (uint)buffer.Length,
Stopwatch = new Stopwatch(),
Pcb = this,
Retransmission = 5,
Payload = payload,
};
var ackNo = segments.SequenceNo + segments.Length;
if (this.SegmentsContexts.TryAdd(ackNo, segments))
{
segments.Stopwatch.Start();
this.AcknowledgeNo += segments.Length;
}
}
}
TcpFrame frame = segments.CreateFrame(this);
this.Locator.Tcp.Output(frame);
return(true);
}
foreach (BufferSegment buffer in Slices(payload))
{
if (!sendto(buffer))
{
return(false);
}
}
return(true);
}
internal virtual bool Ack(long ackno)
{
bool ack = false;
SegmentsContext segments = null;
lock (this.SegmentsContexts)
{
ack = this.SegmentsContexts.Remove(ackno, out segments);
if (ack)
{
segments.Stopwatch.Stop();
UpdateAckTime(segments.Stopwatch.ElapsedMilliseconds);
if (this.State == TcpState.SYN_RCVD)
{
this.State = TcpState.ESTABLISHED;
this.OnOpen(EventArgs.Empty);
}
}
if (this.SegmentsContexts.Count > 0 && ackno <= this.AcknowledgeNo)
{
var rapids = new List <long>();
foreach (var key in this.SegmentsContexts.Keys)
{
if (key > ackno)
{
break;
}
rapids.Add(key);
}
foreach (var key in rapids)
{
this.SegmentsContexts.Remove(key, out segments);
}
}
}
return(ack);
}
private void WorkThread(object state)
{
Stopwatch stopwatch = new Stopwatch();
stopwatch.Start();
while (!this._disposed)
{
if (stopwatch.ElapsedTicks < TcpPcb.MIN_RTO)
{
Thread.Sleep(1);
continue;
}
else
{
stopwatch.Restart();
}
foreach (var pair in _pcbTable)
{
TcpPcb pcb = pair.Value;
if (pcb == null)
{
continue;
}
SortedDictionary <long, SegmentsContext> segments = pcb.SegmentsContexts;
if (segments == null)
{
continue;
}
lock (segments)
{
var remove_segments_keys = new List <long>();
foreach (var segments_pair in segments)
{
SegmentsContext segments_context = segments_pair.Value;
if (segments_context == null)
{
continue;
}
double rto_radix = Math.Pow(1.5, Math.Min(segments_context.Retransmission, (1 + segments_context.Counter)));
if (segments_context.Stopwatch.ElapsedMilliseconds >= (Math.Max(pcb.RTO, TcpPcb.MIN_RTO)
* rto_radix))
{
if (segments_context.Counter++ < segments_context.Retransmission)
{
segments_context.Stopwatch.Restart();
this.Output(segments_context.CreateFrame(pcb));
}
else
{
remove_segments_keys.Add(segments_pair.Key);
}
}
}
foreach (var segments_key in remove_segments_keys)
{
pcb.SegmentsContexts.Remove(segments_key, out SegmentsContext segments_x);
}
}
}
}
}