// Called from any client thread.
public void Send(Item item, CancellationToken token)
{
// initialize handle to wait for.
using (var handle = new ManualResetEventSlim(false))
{
var pendingSend = new PendingSend
{
ManualResetEvent = handle
};
// Make sure the item and pendingSend are put in the same order.
lock (this.sendLock)
{
this.sendQueue.Enqueue(item);
this.pendingSendQueue.Enqueue(pendingSend);
}
// Wait for the just created send handle to notify.
// May throw operation cancelled, in which case the message is
// still enqueued... Maybe fix that later.
handle.Wait(token);
if (!pendingSend.Success)
{
// Now we actually have information why the send
// failed. Pretty cool.
throw new CommunicationException(
pendingSend.Message,
pendingSend.InnerException);
}
}
}
public void TrySendMessage(Message message)
{
var pendingSend = new PendingSend()
{
Message = message
};
_sendQueue.Enqueue(pendingSend);
SendPendingMessages();
}
public Task SendMessageAsync(Message message)
{
var tcs = new TaskCompletionSource <bool>();
var pendingSend = new PendingSend()
{
Message = message,
CompletionSource = tcs
};
_sendQueue.Enqueue(pendingSend);
SendPendingMessages();
return(tcs.Task);
}
private void HandleAck(ushort sequence)
{
lock (_sendLock)
{
if (_sendSequencer.TryGet(sequence, out PendingOutgoingPacket value))
{
// Notify the user about the ack
ChannelRouter.HandlePacketAckedByRemote(connection, channelId, value.NotificationKey);
// Dealloc the memory held by the sequencer
memoryManager.DeAlloc(value.Memory);
// TODO: Remove roundtripping from channeled packets and make specific ping-pong packets
// Get the roundtrp
ulong roundtrip = (ulong)Math.Round((NetTime.Now - value.FirstSent).TotalMilliseconds);
// Report to the connection
connection.AddRoundtripSample(roundtrip);
// Kill the packet
_sendSequencer.Remove(sequence);
if (sequence == (ushort)(_outgoingLowestAckedSequence + 1))
{
// This was the next one.
_outgoingLowestAckedSequence++;
}
}
// Loop from the lowest ack we got
for (ushort i = _outgoingLowestAckedSequence; !_sendSequencer.Contains(i) && SequencingUtils.Distance(i, _lastOutgoingSequence, sizeof(ushort)) <= 0; i++)
{
_outgoingLowestAckedSequence = i;
}
// Check if we can start draining pending pool
while (_pendingSends.Count > 0 && _sendSequencer.CanSet((ushort)(_lastOutgoingSequence + 1)))
{
// Dequeue the pending
PendingSend pending = _pendingSends.Dequeue();
// Sequence it
CreateOutgoingMessageInternal(new ArraySegment <byte>(pending.Memory.Buffer, (int)pending.Memory.VirtualOffset, (int)pending.Memory.VirtualCount), pending.NoMerge, pending.NotificationKey);
// Dealloc
memoryManager.DeAlloc(pending.Memory);
}
}
}
/// <summary>
/// Enqueue a send operation (asynchronously write data to the outgoing stream).
/// </summary>
/// <param name="streamIndex">
/// The index of the target stream.
/// </param>
/// <param name="data">
/// The data to write.
/// </param>
/// <param name="cancellation">
/// An optional <see cref="CancellationToken"/> that can be used to cancel the operation.
/// </param>
/// <returns>
/// A <see cref="Task"/> representing the asynchronous operation.
/// </returns>
Task EnqueueSend(byte streamIndex, ArraySegment <byte> data, CancellationToken cancellation)
{
Log.LogTrace("Enqueuing {DataLength} bytes for sending on stream {StreamIndex}...", data.Count, streamIndex);
PendingSend pendingSend = new PendingSend(streamIndex, data, cancellation);
cancellation.Register(
() => pendingSend.Completion.TrySetCanceled(cancellation)
);
_pendingSends.Add(pendingSend);
Log.LogTrace("Enqueued {DataLength} bytes for sending on stream {StreamIndex}.", data.Count, streamIndex);
return(pendingSend.Completion.Task);
}
public async ValueTask BindAsync(IPEndPoint endPoint)
{
if (!Connected)
{
UdpClient = new UdpClient(endPoint);
_logger.LogInformation($"Starting listening on {endPoint}.");
//Create a new thread to receive and process data.
Tasks.Enqueue(Task.Run(async() =>
{
while (true)
{
var data = await UdpClient.ReceiveAsync();
if (!PendingReceive.ContainsKey(data.RemoteEndPoint))
{
PendingReceive.AddOrUpdate(data.RemoteEndPoint, new ConcurrentQueue <byte[]>(),
(_, queue) => queue);
PendingConnection.Enqueue(data.RemoteEndPoint);
HavePendingSend.AddOrUpdate(data.RemoteEndPoint, false, (_, b) => b);
PendingSend.AddOrUpdate(data.RemoteEndPoint, new ConcurrentQueue <byte[]>(),
(_, queue) => queue);
}
// 0 for normal content
if (data.Buffer[0] == 0)
{
_logger.LogInformation($"Received a standard packet from {data.RemoteEndPoint}.");
var pendingReceive = PendingReceive[data.RemoteEndPoint];
//Add data to pending receive
pendingReceive.Enqueue(data.Buffer[4..]);
//Reply received
await UdpClient.SendAsync(new byte[] { 2, 0, 0, 0 }, 4, data.RemoteEndPoint);
}
// 1 for receive feedback
if (data.Buffer[0] == 1)
{
_logger.LogInformation($"Received a confirm packet from {data.RemoteEndPoint}.");
//Enqueue confirmed info
ConfirmedReceived.Enqueue(data.RemoteEndPoint);
}
}
public virtual void Broadcast(NetBuffer data, NetChannel channel)
{
PendingSend msg = new PendingSend();
msg.message = ProcessOutboundMessage(null, data);
msg.to = null;
msg.channel = channel;
lock (PendingSends)
{
PendingSends.Add(msg);
}
}
public virtual void SendMessage( NetConnection to, NetBuffer message, NetChannel channel )
{
PendingSend msg = new PendingSend();
msg.message = ProcessOutboundMessage(to,message);
msg.to = to;
msg.channel = channel;
lock(PendingSends)
{
PendingSends.Add(msg);
}
}
public void HandleAck(ArraySegment <byte> payload)
{
// Read the sequence number
ushort sequence = (ushort)(payload.Array[payload.Offset] | (ushort)(payload.Array[payload.Offset + 1] << 8));
// Read the raw fragment data
ushort encodedFragment = (ushort)(payload.Array[payload.Offset + 2] | (ushort)(payload.Array[payload.Offset + 3] << 8));
// The fragmentId is the last 15 least significant bits
ushort fragment = (ushort)(encodedFragment & 32767);
// IsFinal is the most significant bit
bool isFinal = (ushort)((encodedFragment & 32768) >> 15) == 1;
lock (_sendLock)
{
if (_sendSequencer.TryGet(sequence, out PendingOutgoingPacketFragmented value) && value.Fragments.VirtualCount > fragment && value.Fragments.Pointers[fragment] != null)
{
// Dealloc the memory held by the sequencer for the packet
((PendingOutgoingFragment)value.Fragments.Pointers[fragment]).DeAlloc(memoryManager);
// TODO: Remove roundtripping from channeled packets and make specific ping-pong packets
// Get the roundtrp
ulong roundtrip = (ulong)Math.Round((NetTime.Now - ((PendingOutgoingFragment)value.Fragments.Pointers[fragment]).FirstSent).TotalMilliseconds);
// Report to the connection
connection.AddRoundtripSample(roundtrip);
// Kill the fragment packet
value.Fragments.Pointers[fragment] = null;
bool hasAllocatedAndAliveFragments = false;
for (int i = 0; i < value.Fragments.VirtualCount; i++)
{
if (value.Fragments.Pointers[i] != null)
{
hasAllocatedAndAliveFragments = true;
break;
}
}
if (!hasAllocatedAndAliveFragments)
{
// Notify user that the packet was acked
ChannelRouter.HandlePacketAckedByRemote(connection, channelId, value.NotificationKey);
// Dealloc the wrapper packet
value.DeAlloc(memoryManager);
// Kill the wrapper packet
_sendSequencer.Remove(sequence);
if (sequence == (ushort)(_outgoingLowestAckedSequence + 1))
{
// This was the next one.
_outgoingLowestAckedSequence++;
}
}
}
// Loop from the lowest ack we got
for (ushort i = _outgoingLowestAckedSequence; !_sendSequencer.TryGet(i, out value) && SequencingUtils.Distance(i, _lastOutgoingSequence, sizeof(ushort)) <= 0; i++)
{
_outgoingLowestAckedSequence = i;
}
// Check if we can start draining pending pool
while (_pendingSends.Count > 0 && _sendSequencer.CanSet((ushort)(_lastOutgoingSequence + 1)))
{
// Dequeue the pending
PendingSend pending = _pendingSends.Dequeue();
// Sequence it
CreateOutgoingMessageInternal(new ArraySegment <byte>(pending.Memory.Buffer, (int)pending.Memory.VirtualOffset, (int)pending.Memory.VirtualCount), pending.NoMerge, pending.NotificationKey);
// Dealloc
memoryManager.DeAlloc(pending.Memory);
}
}
}
private async Task SendLoopAsync(SshConnection connection)
{
CancellationToken abortToken = _abortCts.Token;
try
{
while (true)
{
PendingSend send = await _sendQueue !.Reader.ReadAsync(abortToken); // TODO: maybe use ReadAllAsync
try
{
// Disable send.CancellationToken.
send.CancellationTokenRegistration.Dispose();
if (!send.TaskCompletion.Task.IsCanceled)
{
// If we weren't canceled by send.CancellationToken, do the send.
// We use abortToken instead of send.CancellationToken because
// we can't allow partial sends unless we're aborting the connection.
await connection.SendPacketAsync(send.Packet, abortToken);
SemaphoreSlim?keyExchangeSemaphore = null;
if (send.Packet.MessageType == MessageNumber.SSH_MSG_KEXINIT)
{
keyExchangeSemaphore = _keyReExchangeSemaphore;
_keyReExchangeSemaphore = null;
}
send.TaskCompletion.SetResult(true);
// Don't send any more packets until Key Re-Exchange completed.
if (keyExchangeSemaphore != null)
{
await keyExchangeSemaphore.WaitAsync(abortToken);
keyExchangeSemaphore.Dispose();
}
}
}
catch (Exception e) // SendPacket failed or connection aborted.
{
Abort(e);
// The sender isn't responsible for the fail,
// report this as canceled.
send.TaskCompletion.SetCanceled();
}
}
}
catch (Exception e) // Happens on Abort.
{
// Ensure Abort is called so further SendPacketAsync calls return Canceled.
Abort(e); // In case the Exception was not caused by Abort.
}
finally
{
// Empty _sendQueue and prevent new sends.
if (_sendQueue != null)
{
_sendQueue.Writer.Complete();
while (_sendQueue.Reader.TryRead(out PendingSend send))
{
send.CancellationTokenRegistration.Dispose();
if (!send.TaskCompletion.Task.IsCanceled)
{
send.TaskCompletion.SetCanceled();
}
}
}
}
}
