public bool ScheduleReceive(Action <bool> whenDone)
{
CoreEventSource.ReceiveStart(name, IsAlive);
if (!IsAlive)
{
whenDone(false);
return(false);
}
if (Interlocked.CompareExchange(ref isReceiving, 1, 0) != 0)
{
return(false);
}
recvArgs.UserToken = whenDone;
if (!socket.ReceiveAsync(recvArgs))
{
// receive was done synchronously
ReceiveAsyncCompleted(null, recvArgs);
}
return(true);
}
private void SendAsyncCompleted(object sender, SocketAsyncEventArgs e)
{
var sent = sendArgs.BytesTransferred;
CoreEventSource.SendChunk(name, IsAlive, sent, sendArgs.SocketError);
// failed during send
if (sendArgs.SocketError != SocketError.Success || sent < 1)
{
FinishSending(false);
return;
}
var sendOffset = sendArgs.Offset + sent;
var sendCount = sendArgs.Count - sent;
// OS sent less data than we asked for, so send the remaining data
if (sendCount > 0)
{
PerformSend(sendOffset, sendCount);
}
else
{
Debug.Assert(sendCount == 0);
// all data was sent
sendBuffer.Clear();
FinishSending(true);
}
}
/// <summary>
/// Writes an operation to the output buffer. Handles the case where the op does not fit the buffer fully.
/// </summary>
/// <param name="data"></param>
protected virtual void WriteOp(OpQueueEntry data)
{
if (currentWriteCopier != null)
{
throw new InvalidOperationException("Cannot write an operation while another is in progress.");
}
var request = data.Op.CreateRequest();
if (!request.WriteTo(socket.WriteBuffer)) // no pending IO => fully written
{
readQueue.Enqueue(data);
request.Dispose();
#region Diagnostics
npm.EnqueueReadOp();
CoreEventSource.EnqueueReadOp(name);
LogTo.Trace($"Full send of {data.Op}");
#endregion
}
else
{
// it did not fit into the write buffer, so save the current op
// as "in-progress"; DoRun will loop until it's fully sent
currentWriteOp = data;
currentWriteCopier = request;
LogTo.Trace($"Partial send of {data.Op}");
}
}
/// <summary>
/// Sends the current chunked op. Happens when an op's data cannot fit the write buffer in one pass.
/// </summary>
/// <returns>returns true if further IO is required; false if no inprogress op present or the last chunk was successfully added to the buffer</returns>
private bool ContinueWritingCurrentOp()
{
// check if we have an op in progress
if (currentWriteCopier == null)
{
return(false);
}
if (currentWriteCopier.WriteTo(socket.WriteBuffer))
{
return(true);
}
// last chunk was sent
LogTo.Trace($"Sent & finished {currentWriteOp.Op}");
// op is sent fully; response can be expected
readQueue.Enqueue(currentWriteOp);
#region Diagnostics
npm.EnqueueReadOp();
CoreEventSource.EnqueueReadOp(name);
#endregion
// clean up
currentWriteCopier.Dispose();
currentWriteCopier = null;
currentWriteOp = OpQueueEntry.Empty;
return(false);
}
private void FinishSending(bool success)
{
CoreEventSource.SendStop(name, IsAlive, success);
Volatile.Write(ref isSending, 0);
((Action <bool>)sendArgs.UserToken)?.Invoke(success);
}
private void ReceiveAsyncCompleted(object sender, SocketAsyncEventArgs recvArgs)
{
var received = recvArgs.BytesTransferred;
CoreEventSource.ReceiveChunk(name, IsAlive, received, recvArgs.SocketError);
var success = recvArgs.SocketError == SocketError.Success && received > 0;
recvBuffer.SetDataLength(success ? received : 0);
CoreEventSource.ReceiveStop(name, IsAlive, success);
Volatile.Write(ref isReceiving, 0);
((Action <bool>)recvArgs.UserToken).Invoke(success);
}
/// <summary>
/// Cleans up a ConcurrentQueue, marking all items as failed
/// </summary>
private void FailQueue(ConcurrentQueue <OpQueueEntry> queue, Exception e)
{
OpQueueEntry data;
while (queue.TryDequeue(out data))
{
var t = data.Task;
if (t != null)
{
t.SetException(e);
}
npm.Error();
CoreEventSource.NodeError(name);
}
}
protected virtual OpQueueEntry GetNextOp()
{
OpQueueEntry data;
if (writeQueue.TryDequeue(out data))
{
#region Diagnostics
npm.DequeueWriteOp();
CoreEventSource.DequeueWriteOp(name);
#endregion
return(data);
}
return(OpQueueEntry.Empty);
}
/// <summary>
/// Cleans up an AdvQueue, marking all items as failed
/// </summary>
private void FailQueue(Queue <OpQueueEntry> queue, Exception e)
{
foreach (var data in queue)
{
var t = data.Task;
if (t == null)
{
break;
}
t.TrySetException(e);
npm.Error();
CoreEventSource.NodeError(name);
}
queue.Clear();
}
private void PerformConnect(IPEndPoint endpoint, CancellationToken token)
{
this.endpoint = endpoint;
this.name = endpoint.ToString();
this.IsAlive = false;
var sw = Stopwatch.StartNew();
InitBuffers();
using (var mre = new ManualResetEventSlim(false))
using (var opt = new SocketAsyncEventArgs {
RemoteEndPoint = endpoint
})
{
CoreEventSource.ConnectStart(name);
opt.Completed += (a, b) => mre.Set();
RecreateSocket();
try
{
if (socket.ConnectAsync(opt) &&
!mre.Wait((int)ConnectionTimeout.TotalMilliseconds, token))
{
CoreEventSource.ConnectFail(name, SocketError.TimedOut);
Socket.CancelConnectAsync(opt);
throw new TimeoutException($"Connection timeout {ConnectionTimeout} has been exceeded while trying to connect to {endpoint}");
}
if (opt.SocketError != SocketError.Success)
{
CoreEventSource.ConnectFail(name, opt.SocketError);
throw new IOException($"Could not connect to {endpoint}");
}
IsAlive = true;
}
finally
{
LogTo.Info($"Connected to {endpoint} in {sw.ElapsedMilliseconds} msec");
}
}
}
public bool ScheduleSend(Action <bool> whenDone)
{
CoreEventSource.SendStart(name, IsAlive, sendBuffer.Position);
if (!IsAlive)
{
whenDone(false);
return(false);
}
if (Interlocked.CompareExchange(ref isSending, 1, 0) != 0)
{
return(false);
}
sendArgs.UserToken = whenDone;
PerformSend(sendBuffer.BufferOffset, sendBuffer.Position);
return(true);
}
private void PerformSend(int sendOffset, int sendCount)
{
for (;;)
{
// try sending all our data
sendArgs.SetBuffer(sendOffset, sendCount);
// send is being done asynchrously (SendAsyncCompleted will clean up)
if (socket.SendAsync(sendArgs))
{
break;
}
// send was done synchronously
var sent = sendArgs.BytesTransferred;
CoreEventSource.SendChunk(name, IsAlive, sent, sendArgs.SocketError);
// check for fail
if (sendArgs.SocketError != SocketError.Success || sent < 1)
{
// socket error
FinishSending(false);
break;
}
sendOffset += sent;
sendCount -= sent;
Debug.Assert(sendCount >= 0);
// no data is remaining: quit
// otherwise try sending a new chunk
if (sendCount == 0)
{
sendBuffer.Clear();
FinishSending(true);
break;
}
}
}
public virtual Task <IOperation> Enqueue(IOperation op)
{
var tcs = new TaskCompletionSource <IOperation>();
npm.NewOp();
try
{
if (IsAlive)
{
writeQueue.Enqueue(new OpQueueEntry(op, tcs));
#region Diagnostics
npm.EnqueueWriteOp();
CoreEventSource.EnqueueWriteOp(name);
#endregion
}
else
{
tcs.TrySetException(new IOException(endpoint + " is not alive"));
#region Diagnostics
npm.Error();
CoreEventSource.NodeError(name);
#endregion
}
}
catch (Exception e)
{
tcs.TrySetException(new IOException(endpoint + " enqueue failed. See inner excption for details.", e));
#region Diagnostics
npm.Error();
CoreEventSource.NodeError(name);
#endregion
}
return(tcs.Task);
}
private void TryProcessReceivedData()
{
// process the commands in the readQueue
while (readQueue.Count > 0)
{
// continue filling the previously unfinished response,
// or create a new one
var response = inprogressResponse ?? CreateResponse();
// continue filling the Response object from the buffer
// Read() returns true if further data (IO) is required
// (usually when the current response data is larger than the receive buffer size)
if (response.Read(socket.ReadBuffer))
{
inprogressResponse = response;
LogTo.Trace("Response is not read fully, continue reading from the socket.");
// refill the buffer
_FinishedReading();
owner.NeedsIO(this);
return;
}
// successfully read a response from the read buffer
inprogressResponse = null;
var isHandled = false;
while (!isHandled && readQueue.Count > 0)
{
var data = readQueue.Peek();
Debug.Assert(!data.IsEmpty);
// If the response does not matches the current op, it means it's a
// response to a later command in the queue, so all commands before it
// were silent commands without a response (== usually success).
// So, successful silent ops will receive null as response (since
// we have no real response (or we've ran into a bug))
isHandled = data.Op.Handles(response);
LogTo.Trace($"Command {data.Op} handles reponse: {isHandled}");
// operations are allowed to hanndle subsequent responses
// they returns false when no more IO (response) is required => done processing
if (!data.Op.ProcessResponse(isHandled ? response : null))
{
readQueue.Dequeue();
data.Task.TrySetResult(data.Op);
#region Diagnostics
npm.DequeueReadOp();
CoreEventSource.DequeueReadOp(name);
#endregion
}
}
response.Dispose();
}
LogTo.Trace($"{name} fininshed RECEIVE, unlock read");
_FinishedReading();
}
