/// <summary>
/// It callbacks all operations already sent / or to be written, that do not have a response.
/// Invoked from an IO Thread or a pool thread
/// </summary>
internal void CancelPending(Exception ex, SocketError?socketError = null)
{
_isCanceled = true;
var wasClosed = Interlocked.Exchange(ref _writeState, Connection.WriteStateClosed) == Connection.WriteStateClosed;
if (!wasClosed)
{
Closing?.Invoke(this);
Connection.Logger.Info("Cancelling in Connection {0}, {1} pending operations and write queue {2}", EndPoint.EndpointFriendlyName,
InFlight, _writeQueue.Count);
if (socketError != null)
{
Connection.Logger.Verbose("The socket status received was {0}", socketError.Value);
}
}
if (ex == null || ex is ObjectDisposedException)
{
if (socketError != null)
{
ex = new SocketException((int)socketError.Value);
}
else
{
//It is closing
ex = new SocketException((int)SocketError.NotConnected);
}
}
// Dequeue all the items in the write queue
var ops = new LinkedList <OperationState>();
OperationState state;
while (_writeQueue.TryDequeue(out state))
{
ops.AddLast(state);
}
// Remove every pending operation
while (!_pendingOperations.IsEmpty)
{
Interlocked.MemoryBarrier();
// Remove using a snapshot of the keys
var keys = _pendingOperations.Keys.ToArray();
foreach (var key in keys)
{
if (_pendingOperations.TryRemove(key, out state))
{
ops.AddLast(state);
}
}
}
Interlocked.MemoryBarrier();
OperationState.CallbackMultiple(ops, RequestError.CreateClientError(ex, false), GetTimestamp());
Interlocked.Exchange(ref _inFlight, 0);
}
/// <inheritdoc />
public OperationState Send(IRequest request, Action <IRequestError, Response> callback, int timeoutMillis)
{
if (_isCanceled)
{
// Avoid calling back before returning
Task.Factory.StartNew(() => callback(RequestError.CreateClientError(new SocketException((int)SocketError.NotConnected), true), null),
CancellationToken.None, TaskCreationOptions.None, TaskScheduler.Default);
return(null);
}
IncrementInFlight();
var state = new OperationState(
callback,
request,
timeoutMillis,
_connectionObserver.CreateOperationObserver()
);
_writeQueue.Enqueue(state);
if (state.TimeoutMillis > 0)
{
// timer can be disposed while connection cancellation hasn't been invoked yet
try
{
var requestTimeout = Configuration.Timer.NewTimeout(OnTimeout, state, state.TimeoutMillis);
state.SetTimeout(requestTimeout);
}
catch (Exception ex)
{
// Avoid calling back before returning
Task.Factory.StartNew(() => callback(RequestError.CreateClientError(ex, true), null),
CancellationToken.None, TaskCreationOptions.None, TaskScheduler.Default);
return(null);
}
}
RunWriteQueue();
return(state);
}
/// <inheritdoc />
public OperationState Send(IRequest request, Action <IRequestError, Response> callback, int timeoutMillis)
{
if (_isCanceled)
{
// Avoid calling back before returning
Task.Factory.StartNew(() => callback(RequestError.CreateClientError(new SocketException((int)SocketError.NotConnected), true), null),
CancellationToken.None, TaskCreationOptions.None, TaskScheduler.Default);
return(null);
}
IncrementInFlight();
var state = new OperationState(
callback,
request,
timeoutMillis,
_connectionObserver.CreateOperationObserver()
);
_writeQueue.Enqueue(state);
RunWriteQueue();
return(state);
}
/// <summary>
/// Returns an action that capture the parameters closure
/// </summary>
private Action <MemoryStream, long> CreateResponseAction(
ResultMetadata resultMetadata, ISerializer serializer, FrameHeader header, Action <IRequestError, Response, long> callback)
{
var compressor = Compressor;
void DeserializeResponseStream(MemoryStream stream, long timestamp)
{
Response response = null;
IRequestError error = null;
var nextPosition = stream.Position + header.BodyLength;
try
{
Stream plainTextStream = stream;
if (header.Flags.HasFlag(HeaderFlags.Compression))
{
plainTextStream = compressor.Decompress(new WrappedStream(stream, header.BodyLength));
plainTextStream.Position = 0;
}
response = FrameParser.Parse(new Frame(header, plainTextStream, serializer, resultMetadata));
}
catch (Exception caughtException)
{
error = RequestError.CreateClientError(caughtException, false);
}
if (response is ErrorResponse errorResponse)
{
error = RequestError.CreateServerError(errorResponse);
response = null;
}
//We must advance the position of the stream manually in case it was not correctly parsed
stream.Position = nextPosition;
callback(error, response, timestamp);
}
return(DeserializeResponseStream);
}
private void RunWriteQueueAction()
{
//Dequeue all items until threshold is passed
long totalLength = 0;
RecyclableMemoryStream stream = null;
var timestamp = GetTimestamp();
while (totalLength < Connection.CoalescingThreshold)
{
OperationState state = null;
while (_writeQueue.TryDequeue(out var tempState))
{
if (tempState.CanBeWritten())
{
state = tempState;
break;
}
DecrementInFlight();
}
if (state == null)
{
//No more items in the write queue
break;
}
if (!_freeOperations.TryPop(out short streamId))
{
//Queue it up for later.
_writeQueue.Enqueue(state);
//When receiving the next complete message, we can process it.
Connection.Logger.Info("Enqueued, no streamIds available. If this message is recurrent consider configuring more connections per host or lower the pressure");
break;
}
Connection.Logger.Verbose("Sending #{0} for {1} to {2}", streamId, state.Request.GetType().Name, EndPoint.EndpointFriendlyName);
if (_isCanceled)
{
DecrementInFlight();
state.InvokeCallback(RequestError.CreateClientError(new SocketException((int)SocketError.NotConnected), true), timestamp);
break;
}
_pendingOperations.AddOrUpdate(streamId, state, (k, oldValue) => state);
var startLength = stream?.Length ?? 0;
try
{
//lazy initialize the stream
stream = stream ?? (RecyclableMemoryStream)Configuration.BufferPool.GetStream(Connection.StreamWriteTag);
var frameLength = state.WriteFrame(streamId, stream, Serializer, timestamp);
_connectionObserver.OnBytesSent(frameLength);
totalLength += frameLength;
}
catch (Exception ex)
{
//There was an error while serializing or begin sending
Connection.Logger.Error(ex);
//The request was not written, clear it from pending operations
RemoveFromPending(streamId);
//Callback with the Exception
state.InvokeCallback(RequestError.CreateClientError(ex, true), timestamp);
//Reset the stream to before we started writing this frame
stream?.SetLength(startLength);
break;
}
}
if (totalLength == 0L)
{
// Nothing to write, set the queue as not running
Interlocked.CompareExchange(ref _writeState, Connection.WriteStateInit, Connection.WriteStateRunning);
// Until now, we were preventing other threads to running the queue.
// Check if we can now write:
// a read could have finished (freeing streamIds) or new request could have been added to the queue
if (!_freeOperations.IsEmpty && !_writeQueue.IsEmpty)
{
//The write queue is not empty
//An item was added to the queue but we were running: try to launch a new queue
RunWriteQueue();
}
if (stream != null)
{
//The stream instance could be created if there was an exception while generating the frame
stream.Dispose();
}
return;
}
//Write and close the stream when flushed
// ReSharper disable once PossibleNullReferenceException : if totalLength > 0 the stream is initialized
_tcpSocket.Write(stream, () => stream.Dispose());
}