public IObservable <Response> Send(
[NotNull] Request request,
CancellationToken token = default(CancellationToken))
{
OverlappingPipeClientStream stream = _stream;
if (_state != PipeState.Connected ||
stream == null)
{
// ReSharper disable once AssignNullToNotNullAttribute
return(Observable.Empty <Response>());
}
// ReSharper disable once AssignNullToNotNullAttribute
return(Observable.Create <Response>(
async(observer, t) =>
{
Debug.Assert(observer != null);
using (ITokenSource tokenSource = token.CreateLinked(t))
{
token = tokenSource.Token;
ConnectedCommand cr = new ConnectedCommand(request, observer);
_commandRequests.TryAdd(request.ID, cr);
try
{
await stream.WriteAsync(request.Serialize(), token).ConfigureAwait(false);
await cr.CompletionTask.WithCancellation(token).ConfigureAwait(false);
}
// ReSharper disable once EmptyGeneralCatchClause
catch
{
}
// If the command is not explicitly cancelled and is still running, and we've been cancelled
// then ask the server to cancel.
if (!cr.IsCancelled &&
!cr.IsCompleted &&
token.IsCancellationRequested)
{
try
{
using (CancellationTokenSource cts = Constants.FireAndForgetTokenSource)
await CancelCommand(request.ID, cts.Token).ConfigureAwait(false);
}
catch (TaskCanceledException)
{
}
}
// Remove the command request.
_commandRequests.TryRemove(request.ID, out cr);
}
}));
}
/// <summary>
/// Initializes a new instance of the <see cref="NamedPipeClient" /> class.
/// </summary>
/// <param name="description">The client description.</param>
/// <param name="server">The server.</param>
/// <param name="onReceive">The action to call on receipt of a message.</param>
/// <param name="token">The token.</param>
private NamedPipeClient(
[NotNull] string description,
[NotNull] NamedPipeServerInfo server,
[NotNull] Action <Message> onReceive,
CancellationToken token = default(CancellationToken))
{
if (description == null)
{
throw new ArgumentNullException("description");
}
if (server == null)
{
throw new ArgumentNullException("server");
}
if (onReceive == null)
{
throw new ArgumentNullException("onReceive");
}
_server = server;
_cancellationTokenSource = new CancellationTokenSource();
CancellationToken disposeToken = _cancellationTokenSource.Token;
_clientTask = Task.Run(
async() =>
{
try
{
using (ITokenSource tokenSource = token.CreateLinked(disposeToken))
using (
OverlappingPipeClientStream stream = new OverlappingPipeClientStream(
_server.Host,
_server.FullName,
PipeTransmissionMode.Message))
{
_state = PipeState.Open;
token = tokenSource.Token;
// We need to support cancelling the connect.
await stream.Connect(token).ConfigureAwait(false);
ConnectResponse connectResponse = null;
DisconnectResponse disconnectResponse = null;
if (!token.IsCancellationRequested)
{
// Set the stream.
_stream = stream;
_state = PipeState.AwaitingConnect;
// Kick off a connect request, but don't wait for it's result as we're the task that will receive it!
ConnectRequest connectRequest = new ConnectRequest(description);
await stream.WriteAsync(connectRequest.Serialize(), token).ConfigureAwait(false);
// Keep going as long as we're connected.
try
{
while (stream.IsConnected &&
!disposeToken.IsCancellationRequested)
{
// Read data in.
byte[] data = await stream.ReadAsync(disposeToken).ConfigureAwait(false);
if (data == null)
{
break;
}
// Deserialize the incoming message.
Message message = Message.Deserialize(data);
if (connectResponse == null)
{
// We require a connect response to start
connectResponse = message as ConnectResponse;
if (connectResponse == null ||
connectResponse.ID != connectRequest.ID)
{
break;
}
_state = PipeState.Connected;
_serviceName = connectResponse.ServiceName;
Log.Add(
LoggingLevel.Notification,
() => ClientResources.Not_NamedPipeClient_Connection,
connectResponse.ServiceName);
TaskCompletionSource <NamedPipeClient> ccs =
Interlocked.Exchange(ref _connectionCompletionSource, null);
if (ccs != null)
{
ccs.TrySetResult(this);
}
// Observer the message.
onReceive(message);
continue;
}
// Check for disconnect, we don't observe the message until the disconnect is complete.
disconnectResponse = message as DisconnectResponse;
if (disconnectResponse != null)
{
break;
}
// Observe the message.
onReceive(message);
Response response = message as Response;
if (response == null)
{
continue;
}
ConnectedCommand connectedCommand;
// Check for cancellation responses.
CommandCancelResponse cancelResponse = response as CommandCancelResponse;
if (cancelResponse != null)
{
// Cancel the associated request
if (_commandRequests.TryGetValue(
cancelResponse.CancelledCommandId,
out connectedCommand))
{
// ReSharper disable once PossibleNullReferenceException
connectedCommand.Cancel(cancelResponse);
}
}
// And fall through to complete the response...
// Find command the response is related to, and notify it of the response.
if (!_commandRequests.TryGetValue(response.ID, out connectedCommand))
{
continue;
}
Debug.Assert(connectedCommand != null);
if (connectedCommand.Received(response))
{
_commandRequests.TryRemove(response.ID, out connectedCommand);
}
}
}
catch (TaskCanceledException)
{
}
}
// If we're still connected, and we haven't received a disconnect response, try to send a disconnect request.
if (stream.IsConnected &&
disconnectResponse == null)
{
CancellationTokenSource cts = token.IsCancellationRequested
? new CancellationTokenSource(500)
: null;
try
{
CancellationToken t = cts != null
? cts.Token
: token;
// Try to send disconnect request.
// ReSharper disable once PossibleNullReferenceException
await Send(new DisconnectRequest(), t)
.ToTask(t)
.ConfigureAwait(false);
}
catch (TaskCanceledException)
{
}
finally
{
if (cts != null)
{
cts.Dispose();
}
}
}
// Remove the stream.
_stream = null;
_state = PipeState.Closed;
_serviceName = null;
// If we had a disconnect message observe it now that the disconnect has been actioned,
// this prevents the receiver thinking the connection is still active.
if (disconnectResponse != null)
{
onReceive(disconnectResponse);
ConnectedCommand connectedCommand;
if (_commandRequests.TryGetValue(disconnectResponse.ID, out connectedCommand))
{
Debug.Assert(connectedCommand != null);
if (connectedCommand.Received(disconnectResponse))
{
_commandRequests.TryRemove(disconnectResponse.ID, out connectedCommand);
}
}
}
}
}
catch (IOException ioe)
{
if (!token.IsCancellationRequested)
{
// Common exception caused by sudden disconnect, lower level
Log.Add(
ioe,
LoggingLevel.Information,
() => ClientResources.Err_NamedPipeClient_Failed);
}
}
catch (Exception exception)
{
TaskCanceledException tce = exception as TaskCanceledException;
TaskCompletionSource <NamedPipeClient> ccs = Interlocked.Exchange(
ref _connectionCompletionSource,
null);
if (ccs != null)
{
if (tce != null)
{
ccs.TrySetCanceled();
}
else
{
ccs.TrySetException(exception);
}
}
// We only log if this wasn't a cancellation exception.
if (tce == null &&
!token.IsCancellationRequested)
{
Log.Add(
exception,
LoggingLevel.Error,
() => ClientResources.Err_NamedPipeClient_Failed);
}
}
finally
{
Dispose();
}
},
disposeToken);
}
