Пример #1
0
        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);
                }
            }));
        }
Пример #2
0
        /// <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);
        }