/// <nodoc />
public MultiplexingClient(IClientConfig config, Stream stream)
{
Contract.Requires(config != null);
Contract.Requires(stream != null);
Config = config;
Logger = config.Logger ?? VoidLogger.Instance;
m_stream = stream;
m_pendingRequests = new ConcurrentDictionary <int, TaskSourceSlim <IIpcResult> >();
m_disconnectRequestedByServer = false;
// Receiving Dataflow:
// This generic server will call 'SetResponse' for every received Response. 'SetResponse'
// could be done in parallel, but there is no point, since they all access a shared concurrent
// dictionary and all they do is lookup task completion source and set a result for it.
m_responseListener = new GenericServer <Response>(
name: "MultiplexingClient.ResponseListener",
config: new ServerConfig {
Logger = Logger, MaxConcurrentClients = 1
},
listener: ReceiveResponseAsync,
clientFailuresAreFatal: true);
// Sending Dataflow:
// All 'Send' requests are concurrently queued up here. Processing of this block
// ('SendRequestAsync') must be sequential, because uses the shared connection.
m_sendRequestBlock = new ActionBlock <Request>(
SendRequestAsync,
new ExecutionDataflowBlockOptions
{
MaxDegreeOfParallelism = 1,
});
// set continuations that handle errors (unblock pending requests and set failure as completion of this client)
var continuationDone = TaskSourceSlim.Create <Unit>();
m_responseListener.Completion.ContinueWith(_ => m_sendRequestBlock.Complete());
m_sendRequestBlock.Completion.ContinueWith(async _ =>
{
m_responseListener.Complete();
UnblockPendingRequests(new IpcResult(IpcResultStatus.GenericError, "MultiplexingClient completed before all requests were handled"));
if (!m_disconnectRequestedByServer)
{
var succeeded = await Request.StopRequest.TrySerializeAsync(m_stream);
Logger.Verbose("Sending StopRequest {0}.", succeeded ? "Succeeded" : "Failed");
}
continuationDone.SetResult(Unit.Void);
});
// start listening for responses
m_responseListener.Start(SetResponseAsync);
// set the completion task
m_completion = TaskUtilities.SafeWhenAll(new[] { m_sendRequestBlock.Completion, m_responseListener.Completion, continuationDone.Task });
}
/// <nodoc/>
public RequestHandler(MultiplexingServer <TClient> parent, TClient client)
{
m_parent = parent;
m_client = client;
m_stream = parent.m_connectivityProvider.GetStreamForClient(client);
Name = I($"{parent.Name}.RequestHandler({parent.m_connectivityProvider.Describe(client)})");
m_stopRequestedByClient = false;
m_requestListener = new GenericServer <Request>(
name: Name,
config: m_parent.m_requestHandlingConfig,
listener: AcceptRequestAsync);
m_sendResponseBlock = new ActionBlock <Response>(
SendResponseAsync,
new ExecutionDataflowBlockOptions {
MaxDegreeOfParallelism = 1
}); // streaming must be sequential
// chain block completions: either one completes the other
var continuationDone = TaskSourceSlim.Create <Unit>();
m_requestListener.Completion.ContinueWith(_ => m_sendResponseBlock.Complete());
m_sendResponseBlock.Completion.ContinueWith(async _ =>
{
m_requestListener.Complete();
if (!m_stopRequestedByClient)
{
var succeeded = await Response.DisconnectResponse.TrySerializeAsync(m_stream);
Logger.Verbose("({0}) Sending DisconnectResponse {1}.", Name, succeeded ? "Succeeded" : "Failed");
}
Logger.Verbose("({0}) Disconnecting client...", Name);
bool ok = TryDisconnectClient(m_client);
Logger.Verbose("({0}) Disconnecting client {1}.", Name, ok ? "Succeeded" : "Failed");
continuationDone.SetResult(Unit.Void);
});
// set the completion task to be the completion of both listener and sender blocks, as well as the cleanup continuation
m_completion = TaskUtilities.SafeWhenAll(new[] { m_requestListener.Completion, m_sendResponseBlock.Completion, continuationDone.Task });
}
/// <see cref="GenericServer{TClient}.Complete"/>
public void RequestStop() => m_clientListener.Complete();
internal void RequestStop(string logMessage = null)
{
Logger.Verbose(logMessage ?? "({0}) Stop requested", Name);
m_requestListener.Complete();
}
private void RequestStop(string logMessage)
{
Logger.Verbose(logMessage);
m_responseListener.Complete();
m_sendRequestBlock.Complete();
}