protected override void OnStartFailed()
{
// if the transport failed to start we want to stop it silently.
_stop = true;
_request.Abort();
}
/// <summary>
/// Aborts the currently active polling request thereby forcing a reconnect.
/// This will not trigger OnAbort.
/// </summary>
public void LostConnection()
{
lock (_stopLock)
{
if (_currentRequest != null)
{
_currentRequest.Abort();
}
}
}
/// <summary>
/// Aborts the currently active polling request, does not stop the Polling Request Handler.
/// </summary>
private void Abort()
{
OnAbort(_currentRequest);
if (_currentRequest != null)
{
// This will no-op if the request is already finished
_currentRequest.Abort();
}
}
protected override void OnStart(IConnection connection,
string connectionData,
CancellationToken disconnectToken,
TransportInitializationHandler initializeHandler)
{
if (initializeHandler == null)
{
throw new ArgumentNullException("initializeHandler");
}
// Tie into the OnFailure event so that we can stop the transport silently.
initializeHandler.OnFailure += () =>
{
_stop = true;
_request.Abort();
};
OpenConnection(connection, connectionData, disconnectToken, initializeHandler.Success, initializeHandler.Fail);
}
public void Close()
{
if (_request != null)
{
// Always try to abort the request since close hangs if the connection is
// being held open
_request.Abort();
}
((IDisposable)_response).Dispose();
}
public void AbortRequest()
{
CloseActiveStream();
_request.Abort();
if (statusCode == 0)
{
statusCode = ERROR_CODE_ABORTED;
statusDescription = "Request was aborted";
}
isActive = false;
}
/// <summary>
/// Fully stops the polling loop.
/// </summary>
private void StopPolling()
{
lock (_stopLock)
{
if (Interlocked.Exchange(ref _running, 0) == 1)
{
_disconnectRegistration.Dispose();
// Complete any ongoing calls to Abort()
// If someone calls Abort() later, have it no-op
AbortHandler.CompleteAbort();
if (_currentRequest != null)
{
// This will no-op if the request is already finished
_currentRequest.Abort();
}
}
}
}
public SystemTaskBase GetTask(LoadBalanceWorkload workload, ResourceReservationContext context)
{
lock (this.requestQueueLock)
{
this.BlockedTaskCount = 0;
if (this.requests.Count == 0)
{
return(null);
}
for (int i = 0; i < this.requests.Count; i++)
{
IRequest request = this.requests[i];
if (request.IsBlocked)
{
this.BlockedTaskCount++;
}
else if (request.ShouldCancel(this.settings.IdleRunDelay))
{
request.Abort();
DatabaseRequestLog.Write(request);
this.requests.RemoveAt(i);
i--;
}
else
{
ResourceKey obj2;
ResourceReservation reservation = context.GetReservation(workload, request.Resources, out obj2);
if (reservation != null)
{
this.requests.RemoveAt(i);
return(new LoadBalanceTask(workload, reservation, request));
}
if (ProcessorResourceKey.Local.Equals(obj2))
{
this.BlockedTaskCount = this.requests.Count;
break;
}
this.BlockedTaskCount++;
}
}
}
return(null);
}
private void OpenConnection(IConnection connection,
string data,
CancellationToken disconnectToken,
Action initializeCallback,
Action <Exception> errorCallback)
{
// If we're reconnecting add /connect to the url
bool reconnecting = initializeCallback == null;
var callbackInvoker = new ThreadSafeInvoker();
var requestDisposer = new Disposer();
var url = (reconnecting ? connection.Url : connection.Url + "connect") + GetReceiveQueryString(connection, data);
connection.Trace(TraceLevels.Events, "SSE: GET {0}", url);
HttpClient.Get(url, req =>
{
_request = req;
connection.PrepareRequest(_request);
_request.Accept = "text/event-stream";
}).ContinueWith(task =>
{
if (task.IsFaulted)
{
Exception exception = task.Exception.Unwrap();
if (!ExceptionHelper.IsRequestAborted(exception))
{
if (errorCallback != null)
{
callbackInvoker.Invoke((cb, ex) => cb(ex), errorCallback, exception);
}
else if (reconnecting)
{
// Only raise the error event if we failed to reconnect
connection.OnError(exception);
Reconnect(connection, data, disconnectToken);
}
}
requestDisposer.Dispose();
}
else
{
var response = task.Result;
Stream stream = response.GetStream();
var eventSource = new EventSourceStreamReader(connection, stream);
bool retry = true;
var esCancellationRegistration = disconnectToken.SafeRegister(state =>
{
retry = false;
((IRequest)state).Abort();
},
_request);
eventSource.Opened = () =>
{
// If we're not reconnecting, then we're starting the transport for the first time. Trigger callback only on first start.
if (!reconnecting)
{
callbackInvoker.Invoke(initializeCallback);
}
else if (connection.ChangeState(ConnectionState.Reconnecting, ConnectionState.Connected))
{
// Raise the reconnect event if the connection comes back up
connection.OnReconnected();
}
};
eventSource.Message = sseEvent =>
{
if (sseEvent.EventType == EventType.Data)
{
if (sseEvent.Data.Equals("initialized", StringComparison.OrdinalIgnoreCase))
{
return;
}
bool timedOut;
bool disconnected;
TransportHelper.ProcessResponse(connection, sseEvent.Data, out timedOut, out disconnected);
if (disconnected)
{
retry = false;
connection.Disconnect();
}
}
};
eventSource.Closed = exception =>
{
if (exception != null)
{
// Check if the request is aborted
bool isRequestAborted = ExceptionHelper.IsRequestAborted(exception);
if (!isRequestAborted)
{
// Don't raise exceptions if the request was aborted (connection was stopped).
connection.OnError(exception);
}
}
requestDisposer.Dispose();
esCancellationRegistration.Dispose();
response.Dispose();
if (AbortResetEvent != null)
{
AbortResetEvent.Set();
}
else if (retry)
{
Reconnect(connection, data, disconnectToken);
}
};
eventSource.Start();
}
});
var requestCancellationRegistration = disconnectToken.SafeRegister(state =>
{
if (state != null)
{
// This will no-op if the request is already finished.
((IRequest)state).Abort();
}
if (errorCallback != null)
{
callbackInvoker.Invoke((cb, token) =>
{
#if NET35 || WINDOWS_PHONE
cb(new OperationCanceledException(Resources.Error_ConnectionCancelled));
#else
cb(new OperationCanceledException(Resources.Error_ConnectionCancelled, token));
#endif
}, errorCallback, disconnectToken);
}
}, _request);
requestDisposer.Set(requestCancellationRegistration);
if (errorCallback != null)
{
TaskAsyncHelper.Delay(ConnectionTimeout).Then(() =>
{
callbackInvoker.Invoke((conn, cb) =>
{
// Abort the request before cancelling
_request.Abort();
// Connection timeout occurred
cb(new TimeoutException());
},
connection,
errorCallback);
});
}
}
