public void CancelAsync(object userState)
{
if (userState == null)
{
throw CoreWf.Internals.FxTrace.Exception.ArgumentNull("userState");
}
AsyncInvokeContext context = this.RemoveFromPendingInvokes(userState);
if (context != null)
{
// cancel does not need a timeout since it's bounded by the invoke timeout
if (s_cancelCallback == null)
{
s_cancelCallback = Fx.ThunkCallback(new AsyncCallback(CancelCallback));
}
// cancel only throws TimeoutException and shouldnt throw at all if timeout is infinite
// cancel does not need to raise InvokeCompleted since the InvokeAsync invocation would raise it
IAsyncResult result = context.WorkflowApplication.BeginCancel(TimeSpan.MaxValue, s_cancelCallback, context);
if (result.CompletedSynchronously)
{
context.WorkflowApplication.EndCancel(result);
}
}
}
private void PostInvokeCompletedAndRemove(AsyncInvokeContext context, Exception error)
{
if (context.UserState != null)
{
RemoveFromPendingInvokes(context.UserState);
}
PostInvokeCompleted(context, error);
}
private void CancelCallback(IAsyncResult result)
{
if (result.CompletedSynchronously)
{
return;
}
AsyncInvokeContext context = (AsyncInvokeContext)result.AsyncState;
// cancel only throws TimeoutException and shouldnt throw at all if timeout is infinite
context.WorkflowApplication.EndCancel(result);
}
private void AddToPendingInvokes(AsyncInvokeContext context)
{
lock (ThisLock)
{
if (this.PendingInvokes.ContainsKey(context.UserState))
{
throw CoreWf.Internals.FxTrace.Exception.AsError(new InvalidOperationException(SR.SameUserStateUsedForMultipleInvokes));
}
this.PendingInvokes.Add(context.UserState, context);
}
}
private void PostInvokeCompleted(AsyncInvokeContext context, bool cancelled, Exception error)
{
InvokeCompletedEventArgs e = new InvokeCompletedEventArgs(error, cancelled, context);
if (this.InvokeCompleted == null)
{
context.Operation.OperationCompleted();
}
else
{
context.Operation.PostOperationCompleted(this.RaiseInvokeCompletedCallback, e);
}
}
private void PostInvokeCompleted(AsyncInvokeContext context, Exception error)
{
bool cancelled;
if (error == null)
{
context.WorkflowApplication.GetCompletionStatus(out error, out cancelled);
}
else
{
cancelled = false;
}
PostInvokeCompleted(context, cancelled, error);
}
private void InternalInvokeAsync(IDictionary <string, object> inputs, TimeSpan timeout, object userState)
{
AsyncInvokeContext context = new AsyncInvokeContext(userState, this);
if (userState != null)
{
AddToPendingInvokes(context);
}
Exception error = null;
bool completedSynchronously = false;
try
{
if (s_invokeCallback == null)
{
s_invokeCallback = Fx.ThunkCallback(new AsyncCallback(InvokeCallback));
}
context.Operation.OperationStarted();
IAsyncResult result = WorkflowApplication.BeginInvoke(_workflow, inputs, _extensions, timeout, SynchronizationContext.Current, context, s_invokeCallback, context);
if (result.CompletedSynchronously)
{
context.Outputs = this.EndInvoke(result);
completedSynchronously = true;
}
}
catch (Exception e)
{
if (Fx.IsFatal(e))
{
throw;
}
error = e;
}
if (error != null || completedSynchronously)
{
PostInvokeCompletedAndRemove(context, error);
}
}
private void InvokeCallback(IAsyncResult result)
{
if (result.CompletedSynchronously)
{
return;
}
AsyncInvokeContext context = (AsyncInvokeContext)result.AsyncState;
WorkflowInvoker thisPtr = context.Invoker;
Exception error = null;
try
{
context.Outputs = thisPtr.EndInvoke(result);
}
catch (Exception e)
{
if (Fx.IsFatal(e))
{
throw;
}
error = e;
}
thisPtr.PostInvokeCompletedAndRemove(context, error);
}
internal InvokeCompletedEventArgs(Exception error, bool cancelled, AsyncInvokeContext context)
: base(error, cancelled, context.UserState)
{
this.Outputs = context.Outputs;
}