/// <summary>
/// see RepeatTemplate#WaitForResults
/// </summary>
/// <param name="state"></param>
/// <returns></returns>
protected override bool WaitForResults(IRepeatInternalState state)
{
IResultQueue <IResultHolder> queue = ((ResultQueueInternalState)state).ResultQueue;
bool result = true;
while (queue.IsExpecting())
{
// Careful that no runnables that are not going to finish ever get
// onto the queue, else this may block forever.
IResultHolder future;
try
{
future = queue.Take();
}
catch (ThreadInterruptedException)
{
Thread.CurrentThread.Interrupt();
throw new RepeatException("InterruptedException while waiting for result.");
}
if (future.Error != null)
{
state.GetExceptions().Add(future.Error);
result = false;
}
else
{
RepeatStatus status = future.Result;
result = result && CanContinue(status);
ExecuteAfterInterceptors(future.Context, status);
}
}
Assert.State(queue.IsEmpty(), "Future results queue should be empty at end of batch.");
return(result);
}
/// <summary>
/// Use the TaskExecutor to generate a result. The
/// internal state in this case is a queue of unfinished result holders of
/// IResultHolder. The holder with the return value should not be
/// on the queue when this method exits. The queue is scoped in the calling
/// method so there is no need to synchronize access.
/// </summary>
/// <param name="context"></param>
/// <param name="callback"></param>
/// <param name="state"></param>
/// <returns></returns>
protected override RepeatStatus GetNextResult(IRepeatContext context, RepeatCallback callback,
IRepeatInternalState state)
{
ExecutingRunnable runnable;
IResultQueue <IResultHolder> queue = ((ResultQueueInternalState)state).ResultQueue;
do
{
// Wrap the callback in a runnable that will add its result to the
// queue when it is ready.
runnable = new ExecutingRunnable(callback, context, queue);
// Tell the runnable that it can expect a result. This could have
// been in-lined with the constructor, but it might block, so it's
// better to do it here, since we have the option (it's a private
// class).
runnable.Expect();
//Start the task possibly concurrently / in the future.
_taskExecutor.Execute(new Task(delegate { runnable.Run(); }));
// Allow termination policy to update its state. This must happen
// immediately before or after the call to the task executor.
Update(context);
// Keep going until we get a result that is finished, or early
// termination...
}while (queue.IsEmpty() && !IsComplete(context));
IResultHolder result = queue.Take();
if (result.Error != null)
{
throw result.Error;
}
return(result.Result);
}