internal void RegisterChild(IDataflowDependency childWrapper, bool allowDuplicate)
{
if (ImmutableUtils.TryAddOptimistically(ref m_children, childWrapper))
{
var dataflowDependency = childWrapper as DataflowDependency;
if (dataflowDependency != null)
{
//add myself as parents
ImmutableUtils.AddOptimistically(ref dataflowDependency.Flow.m_parents, this);
}
}
else
{
if (allowDuplicate)
{
LogHelper.Logger.DebugFormat(
"Duplicate child registration ignored in {0}: {1}",
this.FullName,
childWrapper.DisplayName);
return;
}
else
{
throw new ArgumentException("Duplicate child to register in " + this.FullName);
}
}
if (!m_completionTask.IsValueCreated)
{
//eagerly initialize completion task
//would look better if Lazy<T> provides an EagerEvaluate() method
var t = m_completionTask.Value;
}
}
/// <summary>
/// Register a cancellation token source which will be signaled to external components
/// if this dataflow runs into error. (Useful to terminate input stream to the dataflow
/// together with PullFromAsync)
/// </summary>
public void RegisterCancellationTokenSource(CancellationTokenSource cts)
{
ImmutableUtils.AddOptimistically(ref m_ctsList, cts);
if (m_children.Count != 0)
{
}
}
/// <summary>
/// Link the copied data stream to another block
/// </summary>
private void LinkCopyTo(IDataflow <T> other)
{
//first, create a new copy block
Dataflow <T, T> copyBuffer = new BufferBlock <T>(m_dataflowOptions.ToGroupingBlockOption()).ToDataflow(m_dataflowOptions);
RegisterChild(copyBuffer);
copyBuffer.RegisterDependency(m_transformBlock);
var afterAdd = ImmutableUtils.AddOptimistically(ref m_copyBuffers, copyBuffer);
copyBuffer.Name = "Buffer" + afterAdd.Count;
copyBuffer.LinkTo(other);
}
/// <summary>
/// Register an external block as dependency, whose completion will trigger completion of this dataflow
/// if this dependencies finishes as the last amony all dependencies.
/// i.e. Completion of this dataflow will only be triggered after ALL dependencies finish.
/// </summary>
internal void RegisterDependency(IDataflowDependency dependency)
{
bool isFirstDependency = m_dependencies.IsEmpty;
if (!ImmutableUtils.TryAddOptimistically(ref m_dependencies, dependency))
{
LogHelper.Logger.WarnFormat("A dependency registration is ignored by {0} as it is already a dependency: {1}", this.FullName, dependency.DisplayName);
}
if (isFirstDependency)
{
TaskEx.AwaitableWhenAll(() => m_dependencies, f => f.Completion).ContinueWith(
upstreamTask =>
{
if (!this.CompletionTask.IsCompleted)
{
if (upstreamTask.IsFaulted)
{
this.Fault(new LinkedDataflowFailedException());
}
else if (upstreamTask.IsCanceled)
{
this.Fault(new LinkedDataflowCanceledException());
}
else
{
if (m_dependencies.Count > 1)
{
LogHelper.Logger.InfoFormat("{0} All of my dependencies are done. Completing myself.", this.FullName);
}
this.Complete();
}
}
});
}
else
{
LogHelper.Logger.InfoFormat("{0} now has {1} dependencies. (Added {2})", this.FullName, m_dependencies.Count, dependency.DisplayName);
}
}
/// <summary>
/// Register a post dataflow job, which will be executed and awaited after all children of the dataflow is done.
/// The gived job effects the completion task of the dataflow
/// </summary>
/// <param name="postDataflowTask"></param>
public void RegisterPostDataflowTask(Func <Task> postDataflowTask)
{
ImmutableUtils.AddOptimistically(ref m_postDataflowTasks, postDataflowTask);
}