/// <summary>
/// Unschedule selected items for processing and apply an action to each unscheduled item.
/// </summary>
/// <param name="itemSelector">A function to test each element for removal.</param>
/// <param name="processUnscheduled">An optional action to execute on each unscheduled item.</param>
public void Unschedule(Func <T, bool> itemSelector, Action <T> processUnscheduled = null)
{
if (itemSelector == null)
{
throw new ArgumentNullException(nameof(itemSelector));
}
T[] unscheduledItems;
lock (queueLock)
{
var keptItems = processingQueue.Where(x => !itemSelector(x)).ToArray();
unscheduledItems = processingQueue.Where(itemSelector).ToArray();
processingQueue.Clear();
queueSet.Clear();
foreach (var item in keptItems)
{
processingQueue.Enqueue(item);
queueSet.Add(item);
}
}
if (processUnscheduled != null)
{
foreach (var item in unscheduledItems)
{
processUnscheduled(item);
}
}
if (unscheduledItems.Length > 0)
{
Unscheduled?.Invoke(this, BuildEventArgs());
}
}
private void OnUnscheduled()
{
Unscheduled?.Invoke(this, EventArgs.Empty);
}