/// <summary>
/// Start execution, setting the top level work,
/// enqueuing it and starting a shift to execute it.
/// </summary>
public void Start(WorkItem topLevelWorkItem)
{
_topLevelWorkItem = topLevelWorkItem;
Dispatch(topLevelWorkItem, InitialExecutionStrategy(topLevelWorkItem));
var shift = SelectNextShift();
ShiftStarting?.Invoke(shift);
shift.Start();
}
private void OnEndOfShift(WorkShift endingShift)
{
ShiftFinished?.Invoke(endingShift);
WorkShift nextShift = null;
while (true)
{
// Shift has ended but all work may not yet be done
while (_topLevelWorkItem.State != WorkItemState.Complete)
{
// This will return null if all queues are empty.
nextShift = SelectNextShift();
if (nextShift != null)
{
ShiftStarting?.Invoke(nextShift);
nextShift.Start();
return;
}
}
// If the shift has ended for an isolated queue, restore
// the queues and keep trying. Otherwise, we are done.
if (_isolationLevel > 0)
{
RestoreQueues();
}
else
{
break;
}
}
// All done - shutdown all shifts
foreach (var shift in Shifts)
{
shift.ShutDown();
}
}