/// <summary>
/// Queue work item to the pool. The work item
/// will run right away if a thread is available
/// other wise it will be queued. Exact semantics
/// will depend on implementation
/// </summary>
/// <param name="context">the stage's worker
/// execution context</param>
public override void QueueWork(StageWorkerContext context)
{
ThreadPoolUtil.QueueUserWorkItem(StageWorkerThread, context);
}
/// <summary>
/// Gracefully shutdown
/// </summary>
public override void ShutDown()
{
ThreadPoolUtil.Shutdown();
}