package concurrent import "context" // Executor replace go keyword to start a new goroutine // the goroutine should cancel itself if the context passed in has been cancelled // the goroutine started by the executor, is owned by the executor // we can cancel all executors owned by the executor just by stop the executor itself // however Executor interface does not Stop method, the one starting and owning executor // should use the concrete type of executor, instead of this interface. type Executor interface { // Go starts a new goroutine controlled by the context Go(handler func(ctx context.Context)) }