Sealer

func (s *Sealer) run(ctx context.Context) {
	sub := s.blockchain.SubscribeEvents()
	eventCh := sub.GetEventCh()

	for {
		if s.config.DevMode {
			// In dev-mode we wait for new transactions to seal blocks
			select {
			case <-s.wakeCh:
			case <-ctx.Done():
				return
			}
		}

		// start sealing
		subCtx, cancel := context.WithCancel(ctx)
		done := s.sealAsync(subCtx)

		// wait for the sealing to be done
		select {
		case <-done:
			// the sealing process has finished
		case <-ctx.Done():
			// the sealing routine has been canceled
		case <-eventCh:
			// there is a new head, reset sealer
		}

		// cancel the sealing process context
		cancel()

		if ctx.Err() != nil {
			return
		}
	}
}