presto-main/src/main/java/io/prestosql/operator/DriverYieldSignal.java/DriverYieldSignal/reset
class DriverYieldSignal:    public synchronized void reset()
    {
        checkState(yieldFuture != null, "there is no ongoing yield");
        yield.set(false);
        yieldFuture.cancel(true);
        yieldFuture = null;
    }