presto-main/src/main/java/io/prestosql/execution/executor/TaskHandle.java/TaskHandle/splitComplete
class TaskHandle:    public synchronized void splitComplete(PrioritizedSplitRunner split)
    {
        concurrencyController.splitFinished(split.getScheduledNanos(), utilizationSupplier.getAsDouble(), runningLeafSplits.size());
        runningIntermediateSplits.remove(split);
        runningLeafSplits.remove(split);
    }