Github user zhijiangW commented on a diff in the pull request: https://github.com/apache/flink/pull/4559#discussion_r157706951 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/ResultSubpartition.java --- @@ -99,6 +82,23 @@ protected Throwable getFailureCause() { abstract public boolean isReleased(); + /** + * Gets the number of non-event buffers in this subpartition. + */ + abstract public int getBuffersInBacklog(); + + /** + * Decreases the number of non-event buffers by one after fetching a non-event + * buffer from this subpartition. + */ + abstract public void decreaseBuffersInBacklog(Buffer buffer); + + /** + * Increases the number of non-event buffers by one after adding a non-event + * buffer into this subpartition. + */ + abstract public void increaseBuffersInBacklog(Buffer buffer); --- End diff -- Sorry my expression is not correct above. I mean we do not need `decreaseBuffersInBacklog` method in `ResultSubPartition` after modifying the `parent` as `SpillableSubpartition` in `SpilledSubpartitionView`.
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