WindowOperatorQueryFrameProcessor: Avoid writing multiple frames to output channel in runIncrementally() #17373
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Description
With the changes made in #17038, we missed a flow where multiple frames could be written to the output channel in a single iteration of
WindowOperatorQueryFrameProcessor#runIncrementally
. This violates the contract ofrunIncrementally()
and leads to the following error:Channel has no capacity
Sample stacktrace
We missed this flow:
runAllOpsOnBatch()
flushAllRowsAndCols()
, hence writing to the output channel.flushAllRowsAndCols()
again, missing the fact that there's a chance that the input channel might have finished. This ends up attempting to write another frame to the output channel, causing theChannel has no capacity
error.This PR fixes the above problematic flow by checking if the input channel is finished. If it's finished, we re-run
runIncrementally()
instead of step 4.This PR has: