Run the SpringBatchParallelBug Spring application.
The job completes successfully, using two executors for parallelFlowWorks and parallelFlowNoWork.
parallelFlowWorks runs just fine, but parallelFlowNoWork gets hung after running just two tasks.
parallelFlowWorks calls Flow.split.add(Flow[]) just once with a list of Flows that have been built up.
parallelFlowNoWork calls .add(Flow) repeatedly to add its list of Flows.
It is unexpected that these would behave differently, but clearly one works and the other does not.
As a side note, it is unfortunate that to enable parallel workers on steps, that each Step must be wrapped in a Flow. Why does this requirement exist?