[Bug] moneybatcher sample race condition?

What are you really trying to do?

I am trying to learn how to do batching using temporal. I found the moneybatch sample and I wanted to make sure that it can handle requests in parallel.

To simulate the behavior, I changed the workflow to withdraw more times than a single batch size as well as added a delay during the deposit call.
What this lead to is that the workflow would continue to run and not complete, it won't even process a single batch.

Describe the bug

This is related to the condition in the workflow:
Workflow.await(() -> count == batchSize);

If count suddenly goes from 0 to a value greater than batchSize, the workflow will continue to run and not complete.

I am new to temporal, so I am not quite sure how to fix this. Is this a bug in the sample or am I doing something wrong?

Minimal Reproduction

Download this branch:
https://github.com/derwasp/samples-java/tree/derwasp/moneybatcher

Either run ./run-moneybatch-demo.sh and observe the logs.
Or run the test TransferWorkflowTest and see the failure.

Environment/Versions

• OS and processor: M4 Mac
• Temporal Version: (CLI version 1.4.1)
• Are you using Docker or Kubernetes or building Temporal from source? Docker

Additional context

Beginne mit dem moneybatch sample unter core/src/main/java/io/temporal/samples/moneybatch und führe TransferWorkflowTest aus dem verknüpften Reproduktions-Branch aus. Untersuche die Workflow.await-Bedingung und das Test-Setup für Anfragen, die die Größe eines Batches überschreiten. Als erledigt gilt die Aufgabe, wenn der reproduzierte Workflow abgeschlossen wird und die erwarteten Batches verarbeitet, anstatt blockiert zu bleiben.