feat(nested-steps): Stop hardcoding Root context thread#9
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…ler threads in .get().
maschnetwork
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Jan 19, 2026
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maschnetwork
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Thanks for working on this. Some comments to discuss.
examples/src/main/java/com/amazonaws/lambda/durable/examples/NestedStepExample.java
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examples/src/test/java/com/amazonaws/lambda/durable/examples/NestedStepExampleTest.java
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sdk/src/main/java/com/amazonaws/lambda/durable/operation/StepOperation.java
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zhongkechen
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Jan 20, 2026
| this.serDes = serDes; | ||
| this.lambdaContext = lambdaContext; | ||
| this.operationCounter = new AtomicInteger(0); | ||
| this.uniqueThreadName = Thread.currentThread().getName(); // Auto-detect handler thread |
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Is this guaranteed to be unique with all executors? I assume we're going to allow customers to use their own Executor implementation.
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This is a good point @zhongkechen. I actually tested some edge-cases and we should avoid relying on synchronizing the thread name with our tracking of active threads in Execution Manager.
- Users can provide their own executor with their own naming strategy which we would overwrite (bad user experience)
- Thread pools can re-use threads which can lead to side-effects in concurrency scenarios.
A better solution might be to track the currently active thread context with a thread local. Something like:
- DurableContext -> enters "Context" thread
- Step.execute() -> enters "Step" thread
- Step.get() -> check if currently active context is a context or step thread
- RunInChild context can create a new "Context" thread with another name
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I fixed this problem in the newest revision and we raise an exception now when nested step calling happens.
… threads. Merge threadlocal into a single OperationContext record.
…xecution manager.
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Issue Link, if available
#7
Description
This PR removes hardcoding of the "Root" context thread name. Now, the
DurableContextthread default to the name assigned by the managed executor. Steps will run in their own thread and set the thread name on their own in sync with e.g.stepTaskId. This way, we can de-register the calling thread by thread name in.get().We also removed
ThreadTypesince it was unused and only used in DEBUG logs. If we need it again in the future, we can re-add it.Demo/Screenshots
Added NestedStepExample:
Logs (see how step 2 is de-registered from step 1 running
.get()inside step 2). This can be interpreted as handing off control from step 2 (running in "Root" context) to step 1 running in step 2 and then back up the chain.Checklist