Creating a child process during Tool Call causes Worker Shutdown

[raisbecka]

Bug Description

My environment: Windows 11, WSL2 (Ubuntu flavor)

I have a longer running operation that I have tested extensively and it works. Its main loop is a subclass of multiprocessing.Process, and it runs well/indefinitely without error when tested on its own.

I want to run this when a tool call is triggered - supplying the input parameter. I am able to trigger the tool call, the parameter is correct, the child process starts... but then after a short (few seconds) period of time, I get "worker.py:578 - shutting down worker" in the log. I don't see any errors at all, and I have debugging enabled for this subprocess, as well as LiveKit. Nothing that looks suspicious.

To start the subprocess, I am creating an mp.Queue(), passing this to the child process init (subclass of mp.Process), and running p.start(). I then enter an async polling loop to check the queue for updates - using non-blocking queue.get() and asyncio.sleep(). The child process is using the forkserver start method - I can confirm.

I have encapsulated all the above in an async method which I run using asyncio.create_task(). This is the ONLY command in my tool call handler. This task creates the subprocess (tested and working on it's own), starts it, and then indefinitely monitors the queue.

My question is this: Why is the worker getting shutdown? Aside from not being a best practise, what is actually causing the worker shutdown?

Expected Behavior

The tool call returns right away, but the process I created continues running in the background - updating the UI and a state variable until it's done. What happens instead is the worker shuts down after a few seconds (at arbitrary points in the child process execution) and takes the child process down with it.

Reproduction Steps

I cannot even pin down the exact cause, so I don't know.

Operating System

windows 11, wsl2

Models Used

Groq -> Cerebras -> Groq

Package Versions

livekit=1.0.22
livekit-agents=1.2.8
livekit-api=1.0.5

Session/Room/Call IDs

No response

Proposed Solution

I just need to understand why the worker is shutting down, and how to avoid it. I am completely at a loss as to why this is occurring.

Additional Context

Hoping something will jump out at you as the cause. If required otherwise, I can provide some code to help diagnose.

Screenshots and Recordings

No response