feat(server): construct the stack in a persistent event loop#2818
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ashwinb merged 1 commit intollamastack:mainfrom Jul 18, 2025
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feat(server): construct the stack in a persistent event loop#2818ashwinb merged 1 commit intollamastack:mainfrom
ashwinb merged 1 commit intollamastack:mainfrom
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this makes sense to me, one question
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After llamastack#2818, SIGINT will print a stack trace. This is because uvicorn re-raises SIGINT and it gets converted by Python internal signal handler (default handles SIGINT) to KeyboardInterrupt exception. We know simply catch the exception to get a clean exit, this is not changing the behavior on SIGINT. Signed-off-by: Sébastien Han <seb@redhat.com>
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# What does this PR do? After #2818, SIGINT will print a stack trace. This is because uvicorn re-raises SIGINT and it gets converted by Python internal signal handler (default handles SIGINT) to KeyboardInterrupt exception. We know simply catch the exception to get a clean exit, this is not changing the behavior on SIGINT. ## Test Plan Run the server, hit Ctrl+C or `kill -2 <server pid>` and expect a clean exit with no stack trace. Signed-off-by: Sébastien Han <seb@redhat.com>
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When we call
construct_stack(), providers are instantiated andinitialize()is called. This call can end up doing anything at all -- specifically, providers are free to create long running background tasks as part of this. If we wrapped this within aasyncio.run()as in the current code, these tasks get canceled when the stack construction finishes. This is not correct. The PR addresses the issue by creating a persistent event loop which is used for both the stack as well as for running the uvicorn server. In other words, the lifetime of the providers (and downstream async code) is now the same as the lifetime of the uvicorn server.Test Plan
This should not affect any current code since we don't have background tasks created right now. However, #2805 will start using this functionality.