Uvicorn with Thread handle KeyboardInterrupt

[cxheng315]

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Example Code

from fastapi import FastAPI, APIRouter, Query
import uvicorn
import threading

def run_background_task():
        
    while True:
        try:
            print("Auto Every 5 minute Update Data")
            fetch_data()
            time.sleep(60*60)
        except Exception as e:
            print(e)

if __name__ == "__main__":
    try:
        stop_event = asyncio.Event()
        thread = threading.Thread(target=run_background_task)
        thread.start()
        uvicorn.run(app, host="0.0.0.0", port=8000, log_level="info")
    except KeyboardInterrupt:
        # Set the stop event to stop the server and the background task
        # Wait for the background task to stop
        thread.join()
    except Exception as e:
        print(e)

Description

After I pressed Ctrl + C, the KeyboardInterrupt, the uvicorn.run(), server stopped, but the thread unable to terminate.
Seems like uvicorn.run() will handle KeyboardInterrupt internally, so I'm unable to terminate the thread.
How should I do to terminate the uvicorn server and thread the same time when I entered Ctrl + C

Operating System

Windows

Operating System Details

Windows 11

FastAPI Version

0.88.0

Python Version

Python 3.10.6

Additional Context

No response

[NewSouthMjos]

Fast solution: use fastapi-utils repeat_every

[jgould22]

Uvicorn adds a signal handler to the event loop.

https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.loop.add_signal_handler

Also I will have to assume this is a toy example because the example background task will never quit as written.

https://docs.python.org/3/library/signal.html#signals-and-threads

Perhaps you can pass your thread an event and register a callback that sets your event. Then you can check is_set in your thread.

[cxheng315]

Fast solution: use fastapi-utils repeat_every

Problem solved, thank you so much.