Describe the bug

Make a multiprocessing Process and start it.
Right after terminate the process, fastapi itself(parent) terminated.

To Reproduce

Start command: /usr/local/bin/uvicorn worker.stts_api:app --host 127.0.0.1 --port 8445

1. Create a file with:

from fastapi import FastAPI

app = FastAPI()


@app.post('/task/run')
def task_run(task_config: TaskOptionBody):
    proc = multiprocessing.Process(
        target=task.run,
        args=(xxxx,))
    proc.start()
    return task_id

@app.get('/task/abort')
def task_abort(task_id: str):
    proc.terminate()
    return result_OK

3. Run task_run and while the process alive, trigger task_abort
4. After child process terminated then parent(fastApi) terminated as well.

Expected behavior

Parent process should not be terminated after child terminated.

Environment

• OS: Linux
• FastAPI Version 0.54.1
• Python version 3.8.2

Additional context

I tried same code with Flask with gunicorn, it never terminated.