[never_inline]

Here's a use case - singleton instantiation on first request, where instantiation itself requires an async call (eg: to DB or external service).

    _lock = asyncio.Lock()
    _instance = None

    def get_singleton():
      if _instance:
        return _instance
      async with _lock:
        if not _instance:
          _instance = await costly_function()
      return _instance

How do you suggest to replace this?

[duped]

The traditional thing would be to have an init() function that is required to be called at the top of main() or before any other methods that need it. But I agree with your point.

[never_inline]

Now lets say its an async cache instead of singleton.

[duped]

Return the cached item if it exists else spawn a task to update it (doing nothing if the task has already been spawned), await the task and return the cached item.

[never_inline]

Thanks, that's a useful trick.