Method _finalize_one

src/trio/_core/_asyncgens.py:223–243

(
        self,
        agen: AsyncGeneratorType[object, NoReturn],
        name: object,
    )

        sys.set_asyncgen_hooks(*self.prev_hooks)

    async def _finalize_one(
        self,
        agen: AsyncGeneratorType[object, NoReturn],
        name: object,
    ) -> None:
        try:
            # This shield ensures that finalize_asyncgen never exits
            # with an exception, not even a Cancelled. The inside
            # is cancelled so there's no deadlock risk.
            with _core.CancelScope(shield=True) as cancel_scope:
                cancel_scope.cancel(
                    reason="disallow async work when closing async generators during trio shutdown"
                )
                await agen.aclose()
        except BaseException:
            ASYNCGEN_LOGGER.exception(
                "Exception ignored during finalization of async generator %r -- "
                "surround your use of the generator in 'async with aclosing(...):' "
                "to raise exceptions like this in the context where they're generated",
                name,
            )