Allow Interpreter.prepare_main() Even If the Interpreter Is Running?

Feature or enhancement

Proposal:

Currently Interpreter.prepare_main() (from concurrent.interpreters) fails if the interpreter is running. (See Interpreter.is_running(). It may make sense to relax this restriction.

For example, it might make sense for a subinterpreter to call prepare_main() on the main interpreter to share a cross-interpreter Queue. Currently that fails because the main interpreter is always considered to be "running".
The answer for now is "make sure the main interpreter creates any queues it needs to share" and that might be good enough.

It's something I hadn't considered before and I'm not exactly sure yet that allowing it would be the right thing. The problem is that it isn't intuitively obvious to users (or me) how externally modifying an interpreter's __main__ module may affect code running there in a different thread.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

まず concurrent.interpreters.Interpreter.prepare_main() と Interpreter.is_running() を確認し、実行中のインタープリターに対する準備が拒否される理由に焦点を当てます。main への外部からの変更をスレッド間およびサブインタープリター間で許可しても安全かどうかを判断し、そのうえで制限を変更する前に必要な動作とテストを定義します。