Walkthrough

Implements frame-generator bidirectional references via PyAtomicBorrow to break reference cycles, adds Drop implementations for cleanup, enhances asyncio with fork handling and guarded representations, introduces _remote_debugging module, and exposes frame generator introspection.

Changes

Sequence Diagram(s)

sequenceDiagram
    participant Module as Module Init
    participant ForkHook as Fork Hook Registry
    participant Parent as Parent Process
    participant Fork as Fork System Call
    participant Child as Child Process
    participant OnFork as _on_fork Handler
    participant State as Asyncio State

    Module->>ForkHook: Register _on_fork (Unix only)
    Parent->>Fork: fork()
    Fork->>Parent: Continue with child PID
    Fork->>Child: New process created
    Child->>OnFork: Invoke registered hook
    OnFork->>State: Clear per-thread running loop
    OnFork->>State: Clear per-thread running task
    OnFork->>State: Reset _current_tasks dict
    State-->>Child: Clean asyncio state

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~65 minutes

Possibly related PRs

• fix asyncgen finalizer #6761 — Directly modifies async generator finalization and close/set_closed semantics in the same file with overlapping state handling logic.
• Upgrade threading to 3.13.11; sys.setprofile & impl more threading #6691 — Implements post-fork child handling and per-thread async/frame state reset, closely aligned with the fork handling additions.
• Add _asyncio and add test_asyncio  #6838 — Touches _asyncio module with asyncio-related test and module infrastructure changes affecting the same module.

Suggested reviewers

• ShaharNaveh
• fanninpm
• coolreader18

Poem

🐰 The frames and generators dance in pairs,
Yet cycles threaten their affair—
A borrowed reference breaks the knot,
While forks reset what should be forgot.
In Drop we trust, and state's cleaned bright,
The rabbit's work makes asyncio right! ✨

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

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