Function py_os_after_fork_child

crates/vm/src/stdlib/posix.rs:778–824

(vm: &VirtualMachine)

    }

    fn py_os_after_fork_child(vm: &VirtualMachine) {
        #[cfg(feature = "threading")]
        vm.state.stop_the_world.reset_after_fork();

        // Phase 1: Reset all internal locks FIRST.
        // After fork(), locks held by dead parent threads would deadlock
        // if we try to acquire them. This must happen before anything else.
        #[cfg(feature = "threading")]
        reinit_locks_after_fork(vm);

        // Reinit per-object IO buffer locks on std streams.
        // BufferedReader/Writer/TextIOWrapper use PyThreadMutex which can be
        // held by dead parent threads, causing deadlocks on any IO in the child.
        #[cfg(feature = "threading")]
        unsafe {
            crate::stdlib::_io::reinit_std_streams_after_fork(vm)
        };

        // Phase 2: Reset low-level atomic state (no locks needed).
        crate::signal::clear_after_fork();
        crate::stdlib::_signal::_signal::clear_wakeup_fd_after_fork();

        // Reset weakref stripe locks that may have been held during fork.
        #[cfg(feature = "threading")]
        crate::object::reset_weakref_locks_after_fork();

        // Phase 3: Clean up thread state. Locks are now reinit'd so we can
        // acquire them normally instead of using try_lock().
        #[cfg(feature = "threading")]
        crate::stdlib::_thread::after_fork_child(vm);

        // CPython parity: reinit import lock ownership metadata in child
        // and release the lock acquired by PyOS_BeforeFork().
        #[cfg(feature = "threading")]
        unsafe {
            crate::stdlib::_imp::after_fork_child_imp_lock_release()
        };

        // Initialize signal handlers for the child's main thread.
        // When forked from a worker thread, the OnceCell is empty.
        vm.signal_handlers
            .get_or_init(crate::signal::new_signal_handlers);

        // Phase 4: Run Python-level at-fork callbacks.
        let after_forkers_child: Vec<PyObjectRef> = vm.state.after_forkers_child.lock().clone();
        run_at_forkers(after_forkers_child, false, vm);
    }

    /// Reset all parking_lot-based locks in the interpreter state after fork().
    ///