Function cleanup_current_thread_frames

crates/vm/src/vm/thread.rs:426–466

(vm: &VirtualMachine)

/// Cleanup thread slot for the current thread. Called at thread exit.
#[cfg(feature = "threading")]
pub fn cleanup_current_thread_frames(vm: &VirtualMachine) {
    let thread_id = crate::stdlib::_thread::get_ident();
    let current_slot = CURRENT_THREAD_SLOT.with(|slot| slot.borrow().as_ref().cloned());

    // A dying thread should not remain logically ATTACHED while its
    // thread-state slot is being removed.
    #[cfg(all(unix, feature = "threading"))]
    if let Some(slot) = &current_slot {
        let _ = slot.state.compare_exchange(
            THREAD_ATTACHED,
            THREAD_DETACHED,
            Ordering::AcqRel,
            Ordering::Acquire,
        );
    }

    // Guard against OS thread-id reuse races: only remove the registry entry
    // if it still points at this thread's own slot.
    let removed = if let Some(slot) = &current_slot {
        let mut registry = vm.state.thread_frames.lock();
        match registry.get(&thread_id) {
            Some(registered) if Arc::ptr_eq(registered, slot) => registry.remove(&thread_id),
            _ => None,
        }
    } else {
        None
    };
    #[cfg(all(unix, feature = "threading"))]
    if let Some(slot) = &removed
        && vm.state.stop_the_world.requested.load(Ordering::Acquire)
        && thread_id != vm.state.stop_the_world.requester_ident()
        && slot.state.load(Ordering::Relaxed) != THREAD_SUSPENDED
    {
        // A non-requester thread disappeared while stop-the-world is pending.
        // Unblock requester countdown progress.
        vm.state.stop_the_world.notify_thread_gone();
    }
    CURRENT_THREAD_SLOT.with(|s| {
        *s.borrow_mut() = None;
    });
}

/// Reinitialize thread slot after fork. Called in child process.
/// Creates a fresh slot and registers it for the current thread,