Method drop_inner

crates/vm/src/object/core.rs:856–892

weakref_dealloc: remove from list if still linked.

(&self)

    /// weakref_dealloc: remove from list if still linked.
    fn drop_inner(&self) {
        let obj_ptr = self.wr_object.load(Ordering::Acquire);
        if obj_ptr.is_null() {
            return; // Already cleared by WeakRefList::clear()
        }

        let _lock = weakref_lock::lock(obj_ptr as usize);

        // Double-check under lock
        let obj_ptr = self.wr_object.load(Ordering::Relaxed);
        if obj_ptr.is_null() {
            return; // Cleared between our check and lock acquisition
        }

        let obj = unsafe { &*obj_ptr };
        // Safety: if a weakref exists pointing to this object, weakref prefix must be present
        let wrl = obj.0.weakref_list_ref().unwrap();

        // Compute our Py<PyWeak> node pointer from payload address
        let offset = std::mem::offset_of!(PyInner<Self>, payload);
        let py_inner = (self as *const Self)
            .cast::<u8>()
            .wrapping_sub(offset)
            .cast::<PyInner<Self>>();
        let node_ptr = unsafe { NonNull::new_unchecked(py_inner as *mut Py<Self>) };

        // Unlink from list
        unsafe { unlink_weakref(wrl, node_ptr) };

        // Update generic cache if this was it
        if wrl.generic.load(Ordering::Relaxed) == node_ptr.as_ptr() {
            wrl.generic.store(ptr::null_mut(), Ordering::Relaxed);
        }

        // Mark as dead
        self.wr_object.store(ptr::null_mut(), Ordering::Relaxed);
    }
}

impl Drop for PyWeak {