• __weak 使用方式
• objc_initWeak 方法
• storeWeak 实现
• HaveOld、HaveNew 与 CrashIfDeallocating
• storeWeak 方法实现
• StripedMap
• SideTale
• weak_table_t
• weak_register_no_lock
• weak_entry_for_referent
• append_referrer
• weak_entry_insert
• weak_unregister_no_lock
• remove_referrer
• 对象释放 weak 置为 nil
• object_dispose
• objc_destructInstance
• clearDeallocating
• clearDeallocating_slow
• weak_clear_no_lock
• weak_entry_remove
• 参考资料