使双重 meaning in English

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Under the old memory model , this did not render double - checked locking thread - safe , because writes to a volatile field could still be reordered with writes to other nonvolatile fields such as the fields of the newly constructed object , and therefore the volatile instance reference could still hold a reference to an incompletely constructed object
。）在旧的内存模型中，这不能使双重检查锁定成为线程安全的，因为对volatile字段的写仍然会与对其他nonvolatile字段的写（如新构造的对象的字段）一起重新排序，因而volatile实例引用仍然可能包含对一个未构造完的对象的引用。