Java线程-同步问题

Question

来自 Sun 的教程:

Synchronized methods enable a simple strategy for preventing thread interference and memory consistency errors: if an object is visible to more than one thread, all reads or writes to that object's variables are done through synchronized methods. (An important exception: final fields, which cannot be modified after the object is constructed, can be safely read through non-synchronized methods, once the object is constructed) This strategy is effective, but can present problems with liveness, as we'll see later in this lesson.

Q1。上述语句是否意味着，如果一个类的对象要在多个线程之间共享，那么该类的所有实例方法(最终字段的 getters 除外)都应该同步，因为实例方法流程实例变量？

Answer 1

为了了解 Java 中的并发性，我推荐宝贵的 Java Concurrency in Practice .

针对您的具体问题，虽然同步所有方法是实现线程安全的一种快速而肮脏的方法，但它根本无法很好地扩展。考虑一下备受诟病的 Vector 类。每个方法都是同步的，而且效果很糟糕，因为迭代仍然不是线程安全的。