CAS相关
public final native boolean compareAndSwapObject(Object var1, long var2, Object var4, Object var5); public final native boolean compareAndSwapInt(Object var1, long var2, int var4, int var5); public final native boolean compareAndSwapLong(Object var1, long var2, long var4, long var6);
var1 :要根据字段的对象
var2:该对象字段的偏移量
var4:预期值
var5:更新值