Web*/ transient int size; /** * The number of times this HashMap has been structurally modified * Structural modifications are those that change the number of mappings in * the HashMap or otherwise modify its internal structure (e.g., * rehash). This field is used to make iterators on Collection-views of * the HashMap fail-fast. WebApr 11, 2024 · 是java集合的一种错误检测机制,当多个线程对集合进行结构上的改变的操作时,有可能会产生fail-fast 机制。. 例如:假设存在两个线程(线程1、线程2),线程1通过Iterator在遍历集合A中的元素,在某个时候线程2修改了集合A的结构(是结构上面的修 …
java.util: HashMap.java - DocJar
WebMay 28, 2024 · That aside, essentially, “fail-fast” in this sense means that an Iterator over a HashMap will throw an exception if it detects that another thread has modified the targeted HashMap – if you look in the source for HashMap, you will see this is done by simply checking a counter for the number of expected modifications. WebAn instance of HashMap has two parameters that affect its performance: ... Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs. This class is a member of the Java Collections Framework. Since: 1.2 tate and lyle ft
这份Java面试八股文让329人成功进入大厂,堪称2024最 …
WebNov 24, 2024 · So, in the case of Hashtable, depending on whether we need Fail-Safe or Fail-Fast, we can use both an enumerator and an iterator. Example of Fail-Fast in HashMap iterator: Web这就是常说的fail-fast(快速失败)机制,这个就需要从一个变量说起 transient int modCount; 在HashMap中有一个名为modCount的变量,它用来表示集合被修改的次数,修改指的 … Web这就是常说的fail-fast(快速失败)机制,这个就需要从一个变量说起 transient int modCount; 在HashMap中有一个名为modCount的变量,它用来表示集合被修改的次数,修改指的是插入元素或删除元素,可以回去看看上面插入删除的源码,在最后都会对modCount进行自增。 the c970