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修复拼写错误

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tianyu94 2019-07-03 09:44:22 +08:00 committed by GitHub
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docs/java/collection/Java集合框架常见面试题.md
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@ -284,7 +284,7 @@ static class Segment<K,V> extends ReentrantLock implements Serializable {
### JDK1.8 （上面有示意图） ### JDK1.8 （上面有示意图）
ConcurrentHashMap取消了Segment分段锁，采用CAS和synchronized来保证并发安全。数据结构跟HashMap1.8的结构类似，数组+链表/红黑二叉树。Java 8在链表长度超过一定阈值（8）时将链表（寻址时间复杂度为O(N)）转换为红黑树（寻址时间复杂度为O(long(N))） ConcurrentHashMap取消了Segment分段锁，采用CAS和synchronized来保证并发安全。数据结构跟HashMap1.8的结构类似，数组+链表/红黑二叉树。Java 8在链表长度超过一定阈值（8）时将链表（寻址时间复杂度为O(N)）转换为红黑树（寻址时间复杂度为O(log(N))）
synchronized只锁定当前链表或红黑二叉树的首节点，这样只要hash不冲突，就不会产生并发，效率又提升N倍。 synchronized只锁定当前链表或红黑二叉树的首节点，这样只要hash不冲突，就不会产生并发，效率又提升N倍。