3. 并发容器

List

CopyOnWriteArrayList

特点

实现了List接口

内部持有一个ReentrantLock lock = new ReentrantLock();

底层是用volatile transient声明的数组 array

读写分离，写时复制出一个新的数组，完成插入、修改或者移除操作后将新数组赋值给array

参考

https://www.cnblogs.com/simple-focus/p/7439919.html

Set

Queue

ConcurrentLinkedQueue

http://ifeve.com/%E5%B9%B6%E5%8F%91%E9%98%9F%E5%88%97-%E6%97%A0%E7%95%8C%E9%9D%9E%E9%98%BB%E5%A1%9E%E9%98%9F%E5%88%97concurrentlinkedqueue%E5%8E%9F%E7%90%86%E6%8E%A2%E7%A9%B6/

https://my.oschina.net/90888/blog/1624935

并发容器

HashMap之原理及死锁

1.7

结构

数组+链表

initialCapacity：16

为什么是2的n次幂

size：实际键值对数量

loadFactory：负载因子，代表了table的填充度有多少，默认是0.75

threshold：阈值 =capacity*loadFactory

capacity：数组大小

resize

触发时机

大于等于阈值

流程

https://www.cnblogs.com/xiaolovewei/p/7993521.html

https://www.cnblogs.com/liqipeng/p/7759627.html

1.8+

数组+链表/红黑树

红黑树条件

在桶容量大于等于64且链表节点数大于等于8的时候转换为红黑树。当红黑树节点数量小于6时又会转换为链表

由倒叙变为正序，避免了死循环的产生

https://www.jianshu.com/p/4177dc15d658

https://blog.csdn.net/wangming520liwei/article/details/82791636

https://www.cnblogs.com/morethink/p/7762168.html

1.7+ 死循环

https://www.cnblogs.com/tiancai/p/9056393.html

https://blog.csdn.net/lantian0802/article/details/42487803

https://www.jianshu.com/p/13c650a25ed3

https://coolshell.cn/articles/9606.html

https://juejin.im/post/5a224e1551882535c56cb940

场景

丢元素

ConcurrentHashMap

Segment+数组+链表

https://www.jianshu.com/p/cd6cca294c44

https://my.oschina.net/wenbo123/blog/1840330

https://www.jianshu.com/p/6821a2bd9a6d

并发控制

Segment继承了ReentrantLock

方法

put

get

size

Node(CAS)+链表/红黑树

https://juejin.im/entry/59fc786d518825297f3fa968

https://blog.csdn.net/u010723709/article/details/48007881

http://www.jasongj.com/java/concurrenthashmap/

size=baseCount+counterCells.value

数据结构

红黑树

https://www.jianshu.com/p/e136ec79235c

https://www.cnblogs.com/CarpenterLee/p/5503882.html

https://zhuanlan.zhihu.com/p/31805309

https://blog.csdn.net/v_july_v/article/details/6105630

二叉树

https://juejin.im/post/5ab5a01d518825555c1d9a24

https://blog.csdn.net/System_out_print_Boy/article/details/94554967

子主题

优

劣

一边的数 几乎和链表一样了

https://www.cnblogs.com/yueshutong/p/9696216.html

http://ifeve.com/why-is-there-not-concurrent-arraylist-in-java-util-concurrent-package/