package com.google.thread3; import java.lang.management.ManagementFactory; import java.lang.management.ThreadInfo; import java.lang.management.ThreadMXBean; public class ThreadDemo { public static void main(String[] args) { ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean(); ThreadInfo[] dumpAllThreads = threadMXBean.dumpAllThreads(false, false); for (int i = 0; i < dumpAllThreads.length; i++) { ThreadInfo threadInfo = dumpAllThreads[i]; System.out.println(threadInfo.getThreadId()+threadInfo.getThreadName()); } } }
ABA问题
package com.google; import java.util.concurrent.atomic.AtomicInteger; //volatile 不保证原子性 //解决volatile的原子性问题(synchronized)(AtomicInteger--->CAS) class MyData2 { AtomicInteger number = new AtomicInteger(); public void addPlus() { number.addAndGet(1); } } public class Demo2 { public static void main(String[] args) { MyData2 myData2 = new MyData2(); for (int i = 1; i <= 20; i++) { new Thread(() -> { for (int j = 1; j <= 1000; j++) { myData2.addPlus(); } }, "AAA").start(); } while (Thread.activeCount() > 2) { Thread.yield(); } System.out.println(myData2.number); } }
指令重排序
package com.google; //指令重排序 public class Demo3 { public static void main(String[] args) { mySort(); } public static void mySort(){ int x = 11; int y = 12; x = x + 5; y = x * x; System.out.println(x); System.out.println(y); } }
标签:int,void,System,static,ThreadMBean,public,out From: https://www.cnblogs.com/CAOXIAOYANG/p/16925394.html