volatile的不能保证原子性代码

DreamCats · DreamCats · commit 77d09cccf552 · 2020-02-13T01:17:49.000+08:00
diff --git a/Multithread/src/com/juc/volatiletest/VolatileAtomicDemo.java b/Multithread/src/com/juc/volatiletest/VolatileAtomicDemo.java
@@ -0,0 +1,33 @@
+/**
+ * @program JavaBooks
+ * @description: 不能保证原子
+ * @author: mf
+ * @create: 2020/02/13 01:16
+ */
+
+package com.juc.volatiletest;
+
+public class VolatileAtomicDemo {
+    public static volatile int count = 0;
+
+    public static void increase() {
+        count++;
+    }
+
+    public static void main(String[] args) {
+        Thread[] threads = new Thread[20];
+        for(int i = 0; i < threads.length; i++) {
+            threads[i] = new Thread(() -> {
+                for(int j = 0; j < 1000; j++) {
+                    increase();
+                }
+            });
+            threads[i].start();
+        }
+        //等待所有累加线程结束
+        while (Thread.activeCount() > 1) {
+            Thread.yield();
+        }
+        System.out.println(count);
+    }
+}
