程序顺序规则

CPU-Code · CPU-Code · commit beb1f838555f · 2021-07-28T10:44:47.000+08:00
diff --git a/thread/README.md b/thread/README.md
@@ -117,6 +117,7 @@
 ## [volatile](src/main/java/com/cpucode/java/volati)
 
 - [x] [volatile的可见性](src/main/java/com/cpucode/java/volati/VolatileDemo.java)
+- [x] [程序顺序规则](src/main/java/com/cpucode/java/volati/BeforeDemo.java)
 
 - [返回文件目录](#文件目录)
 
diff --git a/thread/src/main/java/com/cpucode/java/volati/BeforeDemo.java b/thread/src/main/java/com/cpucode/java/volati/BeforeDemo.java
@@ -0,0 +1,33 @@
+package com.cpucode.java.volati;
+
+/**
+ * @author : cpucode
+ * @date : 2021/7/28
+ * @time : 10:38
+ * @github : https://github.com/CPU-Code
+ * @csdn : https://blog.csdn.net/qq_44226094
+ */
+public class BeforeDemo {
+    static int a = 0;
+    static volatile boolean flag = false;
+
+    public static void main(String[] args) throws InterruptedException {
+
+        Thread thread = new Thread(() -> {
+            a = 1;
+            flag = true;
+        }, "writer");
+
+        Thread thread2 = new Thread(() -> {
+            if (flag){
+                int x = a;
+
+                System.out.println(x);
+            }
+        }, "reader");
+
+        thread.start();
+        Thread.sleep(500);
+        thread2.start();
+    }
+}
