Memory inconsistency

.idea/workspace.xml

@@ -4,16 +4,10 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="c46989a2-1428-4d1f-9b45-864f22943ab6" name="Changes" comment="">
-      <change afterPath="$PROJECT_DIR$/.gitignore" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/.idea/encodings.xml" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/.idea/vcs.xml" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/README.md" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pom.xml" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/src/main/java/Counter.java" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/src/main/java/RaceConditionExample.java" afterDir="false" />
+    <list default="true" id="c46989a2-1428-4d1f-9b45-864f22943ab6" name="Changes" comment="Thread interference">
+      <change afterPath="$PROJECT_DIR$/src/main/java/MemoryConsistencyErrorExample.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/README.md" beforeDir="false" afterPath="$PROJECT_DIR$/README.md" afterDir="false" />
     </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
@@ -46,7 +40,14 @@
     "SHARE_PROJECT_CONFIGURATION_FILES": "true"
   }
 }]]></component>
-  <component name="RunManager">
+  <component name="RunManager" selected="Application.MemoryConsistencyErrorExample">
+    <configuration name="MemoryConsistencyErrorExample" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
+      <option name="MAIN_CLASS_NAME" value="MemoryConsistencyErrorExample" />
+      <module name="Synchronization" />
+      <method v="2">
+        <option name="Make" enabled="true" />
+      </method>
+    </configuration>
     <configuration name="RaceConditionExample" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
       <option name="MAIN_CLASS_NAME" value="RaceConditionExample" />
       <module name="Synchronization" />
@@ -56,6 +57,7 @@
     </configuration>
     <recent_temporary>
       <list>
+        <item itemvalue="Application.MemoryConsistencyErrorExample" />
         <item itemvalue="Application.RaceConditionExample" />
       </list>
     </recent_temporary>
@@ -69,6 +71,14 @@
       <option name="presentableId" value="Default" />
       <updated>1699638681976</updated>
     </task>
+    <task id="LOCAL-00001" summary="Thread interference">
+      <created>1699642277693</created>
+      <option name="number" value="00001" />
+      <option name="presentableId" value="LOCAL-00001" />
+      <option name="project" value="LOCAL" />
+      <updated>1699642277693</updated>
+    </task>
+    <option name="localTasksCounter" value="2" />
     <servers />
   </component>
   <component name="Vcs.Log.Tabs.Properties">
@@ -82,4 +92,8 @@
       </map>
     </option>
   </component>
+  <component name="VcsManagerConfiguration">
+    <MESSAGE value="Thread interference" />
+    <option name="LAST_COMMIT_MESSAGE" value="Thread interference" />
+  </component>
 </project>
\ No newline at end of file

README.md

@@ -4,6 +4,7 @@
 * Thread Synchronization
   * Race Condition
   * Critical Section
+  * Memory inconsistency
   * 
 * Locks and Atomic Variables
 

src/main/java/MemoryConsistencyErrorExample.java

+public class MemoryConsistencyErrorExample {
+    private static boolean sayHello = false;
+
+    public static void main(String[] args) throws InterruptedException {
+
+        Thread thread = new Thread(() -> {
+            while(!sayHello) {
+            }
+
+            System.out.println("Hello World!");
+
+            while(sayHello) {
+            }
+
+            System.out.println("Good Bye!");
+        });
+
+        thread.start();
+
+        Thread.sleep(1000);
+        System.out.println("Say Hello..");
+        sayHello = true;
+
+        Thread.sleep(1000);
+        System.out.println("Say Bye..");
+        sayHello = false;
+    }
+}
\ No newline at end of file