From 684ba28cc16361f4d3bc6ac4a72c87d2fdc06891 Mon Sep 17 00:00:00 2001
From: johnA1331 <53036378+johnA1331@users.noreply.github.com>
Date: Wed, 5 Jan 2022 20:22:48 +0800
Subject: [PATCH] Update README.md

---
 core-java-modules/core-java-concurrency-advanced-4/README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/core-java-modules/core-java-concurrency-advanced-4/README.md b/core-java-modules/core-java-concurrency-advanced-4/README.md
index db856a2cd6..446a553b88 100644
--- a/core-java-modules/core-java-concurrency-advanced-4/README.md
+++ b/core-java-modules/core-java-concurrency-advanced-4/README.md
@@ -3,3 +3,4 @@
 - [Binary Semaphore vs Reentrant Lock](https://www.baeldung.com/java-binary-semaphore-vs-reentrant-lock)
 - [Bad Practices With Synchronization](https://www.baeldung.com/java-synchronization-bad-practices)
 - [Start Two Threads at the Exact Same Time in Java](https://www.baeldung.com/java-start-two-threads-at-same-time)
+- [Volatile Variables and Thread Safety](https://www.baeldung.com/java-volatile-variables-thread-safety)