From f16bfef10354f1f70bed6c342f9644a171ba8eca Mon Sep 17 00:00:00 2001
From: oscarzhou <oscarzhou0727@icloud.com>
Date: Thu, 29 Apr 2021 22:50:28 +1200
Subject: [PATCH] doc: add explanation of sync.Mutex

---
 README.md | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 2f78b11..8eda6a6 100644
--- a/README.md
+++ b/README.md
@@ -35,4 +35,17 @@ select {
     default: 
         // receive when c is blocked        
 }
-```
\ No newline at end of file
+```
+
+## sync.Mutex  
+
+Channels are great for communication, but what if we don't need communication?  
+
+What if we just want to make sure only one goroutine can access a variable at a time to avoid conflicts? This concept is called `mutual exclusion`, and the conventional name for the data structure that provides it is `mutex`  
+
+Go's standard library provides mutual exclusion with `sync.Mutex` and its two methods: `Lock` and `Unlock`  
+
+
+## sync.WaitGroup  
+
+https://tutorialedge.net/golang/go-waitgroup-tutorial/
\ No newline at end of file