add code dir

Author: cch123

code/empty.go

@@ -0,0 +1,3 @@
+package main
+
+func main() {}

memory_barrier.md

@@ -2,8 +2,30 @@
 
 memory barrier 也称为 memory fence。
 
+```
+```
+
 参考资料：
 
 https://homes.cs.washington.edu/~bornholt/post/memory-models.html
 
 https://people.eecs.berkeley.edu/~rcs/research/interactive_latency.html
+
+https://monkeysayhi.github.io/2017/12/28/%E4%B8%80%E6%96%87%E8%A7%A3%E5%86%B3%E5%86%85%E5%AD%98%E5%B1%8F%E9%9A%9C/
+
+https://blog.csdn.net/zhangxiao93/article/details/42966279
+
+http://kaiyuan.me/2017/09/22/memory-barrier/
+
+https://blog.csdn.net/dd864140130/article/details/56494925
+
+https://preshing.com/20120515/memory-reordering-caught-in-the-act/
+
+https://preshing.com/20120710/memory-barriers-are-like-source-control-operations/
+
+https://preshing.com/20120625/memory-ordering-at-compile-time/
+
+https://preshing.com/20120612/an-introduction-to-lock-free-programming/
+
+https://preshing.com/20130922/acquire-and-release-fences/
+