From 01aad3573b7a9fd2f125c2170a571145a9d9f54e Mon Sep 17 00:00:00 2001
From: Bruce <weichou1229@gmail.com>
Date: Sun, 10 Feb 2019 21:59:57 +0800
Subject: [PATCH] Practice singleton

Signed-off-by: Bruce <weichou1229@gmail.com>
---
 playground/singleton/internal/singleton.go | 27 ++++++++++++++++++++++
 playground/singleton/main.go               | 10 ++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 playground/singleton/internal/singleton.go
 create mode 100644 playground/singleton/main.go

diff --git a/playground/singleton/internal/singleton.go b/playground/singleton/internal/singleton.go
new file mode 100644
index 0000000..804794c
--- /dev/null
+++ b/playground/singleton/internal/singleton.go
@@ -0,0 +1,27 @@
+package internal
+
+import (
+	"fmt"
+	"sync"
+)
+
+// singleton is private struct, it should be created and fetched by GetSingletonObject func
+type singleton struct {
+}
+
+func (singleton) SayHi() {
+	fmt.Println("Hi!")
+}
+
+var (
+	once     sync.Once
+	instance singleton
+)
+
+func GetSingletonObject() singleton {
+	once.Do(func() {
+		instance = singleton{}
+	})
+
+	return instance
+}
diff --git a/playground/singleton/main.go b/playground/singleton/main.go
new file mode 100644
index 0000000..a1ec7ad
--- /dev/null
+++ b/playground/singleton/main.go
@@ -0,0 +1,10 @@
+package main
+
+import (
+	"github.com/weichou1229/go-patterns/playground/singleton/internal"
+)
+
+func main() {
+	var s = internal.GetSingletonObject()
+	s.SayHi()
+}