add singleton

Author: senghoo

03_singleton/singleton.go

@@ -0,0 +1,20 @@
+package singleton
+
+import "sync"
+
+//Singleton 是单例模式类
+type Singleton struct{}
+
+var singletonInst *Singleton
+var singletonInstLock sync.Mutex
+
+//GetInstance 用于获取单例模式对象
+func GetInstance() *Singleton {
+	if singletonInst == nil {
+		singletonInstLock.Lock()
+		if singletonInst == nil {
+			singletonInst = &Singleton{}
+		}
+	}
+	return singletonInst
+}

03_singleton/singleton_test.go

@@ -0,0 +1,11 @@
+package singleton
+
+import "testing"
+
+func TestSingleton(t *testing.T) {
+	ins1 := GetInstance()
+	ins2 := GetInstance()
+	if ins1 != ins2 {
+		t.Fatal("instance is not equal")
+	}
+}