go知识重新整理

Go/DesignPattern/single/single.go

@@ -0,0 +1,24 @@
+/**
+* @Author:zhoutao
+* @Date:2020/12/12 下午4:14
+* @Desc:
+ */
+
+package single
+
+import "sync"
+
+//单例模式：使用懒惰模式的单例模式，使用双重检查加锁保证线程安全
+
+type Singleton struct {
+}
+
+var singelton *Singleton
+var once sync.Once
+
+func GetInstance() *Singleton {
+	once.Do(func() {
+		singelton = &Singleton{}
+	})
+	return singelton
+}

Go/DesignPattern/single/single_test.go

@@ -0,0 +1,45 @@
+/**
+* @Author:zhoutao
+* @Date:2020/12/13 上午10:48
+* @Desc:
+ */
+
+package single
+
+import (
+	"sync"
+	"testing"
+)
+
+const parCount = 100
+
+func TestSingleton(t *testing.T) {
+	ins1 := GetInstance()
+	ins2 := GetInstance()
+	if ins1 != ins2 {
+		t.Fatal("instance is not equal")
+	}
+}
+
+func TestParalleSingleton(t *testing.T) {
+	start := make(chan struct{})
+	wg := sync.WaitGroup{}
+	wg.Add(parCount)
+	instances := [parCount]*Singleton{}
+	for i := 0; i < parCount; i++ {
+		go func(index int) {
+			//等待channel的关闭信号
+			<-start
+			instances[index] = GetInstance()
+			wg.Done()
+		}(i)
+	}
+	//关闭channel，发送关闭信号
+	close(start)
+	wg.Wait()
+	for i := 1; i < parCount; i++ {
+		if instances[i] != instances[i-1] {
+			t.Fatal("instance is not equal")
+		}
+	}
+}