add go experience, for data race

_posts/2024-01-09-go-experience.md

@@ -0,0 +1,46 @@
+---
+layout: post
+title: "go experiences"
+date: 2024-01-11 12:25:06
+description: go experiences 
+tags:
+ - code
+---
+
+- data race 
+[refer](https://www.sohamkamani.com/golang/data-races/?utm_content=cmp-true)
+We don't know which goroutine(main or i=5) will be executed firstly
+```
+func main() {
+	fmt.Println(getNumber())
+}
+
+func getNumber() int {
+	var i int
+	go func() {
+		i = 5
+	}()
+
+	return i
+}
+
+- adding waitgroups
+
+func getNumber() int {
+	var i int
+	// Initialize a waitgroup variable
+	var wg sync.WaitGroup
+	// `Add(1) signifies that there is 1 task that we need to wait for
+	wg.Add(1)
+	go func() {
+		i = 5
+		// Calling `wg.Done` indicates that we are done with the task we are waiting fo
+		wg.Done()
+	}()
+	// `wg.Wait` blocks until `wg.Done` is called the same number of times
+	// as the amount of tasks we have (in this case, 1 time)
+	wg.Wait()
+	return i
+}
+
+```