added an example on method to primitive types

akp1993 · Aug 17, 2019 · b15baba · b15baba
1 parent b7cce8e
commit b15baba
Showing 1 changed file with 29 additions and 0 deletions.
diff --git a/examples/sync-once/main.go b/examples/sync-once/main.go
@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+var (
+	doOnce           sync.Once
+	count, singleton int
+)
+
+func main() {
+	Do()
+	Do()
+	Do()
+}
+
+func Do() {
+	// if once.Do(f) is called multiple times, only the first call will invoke f,
+	// even if f has a different value in each invocation.
+	// once.Do(f) is concurrency safe
+	doOnce.Do(func() {
+		singleton++
+	})
+	count++
+	fmt.Println("Singleton: ", singleton)
+	fmt.Println("Count: ", count)
+}