GO by example, part 4

5-go-by-example/33-timers.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+// built-in timer and ticker features
+func main() {
+
+	// timers represent a single event in the future
+	// tell the timer how long to wait and it provides a channel that will be notified at that time
+	timer1 := time.NewTimer(2 * time.Second)
+
+	// <-timer1.C blocks on the timer’s channel C until it sends a value indicating that the timer fired
+	<-timer1.C
+	fmt.Println("Timer 1 fired")
+
+	// to wait, you could have used time.Sleep
+	timer2 := time.NewTimer(time.Second)
+	go func() {
+		<-timer2.C
+		fmt.Println("Timer 2 fired")
+	}()
+	// one can cancel the timer before it fires
+	stop2 := timer2.Stop()
+	if stop2 {
+		fmt.Println("Timer 2 stopped")
+	}
+
+	// give the timer2 enough time to fire, if it ever was going to, to show it is in fact stopped
+	time.Sleep(2 * time.Second)
+}