Add wait groups

main.go

@@ -12,7 +12,8 @@ package main
 // import "git.sangeeth.dev/gobyexample/closingchannels"
 // import "git.sangeeth.dev/gobyexample/timers"
 // import "git.sangeeth.dev/gobyexample/tickers"
-import "git.sangeeth.dev/gobyexample/workerpools"
+// import "git.sangeeth.dev/gobyexample/workerpools"
+import "git.sangeeth.dev/gobyexample/waitgroups"
 
 func main() {
 	// runes.Runes()
@@ -27,5 +28,6 @@ func main() {
 	// closingchannels.ClosingChannels()
 	// timers.Timers()
 	// tickers.Tickers()
-	workerpools.WorkerPools()
+	// workerpools.WorkerPools()
+	waitgroups.WaitGroups()
 }

waitgroups/waitgroups.go

@@ -0,0 +1,29 @@
+package waitgroups
+
+import (
+	"fmt"
+	"math/rand"
+	"sync"
+	"time"
+)
+
+func worker(id int, wg *sync.WaitGroup) {
+	defer wg.Done()
+	fmt.Printf("worker #%d starting\n", id)
+	time.Sleep(time.Duration((1 + rand.Intn(2))) * time.Second)
+	fmt.Printf("worker #%d exiting\n", id)
+}
+
+func WaitGroups() {
+	numJobs := 3
+	wg := sync.WaitGroup{}
+
+	for i := range numJobs {
+		wg.Add(1)
+		go worker(i, &wg)
+	}
+
+	wg.Wait()
+
+	fmt.Println("Program exiting")
+}