update min Go version to v1.22

With Go v1.22, we can benefit from improved for loops (range over
integers) and don't need to care about the closures and goroutines
pitfall.

Signed-off-by: Robin Hahling <[email protected]>

Author: rolinh

.github/workflows/tests.yml

@@ -14,7 +14,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go-version: ["1.15", "1.19", "1.20"]
+        go-version: ["1.22", "1.23", "1.24"]
     runs-on: ubuntu-latest
     steps:
     - name: Install Go

README.md

@@ -53,7 +53,6 @@ func IsPrime(n int64) bool {
 func main() {
 	wp := workerpool.New(runtime.NumCPU())
 	for i, n := 0, int64(1_000_000_000_000_000_000); n < 1_000_000_000_000_000_100; i, n = i+1, n+1 {
-		n := n // https://golang.org/doc/faq#closures_and_goroutines
 		id := fmt.Sprintf("task #%d", i)
 		// Use Submit to submit tasks for processing. Submit blocks when no
 		// worker is available to pick up the task.

example_test.go

@@ -28,7 +28,6 @@ func IsPrime(n int64) bool {
 func Example() {
 	wp := workerpool.New(runtime.NumCPU())
 	for i, n := 0, int64(1_000_000_000_000_000_000); n < 1_000_000_000_000_000_100; i, n = i+1, n+1 {
-		n := n // https://golang.org/doc/faq#closures_and_goroutines
 		id := fmt.Sprintf("task #%d", i)
 		// Use Submit to submit tasks for processing. Submit blocks when no
 		// worker is available to pick up the task.

go.mod

@@ -1,3 +1,3 @@
 module github.com/cilium/workerpool
 
-go 1.15
+go 1.22

workerpool.go

@@ -171,7 +171,7 @@ func (wp *WorkerPool) Close() error {
 // only be called once during the lifetime of a WorkerPool.
 func (wp *WorkerPool) run(ctx context.Context) {
 	for t := range wp.tasks {
-		t := t
+
 		result := taskResult{id: t.id}
 		wp.results = append(wp.results, &result)
 		wp.workers <- struct{}{}

workerpool_test.go

@@ -120,7 +120,7 @@ func TestWorkerPoolConcurrentTasksCount(t *testing.T) {
 	// working is written to by each task as soon as possible.
 	working := make(chan struct{})
 	// NOTE: schedule one more task than we have workers, hence n+1.
-	for i := 0; i < n+1; i++ {
+	for i := range n + 1 {
 		id := fmt.Sprintf("task #%2d", i)
 		err := wp.Submit(id, func(ctx context.Context) error {
 			select {
@@ -137,7 +137,7 @@ func TestWorkerPoolConcurrentTasksCount(t *testing.T) {
 	}
 
 	// ensure that n workers are busy.
-	for i := 0; i < n; i++ {
+	for i := range n {
 		select {
 		case <-working:
 		case <-time.After(100 * time.Millisecond):
@@ -164,7 +164,7 @@ func TestWorkerPool(t *testing.T) {
 	working := make(chan struct{})
 	var wg sync.WaitGroup
 	wg.Add(numTasks - 1)
-	for i := 0; i < numTasks-1; i++ {
+	for i := range numTasks - 1 {
 		id := fmt.Sprintf("task #%2d", i)
 		err := wp.Submit(id, func(_ context.Context) error {
 			defer wg.Done()
@@ -178,7 +178,7 @@ func TestWorkerPool(t *testing.T) {
 	}
 
 	// ensure n workers are busy
-	for i := 0; i < n; i++ {
+	for range n {
 		<-working
 	}
 
@@ -231,7 +231,7 @@ func TestWorkerPool(t *testing.T) {
 
 	<-ready
 	// un-block the worker routines
-	for i := 0; i < numTasks-1; i++ {
+	for range numTasks - 1 {
 		<-done
 	}
 	// The last task was blocked in wp.run() and not yet scheduled on a worker.
@@ -254,7 +254,7 @@ func TestConcurrentDrain(t *testing.T) {
 	done := make(chan struct{})
 	var wg sync.WaitGroup
 	wg.Add(numTasks)
-	for i := 0; i < numTasks; i++ {
+	for i := range numTasks {
 		id := fmt.Sprintf("task #%2d", i)
 		err := wp.Submit(id, func(_ context.Context) error {
 			defer wg.Done()
@@ -306,7 +306,7 @@ func TestConcurrentDrain(t *testing.T) {
 	}
 
 	// un-block the worker routines to allow the test to complete
-	for i := 0; i < numTasks; i++ {
+	for range numTasks {
 		<-done
 	}
 
@@ -402,7 +402,7 @@ func TestWorkerPoolClose(t *testing.T) {
 	working := make(chan struct{})
 	var wg sync.WaitGroup
 	wg.Add(n)
-	for i := 0; i < n; i++ {
+	for i := range n {
 		id := fmt.Sprintf("task #%2d", i)
 		err := wp.Submit(id, func(ctx context.Context) error {
 			working <- struct{}{}
@@ -416,7 +416,7 @@ func TestWorkerPoolClose(t *testing.T) {
 	}
 
 	// ensure n workers are busy
-	for i := 0; i < n; i++ {
+	for range n {
 		<-working
 	}
 
@@ -436,7 +436,7 @@ func TestWorkerPoolNewWithContext(t *testing.T) {
 	var wg sync.WaitGroup
 	// Create n tasks waiting on the context to be cancelled.
 	wg.Add(n)
-	for i := 0; i < n; i++ {
+	for i := range n {
 		id := fmt.Sprintf("task #%2d", i)
 		err := wp.Submit(id, func(ctx context.Context) error {
 			working <- struct{}{}
@@ -450,7 +450,7 @@ func TestWorkerPoolNewWithContext(t *testing.T) {
 	}
 
 	// ensure n workers are busy
-	for i := 0; i < n; i++ {
+	for range n {
 		<-working
 	}