testing: convert common.hasSub to atomic type

Change-Id: I3d8a9b901efabe62f432c06361826f46c78d2605
Reviewed-on: https://go-review.googlesource.com/c/go/+/426080
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

src/testing/benchmark.go

@@ -242,7 +242,7 @@ func (b *B) run1() bool {
 	b.mu.RLock()
 	finished := b.finished
 	b.mu.RUnlock()
-	if atomic.LoadInt32(&b.hasSub) != 0 || finished {
+	if b.hasSub.Load() || finished {
 		tag := "BENCH"
 		if b.skipped {
 			tag = "SKIP"
@@ -639,7 +639,7 @@ var hideStdoutForTesting = false
 func (b *B) Run(name string, f func(b *B)) bool {
 	// Since b has subbenchmarks, we will no longer run it as a benchmark itself.
 	// Release the lock and acquire it on exit to ensure locks stay paired.
-	atomic.StoreInt32(&b.hasSub, 1)
+	b.hasSub.Store(true)
 	benchmarkLock.Unlock()
 	defer benchmarkLock.Lock()
 
@@ -671,7 +671,7 @@ func (b *B) Run(name string, f func(b *B)) bool {
 	if partial {
 		// Partial name match, like -bench=X/Y matching BenchmarkX.
 		// Only process sub-benchmarks, if any.
-		atomic.StoreInt32(&sub.hasSub, 1)
+		sub.hasSub.Store(true)
 	}
 
 	if b.chatty != nil {

src/testing/testing.go

@@ -539,7 +539,7 @@ type common struct {
 
 	chatty     *chattyPrinter // A copy of chattyPrinter, if the chatty flag is set.
 	bench      bool           // Whether the current test is a benchmark.
-	hasSub     int32          // Written atomically.
+	hasSub     atomic.Bool    // whether there are sub-benchmarks.
 	raceErrors int            // Number of races detected during test.
 	runner     string         // Function name of tRunner running the test.
 
@@ -1459,7 +1459,7 @@ func tRunner(t *T, fn func(t *T)) {
 		// Do not lock t.done to allow race detector to detect race in case
 		// the user does not appropriately synchronize a goroutine.
 		t.done = true
-		if t.parent != nil && atomic.LoadInt32(&t.hasSub) == 0 {
+		if t.parent != nil && !t.hasSub.Load() {
 			t.setRan()
 		}
 	}()
@@ -1486,7 +1486,7 @@ func tRunner(t *T, fn func(t *T)) {
 // Run may be called simultaneously from multiple goroutines, but all such calls
 // must return before the outer test function for t returns.
 func (t *T) Run(name string, f func(t *T)) bool {
-	atomic.StoreInt32(&t.hasSub, 1)
+	t.hasSub.Store(true)
 	testName, ok, _ := t.context.match.fullName(&t.common, name)
 	if !ok || shouldFailFast() {
 		return true