stats: try to imp test

internal/stats/stats_test.go

@@ -165,10 +165,8 @@ func TestStatsCollector(t *testing.T) {
 }
 
 func TestStats_races(t *testing.T) {
-	const unitUpdIvl = time.Second / 2
-
-	idGen := func() (id uint32) { return uint32(time.Now().UnixNano() / int64(unitUpdIvl)) }
-
+	var r uint32
+	idGen := func() (id uint32) { return atomic.LoadUint32(&r) }
 	conf := Config{
 		UnitID:    idGen,
 		Filename:  "./stats.db",
@@ -187,7 +185,11 @@ func TestStats_races(t *testing.T) {
 		return os.Remove(conf.Filename)
 	})
 
-	writeFunc := func(wg *sync.WaitGroup, i int) {
+	waitAtomically := func(control *uint32) {
+		for atomic.LoadUint32(control) == 0 {
+		}
+	}
+	writeFunc := func(wg *sync.WaitGroup, control *uint32, i int) {
 		e := Entry{
 			Domain: fmt.Sprintf("example-%d.org", i),
 			Client: fmt.Sprintf("client_%d", i),
@@ -196,40 +198,41 @@ func TestStats_races(t *testing.T) {
 		}
 
 		wg.Done()
-		wg.Wait()
+		waitAtomically(control)
 
 		s.Update(e)
 	}
-	readFunc := func(wg *sync.WaitGroup) {
+	readFunc := func(wg *sync.WaitGroup, control *uint32) {
 		wg.Done()
-		wg.Wait()
+		waitAtomically(control)
 
 		_, _ = s.getData()
 	}
 
 	const (
 		roundsNum = 3
-		roundsIvl = time.Second
 
 		writersNum = 10
 		readersNum = 5
 	)
 
 	for round := 0; round < roundsNum; round++ {
-		time.Sleep(roundsIvl)
+		atomic.StoreUint32(&r, uint32(round))
 
 		wg := &sync.WaitGroup{}
-		wg.Add(writersNum + readersNum)
-
-		name := fmt.Sprintf("round-%d_%s_since_start", round+1, time.Since(startTime))
-		t.Run(name, func(_ *testing.T) {
-			for i := 0; i < writersNum; i++ {
-				go writeFunc(wg, i)
-			}
-
-			for i := 0; i < readersNum; i++ {
-				go readFunc(wg)
-			}
-		})
+		var control uint32
+
+		for i := 0; i < writersNum; i++ {
+			wg.Add(1)
+			go writeFunc(wg, &control, i)
+		}
+
+		for i := 0; i < readersNum; i++ {
+			wg.Add(1)
+			go readFunc(wg, &control)
+		}
+
+		wg.Wait()
+		atomic.StoreUint32(&control, 1)
 	}
 }