rewrite and fix reference counter

internal/utils/ref_count_test.go

@@ -0,0 +1,77 @@
+package utils
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestRefCounter_AddSub(t *testing.T) {
+	rc := NewRefCounter()
+
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+		rc.Add()
+	}()
+
+	go func() {
+		defer wg.Done()
+		rc.Sub()
+	}()
+
+	wg.Wait()
+
+	select {
+	case <-rc.Zero():
+		// Expected behavior
+	case <-time.After(1 * time.Second):
+		t.Fatal("Expected Zero channel to close, but it didn't")
+	}
+}
+
+func TestRefCounter_MultipleAddSub(t *testing.T) {
+	rc := NewRefCounter()
+
+	var wg sync.WaitGroup
+	numAdds := 5
+	numSubs := 5
+	wg.Add(numAdds + numSubs)
+
+	for range numAdds {
+		go func() {
+			defer wg.Done()
+			rc.Add()
+		}()
+	}
+
+	for range numSubs {
+		go func() {
+			defer wg.Done()
+			rc.Sub()
+		}()
+	}
+
+	wg.Wait()
+
+	select {
+	case <-rc.Zero():
+		// Expected behavior
+	case <-time.After(1 * time.Second):
+		t.Fatal("Expected Zero channel to close, but it didn't")
+	}
+}
+
+func TestRefCounter_ZeroInitially(t *testing.T) {
+	rc := NewRefCounter()
+	rc.Sub() // Bring count to zero
+
+	select {
+	case <-rc.Zero():
+		// Expected behavior
+	case <-time.After(1 * time.Second):
+		t.Fatal("Expected Zero channel to close, but it didn't")
+	}
+}