test(analyze): race-check StoredDir stats against concurrent readers

pkg/analyze/stored_race_test.go

@@ -0,0 +1,58 @@
+package analyze
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/dundee/gdu/v5/internal/testdir"
+	"github.com/dundee/gdu/v5/pkg/fs"
+	"github.com/stretchr/testify/assert"
+)
+
+// TestStoredDirUpdateStatsLockedAgainstReaders recomputes a StoredDir's stats
+// while another goroutine reads them through the synchronized scalar accessors
+// (GetSize, GetUsage, GetFlag, GetMtime, GetItemCount). Those readers take the
+// embedded Dir mutex, so updateStats has to write the same fields under that
+// mutex. Run with -race: without the locking the writes in updateStats race the
+// reads here.
+func TestStoredDirUpdateStatsLockedAgainstReaders(t *testing.T) {
+	fin := testdir.CreateTestDir()
+	defer fin()
+
+	a := CreateStoredAnalyzer("/tmp/badger")
+	dir := a.AnalyzeDir(
+		"test_dir", func(_, _ string) bool { return false }, func(_ string) bool { return false },
+	).(*StoredDir)
+	a.GetDone().Wait()
+
+	const rounds = 200
+
+	stop := make(chan struct{})
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for {
+			select {
+			case <-stop:
+				return
+			default:
+			}
+			_ = dir.GetSize()
+			_ = dir.GetUsage()
+			_ = dir.GetFlag()
+			_ = dir.GetMtime()
+			_ = dir.GetItemCount()
+		}
+	}()
+
+	for range rounds {
+		dir.UpdateStats(make(fs.HardLinkedItems))
+	}
+	close(stop)
+	wg.Wait()
+
+	// stats stay correct after the concurrent recomputation
+	assert.Equal(t, int64(7+4096*3), dir.GetSize())
+	assert.Equal(t, int64(5), dir.GetItemCount())
+}