test: close nodebuffer in db close

trie/triedb/pathdb/database.go

@@ -420,6 +420,7 @@ func (db *Database) Close() error {
 	// Release the memory held by clean cache.
 	db.tree.bottom().resetCache()
 
+	db.tree.bottom().buffer.waitAndStopFlushing()
 	// Close the attached state history freezer.
 	if db.freezer == nil {
 		return nil

trie/triedb/pathdb/nodebufferlist.go

@@ -111,7 +111,7 @@ func newNodeBufferList(
 		persistID: rawdb.ReadPersistentStateID(db),
 		stopCh:    make(chan struct{}),
 	}
-	//go nf.loop()
+	go nf.loop()
 
 	log.Info("new node buffer list", "proposed block interval", nf.wpBlocks,
 		"reserve multi difflayers", nf.rsevMdNum, "difflayers in multidifflayer", nf.dlInMd,
@@ -335,7 +335,16 @@ func (nf *nodebufferlist) getLayers() uint64 {
 
 // waitAndStopFlushing will block unit writing the trie nodes of trienodebuffer to disk.
 func (nf *nodebufferlist) waitAndStopFlushing() {
-	close(nf.stopCh)
+	nf.mux.Lock()
+	nf.baseMux.Lock()
+	nf.flushMux.Lock()
+	defer nf.mux.Unlock()
+	defer nf.baseMux.Unlock()
+	defer nf.flushMux.Unlock()
+	if nf.stopCh != nil {
+		close(nf.stopCh)
+		nf.stopCh = nil
+	}
 	nf.stopFlushing.Store(true)
 	for nf.isFlushing.Load() {
 		time.Sleep(time.Second)