fix: Better lock handling on close (#1023)

Author: alpe

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## v1.3.4, December 17, 2024 
+
+- [#1023](https://github.com/cosmos/iavl/pull/1023) Better lock handling on close
+
+
 ## v1.3.3, December 16, 2024
 
 - [#1018](https://github.com/cosmos/iavl/pull/1018) Cache first version for legacy versions, fix performance regression after upgrade.

nodedb.go

@@ -601,7 +601,7 @@ func (ndb *nodeDB) startPruning() {
 	for {
 		select {
 		case <-ndb.ctx.Done():
-			ndb.done <- struct{}{}
+			close(ndb.done)
 			return
 		default:
 			ndb.mtx.Lock()
@@ -1122,14 +1122,15 @@ func (ndb *nodeDB) traverseOrphans(prevVersion, curVersion int64, fn func(*Node)
 
 // Close the nodeDB.
 func (ndb *nodeDB) Close() error {
-	ndb.mtx.Lock()
-	defer ndb.mtx.Unlock()
-
 	ndb.cancel()
+
 	if ndb.opts.AsyncPruning {
 		<-ndb.done // wait for the pruning process to finish
 	}
 
+	ndb.mtx.Lock()
+	defer ndb.mtx.Unlock()
+
 	if ndb.batch != nil {
 		if err := ndb.batch.Close(); err != nil {
 			return err

nodedb_test.go

@@ -444,4 +444,5 @@ func TestCloseNodeDB(t *testing.T) {
 	opts.AsyncPruning = true
 	ndb := newNodeDB(db, 0, opts, NewNopLogger())
 	require.NoError(t, ndb.Close())
+	require.NoError(t, ndb.Close()) // must not block or fail on second call
 }