Add finalizers to delete trackers

For safety, set a finalizer to make sure delete trackers are always
closed.

Signed-off-by: Jussi Maki <[email protected]>

deletetracker.go

@@ -4,6 +4,7 @@
 package statedb
 
 import (
+	"runtime"
 	"sync/atomic"
 
 	"github.com/cilium/statedb/index"
@@ -54,8 +55,14 @@ func (dt *deleteTracker[Obj]) mark(upTo Revision) {
 }
 
 func (dt *deleteTracker[Obj]) close() {
+	if dt.db == nil {
+		return
+	}
+	runtime.SetFinalizer(dt, nil)
+
 	// Remove the delete tracker from the table.
 	txn := dt.db.WriteTxn(dt.table).getTxn()
+	dt.db = nil
 	db := txn.db
 	table := txn.modifiedTables[dt.table.tablePos()]
 	if table == nil {
@@ -72,6 +79,7 @@ func (dt *deleteTracker[Obj]) close() {
 	case db.gcTrigger <- struct{}{}:
 	default:
 	}
+
 }
 
 var closedWatchChannel = func() <-chan struct{} {

txn.go

@@ -251,8 +251,11 @@ func (txn *txn) addDeleteTracker(meta TableMeta, trackerName string, dt anyDelet
 	table := txn.modifiedTables[meta.tablePos()]
 	table.deleteTrackers, _, _ = table.deleteTrackers.Insert([]byte(trackerName), dt)
 	txn.db.metrics.DeleteTrackerCount(meta.Name(), table.deleteTrackers.Len())
-	return nil
 
+	// Add a finalizer to make sure delete trackers are always closed.
+	runtime.SetFinalizer(dt, func(dt anyDeleteTracker) { dt.close() })
+
+	return nil
 }
 
 func (txn *txn) Delete(meta TableMeta, guardRevision Revision, data any) (object, bool, error) {

types.go

@@ -356,6 +356,7 @@ type anyIndexer struct {
 type anyDeleteTracker interface {
 	setRevision(uint64)
 	getRevision() uint64
+	close()
 }
 
 type indexEntry struct {