dht/kbucket: race condition fix

routing/kbucket/bucket.go

@@ -19,6 +19,17 @@ func newBucket() *Bucket {
 	return b
 }
 
+func (b *Bucket) Peers() []peer.ID {
+	b.lk.RLock()
+	defer b.lk.RUnlock()
+	ps := make([]peer.ID, 0, b.list.Len())
+	for e := b.list.Front(); e != nil; e = e.Next() {
+		id := e.Value.(peer.ID)
+		ps = append(ps, id)
+	}
+	return ps
+}
+
 func (b *Bucket) find(id peer.ID) *list.Element {
 	b.lk.RLock()
 	defer b.lk.RUnlock()
@@ -81,7 +92,3 @@ func (b *Bucket) Split(cpl int, target ID) *Bucket {
 	}
 	return newbuck
 }
-
-func (b *Bucket) getIter() *list.Element {
-	return b.list.Front()
-}

routing/kbucket/table.go

@@ -176,11 +176,11 @@ func (rt *RoutingTable) Size() int {
 // NOTE: This is potentially unsafe... use at your own risk
 func (rt *RoutingTable) ListPeers() []peer.ID {
 	var peers []peer.ID
+	rt.tabLock.RLock()
 	for _, buck := range rt.Buckets {
-		for e := buck.getIter(); e != nil; e = e.Next() {
-			peers = append(peers, e.Value.(peer.ID))
-		}
+		peers = append(peers, buck.Peers()...)
 	}
+	rt.tabLock.RUnlock()
 	return peers
 }