WIP: fix wantlist clearing by closing down session

License: MIT
Signed-off-by: Jeromy <jeromyj@gmail.com>

exchange/bitswap/session.go

@@ -84,6 +84,14 @@ func (bs *Bitswap) NewSession(ctx context.Context) *Session {
 
 func (bs *Bitswap) removeSession(s *Session) {
 	s.notif.Shutdown()
+
+	live := make([]*cid.Cid, 0, len(s.liveWants))
+	for c := range s.liveWants {
+		cs, _ := cid.Cast([]byte(c))
+		live = append(live, cs)
+	}
+	bs.CancelWants(live, s.id)
+
 	bs.sessLk.Lock()
 	defer bs.sessLk.Unlock()
 	for i := 0; i < len(bs.sessions); i++ {

exchange/bitswap/session_test.go

@@ -285,3 +285,36 @@ func TestMultipleSessions(t *testing.T) {
 	}
 	_ = blkch
 }
+
+func TestWantlistClearsOnCancel(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	vnet := getVirtualNetwork()
+	sesgen := NewTestSessionGenerator(vnet)
+	defer sesgen.Close()
+	bgen := blocksutil.NewBlockGenerator()
+
+	blks := bgen.Blocks(10)
+	var cids []*cid.Cid
+	for _, blk := range blks {
+		cids = append(cids, blk.Cid())
+	}
+
+	inst := sesgen.Instances(1)
+
+	a := inst[0]
+
+	ctx1, cancel1 := context.WithCancel(ctx)
+	ses := a.Exchange.NewSession(ctx1)
+
+	_, err := ses.GetBlocks(ctx, cids)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cancel1()
+
+	if len(a.Exchange.GetWantlist()) > 0 {
+		t.Fatal("expected empty wantlist")
+	}
+}