make sure not to orphan any extra goroutines

exchange/bitswap/bitswap.go

@@ -368,14 +368,19 @@ func (bs *bitswap) wantNewBlocks(ctx context.Context, bkeys []u.Key) {
 	for i, k := range bkeys {
 		message.AddEntry(k, kMaxPriority-i)
 	}
+
+	wg := sync.WaitGroup{}
 	for _, p := range bs.engine.Peers() {
+		wg.Add(1)
 		go func(p peer.ID) {
+			defer wg.Done()
 			err := bs.send(ctx, p, message)
 			if err != nil {
 				log.Debugf("Error sending message: %s", err)
 			}
 		}(p)
 	}
+	wg.Wait()
 }
 
 func (bs *bitswap) ReceiveError(err error) {

exchange/bitswap/workers.go

@@ -90,7 +90,11 @@ func (bs *bitswap) clientWorker(parent context.Context) {
 				bs.wantlist.Add(k, kMaxPriority-i)
 			}
 
-			bs.wantNewBlocks(req.ctx, keys)
+			done := make(chan struct{})
+			go func() {
+				bs.wantNewBlocks(req.ctx, keys)
+				close(done)
+			}()
 
 			// NB: Optimization. Assumes that providers of key[0] are likely to
 			// be able to provide for all keys. This currently holds true in most
@@ -101,6 +105,10 @@ func (bs *bitswap) clientWorker(parent context.Context) {
 			if err != nil {
 				log.Debugf("error sending wantlist: %s", err)
 			}
+
+			// Wait for wantNewBlocks to finish
+			<-done
+
 		case <-parent.Done():
 			return
 		}