engine(test): make the test peer tagger more reliable

decision/engine_test.go

@@ -19,38 +19,63 @@ import (
 	testutil "github.com/libp2p/go-libp2p-core/test"
 )
 
+type peerTag struct {
+	done  chan struct{}
+	peers map[peer.ID]int
+}
+
 type fakePeerTagger struct {
 	lk   sync.Mutex
-	wait        sync.WaitGroup
-	taggedPeers []peer.ID
+	tags map[string]*peerTag
 }
 
 func (fpt *fakePeerTagger) TagPeer(p peer.ID, tag string, n int) {
-	fpt.wait.Add(1)
-
 	fpt.lk.Lock()
 	defer fpt.lk.Unlock()
-	fpt.taggedPeers = append(fpt.taggedPeers, p)
+	if fpt.tags == nil {
+		fpt.tags = make(map[string]*peerTag, 1)
+	}
+	pt, ok := fpt.tags[tag]
+	if !ok {
+		pt = &peerTag{peers: make(map[peer.ID]int, 1), done: make(chan struct{})}
+		fpt.tags[tag] = pt
+	}
+	pt.peers[p] = n
 }
 
 func (fpt *fakePeerTagger) UntagPeer(p peer.ID, tag string) {
-	defer fpt.wait.Done()
-
 	fpt.lk.Lock()
 	defer fpt.lk.Unlock()
-	for i := 0; i < len(fpt.taggedPeers); i++ {
-		if fpt.taggedPeers[i] == p {
-			fpt.taggedPeers[i] = fpt.taggedPeers[len(fpt.taggedPeers)-1]
-			fpt.taggedPeers = fpt.taggedPeers[:len(fpt.taggedPeers)-1]
+	pt := fpt.tags[tag]
+	if pt == nil {
 		return
 	}
+	delete(pt.peers, p)
+	if len(pt.peers) == 0 {
+		close(pt.done)
+		delete(fpt.tags, tag)
 	}
 }
 
-func (fpt *fakePeerTagger) count() int {
+func (fpt *fakePeerTagger) count(tag string) int {
 	fpt.lk.Lock()
 	defer fpt.lk.Unlock()
-	return len(fpt.taggedPeers)
+	if pt, ok := fpt.tags[tag]; ok {
+		return len(pt.peers)
+	}
+	return 0
+}
+
+func (fpt *fakePeerTagger) wait(tag string) {
+	fpt.lk.Lock()
+	pt := fpt.tags[tag]
+	if pt == nil {
+		fpt.lk.Unlock()
+		return
+	}
+	doneCh := pt.done
+	fpt.lk.Unlock()
+	<-doneCh
 }
 
 type engineSet struct {
@@ -241,13 +266,13 @@ func TestTaggingPeers(t *testing.T) {
 	next := <-sanfrancisco.Engine.Outbox()
 	envelope := <-next
 
-	if sanfrancisco.PeerTagger.count() != 1 {
+	if sanfrancisco.PeerTagger.count(sanfrancisco.Engine.tagQueued) != 1 {
 		t.Fatal("Incorrect number of peers tagged")
 	}
 	envelope.Sent()
 	<-sanfrancisco.Engine.Outbox()
-	sanfrancisco.PeerTagger.wait.Wait()
-	if sanfrancisco.PeerTagger.count() != 0 {
+	sanfrancisco.PeerTagger.wait(sanfrancisco.Engine.tagQueued)
+	if sanfrancisco.PeerTagger.count(sanfrancisco.Engine.tagQueued) != 0 {
 		t.Fatal("Peers should be untagged but weren't")
 	}
 }