Merge pull request #477 from libp2p/feat/cancel-dht-context

Close context correctly

Author: Stebalien

dht.go

@@ -111,12 +111,6 @@ func New(ctx context.Context, h host.Host, options ...opts.Option) (*IpfsDHT, er
 	// register for network notifs.
 	dht.host.Network().Notify((*netNotifiee)(dht))
 
-	dht.proc = goprocessctx.WithContextAndTeardown(ctx, func() error {
-		// remove ourselves from network notifs.
-		dht.host.Network().StopNotify((*netNotifiee)(dht))
-		return nil
-	})
-
 	dht.proc.AddChild(dht.providers.Process())
 	dht.Validator = cfg.Validator
 
@@ -172,16 +166,26 @@ func makeDHT(ctx context.Context, h host.Host, cfg *opts.Options) *IpfsDHT {
 		peerstore:        h.Peerstore(),
 		host:             h,
 		strmap:           make(map[peer.ID]*messageSender),
-		ctx:              ctx,
-		providers:        providers.NewProviderManager(ctx, h.ID(), cfg.Datastore),
 		birth:            time.Now(),
 		routingTable:     rt,
 		protocols:        cfg.Protocols,
 		bucketSize:       cfg.BucketSize,
 		triggerRtRefresh: make(chan chan<- error),
 	}
 
-	dht.ctx = dht.newContextWithLocalTags(ctx)
+	// create a DHT proc with the given teardown
+	dht.proc = goprocess.WithTeardown(func() error {
+		// remove ourselves from network notifs.
+		dht.host.Network().StopNotify((*netNotifiee)(dht))
+		return nil
+	})
+
+	// create a tagged context derived from the original context
+	ctxTags := dht.newContextWithLocalTags(ctx)
+	// the DHT context should be done when the process is closed
+	dht.ctx = goprocessctx.WithProcessClosing(ctxTags, dht.proc)
+
+	dht.providers = providers.NewProviderManager(dht.ctx, h.ID(), cfg.Datastore)
 
 	return dht
 }

dht_test.go

@@ -402,6 +402,30 @@ func TestValueSetInvalid(t *testing.T) {
 	testSetGet("valid", true, "newer", nil)
 }
 
+func TestContextShutDown(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	dht := setupDHT(ctx, t, false)
+
+	// context is alive
+	select {
+	case <-dht.Context().Done():
+		t.Fatal("context should not be done")
+	default:
+	}
+
+	// shut down dht
+	require.NoError(t, dht.Close())
+
+	// now context should be done
+	select {
+	case <-dht.Context().Done():
+	default:
+		t.Fatal("context should be done")
+	}
+}
+
 func TestSearchValue(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()