Merge pull request #760 from ipfs/marco/drop-stream-reference

[skip changelog] fix: Drop stream references on Close/Reset

Author: gammazero

CHANGELOG.md

@@ -28,6 +28,7 @@ The following emojis are used to highlight certain changes:
 - 🛠 `blockstore` and `blockservice`'s `WriteThrough()` option now takes an "enabled" parameter: `WriteThrough(enabled bool)`.
 - Replaced unmaintained mock time implementation uses in tests: [from](github.com/benbjohnson/clock) => [to](github.com/filecoin-project/go-clock)
 - updated to go-libp2p to [v0.38.0](https://github.com/libp2p/go-libp2p/releases/tag/v0.38.0)
+- `bitswap/client`: if a libp2p connection has a context, use `context.AfterFunc` to cleanup the connection.
 
 
 ### Removed

bitswap/network/ipfs_impl.go

@@ -82,18 +82,45 @@ type impl struct {
 	receivers []Receiver
 }
 
+// interfaceWrapper is concrete type that wraps an interface. Necessary because
+// atomic.Value needs the same type and can not Store(nil). This indirection
+// allows us to store nil.
+type interfaceWrapper[T any] struct {
+	t T
+}
+type atomicInterface[T any] struct {
+	iface atomic.Value
+}
+
+func (a *atomicInterface[T]) Load() T {
+	var v T
+	x := a.iface.Load()
+	if x != nil {
+		return x.(interfaceWrapper[T]).t
+	}
+	return v
+}
+
+func (a *atomicInterface[T]) Store(v T) {
+	a.iface.Store(interfaceWrapper[T]{v})
+}
+
 type streamMessageSender struct {
-	to        peer.ID
-	stream    network.Stream
-	connected bool
-	bsnet     *impl
-	opts      *MessageSenderOpts
+	to     peer.ID
+	stream atomicInterface[network.Stream]
+	bsnet  *impl
+	opts   *MessageSenderOpts
+}
+
+type HasContext interface {
+	Context() context.Context
 }
 
 // Open a stream to the remote peer
 func (s *streamMessageSender) Connect(ctx context.Context) (network.Stream, error) {
-	if s.connected {
-		return s.stream, nil
+	stream := s.stream.Load()
+	if stream != nil {
+		return stream, nil
 	}
 
 	tctx, cancel := context.WithTimeout(ctx, s.opts.SendTimeout)
@@ -107,30 +134,45 @@ func (s *streamMessageSender) Connect(ctx context.Context) (network.Stream, erro
 	if err != nil {
 		return nil, err
 	}
+	if withCtx, ok := stream.Conn().(HasContext); ok {
+		context.AfterFunc(withCtx.Context(), func() {
+			s.stream.Store(nil)
+		})
+	}
 
-	s.stream = stream
-	s.connected = true
-	return s.stream, nil
+	s.stream.Store(stream)
+	return stream, nil
 }
 
 // Reset the stream
 func (s *streamMessageSender) Reset() error {
-	if s.stream != nil {
-		err := s.stream.Reset()
-		s.connected = false
+	stream := s.stream.Load()
+	if stream != nil {
+		err := stream.Reset()
+		s.stream.Store(nil)
 		return err
 	}
 	return nil
 }
 
 // Close the stream
 func (s *streamMessageSender) Close() error {
-	return s.stream.Close()
+	stream := s.stream.Load()
+	if stream != nil {
+		err := stream.Close()
+		s.stream.Store(nil)
+		return err
+	}
+	return nil
 }
 
 // Indicates whether the peer supports HAVE / DONT_HAVE messages
 func (s *streamMessageSender) SupportsHave() bool {
-	return s.bsnet.SupportsHave(s.stream.Protocol())
+	stream := s.stream.Load()
+	if stream == nil {
+		return false
+	}
+	return s.bsnet.SupportsHave(stream.Protocol())
 }
 
 // Send a message to the peer, attempting multiple times