Cherrypick #8657 and #8667 to v1.77.x

examples/go.mod

@@ -74,7 +74,7 @@ require (
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.3 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect

examples/go.sum

@@ -4125,8 +4125,9 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
 golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=

gcp/observability/go.mod

@@ -51,7 +51,7 @@ require (
 	go.opentelemetry.io/otel/metric v1.38.0 // indirect
 	go.opentelemetry.io/otel/trace v1.38.0 // indirect
 	golang.org/x/crypto v0.43.0 // indirect
-	golang.org/x/net v0.46.0 // indirect
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 // indirect
 	golang.org/x/sync v0.17.0 // indirect
 	golang.org/x/sys v0.37.0 // indirect
 	golang.org/x/text v0.30.0 // indirect

gcp/observability/go.sum

@@ -3813,8 +3813,8 @@ golang.org/x/net v0.42.0/go.mod h1:FF1RA5d3u7nAYA4z2TkclSCKh68eSXtiFwcWQpPXdt8=
 golang.org/x/net v0.43.0/go.mod h1:vhO1fvI4dGsIjh73sWfUVjj3N7CA9WkKJNQm2svM6Jg=
 golang.org/x/net v0.44.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
 golang.org/x/net v0.45.0/go.mod h1:ECOoLqd5U3Lhyeyo/QDCEVQ4sNgYsqvCZ722XogGieY=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20191202225959-858c2ad4c8b6/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=

go.mod

@@ -18,7 +18,7 @@ require (
 	go.opentelemetry.io/otel/sdk v1.38.0
 	go.opentelemetry.io/otel/sdk/metric v1.38.0
 	go.opentelemetry.io/otel/trace v1.38.0
-	golang.org/x/net v0.46.0
+	golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82
 	golang.org/x/oauth2 v0.32.0
 	golang.org/x/sync v0.17.0
 	golang.org/x/sys v0.37.0

go.sum

@@ -57,8 +57,8 @@ go.opentelemetry.io/otel/trace v1.38.0 h1:Fxk5bKrDZJUH+AMyyIXGcFAPah0oRcT+LuNtJr
 go.opentelemetry.io/otel/trace v1.38.0/go.mod h1:j1P9ivuFsTceSWe1oY+EeW3sc+Pp42sO++GHkg4wwhs=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
-golang.org/x/net v0.46.0 h1:giFlY12I07fugqwPuWJi68oOnpfqFnJIJzaIIm2JVV4=
-golang.org/x/net v0.46.0/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82 h1:6/3JGEh1C88g7m+qzzTbl3A0FtsLguXieqofVLU/JAo=
+golang.org/x/net v0.46.1-0.20251013234738-63d1a5100f82/go.mod h1:Q9BGdFy1y4nkUwiLvT5qtyhAnEHgnQ/zd8PfU6nc210=
 golang.org/x/oauth2 v0.32.0 h1:jsCblLleRMDrxMN29H3z/k1KliIvpLgCkE6R8FXXNgY=
 golang.org/x/oauth2 v0.32.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
 golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=

internal/transport/controlbuf.go

@@ -496,6 +496,16 @@ const (
 	serverSide
 )
 
+// maxWriteBufSize is the maximum length (number of elements) the cached
+// writeBuf can grow to. The length depends on the number of buffers
+// contained within the BufferSlice produced by the codec, which is
+// generally small.
+//
+// If a writeBuf larger than this limit is required, it will be allocated
+// and freed after use, rather than being cached. This avoids holding
+// on to large amounts of memory.
+const maxWriteBufSize = 64
+
 // Loopy receives frames from the control buffer.
 // Each frame is handled individually; most of the work done by loopy goes
 // into handling data frames. Loopy maintains a queue of active streams, and each
@@ -530,6 +540,8 @@ type loopyWriter struct {
 
 	// Side-specific handlers
 	ssGoAwayHandler func(*goAway) (bool, error)
+
+	writeBuf [][]byte // cached slice to avoid heap allocations for calls to mem.Reader.Peek.
 }
 
 func newLoopyWriter(s side, fr *framer, cbuf *controlBuffer, bdpEst *bdpEstimator, conn net.Conn, logger *grpclog.PrefixLogger, goAwayHandler func(*goAway) (bool, error), bufferPool mem.BufferPool) *loopyWriter {
@@ -962,11 +974,11 @@ func (l *loopyWriter) processData() (bool, error) {
 
 	if len(dataItem.h) == 0 && reader.Remaining() == 0 { // Empty data frame
 		// Client sends out empty data frame with endStream = true
-		if err := l.framer.fr.WriteData(dataItem.streamID, dataItem.endStream, nil); err != nil {
+		if err := l.framer.writeData(dataItem.streamID, dataItem.endStream, nil); err != nil {
 			return false, err
 		}
 		str.itl.dequeue() // remove the empty data item from stream
-		_ = reader.Close()
+		reader.Close()
 		if str.itl.isEmpty() {
 			str.state = empty
 		} else if trailer, ok := str.itl.peek().(*headerFrame); ok { // the next item is trailers.
@@ -999,25 +1011,20 @@ func (l *loopyWriter) processData() (bool, error) {
 	remainingBytes := len(dataItem.h) + reader.Remaining() - hSize - dSize
 	size := hSize + dSize
 
-	var buf *[]byte
-
-	if hSize != 0 && dSize == 0 {
-		buf = &dataItem.h
-	} else {
-		// Note: this is only necessary because the http2.Framer does not support
-		// partially writing a frame, so the sequence must be materialized into a buffer.
-		// TODO: Revisit once https://github.com/golang/go/issues/66655 is addressed.
-		pool := l.bufferPool
-		if pool == nil {
-			// Note that this is only supposed to be nil in tests. Otherwise, stream is
-			// always initialized with a BufferPool.
-			pool = mem.DefaultBufferPool()
+	l.writeBuf = l.writeBuf[:0]
+	if hSize > 0 {
+		l.writeBuf = append(l.writeBuf, dataItem.h[:hSize])
+	}
+	if dSize > 0 {
+		var err error
+		l.writeBuf, err = reader.Peek(dSize, l.writeBuf)
+		if err != nil {
+			// This must never happen since the reader must have at least dSize
+			// bytes.
+			// Log an error to fail tests.
+			l.logger.Errorf("unexpected error while reading Data frame payload: %v", err)
+			return false, err
 		}
-		buf = pool.Get(size)
-		defer pool.Put(buf)
-
-		copy((*buf)[:hSize], dataItem.h)
-		_, _ = reader.Read((*buf)[hSize:])
 	}
 
 	// Now that outgoing flow controls are checked we can replenish str's write quota
@@ -1030,15 +1037,22 @@ func (l *loopyWriter) processData() (bool, error) {
 	if dataItem.onEachWrite != nil {
 		dataItem.onEachWrite()
 	}
-	if err := l.framer.fr.WriteData(dataItem.streamID, endStream, (*buf)[:size]); err != nil {
+	err := l.framer.writeData(dataItem.streamID, endStream, l.writeBuf)
+	reader.Discard(dSize)
+	if cap(l.writeBuf) > maxWriteBufSize {
+		l.writeBuf = nil
+	} else {
+		clear(l.writeBuf)
+	}
+	if err != nil {
 		return false, err
 	}
 	str.bytesOutStanding += size
 	l.sendQuota -= uint32(size)
 	dataItem.h = dataItem.h[hSize:]
 
 	if remainingBytes == 0 { // All the data from that message was written out.
-		_ = reader.Close()
+		reader.Close()
 		str.itl.dequeue()
 	}
 	if str.itl.isEmpty() {

internal/transport/http2_client.go

@@ -336,7 +336,7 @@ func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 		writerDone:            make(chan struct{}),
 		goAway:                make(chan struct{}),
 		keepaliveDone:         make(chan struct{}),
-		framer:                newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize),
+		framer:                newFramer(conn, writeBufSize, readBufSize, opts.SharedWriteBuffer, maxHeaderListSize, opts.BufferPool),
 		fc:                    &trInFlow{limit: uint32(icwz)},
 		scheme:                scheme,
 		activeStreams:         make(map[uint32]*ClientStream),
@@ -1170,7 +1170,7 @@ func (t *http2Client) updateFlowControl(n uint32) {
 	})
 }
 
-func (t *http2Client) handleData(f *http2.DataFrame) {
+func (t *http2Client) handleData(f *parsedDataFrame) {
 	size := f.Header().Length
 	var sendBDPPing bool
 	if t.bdpEst != nil {
@@ -1214,22 +1214,15 @@ func (t *http2Client) handleData(f *http2.DataFrame) {
 			t.closeStream(s, io.EOF, true, http2.ErrCodeFlowControl, status.New(codes.Internal, err.Error()), nil, false)
 			return
 		}
+		dataLen := f.data.Len()
 		if f.Header().Flags.Has(http2.FlagDataPadded) {
-			if w := s.fc.onRead(size - uint32(len(f.Data()))); w > 0 {
+			if w := s.fc.onRead(size - uint32(dataLen)); w > 0 {
 				t.controlBuf.put(&outgoingWindowUpdate{s.id, w})
 			}
 		}
-		// TODO(bradfitz, zhaoq): A copy is required here because there is no
-		// guarantee f.Data() is consumed before the arrival of next frame.
-		// Can this copy be eliminated?
-		if len(f.Data()) > 0 {
-			pool := t.bufferPool
-			if pool == nil {
-				// Note that this is only supposed to be nil in tests. Otherwise, stream is
-				// always initialized with a BufferPool.
-				pool = mem.DefaultBufferPool()
-			}
-			s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
+		if dataLen > 0 {
+			f.data.Ref()
+			s.write(recvMsg{buffer: f.data})
 		}
 	}
 	// The server has closed the stream without sending trailers.  Record that
@@ -1659,7 +1652,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 	// loop to keep reading incoming messages on this transport.
 	for {
 		t.controlBuf.throttle()
-		frame, err := t.framer.fr.ReadFrame()
+		frame, err := t.framer.readFrame()
 		if t.keepaliveEnabled {
 			atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		}
@@ -1674,7 +1667,7 @@ func (t *http2Client) reader(errCh chan<- error) {
 				if s != nil {
 					// use error detail to provide better err message
 					code := http2ErrConvTab[se.Code]
-					errorDetail := t.framer.fr.ErrorDetail()
+					errorDetail := t.framer.errorDetail()
 					var msg string
 					if errorDetail != nil {
 						msg = errorDetail.Error()
@@ -1692,8 +1685,9 @@ func (t *http2Client) reader(errCh chan<- error) {
 		switch frame := frame.(type) {
 		case *http2.MetaHeadersFrame:
 			t.operateHeaders(frame)
-		case *http2.DataFrame:
+		case *parsedDataFrame:
 			t.handleData(frame)
+			frame.data.Free()
 		case *http2.RSTStreamFrame:
 			t.handleRSTStream(frame)
 		case *http2.SettingsFrame:

internal/transport/http2_server.go

@@ -169,7 +169,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	if config.MaxHeaderListSize != nil {
 		maxHeaderListSize = *config.MaxHeaderListSize
 	}
-	framer := newFramer(conn, writeBufSize, readBufSize, config.SharedWriteBuffer, maxHeaderListSize)
+	framer := newFramer(conn, writeBufSize, readBufSize, config.SharedWriteBuffer, maxHeaderListSize, config.BufferPool)
 	// Send initial settings as connection preface to client.
 	isettings := []http2.Setting{{
 		ID:  http2.SettingMaxFrameSize,
@@ -670,7 +670,7 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStre
 	}()
 	for {
 		t.controlBuf.throttle()
-		frame, err := t.framer.fr.ReadFrame()
+		frame, err := t.framer.readFrame()
 		atomic.StoreInt64(&t.lastRead, time.Now().UnixNano())
 		if err != nil {
 			if se, ok := err.(http2.StreamError); ok {
@@ -707,8 +707,9 @@ func (t *http2Server) HandleStreams(ctx context.Context, handle func(*ServerStre
 				})
 				continue
 			}
-		case *http2.DataFrame:
+		case *parsedDataFrame:
 			t.handleData(frame)
+			frame.data.Free()
 		case *http2.RSTStreamFrame:
 			t.handleRSTStream(frame)
 		case *http2.SettingsFrame:
@@ -788,7 +789,7 @@ func (t *http2Server) updateFlowControl(n uint32) {
 
 }
 
-func (t *http2Server) handleData(f *http2.DataFrame) {
+func (t *http2Server) handleData(f *parsedDataFrame) {
 	size := f.Header().Length
 	var sendBDPPing bool
 	if t.bdpEst != nil {
@@ -833,22 +834,15 @@ func (t *http2Server) handleData(f *http2.DataFrame) {
 			t.closeStream(s, true, http2.ErrCodeFlowControl, false)
 			return
 		}
+		dataLen := f.data.Len()
 		if f.Header().Flags.Has(http2.FlagDataPadded) {
-			if w := s.fc.onRead(size - uint32(len(f.Data()))); w > 0 {
+			if w := s.fc.onRead(size - uint32(dataLen)); w > 0 {
 				t.controlBuf.put(&outgoingWindowUpdate{s.id, w})
 			}
 		}
-		// TODO(bradfitz, zhaoq): A copy is required here because there is no
-		// guarantee f.Data() is consumed before the arrival of next frame.
-		// Can this copy be eliminated?
-		if len(f.Data()) > 0 {
-			pool := t.bufferPool
-			if pool == nil {
-				// Note that this is only supposed to be nil in tests. Otherwise, stream is
-				// always initialized with a BufferPool.
-				pool = mem.DefaultBufferPool()
-			}
-			s.write(recvMsg{buffer: mem.Copy(f.Data(), pool)})
+		if dataLen > 0 {
+			f.data.Ref()
+			s.write(recvMsg{buffer: f.data})
 		}
 	}
 	if f.StreamEnded() {