Update dependencies

vendor/golang.org/x/net/http2/server.go

@@ -110,9 +110,41 @@ type Server struct {
 	// activity for the purposes of IdleTimeout.
 	IdleTimeout time.Duration
 
+	// MaxUploadBufferPerConnection is the size of the initial flow
+	// control window for each connections. The HTTP/2 spec does not
+	// allow this to be smaller than 65535 or larger than 2^32-1.
+	// If the value is outside this range, a default value will be
+	// used instead.
+	MaxUploadBufferPerConnection int32
+
+	// MaxUploadBufferPerStream is the size of the initial flow control
+	// window for each stream. The HTTP/2 spec does not allow this to
+	// be larger than 2^32-1. If the value is zero or larger than the
+	// maximum, a default value will be used instead.
+	MaxUploadBufferPerStream int32
+
 	// NewWriteScheduler constructs a write scheduler for a connection.
 	// If nil, a default scheduler is chosen.
 	NewWriteScheduler func() WriteScheduler
+
+	// Internal state. This is a pointer (rather than embedded directly)
+	// so that we don't embed a Mutex in this struct, which will make the
+	// struct non-copyable, which might break some callers.
+	state *serverInternalState
+}
+
+func (s *Server) initialConnRecvWindowSize() int32 {
+	if s.MaxUploadBufferPerConnection > initialWindowSize {
+		return s.MaxUploadBufferPerConnection
+	}
+	return 1 << 20
+}
+
+func (s *Server) initialStreamRecvWindowSize() int32 {
+	if s.MaxUploadBufferPerStream > 0 {
+		return s.MaxUploadBufferPerStream
+	}
+	return 1 << 20
 }
 
 func (s *Server) maxReadFrameSize() uint32 {
@@ -129,6 +161,40 @@ func (s *Server) maxConcurrentStreams() uint32 {
 	return defaultMaxStreams
 }
 
+type serverInternalState struct {
+	mu          sync.Mutex
+	activeConns map[*serverConn]struct{}
+}
+
+func (s *serverInternalState) registerConn(sc *serverConn) {
+	if s == nil {
+		return // if the Server was used without calling ConfigureServer
+	}
+	s.mu.Lock()
+	s.activeConns[sc] = struct{}{}
+	s.mu.Unlock()
+}
+
+func (s *serverInternalState) unregisterConn(sc *serverConn) {
+	if s == nil {
+		return // if the Server was used without calling ConfigureServer
+	}
+	s.mu.Lock()
+	delete(s.activeConns, sc)
+	s.mu.Unlock()
+}
+
+func (s *serverInternalState) startGracefulShutdown() {
+	if s == nil {
+		return // if the Server was used without calling ConfigureServer
+	}
+	s.mu.Lock()
+	for sc := range s.activeConns {
+		sc.startGracefulShutdown()
+	}
+	s.mu.Unlock()
+}
+
 // ConfigureServer adds HTTP/2 support to a net/http Server.
 //
 // The configuration conf may be nil.
@@ -141,9 +207,13 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 	if conf == nil {
 		conf = new(Server)
 	}
+	conf.state = &serverInternalState{activeConns: make(map[*serverConn]struct{})}
 	if err := configureServer18(s, conf); err != nil {
 		return err
 	}
+	if err := configureServer19(s, conf); err != nil {
+		return err
+	}
 
 	if s.TLSConfig == nil {
 		s.TLSConfig = new(tls.Config)
@@ -255,27 +325,39 @@ func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
 	defer cancel()
 
 	sc := &serverConn{
-		srv:               s,
-		hs:                opts.baseConfig(),
-		conn:              c,
-		baseCtx:           baseCtx,
-		remoteAddrStr:     c.RemoteAddr().String(),
-		bw:                newBufferedWriter(c),
-		handler:           opts.handler(),
-		streams:           make(map[uint32]*stream),
-		readFrameCh:       make(chan readFrameResult),
-		wantWriteFrameCh:  make(chan FrameWriteRequest, 8),
-		wantStartPushCh:   make(chan startPushRequest, 8),
-		wroteFrameCh:      make(chan frameWriteResult, 1), // buffered; one send in writeFrameAsync
-		bodyReadCh:        make(chan bodyReadMsg),         // buffering doesn't matter either way
-		doneServing:       make(chan struct{}),
-		clientMaxStreams:  math.MaxUint32, // Section 6.5.2: "Initially, there is no limit to this value"
-		advMaxStreams:     s.maxConcurrentStreams(),
-		initialWindowSize: initialWindowSize,
-		maxFrameSize:      initialMaxFrameSize,
-		headerTableSize:   initialHeaderTableSize,
-		serveG:            newGoroutineLock(),
-		pushEnabled:       true,
+		srv:                         s,
+		hs:                          opts.baseConfig(),
+		conn:                        c,
+		baseCtx:                     baseCtx,
+		remoteAddrStr:               c.RemoteAddr().String(),
+		bw:                          newBufferedWriter(c),
+		handler:                     opts.handler(),
+		streams:                     make(map[uint32]*stream),
+		readFrameCh:                 make(chan readFrameResult),
+		wantWriteFrameCh:            make(chan FrameWriteRequest, 8),
+		serveMsgCh:                  make(chan interface{}, 8),
+		wroteFrameCh:                make(chan frameWriteResult, 1), // buffered; one send in writeFrameAsync
+		bodyReadCh:                  make(chan bodyReadMsg),         // buffering doesn't matter either way
+		doneServing:                 make(chan struct{}),
+		clientMaxStreams:            math.MaxUint32, // Section 6.5.2: "Initially, there is no limit to this value"
+		advMaxStreams:               s.maxConcurrentStreams(),
+		initialStreamSendWindowSize: initialWindowSize,
+		maxFrameSize:                initialMaxFrameSize,
+		headerTableSize:             initialHeaderTableSize,
+		serveG:                      newGoroutineLock(),
+		pushEnabled:                 true,
+	}
+
+	s.state.registerConn(sc)
+	defer s.state.unregisterConn(sc)
+
+	// The net/http package sets the write deadline from the
+	// http.Server.WriteTimeout during the TLS handshake, but then
+	// passes the connection off to us with the deadline already set.
+	// Write deadlines are set per stream in serverConn.newStream.
+	// Disarm the net.Conn write deadline here.
+	if sc.hs.WriteTimeout != 0 {
+		sc.conn.SetWriteDeadline(time.Time{})
 	}
 
 	if s.NewWriteScheduler != nil {
@@ -284,6 +366,9 @@ func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
 		sc.writeSched = NewRandomWriteScheduler()
 	}
 
+	// These start at the RFC-specified defaults. If there is a higher
+	// configured value for inflow, that will be updated when we send a
+	// WINDOW_UPDATE shortly after sending SETTINGS.
 	sc.flow.add(initialWindowSize)
 	sc.inflow.add(initialWindowSize)
 	sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf)
@@ -366,10 +451,9 @@ type serverConn struct {
 	doneServing      chan struct{}          // closed when serverConn.serve ends
 	readFrameCh      chan readFrameResult   // written by serverConn.readFrames
 	wantWriteFrameCh chan FrameWriteRequest // from handlers -> serve
-	wantStartPushCh  chan startPushRequest  // from handlers -> serve
 	wroteFrameCh     chan frameWriteResult  // from writeFrameAsync -> serve, tickles more frame writes
 	bodyReadCh       chan bodyReadMsg       // from handlers -> serve
-	testHookCh       chan func(int)         // code to run on the serve loop
+	serveMsgCh       chan interface{}       // misc messages & code to send to / run on the serve loop
 	flow             flow                   // conn-wide (not stream-specific) outbound flow control
 	inflow           flow                   // conn-wide inbound flow control
 	tlsState         *tls.ConnectionState   // shared by all handlers, like net/http
@@ -377,38 +461,39 @@ type serverConn struct {
 	writeSched       WriteScheduler
 
 	// Everything following is owned by the serve loop; use serveG.check():
-	serveG                goroutineLock // used to verify funcs are on serve()
-	pushEnabled           bool
-	sawFirstSettings      bool // got the initial SETTINGS frame after the preface
-	needToSendSettingsAck bool
-	unackedSettings       int    // how many SETTINGS have we sent without ACKs?
-	clientMaxStreams      uint32 // SETTINGS_MAX_CONCURRENT_STREAMS from client (our PUSH_PROMISE limit)
-	advMaxStreams         uint32 // our SETTINGS_MAX_CONCURRENT_STREAMS advertised the client
-	curClientStreams      uint32 // number of open streams initiated by the client
-	curPushedStreams      uint32 // number of open streams initiated by server push
-	maxClientStreamID     uint32 // max ever seen from client (odd), or 0 if there have been no client requests
-	maxPushPromiseID      uint32 // ID of the last push promise (even), or 0 if there have been no pushes
-	streams               map[uint32]*stream
-	initialWindowSize     int32
-	maxFrameSize          int32
-	headerTableSize       uint32
-	peerMaxHeaderListSize uint32            // zero means unknown (default)
-	canonHeader           map[string]string // http2-lower-case -> Go-Canonical-Case
-	writingFrame          bool              // started writing a frame (on serve goroutine or separate)
-	writingFrameAsync     bool              // started a frame on its own goroutine but haven't heard back on wroteFrameCh
-	needsFrameFlush       bool              // last frame write wasn't a flush
-	inGoAway              bool              // we've started to or sent GOAWAY
-	inFrameScheduleLoop   bool              // whether we're in the scheduleFrameWrite loop
-	needToSendGoAway      bool              // we need to schedule a GOAWAY frame write
-	goAwayCode            ErrCode
-	shutdownTimerCh       <-chan time.Time // nil until used
-	shutdownTimer         *time.Timer      // nil until used
-	idleTimer             *time.Timer      // nil if unused
-	idleTimerCh           <-chan time.Time // nil if unused
+	serveG                      goroutineLock // used to verify funcs are on serve()
+	pushEnabled                 bool
+	sawFirstSettings            bool // got the initial SETTINGS frame after the preface
+	needToSendSettingsAck       bool
+	unackedSettings             int    // how many SETTINGS have we sent without ACKs?
+	clientMaxStreams            uint32 // SETTINGS_MAX_CONCURRENT_STREAMS from client (our PUSH_PROMISE limit)
+	advMaxStreams               uint32 // our SETTINGS_MAX_CONCURRENT_STREAMS advertised the client
+	curClientStreams            uint32 // number of open streams initiated by the client
+	curPushedStreams            uint32 // number of open streams initiated by server push
+	maxClientStreamID           uint32 // max ever seen from client (odd), or 0 if there have been no client requests
+	maxPushPromiseID            uint32 // ID of the last push promise (even), or 0 if there have been no pushes
+	streams                     map[uint32]*stream
+	initialStreamSendWindowSize int32
+	maxFrameSize                int32
+	headerTableSize             uint32
+	peerMaxHeaderListSize       uint32            // zero means unknown (default)
+	canonHeader                 map[string]string // http2-lower-case -> Go-Canonical-Case
+	writingFrame                bool              // started writing a frame (on serve goroutine or separate)
+	writingFrameAsync           bool              // started a frame on its own goroutine but haven't heard back on wroteFrameCh
+	needsFrameFlush             bool              // last frame write wasn't a flush
+	inGoAway                    bool              // we've started to or sent GOAWAY
+	inFrameScheduleLoop         bool              // whether we're in the scheduleFrameWrite loop
+	needToSendGoAway            bool              // we need to schedule a GOAWAY frame write
+	goAwayCode                  ErrCode
+	shutdownTimer               *time.Timer // nil until used
+	idleTimer                   *time.Timer // nil if unused
 
 	// Owned by the writeFrameAsync goroutine:
 	headerWriteBuf bytes.Buffer
 	hpackEncoder   *hpack.Encoder
+
+	// Used by startGracefulShutdown.
+	shutdownOnce sync.Once
 }
 
 func (sc *serverConn) maxHeaderListSize() uint32 {
@@ -453,10 +538,10 @@ type stream struct {
 	numTrailerValues int64
 	weight           uint8
 	state            streamState
-	resetQueued      bool   // RST_STREAM queued for write; set by sc.resetStream
-	gotTrailerHeader bool   // HEADER frame for trailers was seen
-	wroteHeaders     bool   // whether we wrote headers (not status 100)
-	reqBuf           []byte // if non-nil, body pipe buffer to return later at EOF
+	resetQueued      bool        // RST_STREAM queued for write; set by sc.resetStream
+	gotTrailerHeader bool        // HEADER frame for trailers was seen
+	wroteHeaders     bool        // whether we wrote headers (not status 100)
+	writeDeadline    *time.Timer // nil if unused
 
 	trailer    http.Header // accumulated trailers
 	reqTrailer http.Header // handler's Request.Trailer
@@ -686,48 +771,48 @@ func (sc *serverConn) serve() {
 			{SettingMaxFrameSize, sc.srv.maxReadFrameSize()},
 			{SettingMaxConcurrentStreams, sc.advMaxStreams},
 			{SettingMaxHeaderListSize, sc.maxHeaderListSize()},
-
-			// TODO: more actual settings, notably
-			// SettingInitialWindowSize, but then we also
-			// want to bump up the conn window size the
-			// same amount here right after the settings
+			{SettingInitialWindowSize, uint32(sc.srv.initialStreamRecvWindowSize())},
 		},
 	})
 	sc.unackedSettings++
 
+	// Each connection starts with intialWindowSize inflow tokens.
+	// If a higher value is configured, we add more tokens.
+	if diff := sc.srv.initialConnRecvWindowSize() - initialWindowSize; diff > 0 {
+		sc.sendWindowUpdate(nil, int(diff))
+	}
+
 	if err := sc.readPreface(); err != nil {
 		sc.condlogf(err, "http2: server: error reading preface from client %v: %v", sc.conn.RemoteAddr(), err)
 		return
 	}
 	// Now that we've got the preface, get us out of the
-	// "StateNew" state.  We can't go directly to idle, though.
+	// "StateNew" state. We can't go directly to idle, though.
 	// Active means we read some data and anticipate a request. We'll
 	// do another Active when we get a HEADERS frame.
 	sc.setConnState(http.StateActive)
 	sc.setConnState(http.StateIdle)
 
 	if sc.srv.IdleTimeout != 0 {
-		sc.idleTimer = time.NewTimer(sc.srv.IdleTimeout)
+		sc.idleTimer = time.AfterFunc(sc.srv.IdleTimeout, sc.onIdleTimer)
 		defer sc.idleTimer.Stop()
-		sc.idleTimerCh = sc.idleTimer.C
-	}
-
-	var gracefulShutdownCh <-chan struct{}
-	if sc.hs != nil {
-		gracefulShutdownCh = h1ServerShutdownChan(sc.hs)
 	}
 
 	go sc.readFrames() // closed by defer sc.conn.Close above
 
-	settingsTimer := time.NewTimer(firstSettingsTimeout)
+	settingsTimer := time.AfterFunc(firstSettingsTimeout, sc.onSettingsTimer)
+	defer settingsTimer.Stop()
+
 	loopNum := 0
 	for {
 		loopNum++
 		select {
 		case wr := <-sc.wantWriteFrameCh:
+			if se, ok := wr.write.(StreamError); ok {
+				sc.resetStream(se)
+				break
+			}
 			sc.writeFrame(wr)
-		case spr := <-sc.wantStartPushCh:
-			sc.startPush(spr)
 		case res := <-sc.wroteFrameCh:
 			sc.wroteFrame(res)
 		case res := <-sc.readFrameCh:
@@ -735,26 +820,37 @@ func (sc *serverConn) serve() {
 				return
 			}
 			res.readMore()
-			if settingsTimer.C != nil {
+			if settingsTimer != nil {
 				settingsTimer.Stop()
-				settingsTimer.C = nil
+				settingsTimer = nil
 			}
 		case m := <-sc.bodyReadCh:
 			sc.noteBodyRead(m.st, m.n)
-		case <-settingsTimer.C:
-			sc.logf("timeout waiting for SETTINGS frames from %v", sc.conn.RemoteAddr())
-			return
-		case <-gracefulShutdownCh:
-			gracefulShutdownCh = nil
-			sc.startGracefulShutdown()
-		case <-sc.shutdownTimerCh:
-			sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr())
-			return
-		case <-sc.idleTimerCh:
-			sc.vlogf("connection is idle")
-			sc.goAway(ErrCodeNo)
-		case fn := <-sc.testHookCh:
-			fn(loopNum)
+		case msg := <-sc.serveMsgCh:
+			switch v := msg.(type) {
+			case func(int):
+				v(loopNum) // for testing
+			case *serverMessage:
+				switch v {
+				case settingsTimerMsg:
+					sc.logf("timeout waiting for SETTINGS frames from %v", sc.conn.RemoteAddr())
+					return
+				case idleTimerMsg:
+					sc.vlogf("connection is idle")
+					sc.goAway(ErrCodeNo)
+				case shutdownTimerMsg:
+					sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr())
+					return
+				case gracefulShutdownMsg:
+					sc.startGracefulShutdownInternal()
+				default:
+					panic("unknown timer")
+				}
+			case *startPushRequest:
+				sc.startPush(v)
+			default:
+				panic(fmt.Sprintf("unexpected type %T", v))
+			}
 		}
 
 		if sc.inGoAway && sc.curOpenStreams() == 0 && !sc.needToSendGoAway && !sc.writingFrame {
@@ -763,6 +859,36 @@ func (sc *serverConn) serve() {
 	}
 }
 
+func (sc *serverConn) awaitGracefulShutdown(sharedCh <-chan struct{}, privateCh chan struct{}) {
+	select {
+	case <-sc.doneServing:
+	case <-sharedCh:
+		close(privateCh)
+	}
+}
+
+type serverMessage int
+
+// Message values sent to serveMsgCh.
+var (
+	settingsTimerMsg    = new(serverMessage)
+	idleTimerMsg        = new(serverMessage)
+	shutdownTimerMsg    = new(serverMessage)
+	gracefulShutdownMsg = new(serverMessage)
+)
+
+func (sc *serverConn) onSettingsTimer() { sc.sendServeMsg(settingsTimerMsg) }
+func (sc *serverConn) onIdleTimer()     { sc.sendServeMsg(idleTimerMsg) }
+func (sc *serverConn) onShutdownTimer() { sc.sendServeMsg(shutdownTimerMsg) }
+
+func (sc *serverConn) sendServeMsg(msg interface{}) {
+	sc.serveG.checkNotOn() // NOT
+	select {
+	case sc.serveMsgCh <- msg:
+	case <-sc.doneServing:
+	}
+}
+
 // readPreface reads the ClientPreface greeting from the peer
 // or returns an error on timeout or an invalid greeting.
 func (sc *serverConn) readPreface() error {
@@ -1004,7 +1130,11 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 			// stateClosed after the RST_STREAM frame is
 			// written.
 			st.state = stateHalfClosedLocal
-			sc.resetStream(streamError(st.id, ErrCodeCancel))
+			// Section 8.1: a server MAY request that the client abort
+			// transmission of a request without error by sending a
+			// RST_STREAM with an error code of NO_ERROR after sending
+			// a complete response.
+			sc.resetStream(streamError(st.id, ErrCodeNo))
 		case stateHalfClosedRemote:
 			sc.closeStream(st, errHandlerComplete)
 		}
@@ -1076,10 +1206,19 @@ func (sc *serverConn) scheduleFrameWrite() {
 	sc.inFrameScheduleLoop = false
 }
 
-// startGracefulShutdown sends a GOAWAY with ErrCodeNo to tell the
-// client we're gracefully shutting down. The connection isn't closed
-// until all current streams are done.
+// startGracefulShutdown gracefully shuts down a connection. This
+// sends GOAWAY with ErrCodeNo to tell the client we're gracefully
+// shutting down. The connection isn't closed until all current
+// streams are done.
+//
+// startGracefulShutdown returns immediately; it does not wait until
+// the connection has shut down.
 func (sc *serverConn) startGracefulShutdown() {
+	sc.serveG.checkNotOn() // NOT
+	sc.shutdownOnce.Do(func() { sc.sendServeMsg(gracefulShutdownMsg) })
+}
+
+func (sc *serverConn) startGracefulShutdownInternal() {
 	sc.goAwayIn(ErrCodeNo, 0)
 }
 
@@ -1111,8 +1250,7 @@ func (sc *serverConn) goAwayIn(code ErrCode, forceCloseIn time.Duration) {
 
 func (sc *serverConn) shutDownIn(d time.Duration) {
 	sc.serveG.check()
-	sc.shutdownTimer = time.NewTimer(d)
-	sc.shutdownTimerCh = sc.shutdownTimer.C
+	sc.shutdownTimer = time.AfterFunc(d, sc.onShutdownTimer)
 }
 
 func (sc *serverConn) resetStream(se StreamError) {
@@ -1295,6 +1433,9 @@ func (sc *serverConn) closeStream(st *stream, err error) {
 		panic(fmt.Sprintf("invariant; can't close stream in state %v", st.state))
 	}
 	st.state = stateClosed
+	if st.writeDeadline != nil {
+		st.writeDeadline.Stop()
+	}
 	if st.isPushed() {
 		sc.curPushedStreams--
 	} else {
@@ -1307,7 +1448,7 @@ func (sc *serverConn) closeStream(st *stream, err error) {
 			sc.idleTimer.Reset(sc.srv.IdleTimeout)
 		}
 		if h1ServerKeepAlivesDisabled(sc.hs) {
-			sc.startGracefulShutdown()
+			sc.startGracefulShutdownInternal()
 		}
 	}
 	if p := st.body; p != nil {
@@ -1385,9 +1526,9 @@ func (sc *serverConn) processSettingInitialWindowSize(val uint32) error {
 	// adjust the size of all stream flow control windows that it
 	// maintains by the difference between the new value and the
 	// old value."
-	old := sc.initialWindowSize
-	sc.initialWindowSize = int32(val)
-	growth := sc.initialWindowSize - old // may be negative
+	old := sc.initialStreamSendWindowSize
+	sc.initialStreamSendWindowSize = int32(val)
+	growth := int32(val) - old // may be negative
 	for _, st := range sc.streams {
 		if !st.flow.add(growth) {
 			// 6.9.2 Initial Flow Control Window Size
@@ -1494,7 +1635,7 @@ func (sc *serverConn) processGoAway(f *GoAwayFrame) error {
 	} else {
 		sc.vlogf("http2: received GOAWAY %+v, starting graceful shutdown", f)
 	}
-	sc.startGracefulShutdown()
+	sc.startGracefulShutdownInternal()
 	// http://tools.ietf.org/html/rfc7540#section-6.8
 	// We should not create any new streams, which means we should disable push.
 	sc.pushEnabled = false
@@ -1533,6 +1674,12 @@ func (st *stream) copyTrailersToHandlerRequest() {
 	}
 }
 
+// onWriteTimeout is run on its own goroutine (from time.AfterFunc)
+// when the stream's WriteTimeout has fired.
+func (st *stream) onWriteTimeout() {
+	st.sc.writeFrameFromHandler(FrameWriteRequest{write: streamError(st.id, ErrCodeInternal)})
+}
+
 func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	sc.serveG.check()
 	id := f.StreamID
@@ -1709,9 +1856,12 @@ func (sc *serverConn) newStream(id, pusherID uint32, state streamState) *stream
 	}
 	st.cw.Init()
 	st.flow.conn = &sc.flow // link to conn-level counter
-	st.flow.add(sc.initialWindowSize)
-	st.inflow.conn = &sc.inflow      // link to conn-level counter
-	st.inflow.add(initialWindowSize) // TODO: update this when we send a higher initial window size in the initial settings
+	st.flow.add(sc.initialStreamSendWindowSize)
+	st.inflow.conn = &sc.inflow // link to conn-level counter
+	st.inflow.add(sc.srv.initialStreamRecvWindowSize())
+	if sc.hs.WriteTimeout != 0 {
+		st.writeDeadline = time.AfterFunc(sc.hs.WriteTimeout, st.onWriteTimeout)
+	}
 
 	sc.streams[id] = st
 	sc.writeSched.OpenStream(st.id, OpenStreamOptions{PusherID: pusherID})
@@ -1775,16 +1925,14 @@ func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*res
 		return nil, nil, err
 	}
 	if bodyOpen {
-		st.reqBuf = getRequestBodyBuf()
-		req.Body.(*requestBody).pipe = &pipe{
-			b: &fixedBuffer{buf: st.reqBuf},
-		}
-
 		if vv, ok := rp.header["Content-Length"]; ok {
 			req.ContentLength, _ = strconv.ParseInt(vv[0], 10, 64)
 		} else {
 			req.ContentLength = -1
 		}
+		req.Body.(*requestBody).pipe = &pipe{
+			b: &dataBuffer{expected: req.ContentLength},
+		}
 	}
 	return rw, req, nil
 }
@@ -1880,24 +2028,6 @@ func (sc *serverConn) newWriterAndRequestNoBody(st *stream, rp requestParam) (*r
 	return rw, req, nil
 }
 
-var reqBodyCache = make(chan []byte, 8)
-
-func getRequestBodyBuf() []byte {
-	select {
-	case b := <-reqBodyCache:
-		return b
-	default:
-		return make([]byte, initialWindowSize)
-	}
-}
-
-func putRequestBodyBuf(b []byte) {
-	select {
-	case reqBodyCache <- b:
-	default:
-	}
-}
-
 // Run on its own goroutine.
 func (sc *serverConn) runHandler(rw *responseWriter, req *http.Request, handler func(http.ResponseWriter, *http.Request)) {
 	didPanic := true
@@ -1993,12 +2123,6 @@ func (sc *serverConn) noteBodyReadFromHandler(st *stream, n int, err error) {
 		case <-sc.doneServing:
 		}
 	}
-	if err == io.EOF {
-		if buf := st.reqBuf; buf != nil {
-			st.reqBuf = nil // shouldn't matter; field unused by other
-			putRequestBodyBuf(buf)
-		}
-	}
 }
 
 func (sc *serverConn) noteBodyRead(st *stream, n int) {
@@ -2093,8 +2217,8 @@ func (b *requestBody) Read(p []byte) (n int, err error) {
 	return
 }
 
-// responseWriter is the http.ResponseWriter implementation.  It's
-// intentionally small (1 pointer wide) to minimize garbage.  The
+// responseWriter is the http.ResponseWriter implementation. It's
+// intentionally small (1 pointer wide) to minimize garbage. The
 // responseWriterState pointer inside is zeroed at the end of a
 // request (in handlerDone) and calls on the responseWriter thereafter
 // simply crash (caller's mistake), but the much larger responseWriterState
@@ -2268,7 +2392,7 @@ const TrailerPrefix = "Trailer:"
 // says you SHOULD (but not must) predeclare any trailers in the
 // header, the official ResponseWriter rules said trailers in Go must
 // be predeclared, and then we reuse the same ResponseWriter.Header()
-// map to mean both Headers and Trailers.  When it's time to write the
+// map to mean both Headers and Trailers. When it's time to write the
 // Trailers, we pick out the fields of Headers that were declared as
 // trailers. That worked for a while, until we found the first major
 // user of Trailers in the wild: gRPC (using them only over http2),
@@ -2504,7 +2628,7 @@ func (w *responseWriter) push(target string, opts pushOptions) error {
 		return fmt.Errorf("method %q must be GET or HEAD", opts.Method)
 	}
 
-	msg := startPushRequest{
+	msg := &startPushRequest{
 		parent: st,
 		method: opts.Method,
 		url:    u,
@@ -2517,7 +2641,7 @@ func (w *responseWriter) push(target string, opts pushOptions) error {
 		return errClientDisconnected
 	case <-st.cw:
 		return errStreamClosed
-	case sc.wantStartPushCh <- msg:
+	case sc.serveMsgCh <- msg:
 	}
 
 	select {
@@ -2539,7 +2663,7 @@ type startPushRequest struct {
 	done   chan error
 }
 
-func (sc *serverConn) startPush(msg startPushRequest) {
+func (sc *serverConn) startPush(msg *startPushRequest) {
 	sc.serveG.check()
 
 	// http://tools.ietf.org/html/rfc7540#section-6.6.
@@ -2578,7 +2702,7 @@ func (sc *serverConn) startPush(msg startPushRequest) {
 		// A server that is unable to establish a new stream identifier can send a GOAWAY
 		// frame so that the client is forced to open a new connection for new streams.
 		if sc.maxPushPromiseID+2 >= 1<<31 {
-			sc.startGracefulShutdown()
+			sc.startGracefulShutdownInternal()
 			return 0, ErrPushLimitReached
 		}
 		sc.maxPushPromiseID += 2
@@ -2703,31 +2827,6 @@ var badTrailer = map[string]bool{
 	"Www-Authenticate":    true,
 }
 
-// h1ServerShutdownChan returns a channel that will be closed when the
-// provided *http.Server wants to shut down.
-//
-// This is a somewhat hacky way to get at http1 innards. It works
-// when the http2 code is bundled into the net/http package in the
-// standard library. The alternatives ended up making the cmd/go tool
-// depend on http Servers. This is the lightest option for now.
-// This is tested via the TestServeShutdown* tests in net/http.
-func h1ServerShutdownChan(hs *http.Server) <-chan struct{} {
-	if fn := testh1ServerShutdownChan; fn != nil {
-		return fn(hs)
-	}
-	var x interface{} = hs
-	type I interface {
-		getDoneChan() <-chan struct{}
-	}
-	if hs, ok := x.(I); ok {
-		return hs.getDoneChan()
-	}
-	return nil
-}
-
-// optional test hook for h1ServerShutdownChan.
-var testh1ServerShutdownChan func(hs *http.Server) <-chan struct{}
-
 // h1ServerKeepAlivesDisabled reports whether hs has its keep-alives
 // disabled. See comments on h1ServerShutdownChan above for why
 // the code is written this way.