处理AI胡乱生成的乱摊子

2025-09-07 20:31:38 +08:00
parent c377a0784d
commit ba513e0827
202 changed files with 11751 additions and 67183 deletions
--- a/vendor/golang.org/x/net/http2/transport.go
+++ b/vendor/golang.org/x/net/http2/transport.go
@@ -19,12 +19,12 @@ import (
 	"io/fs"
 	"log"
 	"math"
+	"math/bits"
 	mathrand "math/rand"
 	"net"
 	"net/http"
 	"net/http/httptrace"
 	"net/textproto"
-	"os"
 	"sort"
 	"strconv"
 	"strings"
@@ -146,6 +146,12 @@ type Transport struct {
 	// waiting for their turn.
 	StrictMaxConcurrentStreams bool

+	// IdleConnTimeout is the maximum amount of time an idle
+	// (keep-alive) connection will remain idle before closing
+	// itself.
+	// Zero means no limit.
+	IdleConnTimeout time.Duration
+
 	// ReadIdleTimeout is the timeout after which a health check using ping
 	// frame will be carried out if no frame is received on the connection.
 	// Note that a ping response will is considered a received frame, so if
@@ -177,43 +183,69 @@ type Transport struct {

 	connPoolOnce  sync.Once
 	connPoolOrDef ClientConnPool // non-nil version of ConnPool
+
+	*transportTestHooks
+}
+
+// Hook points used for testing.
+// Outside of tests, t.transportTestHooks is nil and these all have minimal implementations.
+// Inside tests, see the testSyncHooks function docs.
+
+type transportTestHooks struct {
+	newclientconn func(*ClientConn)
+	group         synctestGroupInterface
+}
+
+func (t *Transport) markNewGoroutine() {
+	if t != nil && t.transportTestHooks != nil {
+		t.transportTestHooks.group.Join()
+	}
+}
+
+// newTimer creates a new time.Timer, or a synthetic timer in tests.
+func (t *Transport) newTimer(d time.Duration) timer {
+	if t.transportTestHooks != nil {
+		return t.transportTestHooks.group.NewTimer(d)
+	}
+	return timeTimer{time.NewTimer(d)}
+}
+
+// afterFunc creates a new time.AfterFunc timer, or a synthetic timer in tests.
+func (t *Transport) afterFunc(d time.Duration, f func()) timer {
+	if t.transportTestHooks != nil {
+		return t.transportTestHooks.group.AfterFunc(d, f)
+	}
+	return timeTimer{time.AfterFunc(d, f)}
+}
+
+func (t *Transport) contextWithTimeout(ctx context.Context, d time.Duration) (context.Context, context.CancelFunc) {
+	if t.transportTestHooks != nil {
+		return t.transportTestHooks.group.ContextWithTimeout(ctx, d)
+	}
+	return context.WithTimeout(ctx, d)
 }

 func (t *Transport) maxHeaderListSize() uint32 {
-	if t.MaxHeaderListSize == 0 {
+	n := int64(t.MaxHeaderListSize)
+	if t.t1 != nil && t.t1.MaxResponseHeaderBytes != 0 {
+		n = t.t1.MaxResponseHeaderBytes
+		if n > 0 {
+			n = adjustHTTP1MaxHeaderSize(n)
+		}
+	}
+	if n <= 0 {
 		return 10 << 20
 	}
-	if t.MaxHeaderListSize == 0xffffffff {
+	if n >= 0xffffffff {
 		return 0
 	}
-	return t.MaxHeaderListSize
-}
-
-func (t *Transport) maxFrameReadSize() uint32 {
-	if t.MaxReadFrameSize == 0 {
-		return 0 // use the default provided by the peer
-	}
-	if t.MaxReadFrameSize < minMaxFrameSize {
-		return minMaxFrameSize
-	}
-	if t.MaxReadFrameSize > maxFrameSize {
-		return maxFrameSize
-	}
-	return t.MaxReadFrameSize
+	return uint32(n)
 }

 func (t *Transport) disableCompression() bool {
 	return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression)
 }

-func (t *Transport) pingTimeout() time.Duration {
-	if t.PingTimeout == 0 {
-		return 15 * time.Second
-	}
-	return t.PingTimeout
-
-}
-
 // ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
 // It returns an error if t1 has already been HTTP/2-enabled.
 //
@@ -290,8 +322,7 @@ func (t *Transport) initConnPool() {
 // HTTP/2 server.
 type ClientConn struct {
 	t             *Transport
-	tconn         net.Conn // usually *tls.Conn, except specialized impls
-	tconnClosed   bool
+	tconn         net.Conn             // usually *tls.Conn, except specialized impls
 	tlsState      *tls.ConnectionState // nil only for specialized impls
 	reused        uint32               // whether conn is being reused; atomic
 	singleUse     bool                 // whether being used for a single http.Request
@@ -302,7 +333,7 @@ type ClientConn struct {
 	readerErr  error         // set before readerDone is closed

 	idleTimeout time.Duration // or 0 for never
-	idleTimer   *time.Timer
+	idleTimer   timer

 	mu              sync.Mutex // guards following
 	cond            *sync.Cond // hold mu; broadcast on flow/closed changes
@@ -324,11 +355,14 @@ type ClientConn struct {
 	lastActive      time.Time
 	lastIdle        time.Time // time last idle
 	// Settings from peer: (also guarded by wmu)
-	maxFrameSize           uint32
-	maxConcurrentStreams   uint32
-	peerMaxHeaderListSize  uint64
-	peerMaxHeaderTableSize uint32
-	initialWindowSize      uint32
+	maxFrameSize                uint32
+	maxConcurrentStreams        uint32
+	peerMaxHeaderListSize       uint64
+	peerMaxHeaderTableSize      uint32
+	initialWindowSize           uint32
+	initialStreamRecvWindowSize int32
+	readIdleTimeout             time.Duration
+	pingTimeout                 time.Duration

 	// reqHeaderMu is a 1-element semaphore channel controlling access to sending new requests.
 	// Write to reqHeaderMu to lock it, read from it to unlock.
@@ -446,12 +480,14 @@ func (cs *clientStream) closeReqBodyLocked() {
 	cs.reqBodyClosed = make(chan struct{})
 	reqBodyClosed := cs.reqBodyClosed
 	go func() {
+		cs.cc.t.markNewGoroutine()
 		cs.reqBody.Close()
 		close(reqBodyClosed)
 	}()
 }

 type stickyErrWriter struct {
+	group   synctestGroupInterface
 	conn    net.Conn
 	timeout time.Duration
 	err     *error
@@ -461,22 +497,9 @@ func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
 	if *sew.err != nil {
 		return 0, *sew.err
 	}
-	for {
-		if sew.timeout != 0 {
-			sew.conn.SetWriteDeadline(time.Now().Add(sew.timeout))
-		}
-		nn, err := sew.conn.Write(p[n:])
-		n += nn
-		if n < len(p) && nn > 0 && errors.Is(err, os.ErrDeadlineExceeded) {
-			// Keep extending the deadline so long as we're making progress.
-			continue
-		}
-		if sew.timeout != 0 {
-			sew.conn.SetWriteDeadline(time.Time{})
-		}
-		*sew.err = err
-		return n, err
-	}
+	n, err = writeWithByteTimeout(sew.group, sew.conn, sew.timeout, p)
+	*sew.err = err
+	return n, err
 }

 // noCachedConnError is the concrete type of ErrNoCachedConn, which
@@ -518,11 +541,14 @@ func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
 func authorityAddr(scheme string, authority string) (addr string) {
 	host, port, err := net.SplitHostPort(authority)
 	if err != nil { // authority didn't have a port
+		host = authority
+		port = ""
+	}
+	if port == "" { // authority's port was empty
 		port = "443"
 		if scheme == "http" {
 			port = "80"
 		}
-		host = authority
 	}
 	if a, err := idna.ToASCII(host); err == nil {
 		host = a
@@ -534,15 +560,6 @@ func authorityAddr(scheme string, authority string) (addr string) {
 	return net.JoinHostPort(host, port)
 }

-var retryBackoffHook func(time.Duration) *time.Timer
-
-func backoffNewTimer(d time.Duration) *time.Timer {
-	if retryBackoffHook != nil {
-		return retryBackoffHook(d)
-	}
-	return time.NewTimer(d)
-}
-
 // RoundTripOpt is like RoundTrip, but takes options.
 func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
 	if !(req.URL.Scheme == "https" || (req.URL.Scheme == "http" && t.AllowHTTP)) {
@@ -570,13 +587,13 @@ func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Res
 				backoff := float64(uint(1) << (uint(retry) - 1))
 				backoff += backoff * (0.1 * mathrand.Float64())
 				d := time.Second * time.Duration(backoff)
-				timer := backoffNewTimer(d)
+				tm := t.newTimer(d)
 				select {
-				case <-timer.C:
+				case <-tm.C():
 					t.vlogf("RoundTrip retrying after failure: %v", roundTripErr)
 					continue
 				case <-req.Context().Done():
-					timer.Stop()
+					tm.Stop()
 					err = req.Context().Err()
 				}
 			}
@@ -655,6 +672,9 @@ func canRetryError(err error) bool {
 }

 func (t *Transport) dialClientConn(ctx context.Context, addr string, singleUse bool) (*ClientConn, error) {
+	if t.transportTestHooks != nil {
+		return t.newClientConn(nil, singleUse)
+	}
 	host, _, err := net.SplitHostPort(addr)
 	if err != nil {
 		return nil, err
@@ -714,43 +734,36 @@ func (t *Transport) expectContinueTimeout() time.Duration {
 	return t.t1.ExpectContinueTimeout
 }

-func (t *Transport) maxDecoderHeaderTableSize() uint32 {
-	if v := t.MaxDecoderHeaderTableSize; v > 0 {
-		return v
-	}
-	return initialHeaderTableSize
-}
-
-func (t *Transport) maxEncoderHeaderTableSize() uint32 {
-	if v := t.MaxEncoderHeaderTableSize; v > 0 {
-		return v
-	}
-	return initialHeaderTableSize
-}
-
 func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
 	return t.newClientConn(c, t.disableKeepAlives())
 }

 func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, error) {
+	conf := configFromTransport(t)
 	cc := &ClientConn{
-		t:                     t,
-		tconn:                 c,
-		readerDone:            make(chan struct{}),
-		nextStreamID:          1,
-		maxFrameSize:          16 << 10,                    // spec default
-		initialWindowSize:     65535,                       // spec default
-		maxConcurrentStreams:  initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings.
-		peerMaxHeaderListSize: 0xffffffffffffffff,          // "infinite", per spec. Use 2^64-1 instead.
-		streams:               make(map[uint32]*clientStream),
-		singleUse:             singleUse,
-		wantSettingsAck:       true,
-		pings:                 make(map[[8]byte]chan struct{}),
-		reqHeaderMu:           make(chan struct{}, 1),
+		t:                           t,
+		tconn:                       c,
+		readerDone:                  make(chan struct{}),
+		nextStreamID:                1,
+		maxFrameSize:                16 << 10, // spec default
+		initialWindowSize:           65535,    // spec default
+		initialStreamRecvWindowSize: conf.MaxUploadBufferPerStream,
+		maxConcurrentStreams:        initialMaxConcurrentStreams, // "infinite", per spec. Use a smaller value until we have received server settings.
+		peerMaxHeaderListSize:       0xffffffffffffffff,          // "infinite", per spec. Use 2^64-1 instead.
+		streams:                     make(map[uint32]*clientStream),
+		singleUse:                   singleUse,
+		wantSettingsAck:             true,
+		readIdleTimeout:             conf.SendPingTimeout,
+		pingTimeout:                 conf.PingTimeout,
+		pings:                       make(map[[8]byte]chan struct{}),
+		reqHeaderMu:                 make(chan struct{}, 1),
 	}
-	if d := t.idleConnTimeout(); d != 0 {
-		cc.idleTimeout = d
-		cc.idleTimer = time.AfterFunc(d, cc.onIdleTimeout)
+	var group synctestGroupInterface
+	if t.transportTestHooks != nil {
+		t.markNewGoroutine()
+		t.transportTestHooks.newclientconn(cc)
+		c = cc.tconn
+		group = t.group
 	}
 	if VerboseLogs {
 		t.vlogf("http2: Transport creating client conn %p to %v", cc, c.RemoteAddr())
@@ -762,30 +775,25 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro
 	// TODO: adjust this writer size to account for frame size +
 	// MTU + crypto/tls record padding.
 	cc.bw = bufio.NewWriter(stickyErrWriter{
+		group:   group,
 		conn:    c,
-		timeout: t.WriteByteTimeout,
+		timeout: conf.WriteByteTimeout,
 		err:     &cc.werr,
 	})
 	cc.br = bufio.NewReader(c)
 	cc.fr = NewFramer(cc.bw, cc.br)
-	if t.maxFrameReadSize() != 0 {
-		cc.fr.SetMaxReadFrameSize(t.maxFrameReadSize())
-	}
+	cc.fr.SetMaxReadFrameSize(conf.MaxReadFrameSize)
 	if t.CountError != nil {
 		cc.fr.countError = t.CountError
 	}
-	maxHeaderTableSize := t.maxDecoderHeaderTableSize()
+	maxHeaderTableSize := conf.MaxDecoderHeaderTableSize
 	cc.fr.ReadMetaHeaders = hpack.NewDecoder(maxHeaderTableSize, nil)
 	cc.fr.MaxHeaderListSize = t.maxHeaderListSize()

 	cc.henc = hpack.NewEncoder(&cc.hbuf)
-	cc.henc.SetMaxDynamicTableSizeLimit(t.maxEncoderHeaderTableSize())
+	cc.henc.SetMaxDynamicTableSizeLimit(conf.MaxEncoderHeaderTableSize)
 	cc.peerMaxHeaderTableSize = initialHeaderTableSize

-	if t.AllowHTTP {
-		cc.nextStreamID = 3
-	}
-
 	if cs, ok := c.(connectionStater); ok {
 		state := cs.ConnectionState()
 		cc.tlsState = &state
@@ -793,11 +801,9 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro

 	initialSettings := []Setting{
 		{ID: SettingEnablePush, Val: 0},
-		{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow},
-	}
-	if max := t.maxFrameReadSize(); max != 0 {
-		initialSettings = append(initialSettings, Setting{ID: SettingMaxFrameSize, Val: max})
+		{ID: SettingInitialWindowSize, Val: uint32(cc.initialStreamRecvWindowSize)},
 	}
+	initialSettings = append(initialSettings, Setting{ID: SettingMaxFrameSize, Val: conf.MaxReadFrameSize})
 	if max := t.maxHeaderListSize(); max != 0 {
 		initialSettings = append(initialSettings, Setting{ID: SettingMaxHeaderListSize, Val: max})
 	}
@@ -807,23 +813,29 @@ func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, erro

 	cc.bw.Write(clientPreface)
 	cc.fr.WriteSettings(initialSettings...)
-	cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow)
-	cc.inflow.init(transportDefaultConnFlow + initialWindowSize)
+	cc.fr.WriteWindowUpdate(0, uint32(conf.MaxUploadBufferPerConnection))
+	cc.inflow.init(conf.MaxUploadBufferPerConnection + initialWindowSize)
 	cc.bw.Flush()
 	if cc.werr != nil {
 		cc.Close()
 		return nil, cc.werr
 	}

+	// Start the idle timer after the connection is fully initialized.
+	if d := t.idleConnTimeout(); d != 0 {
+		cc.idleTimeout = d
+		cc.idleTimer = t.afterFunc(d, cc.onIdleTimeout)
+	}
+
 	go cc.readLoop()
 	return cc, nil
 }

 func (cc *ClientConn) healthCheck() {
-	pingTimeout := cc.t.pingTimeout()
+	pingTimeout := cc.pingTimeout
 	// We don't need to periodically ping in the health check, because the readLoop of ClientConn will
 	// trigger the healthCheck again if there is no frame received.
-	ctx, cancel := context.WithTimeout(context.Background(), pingTimeout)
+	ctx, cancel := cc.t.contextWithTimeout(context.Background(), pingTimeout)
 	defer cancel()
 	cc.vlogf("http2: Transport sending health check")
 	err := cc.Ping(ctx)
@@ -858,7 +870,20 @@ func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
 	}
 	last := f.LastStreamID
 	for streamID, cs := range cc.streams {
-		if streamID > last {
+		if streamID <= last {
+			// The server's GOAWAY indicates that it received this stream.
+			// It will either finish processing it, or close the connection
+			// without doing so. Either way, leave the stream alone for now.
+			continue
+		}
+		if streamID == 1 && cc.goAway.ErrCode != ErrCodeNo {
+			// Don't retry the first stream on a connection if we get a non-NO error.
+			// If the server is sending an error on a new connection,
+			// retrying the request on a new one probably isn't going to work.
+			cs.abortStreamLocked(fmt.Errorf("http2: Transport received GOAWAY from server ErrCode:%v", cc.goAway.ErrCode))
+		} else {
+			// Aborting the stream with errClentConnGotGoAway indicates that
+			// the request should be retried on a new connection.
 			cs.abortStreamLocked(errClientConnGotGoAway)
 		}
 	}
@@ -1015,7 +1040,7 @@ func (cc *ClientConn) forceCloseConn() {
 	if !ok {
 		return
 	}
-	if nc := tlsUnderlyingConn(tc); nc != nil {
+	if nc := tc.NetConn(); nc != nil {
 		nc.Close()
 	}
 }
@@ -1054,6 +1079,7 @@ func (cc *ClientConn) Shutdown(ctx context.Context) error {
 	done := make(chan struct{})
 	cancelled := false // guarded by cc.mu
 	go func() {
+		cc.t.markNewGoroutine()
 		cc.mu.Lock()
 		defer cc.mu.Unlock()
 		for {
@@ -1212,6 +1238,10 @@ func (cc *ClientConn) decrStreamReservationsLocked() {
 }

 func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
+	return cc.roundTrip(req, nil)
+}
+
+func (cc *ClientConn) roundTrip(req *http.Request, streamf func(*clientStream)) (*http.Response, error) {
 	ctx := req.Context()
 	cs := &clientStream{
 		cc:                   cc,
@@ -1226,7 +1256,28 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 		respHeaderRecv:       make(chan struct{}),
 		donec:                make(chan struct{}),
 	}
-	go cs.doRequest(req)
+
+	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
+	if !cc.t.disableCompression() &&
+		req.Header.Get("Accept-Encoding") == "" &&
+		req.Header.Get("Range") == "" &&
+		!cs.isHead {
+		// Request gzip only, not deflate. Deflate is ambiguous and
+		// not as universally supported anyway.
+		// See: https://zlib.net/zlib_faq.html#faq39
+		//
+		// Note that we don't request this for HEAD requests,
+		// due to a bug in nginx:
+		//   http://trac.nginx.org/nginx/ticket/358
+		//   https://golang.org/issue/5522
+		//
+		// We don't request gzip if the request is for a range, since
+		// auto-decoding a portion of a gzipped document will just fail
+		// anyway. See https://golang.org/issue/8923
+		cs.requestedGzip = true
+	}
+
+	go cs.doRequest(req, streamf)

 	waitDone := func() error {
 		select {
@@ -1268,21 +1319,23 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {

 	cancelRequest := func(cs *clientStream, err error) error {
 		cs.cc.mu.Lock()
-		defer cs.cc.mu.Unlock()
-		cs.abortStreamLocked(err)
-		if cs.ID != 0 {
-			// This request may have failed because of a problem with the connection,
-			// or for some unrelated reason. (For example, the user might have canceled
-			// the request without waiting for a response.) Mark the connection as
-			// not reusable, since trying to reuse a dead connection is worse than
-			// unnecessarily creating a new one.
-			//
-			// If cs.ID is 0, then the request was never allocated a stream ID and
-			// whatever went wrong was unrelated to the connection. We might have
-			// timed out waiting for a stream slot when StrictMaxConcurrentStreams
-			// is set, for example, in which case retrying on a different connection
-			// will not help.
-			cs.cc.doNotReuse = true
+		bodyClosed := cs.reqBodyClosed
+		cs.cc.mu.Unlock()
+		// Wait for the request body to be closed.
+		//
+		// If nothing closed the body before now, abortStreamLocked
+		// will have started a goroutine to close it.
+		//
+		// Closing the body before returning avoids a race condition
+		// with net/http checking its readTrackingBody to see if the
+		// body was read from or closed. See golang/go#60041.
+		//
+		// The body is closed in a separate goroutine without the
+		// connection mutex held, but dropping the mutex before waiting
+		// will keep us from holding it indefinitely if the body
+		// close is slow for some reason.
+		if bodyClosed != nil {
+			<-bodyClosed
 		}
 		return err
 	}
@@ -1301,11 +1354,14 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 				return handleResponseHeaders()
 			default:
 				waitDone()
-				return nil, cancelRequest(cs, cs.abortErr)
+				return nil, cs.abortErr
 			}
 		case <-ctx.Done():
-			return nil, cancelRequest(cs, ctx.Err())
+			err := ctx.Err()
+			cs.abortStream(err)
+			return nil, cancelRequest(cs, err)
 		case <-cs.reqCancel:
+			cs.abortStream(errRequestCanceled)
 			return nil, cancelRequest(cs, errRequestCanceled)
 		}
 	}
@@ -1314,8 +1370,9 @@ func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
 // doRequest runs for the duration of the request lifetime.
 //
 // It sends the request and performs post-request cleanup (closing Request.Body, etc.).
-func (cs *clientStream) doRequest(req *http.Request) {
-	err := cs.writeRequest(req)
+func (cs *clientStream) doRequest(req *http.Request, streamf func(*clientStream)) {
+	cs.cc.t.markNewGoroutine()
+	err := cs.writeRequest(req, streamf)
 	cs.cleanupWriteRequest(err)
 }

@@ -1326,7 +1383,7 @@ func (cs *clientStream) doRequest(req *http.Request) {
 //
 // It returns non-nil if the request ends otherwise.
 // If the returned error is StreamError, the error Code may be used in resetting the stream.
-func (cs *clientStream) writeRequest(req *http.Request) (err error) {
+func (cs *clientStream) writeRequest(req *http.Request, streamf func(*clientStream)) (err error) {
 	cc := cs.cc
 	ctx := cs.ctx

@@ -1364,24 +1421,8 @@ func (cs *clientStream) writeRequest(req *http.Request) (err error) {
 	}
 	cc.mu.Unlock()

-	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
-	if !cc.t.disableCompression() &&
-		req.Header.Get("Accept-Encoding") == "" &&
-		req.Header.Get("Range") == "" &&
-		!cs.isHead {
-		// Request gzip only, not deflate. Deflate is ambiguous and
-		// not as universally supported anyway.
-		// See: https://zlib.net/zlib_faq.html#faq39
-		//
-		// Note that we don't request this for HEAD requests,
-		// due to a bug in nginx:
-		//   http://trac.nginx.org/nginx/ticket/358
-		//   https://golang.org/issue/5522
-		//
-		// We don't request gzip if the request is for a range, since
-		// auto-decoding a portion of a gzipped document will just fail
-		// anyway. See https://golang.org/issue/8923
-		cs.requestedGzip = true
+	if streamf != nil {
+		streamf(cs)
 	}

 	continueTimeout := cc.t.expectContinueTimeout()
@@ -1444,9 +1485,9 @@ func (cs *clientStream) writeRequest(req *http.Request) (err error) {
 	var respHeaderTimer <-chan time.Time
 	var respHeaderRecv chan struct{}
 	if d := cc.responseHeaderTimeout(); d != 0 {
-		timer := time.NewTimer(d)
+		timer := cc.t.newTimer(d)
 		defer timer.Stop()
-		respHeaderTimer = timer.C
+		respHeaderTimer = timer.C()
 		respHeaderRecv = cs.respHeaderRecv
 	}
 	// Wait until the peer half-closes its end of the stream,
@@ -1672,7 +1713,27 @@ func (cs *clientStream) frameScratchBufferLen(maxFrameSize int) int {
 	return int(n) // doesn't truncate; max is 512K
 }

-var bufPool sync.Pool // of *[]byte
+// Seven bufPools manage different frame sizes. This helps to avoid scenarios where long-running
+// streaming requests using small frame sizes occupy large buffers initially allocated for prior
+// requests needing big buffers. The size ranges are as follows:
+// {0 KB, 16 KB], {16 KB, 32 KB], {32 KB, 64 KB], {64 KB, 128 KB], {128 KB, 256 KB],
+// {256 KB, 512 KB], {512 KB, infinity}
+// In practice, the maximum scratch buffer size should not exceed 512 KB due to
+// frameScratchBufferLen(maxFrameSize), thus the "infinity pool" should never be used.
+// It exists mainly as a safety measure, for potential future increases in max buffer size.
+var bufPools [7]sync.Pool // of *[]byte
+func bufPoolIndex(size int) int {
+	if size <= 16384 {
+		return 0
+	}
+	size -= 1
+	bits := bits.Len(uint(size))
+	index := bits - 14
+	if index >= len(bufPools) {
+		return len(bufPools) - 1
+	}
+	return index
+}

 func (cs *clientStream) writeRequestBody(req *http.Request) (err error) {
 	cc := cs.cc
@@ -1690,12 +1751,13 @@ func (cs *clientStream) writeRequestBody(req *http.Request) (err error) {
 	// Scratch buffer for reading into & writing from.
 	scratchLen := cs.frameScratchBufferLen(maxFrameSize)
 	var buf []byte
-	if bp, ok := bufPool.Get().(*[]byte); ok && len(*bp) >= scratchLen {
-		defer bufPool.Put(bp)
+	index := bufPoolIndex(scratchLen)
+	if bp, ok := bufPools[index].Get().(*[]byte); ok && len(*bp) >= scratchLen {
+		defer bufPools[index].Put(bp)
 		buf = *bp
 	} else {
 		buf = make([]byte, scratchLen)
-		defer bufPool.Put(&buf)
+		defer bufPools[index].Put(&buf)
 	}

 	var sawEOF bool
@@ -1846,6 +1908,22 @@ func (cs *clientStream) awaitFlowControl(maxBytes int) (taken int32, err error)
 	}
 }

+func validateHeaders(hdrs http.Header) string {
+	for k, vv := range hdrs {
+		if !httpguts.ValidHeaderFieldName(k) {
+			return fmt.Sprintf("name %q", k)
+		}
+		for _, v := range vv {
+			if !httpguts.ValidHeaderFieldValue(v) {
+				// Don't include the value in the error,
+				// because it may be sensitive.
+				return fmt.Sprintf("value for header %q", k)
+			}
+		}
+	}
+	return ""
+}
+
 var errNilRequestURL = errors.New("http2: Request.URI is nil")

 // requires cc.wmu be held.
@@ -1863,6 +1941,9 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 	if err != nil {
 		return nil, err
 	}
+	if !httpguts.ValidHostHeader(host) {
+		return nil, errors.New("http2: invalid Host header")
+	}

 	var path string
 	if req.Method != "CONNECT" {
@@ -1880,26 +1961,21 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 		}
 	}

-	// Check for any invalid headers and return an error before we
+	// Check for any invalid headers+trailers and return an error before we
 	// potentially pollute our hpack state. (We want to be able to
 	// continue to reuse the hpack encoder for future requests)
-	for k, vv := range req.Header {
-		if !httpguts.ValidHeaderFieldName(k) {
-			return nil, fmt.Errorf("invalid HTTP header name %q", k)
-		}
-		for _, v := range vv {
-			if !httpguts.ValidHeaderFieldValue(v) {
-				// Don't include the value in the error, because it may be sensitive.
-				return nil, fmt.Errorf("invalid HTTP header value for header %q", k)
-			}
-		}
+	if err := validateHeaders(req.Header); err != "" {
+		return nil, fmt.Errorf("invalid HTTP header %s", err)
+	}
+	if err := validateHeaders(req.Trailer); err != "" {
+		return nil, fmt.Errorf("invalid HTTP trailer %s", err)
 	}

 	enumerateHeaders := func(f func(name, value string)) {
 		// 8.1.2.3 Request Pseudo-Header Fields
 		// The :path pseudo-header field includes the path and query parts of the
 		// target URI (the path-absolute production and optionally a '?' character
-		// followed by the query production (see Sections 3.3 and 3.4 of
+		// followed by the query production, see Sections 3.3 and 3.4 of
 		// [RFC3986]).
 		f(":authority", host)
 		m := req.Method
@@ -2088,7 +2164,7 @@ type resAndError struct {
 func (cc *ClientConn) addStreamLocked(cs *clientStream) {
 	cs.flow.add(int32(cc.initialWindowSize))
 	cs.flow.setConnFlow(&cc.flow)
-	cs.inflow.init(transportDefaultStreamFlow)
+	cs.inflow.init(cc.initialStreamRecvWindowSize)
 	cs.ID = cc.nextStreamID
 	cc.nextStreamID += 2
 	cc.streams[cs.ID] = cs
@@ -2133,6 +2209,7 @@ type clientConnReadLoop struct {

 // readLoop runs in its own goroutine and reads and dispatches frames.
 func (cc *ClientConn) readLoop() {
+	cc.t.markNewGoroutine()
 	rl := &clientConnReadLoop{cc: cc}
 	defer rl.cleanup()
 	cc.readerErr = rl.run()
@@ -2233,11 +2310,10 @@ func (cc *ClientConn) countReadFrameError(err error) {
 func (rl *clientConnReadLoop) run() error {
 	cc := rl.cc
 	gotSettings := false
-	readIdleTimeout := cc.t.ReadIdleTimeout
-	var t *time.Timer
+	readIdleTimeout := cc.readIdleTimeout
+	var t timer
 	if readIdleTimeout != 0 {
-		t = time.AfterFunc(readIdleTimeout, cc.healthCheck)
-		defer t.Stop()
+		t = cc.t.afterFunc(readIdleTimeout, cc.healthCheck)
 	}
 	for {
 		f, err := cc.fr.ReadFrame()
@@ -2652,7 +2728,7 @@ func (rl *clientConnReadLoop) processData(f *DataFrame) error {
 		})
 		return nil
 	}
-	if !cs.firstByte {
+	if !cs.pastHeaders {
 		cc.logf("protocol error: received DATA before a HEADERS frame")
 		rl.endStreamError(cs, StreamError{
 			StreamID: f.StreamID,
@@ -2879,6 +2955,15 @@ func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error {
 		fl = &cs.flow
 	}
 	if !fl.add(int32(f.Increment)) {
+		// For stream, the sender sends RST_STREAM with an error code of FLOW_CONTROL_ERROR
+		if cs != nil {
+			rl.endStreamError(cs, StreamError{
+				StreamID: f.StreamID,
+				Code:     ErrCodeFlowControl,
+			})
+			return nil
+		}
+
 		return ConnectionError(ErrCodeFlowControl)
 	}
 	cc.cond.Broadcast()
@@ -2923,24 +3008,26 @@ func (cc *ClientConn) Ping(ctx context.Context) error {
 		}
 		cc.mu.Unlock()
 	}
-	errc := make(chan error, 1)
+	var pingError error
+	errc := make(chan struct{})
 	go func() {
+		cc.t.markNewGoroutine()
 		cc.wmu.Lock()
 		defer cc.wmu.Unlock()
-		if err := cc.fr.WritePing(false, p); err != nil {
-			errc <- err
+		if pingError = cc.fr.WritePing(false, p); pingError != nil {
+			close(errc)
 			return
 		}
-		if err := cc.bw.Flush(); err != nil {
-			errc <- err
+		if pingError = cc.bw.Flush(); pingError != nil {
+			close(errc)
 			return
 		}
 	}()
 	select {
 	case <-c:
 		return nil
-	case err := <-errc:
-		return err
+	case <-errc:
+		return pingError
 	case <-ctx.Done():
 		return ctx.Err()
 	case <-cc.readerDone:
@@ -3109,9 +3196,17 @@ func (rt noDialH2RoundTripper) RoundTrip(req *http.Request) (*http.Response, err
 }

 func (t *Transport) idleConnTimeout() time.Duration {
+	// to keep things backwards compatible, we use non-zero values of
+	// IdleConnTimeout, followed by using the IdleConnTimeout on the underlying
+	// http1 transport, followed by 0
+	if t.IdleConnTimeout != 0 {
+		return t.IdleConnTimeout
+	}
+
 	if t.t1 != nil {
 		return t.t1.IdleConnTimeout
 	}
+
 	return 0
 }

@@ -3169,3 +3264,34 @@ func traceFirstResponseByte(trace *httptrace.ClientTrace) {
 		trace.GotFirstResponseByte()
 	}
 }
+
+func traceHasWroteHeaderField(trace *httptrace.ClientTrace) bool {
+	return trace != nil && trace.WroteHeaderField != nil
+}
+
+func traceWroteHeaderField(trace *httptrace.ClientTrace, k, v string) {
+	if trace != nil && trace.WroteHeaderField != nil {
+		trace.WroteHeaderField(k, []string{v})
+	}
+}
+
+func traceGot1xxResponseFunc(trace *httptrace.ClientTrace) func(int, textproto.MIMEHeader) error {
+	if trace != nil {
+		return trace.Got1xxResponse
+	}
+	return nil
+}
+
+// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS
+// connection.
+func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	dialer := &tls.Dialer{
+		Config: cfg,
+	}
+	cn, err := dialer.DialContext(ctx, network, addr)
+	if err != nil {
+		return nil, err
+	}
+	tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
+	return tlsCn, nil
+}