Imported Upstream version 1.4upstream/1.4

6 files changed, 1481 insertions, 0 deletions

diff --git a/src/net/http/httputil/dump.go b/src/net/http/httputil/dump.go
new file mode 100644
index 000000000..ac8f103f9
--- /dev/null
+++ b/src/net/http/httputil/dump.go
@@ -0,0 +1,284 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package httputil
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// One of the copies, say from b to r2, could be avoided by using a more
+// elaborate trick where the other copy is made during Request/Response.Write.
+// This would complicate things too much, given that these functions are for
+// debugging only.
+func drainBody(b io.ReadCloser) (r1, r2 io.ReadCloser, err error) {
+	var buf bytes.Buffer
+	if _, err = buf.ReadFrom(b); err != nil {
+		return nil, nil, err
+	}
+	if err = b.Close(); err != nil {
+		return nil, nil, err
+	}
+	return ioutil.NopCloser(&buf), ioutil.NopCloser(bytes.NewReader(buf.Bytes())), nil
+}
+
+// dumpConn is a net.Conn which writes to Writer and reads from Reader
+type dumpConn struct {
+	io.Writer
+	io.Reader
+}
+
+func (c *dumpConn) Close() error                       { return nil }
+func (c *dumpConn) LocalAddr() net.Addr                { return nil }
+func (c *dumpConn) RemoteAddr() net.Addr               { return nil }
+func (c *dumpConn) SetDeadline(t time.Time) error      { return nil }
+func (c *dumpConn) SetReadDeadline(t time.Time) error  { return nil }
+func (c *dumpConn) SetWriteDeadline(t time.Time) error { return nil }
+
+type neverEnding byte
+
+func (b neverEnding) Read(p []byte) (n int, err error) {
+	for i := range p {
+		p[i] = byte(b)
+	}
+	return len(p), nil
+}
+
+// DumpRequestOut is like DumpRequest but includes
+// headers that the standard http.Transport adds,
+// such as User-Agent.
+func DumpRequestOut(req *http.Request, body bool) ([]byte, error) {
+	save := req.Body
+	dummyBody := false
+	if !body || req.Body == nil {
+		req.Body = nil
+		if req.ContentLength != 0 {
+			req.Body = ioutil.NopCloser(io.LimitReader(neverEnding('x'), req.ContentLength))
+			dummyBody = true
+		}
+	} else {
+		var err error
+		save, req.Body, err = drainBody(req.Body)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// Since we're using the actual Transport code to write the request,
+	// switch to http so the Transport doesn't try to do an SSL
+	// negotiation with our dumpConn and its bytes.Buffer & pipe.
+	// The wire format for https and http are the same, anyway.
+	reqSend := req
+	if req.URL.Scheme == "https" {
+		reqSend = new(http.Request)
+		*reqSend = *req
+		reqSend.URL = new(url.URL)
+		*reqSend.URL = *req.URL
+		reqSend.URL.Scheme = "http"
+	}
+
+	// Use the actual Transport code to record what we would send
+	// on the wire, but not using TCP.  Use a Transport with a
+	// custom dialer that returns a fake net.Conn that waits
+	// for the full input (and recording it), and then responds
+	// with a dummy response.
+	var buf bytes.Buffer // records the output
+	pr, pw := io.Pipe()
+	defer pr.Close()
+	defer pw.Close()
+	dr := &delegateReader{c: make(chan io.Reader)}
+	// Wait for the request before replying with a dummy response:
+	go func() {
+		req, err := http.ReadRequest(bufio.NewReader(pr))
+		if err == nil {
+			// Ensure all the body is read; otherwise
+			// we'll get a partial dump.
+			io.Copy(ioutil.Discard, req.Body)
+			req.Body.Close()
+		}
+		dr.c <- strings.NewReader("HTTP/1.1 204 No Content\r\n\r\n")
+	}()
+
+	t := &http.Transport{
+		DisableKeepAlives: true,
+		Dial: func(net, addr string) (net.Conn, error) {
+			return &dumpConn{io.MultiWriter(&buf, pw), dr}, nil
+		},
+	}
+
+	_, err := t.RoundTrip(reqSend)
+
+	req.Body = save
+	if err != nil {
+		return nil, err
+	}
+	dump := buf.Bytes()
+
+	// If we used a dummy body above, remove it now.
+	// TODO: if the req.ContentLength is large, we allocate memory
+	// unnecessarily just to slice it off here.  But this is just
+	// a debug function, so this is acceptable for now. We could
+	// discard the body earlier if this matters.
+	if dummyBody {
+		if i := bytes.Index(dump, []byte("\r\n\r\n")); i >= 0 {
+			dump = dump[:i+4]
+		}
+	}
+	return dump, nil
+}
+
+// delegateReader is a reader that delegates to another reader,
+// once it arrives on a channel.
+type delegateReader struct {
+	c chan io.Reader
+	r io.Reader // nil until received from c
+}
+
+func (r *delegateReader) Read(p []byte) (int, error) {
+	if r.r == nil {
+		r.r = <-r.c
+	}
+	return r.r.Read(p)
+}
+
+// Return value if nonempty, def otherwise.
+func valueOrDefault(value, def string) string {
+	if value != "" {
+		return value
+	}
+	return def
+}
+
+var reqWriteExcludeHeaderDump = map[string]bool{
+	"Host":              true, // not in Header map anyway
+	"Content-Length":    true,
+	"Transfer-Encoding": true,
+	"Trailer":           true,
+}
+
+// dumpAsReceived writes req to w in the form as it was received, or
+// at least as accurately as possible from the information retained in
+// the request.
+func dumpAsReceived(req *http.Request, w io.Writer) error {
+	return nil
+}
+
+// DumpRequest returns the as-received wire representation of req,
+// optionally including the request body, for debugging.
+// DumpRequest is semantically a no-op, but in order to
+// dump the body, it reads the body data into memory and
+// changes req.Body to refer to the in-memory copy.
+// The documentation for http.Request.Write details which fields
+// of req are used.
+func DumpRequest(req *http.Request, body bool) (dump []byte, err error) {
+	save := req.Body
+	if !body || req.Body == nil {
+		req.Body = nil
+	} else {
+		save, req.Body, err = drainBody(req.Body)
+		if err != nil {
+			return
+		}
+	}
+
+	var b bytes.Buffer
+
+	fmt.Fprintf(&b, "%s %s HTTP/%d.%d\r\n", valueOrDefault(req.Method, "GET"),
+		req.URL.RequestURI(), req.ProtoMajor, req.ProtoMinor)
+
+	host := req.Host
+	if host == "" && req.URL != nil {
+		host = req.URL.Host
+	}
+	if host != "" {
+		fmt.Fprintf(&b, "Host: %s\r\n", host)
+	}
+
+	chunked := len(req.TransferEncoding) > 0 && req.TransferEncoding[0] == "chunked"
+	if len(req.TransferEncoding) > 0 {
+		fmt.Fprintf(&b, "Transfer-Encoding: %s\r\n", strings.Join(req.TransferEncoding, ","))
+	}
+	if req.Close {
+		fmt.Fprintf(&b, "Connection: close\r\n")
+	}
+
+	err = req.Header.WriteSubset(&b, reqWriteExcludeHeaderDump)
+	if err != nil {
+		return
+	}
+
+	io.WriteString(&b, "\r\n")
+
+	if req.Body != nil {
+		var dest io.Writer = &b
+		if chunked {
+			dest = NewChunkedWriter(dest)
+		}
+		_, err = io.Copy(dest, req.Body)
+		if chunked {
+			dest.(io.Closer).Close()
+			io.WriteString(&b, "\r\n")
+		}
+	}
+
+	req.Body = save
+	if err != nil {
+		return
+	}
+	dump = b.Bytes()
+	return
+}
+
+// errNoBody is a sentinel error value used by failureToReadBody so we can detect
+// that the lack of body was intentional.
+var errNoBody = errors.New("sentinel error value")
+
+// failureToReadBody is a io.ReadCloser that just returns errNoBody on
+// Read.  It's swapped in when we don't actually want to consume the
+// body, but need a non-nil one, and want to distinguish the error
+// from reading the dummy body.
+type failureToReadBody struct{}
+
+func (failureToReadBody) Read([]byte) (int, error) { return 0, errNoBody }
+func (failureToReadBody) Close() error             { return nil }
+
+var emptyBody = ioutil.NopCloser(strings.NewReader(""))
+
+// DumpResponse is like DumpRequest but dumps a response.
+func DumpResponse(resp *http.Response, body bool) (dump []byte, err error) {
+	var b bytes.Buffer
+	save := resp.Body
+	savecl := resp.ContentLength
+
+	if !body {
+		resp.Body = failureToReadBody{}
+	} else if resp.Body == nil {
+		resp.Body = emptyBody
+	} else {
+		save, resp.Body, err = drainBody(resp.Body)
+		if err != nil {
+			return
+		}
+	}
+	err = resp.Write(&b)
+	if err == errNoBody {
+		err = nil
+	}
+	resp.Body = save
+	resp.ContentLength = savecl
+	if err != nil {
+		return nil, err
+	}
+	return b.Bytes(), nil
+}
diff --git a/src/net/http/httputil/dump_test.go b/src/net/http/httputil/dump_test.go
new file mode 100644
index 000000000..024ee5a86
--- /dev/null
+++ b/src/net/http/httputil/dump_test.go
@@ -0,0 +1,291 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package httputil
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+type dumpTest struct {
+	Req  http.Request
+	Body interface{} // optional []byte or func() io.ReadCloser to populate Req.Body
+
+	WantDump    string
+	WantDumpOut string
+	NoBody      bool // if true, set DumpRequest{,Out} body to false
+}
+
+var dumpTests = []dumpTest{
+
+	// HTTP/1.1 => chunked coding; body; empty trailer
+	{
+		Req: http.Request{
+			Method: "GET",
+			URL: &url.URL{
+				Scheme: "http",
+				Host:   "www.google.com",
+				Path:   "/search",
+			},
+			ProtoMajor:       1,
+			ProtoMinor:       1,
+			TransferEncoding: []string{"chunked"},
+		},
+
+		Body: []byte("abcdef"),
+
+		WantDump: "GET /search HTTP/1.1\r\n" +
+			"Host: www.google.com\r\n" +
+			"Transfer-Encoding: chunked\r\n\r\n" +
+			chunk("abcdef") + chunk(""),
+	},
+
+	// Verify that DumpRequest preserves the HTTP version number, doesn't add a Host,
+	// and doesn't add a User-Agent.
+	{
+		Req: http.Request{
+			Method:     "GET",
+			URL:        mustParseURL("/foo"),
+			ProtoMajor: 1,
+			ProtoMinor: 0,
+			Header: http.Header{
+				"X-Foo": []string{"X-Bar"},
+			},
+		},
+
+		WantDump: "GET /foo HTTP/1.0\r\n" +
+			"X-Foo: X-Bar\r\n\r\n",
+	},
+
+	{
+		Req: *mustNewRequest("GET", "http://example.com/foo", nil),
+
+		WantDumpOut: "GET /foo HTTP/1.1\r\n" +
+			"Host: example.com\r\n" +
+			"User-Agent: Go 1.1 package http\r\n" +
+			"Accept-Encoding: gzip\r\n\r\n",
+	},
+
+	// Test that an https URL doesn't try to do an SSL negotiation
+	// with a bytes.Buffer and hang with all goroutines not
+	// runnable.
+	{
+		Req: *mustNewRequest("GET", "https://example.com/foo", nil),
+
+		WantDumpOut: "GET /foo HTTP/1.1\r\n" +
+			"Host: example.com\r\n" +
+			"User-Agent: Go 1.1 package http\r\n" +
+			"Accept-Encoding: gzip\r\n\r\n",
+	},
+
+	// Request with Body, but Dump requested without it.
+	{
+		Req: http.Request{
+			Method: "POST",
+			URL: &url.URL{
+				Scheme: "http",
+				Host:   "post.tld",
+				Path:   "/",
+			},
+			ContentLength: 6,
+			ProtoMajor:    1,
+			ProtoMinor:    1,
+		},
+
+		Body: []byte("abcdef"),
+
+		WantDumpOut: "POST / HTTP/1.1\r\n" +
+			"Host: post.tld\r\n" +
+			"User-Agent: Go 1.1 package http\r\n" +
+			"Content-Length: 6\r\n" +
+			"Accept-Encoding: gzip\r\n\r\n",
+
+		NoBody: true,
+	},
+
+	// Request with Body > 8196 (default buffer size)
+	{
+		Req: http.Request{
+			Method: "POST",
+			URL: &url.URL{
+				Scheme: "http",
+				Host:   "post.tld",
+				Path:   "/",
+			},
+			ContentLength: 8193,
+			ProtoMajor:    1,
+			ProtoMinor:    1,
+		},
+
+		Body: bytes.Repeat([]byte("a"), 8193),
+
+		WantDumpOut: "POST / HTTP/1.1\r\n" +
+			"Host: post.tld\r\n" +
+			"User-Agent: Go 1.1 package http\r\n" +
+			"Content-Length: 8193\r\n" +
+			"Accept-Encoding: gzip\r\n\r\n" +
+			strings.Repeat("a", 8193),
+	},
+}
+
+func TestDumpRequest(t *testing.T) {
+	numg0 := runtime.NumGoroutine()
+	for i, tt := range dumpTests {
+		setBody := func() {
+			if tt.Body == nil {
+				return
+			}
+			switch b := tt.Body.(type) {
+			case []byte:
+				tt.Req.Body = ioutil.NopCloser(bytes.NewReader(b))
+			case func() io.ReadCloser:
+				tt.Req.Body = b()
+			default:
+				t.Fatalf("Test %d: unsupported Body of %T", i, tt.Body)
+			}
+		}
+		setBody()
+		if tt.Req.Header == nil {
+			tt.Req.Header = make(http.Header)
+		}
+
+		if tt.WantDump != "" {
+			setBody()
+			dump, err := DumpRequest(&tt.Req, !tt.NoBody)
+			if err != nil {
+				t.Errorf("DumpRequest #%d: %s", i, err)
+				continue
+			}
+			if string(dump) != tt.WantDump {
+				t.Errorf("DumpRequest %d, expecting:\n%s\nGot:\n%s\n", i, tt.WantDump, string(dump))
+				continue
+			}
+		}
+
+		if tt.WantDumpOut != "" {
+			setBody()
+			dump, err := DumpRequestOut(&tt.Req, !tt.NoBody)
+			if err != nil {
+				t.Errorf("DumpRequestOut #%d: %s", i, err)
+				continue
+			}
+			if string(dump) != tt.WantDumpOut {
+				t.Errorf("DumpRequestOut %d, expecting:\n%s\nGot:\n%s\n", i, tt.WantDumpOut, string(dump))
+				continue
+			}
+		}
+	}
+	if dg := runtime.NumGoroutine() - numg0; dg > 4 {
+		buf := make([]byte, 4096)
+		buf = buf[:runtime.Stack(buf, true)]
+		t.Errorf("Unexpectedly large number of new goroutines: %d new: %s", dg, buf)
+	}
+}
+
+func chunk(s string) string {
+	return fmt.Sprintf("%x\r\n%s\r\n", len(s), s)
+}
+
+func mustParseURL(s string) *url.URL {
+	u, err := url.Parse(s)
+	if err != nil {
+		panic(fmt.Sprintf("Error parsing URL %q: %v", s, err))
+	}
+	return u
+}
+
+func mustNewRequest(method, url string, body io.Reader) *http.Request {
+	req, err := http.NewRequest(method, url, body)
+	if err != nil {
+		panic(fmt.Sprintf("NewRequest(%q, %q, %p) err = %v", method, url, body, err))
+	}
+	return req
+}
+
+var dumpResTests = []struct {
+	res  *http.Response
+	body bool
+	want string
+}{
+	{
+		res: &http.Response{
+			Status:        "200 OK",
+			StatusCode:    200,
+			Proto:         "HTTP/1.1",
+			ProtoMajor:    1,
+			ProtoMinor:    1,
+			ContentLength: 50,
+			Header: http.Header{
+				"Foo": []string{"Bar"},
+			},
+			Body: ioutil.NopCloser(strings.NewReader("foo")), // shouldn't be used
+		},
+		body: false, // to verify we see 50, not empty or 3.
+		want: `HTTP/1.1 200 OK
+Content-Length: 50
+Foo: Bar`,
+	},
+
+	{
+		res: &http.Response{
+			Status:        "200 OK",
+			StatusCode:    200,
+			Proto:         "HTTP/1.1",
+			ProtoMajor:    1,
+			ProtoMinor:    1,
+			ContentLength: 3,
+			Body:          ioutil.NopCloser(strings.NewReader("foo")),
+		},
+		body: true,
+		want: `HTTP/1.1 200 OK
+Content-Length: 3
+
+foo`,
+	},
+
+	{
+		res: &http.Response{
+			Status:           "200 OK",
+			StatusCode:       200,
+			Proto:            "HTTP/1.1",
+			ProtoMajor:       1,
+			ProtoMinor:       1,
+			ContentLength:    -1,
+			Body:             ioutil.NopCloser(strings.NewReader("foo")),
+			TransferEncoding: []string{"chunked"},
+		},
+		body: true,
+		want: `HTTP/1.1 200 OK
+Transfer-Encoding: chunked
+
+3
+foo
+0`,
+	},
+}
+
+func TestDumpResponse(t *testing.T) {
+	for i, tt := range dumpResTests {
+		gotb, err := DumpResponse(tt.res, tt.body)
+		if err != nil {
+			t.Errorf("%d. DumpResponse = %v", i, err)
+			continue
+		}
+		got := string(gotb)
+		got = strings.TrimSpace(got)
+		got = strings.Replace(got, "\r", "", -1)
+
+		if got != tt.want {
+			t.Errorf("%d.\nDumpResponse got:\n%s\n\nWant:\n%s\n", i, got, tt.want)
+		}
+	}
+}
diff --git a/src/net/http/httputil/httputil.go b/src/net/http/httputil/httputil.go
new file mode 100644
index 000000000..2e523e9e2
--- /dev/null
+++ b/src/net/http/httputil/httputil.go
@@ -0,0 +1,39 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package httputil provides HTTP utility functions, complementing the
+// more common ones in the net/http package.
+package httputil
+
+import (
+	"io"
+	"net/http/internal"
+)
+
+// NewChunkedReader returns a new chunkedReader that translates the data read from r
+// out of HTTP "chunked" format before returning it.
+// The chunkedReader returns io.EOF when the final 0-length chunk is read.
+//
+// NewChunkedReader is not needed by normal applications. The http package
+// automatically decodes chunking when reading response bodies.
+func NewChunkedReader(r io.Reader) io.Reader {
+	return internal.NewChunkedReader(r)
+}
+
+// NewChunkedWriter returns a new chunkedWriter that translates writes into HTTP
+// "chunked" format before writing them to w. Closing the returned chunkedWriter
+// sends the final 0-length chunk that marks the end of the stream.
+//
+// NewChunkedWriter is not needed by normal applications. The http
+// package adds chunking automatically if handlers don't set a
+// Content-Length header. Using NewChunkedWriter inside a handler
+// would result in double chunking or chunking with a Content-Length
+// length, both of which are wrong.
+func NewChunkedWriter(w io.Writer) io.WriteCloser {
+	return internal.NewChunkedWriter(w)
+}
+
+// ErrLineTooLong is returned when reading malformed chunked data
+// with lines that are too long.
+var ErrLineTooLong = internal.ErrLineTooLong
diff --git a/src/net/http/httputil/persist.go b/src/net/http/httputil/persist.go
new file mode 100644
index 000000000..987bcc96b
--- /dev/null
+++ b/src/net/http/httputil/persist.go
@@ -0,0 +1,429 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package httputil
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"net"
+	"net/http"
+	"net/textproto"
+	"sync"
+)
+
+var (
+	ErrPersistEOF = &http.ProtocolError{ErrorString: "persistent connection closed"}
+	ErrClosed     = &http.ProtocolError{ErrorString: "connection closed by user"}
+	ErrPipeline   = &http.ProtocolError{ErrorString: "pipeline error"}
+)
+
+// This is an API usage error - the local side is closed.
+// ErrPersistEOF (above) reports that the remote side is closed.
+var errClosed = errors.New("i/o operation on closed connection")
+
+// A ServerConn reads requests and sends responses over an underlying
+// connection, until the HTTP keepalive logic commands an end. ServerConn
+// also allows hijacking the underlying connection by calling Hijack
+// to regain control over the connection. ServerConn supports pipe-lining,
+// i.e. requests can be read out of sync (but in the same order) while the
+// respective responses are sent.
+//
+// ServerConn is low-level and old. Applications should instead use Server
+// in the net/http package.
+type ServerConn struct {
+	lk              sync.Mutex // read-write protects the following fields
+	c               net.Conn
+	r               *bufio.Reader
+	re, we          error // read/write errors
+	lastbody        io.ReadCloser
+	nread, nwritten int
+	pipereq         map[*http.Request]uint
+
+	pipe textproto.Pipeline
+}
+
+// NewServerConn returns a new ServerConn reading and writing c. If r is not
+// nil, it is the buffer to use when reading c.
+//
+// ServerConn is low-level and old. Applications should instead use Server
+// in the net/http package.
+func NewServerConn(c net.Conn, r *bufio.Reader) *ServerConn {
+	if r == nil {
+		r = bufio.NewReader(c)
+	}
+	return &ServerConn{c: c, r: r, pipereq: make(map[*http.Request]uint)}
+}
+
+// Hijack detaches the ServerConn and returns the underlying connection as well
+// as the read-side bufio which may have some left over data. Hijack may be
+// called before Read has signaled the end of the keep-alive logic. The user
+// should not call Hijack while Read or Write is in progress.
+func (sc *ServerConn) Hijack() (c net.Conn, r *bufio.Reader) {
+	sc.lk.Lock()
+	defer sc.lk.Unlock()
+	c = sc.c
+	r = sc.r
+	sc.c = nil
+	sc.r = nil
+	return
+}
+
+// Close calls Hijack and then also closes the underlying connection
+func (sc *ServerConn) Close() error {
+	c, _ := sc.Hijack()
+	if c != nil {
+		return c.Close()
+	}
+	return nil
+}
+
+// Read returns the next request on the wire. An ErrPersistEOF is returned if
+// it is gracefully determined that there are no more requests (e.g. after the
+// first request on an HTTP/1.0 connection, or after a Connection:close on a
+// HTTP/1.1 connection).
+func (sc *ServerConn) Read() (req *http.Request, err error) {
+
+	// Ensure ordered execution of Reads and Writes
+	id := sc.pipe.Next()
+	sc.pipe.StartRequest(id)
+	defer func() {
+		sc.pipe.EndRequest(id)
+		if req == nil {
+			sc.pipe.StartResponse(id)
+			sc.pipe.EndResponse(id)
+		} else {
+			// Remember the pipeline id of this request
+			sc.lk.Lock()
+			sc.pipereq[req] = id
+			sc.lk.Unlock()
+		}
+	}()
+
+	sc.lk.Lock()
+	if sc.we != nil { // no point receiving if write-side broken or closed
+		defer sc.lk.Unlock()
+		return nil, sc.we
+	}
+	if sc.re != nil {
+		defer sc.lk.Unlock()
+		return nil, sc.re
+	}
+	if sc.r == nil { // connection closed by user in the meantime
+		defer sc.lk.Unlock()
+		return nil, errClosed
+	}
+	r := sc.r
+	lastbody := sc.lastbody
+	sc.lastbody = nil
+	sc.lk.Unlock()
+
+	// Make sure body is fully consumed, even if user does not call body.Close
+	if lastbody != nil {
+		// body.Close is assumed to be idempotent and multiple calls to
+		// it should return the error that its first invocation
+		// returned.
+		err = lastbody.Close()
+		if err != nil {
+			sc.lk.Lock()
+			defer sc.lk.Unlock()
+			sc.re = err
+			return nil, err
+		}
+	}
+
+	req, err = http.ReadRequest(r)
+	sc.lk.Lock()
+	defer sc.lk.Unlock()
+	if err != nil {
+		if err == io.ErrUnexpectedEOF {
+			// A close from the opposing client is treated as a
+			// graceful close, even if there was some unparse-able
+			// data before the close.
+			sc.re = ErrPersistEOF
+			return nil, sc.re
+		} else {
+			sc.re = err
+			return req, err
+		}
+	}
+	sc.lastbody = req.Body
+	sc.nread++
+	if req.Close {
+		sc.re = ErrPersistEOF
+		return req, sc.re
+	}
+	return req, err
+}
+
+// Pending returns the number of unanswered requests
+// that have been received on the connection.
+func (sc *ServerConn) Pending() int {
+	sc.lk.Lock()
+	defer sc.lk.Unlock()
+	return sc.nread - sc.nwritten
+}
+
+// Write writes resp in response to req. To close the connection gracefully, set the
+// Response.Close field to true. Write should be considered operational until
+// it returns an error, regardless of any errors returned on the Read side.
+func (sc *ServerConn) Write(req *http.Request, resp *http.Response) error {
+
+	// Retrieve the pipeline ID of this request/response pair
+	sc.lk.Lock()
+	id, ok := sc.pipereq[req]
+	delete(sc.pipereq, req)
+	if !ok {
+		sc.lk.Unlock()
+		return ErrPipeline
+	}
+	sc.lk.Unlock()
+
+	// Ensure pipeline order
+	sc.pipe.StartResponse(id)
+	defer sc.pipe.EndResponse(id)
+
+	sc.lk.Lock()
+	if sc.we != nil {
+		defer sc.lk.Unlock()
+		return sc.we
+	}
+	if sc.c == nil { // connection closed by user in the meantime
+		defer sc.lk.Unlock()
+		return ErrClosed
+	}
+	c := sc.c
+	if sc.nread <= sc.nwritten {
+		defer sc.lk.Unlock()
+		return errors.New("persist server pipe count")
+	}
+	if resp.Close {
+		// After signaling a keep-alive close, any pipelined unread
+		// requests will be lost. It is up to the user to drain them
+		// before signaling.
+		sc.re = ErrPersistEOF
+	}
+	sc.lk.Unlock()
+
+	err := resp.Write(c)
+	sc.lk.Lock()
+	defer sc.lk.Unlock()
+	if err != nil {
+		sc.we = err
+		return err
+	}
+	sc.nwritten++
+
+	return nil
+}
+
+// A ClientConn sends request and receives headers over an underlying
+// connection, while respecting the HTTP keepalive logic. ClientConn
+// supports hijacking the connection calling Hijack to
+// regain control of the underlying net.Conn and deal with it as desired.
+//
+// ClientConn is low-level and old. Applications should instead use
+// Client or Transport in the net/http package.
+type ClientConn struct {
+	lk              sync.Mutex // read-write protects the following fields
+	c               net.Conn
+	r               *bufio.Reader
+	re, we          error // read/write errors
+	lastbody        io.ReadCloser
+	nread, nwritten int
+	pipereq         map[*http.Request]uint
+
+	pipe     textproto.Pipeline
+	writeReq func(*http.Request, io.Writer) error
+}
+
+// NewClientConn returns a new ClientConn reading and writing c.  If r is not
+// nil, it is the buffer to use when reading c.
+//
+// ClientConn is low-level and old. Applications should use Client or
+// Transport in the net/http package.
+func NewClientConn(c net.Conn, r *bufio.Reader) *ClientConn {
+	if r == nil {
+		r = bufio.NewReader(c)
+	}
+	return &ClientConn{
+		c:        c,
+		r:        r,
+		pipereq:  make(map[*http.Request]uint),
+		writeReq: (*http.Request).Write,
+	}
+}
+
+// NewProxyClientConn works like NewClientConn but writes Requests
+// using Request's WriteProxy method.
+//
+// New code should not use NewProxyClientConn. See Client or
+// Transport in the net/http package instead.
+func NewProxyClientConn(c net.Conn, r *bufio.Reader) *ClientConn {
+	cc := NewClientConn(c, r)
+	cc.writeReq = (*http.Request).WriteProxy
+	return cc
+}
+
+// Hijack detaches the ClientConn and returns the underlying connection as well
+// as the read-side bufio which may have some left over data. Hijack may be
+// called before the user or Read have signaled the end of the keep-alive
+// logic. The user should not call Hijack while Read or Write is in progress.
+func (cc *ClientConn) Hijack() (c net.Conn, r *bufio.Reader) {
+	cc.lk.Lock()
+	defer cc.lk.Unlock()
+	c = cc.c
+	r = cc.r
+	cc.c = nil
+	cc.r = nil
+	return
+}
+
+// Close calls Hijack and then also closes the underlying connection
+func (cc *ClientConn) Close() error {
+	c, _ := cc.Hijack()
+	if c != nil {
+		return c.Close()
+	}
+	return nil
+}
+
+// Write writes a request. An ErrPersistEOF error is returned if the connection
+// has been closed in an HTTP keepalive sense. If req.Close equals true, the
+// keepalive connection is logically closed after this request and the opposing
+// server is informed. An ErrUnexpectedEOF indicates the remote closed the
+// underlying TCP connection, which is usually considered as graceful close.
+func (cc *ClientConn) Write(req *http.Request) (err error) {
+
+	// Ensure ordered execution of Writes
+	id := cc.pipe.Next()
+	cc.pipe.StartRequest(id)
+	defer func() {
+		cc.pipe.EndRequest(id)
+		if err != nil {
+			cc.pipe.StartResponse(id)
+			cc.pipe.EndResponse(id)
+		} else {
+			// Remember the pipeline id of this request
+			cc.lk.Lock()
+			cc.pipereq[req] = id
+			cc.lk.Unlock()
+		}
+	}()
+
+	cc.lk.Lock()
+	if cc.re != nil { // no point sending if read-side closed or broken
+		defer cc.lk.Unlock()
+		return cc.re
+	}
+	if cc.we != nil {
+		defer cc.lk.Unlock()
+		return cc.we
+	}
+	if cc.c == nil { // connection closed by user in the meantime
+		defer cc.lk.Unlock()
+		return errClosed
+	}
+	c := cc.c
+	if req.Close {
+		// We write the EOF to the write-side error, because there
+		// still might be some pipelined reads
+		cc.we = ErrPersistEOF
+	}
+	cc.lk.Unlock()
+
+	err = cc.writeReq(req, c)
+	cc.lk.Lock()
+	defer cc.lk.Unlock()
+	if err != nil {
+		cc.we = err
+		return err
+	}
+	cc.nwritten++
+
+	return nil
+}
+
+// Pending returns the number of unanswered requests
+// that have been sent on the connection.
+func (cc *ClientConn) Pending() int {
+	cc.lk.Lock()
+	defer cc.lk.Unlock()
+	return cc.nwritten - cc.nread
+}
+
+// Read reads the next response from the wire. A valid response might be
+// returned together with an ErrPersistEOF, which means that the remote
+// requested that this be the last request serviced. Read can be called
+// concurrently with Write, but not with another Read.
+func (cc *ClientConn) Read(req *http.Request) (resp *http.Response, err error) {
+	// Retrieve the pipeline ID of this request/response pair
+	cc.lk.Lock()
+	id, ok := cc.pipereq[req]
+	delete(cc.pipereq, req)
+	if !ok {
+		cc.lk.Unlock()
+		return nil, ErrPipeline
+	}
+	cc.lk.Unlock()
+
+	// Ensure pipeline order
+	cc.pipe.StartResponse(id)
+	defer cc.pipe.EndResponse(id)
+
+	cc.lk.Lock()
+	if cc.re != nil {
+		defer cc.lk.Unlock()
+		return nil, cc.re
+	}
+	if cc.r == nil { // connection closed by user in the meantime
+		defer cc.lk.Unlock()
+		return nil, errClosed
+	}
+	r := cc.r
+	lastbody := cc.lastbody
+	cc.lastbody = nil
+	cc.lk.Unlock()
+
+	// Make sure body is fully consumed, even if user does not call body.Close
+	if lastbody != nil {
+		// body.Close is assumed to be idempotent and multiple calls to
+		// it should return the error that its first invocation
+		// returned.
+		err = lastbody.Close()
+		if err != nil {
+			cc.lk.Lock()
+			defer cc.lk.Unlock()
+			cc.re = err
+			return nil, err
+		}
+	}
+
+	resp, err = http.ReadResponse(r, req)
+	cc.lk.Lock()
+	defer cc.lk.Unlock()
+	if err != nil {
+		cc.re = err
+		return resp, err
+	}
+	cc.lastbody = resp.Body
+
+	cc.nread++
+
+	if resp.Close {
+		cc.re = ErrPersistEOF // don't send any more requests
+		return resp, cc.re
+	}
+	return resp, err
+}
+
+// Do is convenience method that writes a request and reads a response.
+func (cc *ClientConn) Do(req *http.Request) (resp *http.Response, err error) {
+	err = cc.Write(req)
+	if err != nil {
+		return
+	}
+	return cc.Read(req)
+}
diff --git a/src/net/http/httputil/reverseproxy.go b/src/net/http/httputil/reverseproxy.go
new file mode 100644
index 000000000..ab4637018
--- /dev/null
+++ b/src/net/http/httputil/reverseproxy.go
@@ -0,0 +1,225 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP reverse proxy handler
+
+package httputil
+
+import (
+	"io"
+	"log"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+// onExitFlushLoop is a callback set by tests to detect the state of the
+// flushLoop() goroutine.
+var onExitFlushLoop func()
+
+// ReverseProxy is an HTTP Handler that takes an incoming request and
+// sends it to another server, proxying the response back to the
+// client.
+type ReverseProxy struct {
+	// Director must be a function which modifies
+	// the request into a new request to be sent
+	// using Transport. Its response is then copied
+	// back to the original client unmodified.
+	Director func(*http.Request)
+
+	// The transport used to perform proxy requests.
+	// If nil, http.DefaultTransport is used.
+	Transport http.RoundTripper
+
+	// FlushInterval specifies the flush interval
+	// to flush to the client while copying the
+	// response body.
+	// If zero, no periodic flushing is done.
+	FlushInterval time.Duration
+
+	// ErrorLog specifies an optional logger for errors
+	// that occur when attempting to proxy the request.
+	// If nil, logging goes to os.Stderr via the log package's
+	// standard logger.
+	ErrorLog *log.Logger
+}
+
+func singleJoiningSlash(a, b string) string {
+	aslash := strings.HasSuffix(a, "/")
+	bslash := strings.HasPrefix(b, "/")
+	switch {
+	case aslash && bslash:
+		return a + b[1:]
+	case !aslash && !bslash:
+		return a + "/" + b
+	}
+	return a + b
+}
+
+// NewSingleHostReverseProxy returns a new ReverseProxy that rewrites
+// URLs to the scheme, host, and base path provided in target. If the
+// target's path is "/base" and the incoming request was for "/dir",
+// the target request will be for /base/dir.
+func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy {
+	targetQuery := target.RawQuery
+	director := func(req *http.Request) {
+		req.URL.Scheme = target.Scheme
+		req.URL.Host = target.Host
+		req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path)
+		if targetQuery == "" || req.URL.RawQuery == "" {
+			req.URL.RawQuery = targetQuery + req.URL.RawQuery
+		} else {
+			req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+		}
+	}
+	return &ReverseProxy{Director: director}
+}
+
+func copyHeader(dst, src http.Header) {
+	for k, vv := range src {
+		for _, v := range vv {
+			dst.Add(k, v)
+		}
+	}
+}
+
+// Hop-by-hop headers. These are removed when sent to the backend.
+// http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
+var hopHeaders = []string{
+	"Connection",
+	"Keep-Alive",
+	"Proxy-Authenticate",
+	"Proxy-Authorization",
+	"Te", // canonicalized version of "TE"
+	"Trailers",
+	"Transfer-Encoding",
+	"Upgrade",
+}
+
+func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	transport := p.Transport
+	if transport == nil {
+		transport = http.DefaultTransport
+	}
+
+	outreq := new(http.Request)
+	*outreq = *req // includes shallow copies of maps, but okay
+
+	p.Director(outreq)
+	outreq.Proto = "HTTP/1.1"
+	outreq.ProtoMajor = 1
+	outreq.ProtoMinor = 1
+	outreq.Close = false
+
+	// Remove hop-by-hop headers to the backend.  Especially
+	// important is "Connection" because we want a persistent
+	// connection, regardless of what the client sent to us.  This
+	// is modifying the same underlying map from req (shallow
+	// copied above) so we only copy it if necessary.
+	copiedHeaders := false
+	for _, h := range hopHeaders {
+		if outreq.Header.Get(h) != "" {
+			if !copiedHeaders {
+				outreq.Header = make(http.Header)
+				copyHeader(outreq.Header, req.Header)
+				copiedHeaders = true
+			}
+			outreq.Header.Del(h)
+		}
+	}
+
+	if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
+		// If we aren't the first proxy retain prior
+		// X-Forwarded-For information as a comma+space
+		// separated list and fold multiple headers into one.
+		if prior, ok := outreq.Header["X-Forwarded-For"]; ok {
+			clientIP = strings.Join(prior, ", ") + ", " + clientIP
+		}
+		outreq.Header.Set("X-Forwarded-For", clientIP)
+	}
+
+	res, err := transport.RoundTrip(outreq)
+	if err != nil {
+		p.logf("http: proxy error: %v", err)
+		rw.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+	defer res.Body.Close()
+
+	for _, h := range hopHeaders {
+		res.Header.Del(h)
+	}
+
+	copyHeader(rw.Header(), res.Header)
+
+	rw.WriteHeader(res.StatusCode)
+	p.copyResponse(rw, res.Body)
+}
+
+func (p *ReverseProxy) copyResponse(dst io.Writer, src io.Reader) {
+	if p.FlushInterval != 0 {
+		if wf, ok := dst.(writeFlusher); ok {
+			mlw := &maxLatencyWriter{
+				dst:     wf,
+				latency: p.FlushInterval,
+				done:    make(chan bool),
+			}
+			go mlw.flushLoop()
+			defer mlw.stop()
+			dst = mlw
+		}
+	}
+
+	io.Copy(dst, src)
+}
+
+func (p *ReverseProxy) logf(format string, args ...interface{}) {
+	if p.ErrorLog != nil {
+		p.ErrorLog.Printf(format, args...)
+	} else {
+		log.Printf(format, args...)
+	}
+}
+
+type writeFlusher interface {
+	io.Writer
+	http.Flusher
+}
+
+type maxLatencyWriter struct {
+	dst     writeFlusher
+	latency time.Duration
+
+	lk   sync.Mutex // protects Write + Flush
+	done chan bool
+}
+
+func (m *maxLatencyWriter) Write(p []byte) (int, error) {
+	m.lk.Lock()
+	defer m.lk.Unlock()
+	return m.dst.Write(p)
+}
+
+func (m *maxLatencyWriter) flushLoop() {
+	t := time.NewTicker(m.latency)
+	defer t.Stop()
+	for {
+		select {
+		case <-m.done:
+			if onExitFlushLoop != nil {
+				onExitFlushLoop()
+			}
+			return
+		case <-t.C:
+			m.lk.Lock()
+			m.dst.Flush()
+			m.lk.Unlock()
+		}
+	}
+}
+
+func (m *maxLatencyWriter) stop() { m.done <- true }
diff --git a/src/net/http/httputil/reverseproxy_test.go b/src/net/http/httputil/reverseproxy_test.go
new file mode 100644
index 000000000..e9539b44b
--- /dev/null
+++ b/src/net/http/httputil/reverseproxy_test.go
@@ -0,0 +1,213 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Reverse proxy tests.
+
+package httputil
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+)
+
+const fakeHopHeader = "X-Fake-Hop-Header-For-Test"
+
+func init() {
+	hopHeaders = append(hopHeaders, fakeHopHeader)
+}
+
+func TestReverseProxy(t *testing.T) {
+	const backendResponse = "I am the backend"
+	const backendStatus = 404
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if len(r.TransferEncoding) > 0 {
+			t.Errorf("backend got unexpected TransferEncoding: %v", r.TransferEncoding)
+		}
+		if r.Header.Get("X-Forwarded-For") == "" {
+			t.Errorf("didn't get X-Forwarded-For header")
+		}
+		if c := r.Header.Get("Connection"); c != "" {
+			t.Errorf("handler got Connection header value %q", c)
+		}
+		if c := r.Header.Get("Upgrade"); c != "" {
+			t.Errorf("handler got Upgrade header value %q", c)
+		}
+		if g, e := r.Host, "some-name"; g != e {
+			t.Errorf("backend got Host header %q, want %q", g, e)
+		}
+		w.Header().Set("X-Foo", "bar")
+		w.Header().Set("Upgrade", "foo")
+		w.Header().Set(fakeHopHeader, "foo")
+		w.Header().Add("X-Multi-Value", "foo")
+		w.Header().Add("X-Multi-Value", "bar")
+		http.SetCookie(w, &http.Cookie{Name: "flavor", Value: "chocolateChip"})
+		w.WriteHeader(backendStatus)
+		w.Write([]byte(backendResponse))
+	}))
+	defer backend.Close()
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+
+	getReq, _ := http.NewRequest("GET", frontend.URL, nil)
+	getReq.Host = "some-name"
+	getReq.Header.Set("Connection", "close")
+	getReq.Header.Set("Upgrade", "foo")
+	getReq.Close = true
+	res, err := http.DefaultClient.Do(getReq)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if g, e := res.StatusCode, backendStatus; g != e {
+		t.Errorf("got res.StatusCode %d; expected %d", g, e)
+	}
+	if g, e := res.Header.Get("X-Foo"), "bar"; g != e {
+		t.Errorf("got X-Foo %q; expected %q", g, e)
+	}
+	if c := res.Header.Get(fakeHopHeader); c != "" {
+		t.Errorf("got %s header value %q", fakeHopHeader, c)
+	}
+	if g, e := len(res.Header["X-Multi-Value"]), 2; g != e {
+		t.Errorf("got %d X-Multi-Value header values; expected %d", g, e)
+	}
+	if g, e := len(res.Header["Set-Cookie"]), 1; g != e {
+		t.Fatalf("got %d SetCookies, want %d", g, e)
+	}
+	if cookie := res.Cookies()[0]; cookie.Name != "flavor" {
+		t.Errorf("unexpected cookie %q", cookie.Name)
+	}
+	bodyBytes, _ := ioutil.ReadAll(res.Body)
+	if g, e := string(bodyBytes), backendResponse; g != e {
+		t.Errorf("got body %q; expected %q", g, e)
+	}
+}
+
+func TestXForwardedFor(t *testing.T) {
+	const prevForwardedFor = "client ip"
+	const backendResponse = "I am the backend"
+	const backendStatus = 404
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("X-Forwarded-For") == "" {
+			t.Errorf("didn't get X-Forwarded-For header")
+		}
+		if !strings.Contains(r.Header.Get("X-Forwarded-For"), prevForwardedFor) {
+			t.Errorf("X-Forwarded-For didn't contain prior data")
+		}
+		w.WriteHeader(backendStatus)
+		w.Write([]byte(backendResponse))
+	}))
+	defer backend.Close()
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+
+	getReq, _ := http.NewRequest("GET", frontend.URL, nil)
+	getReq.Host = "some-name"
+	getReq.Header.Set("Connection", "close")
+	getReq.Header.Set("X-Forwarded-For", prevForwardedFor)
+	getReq.Close = true
+	res, err := http.DefaultClient.Do(getReq)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if g, e := res.StatusCode, backendStatus; g != e {
+		t.Errorf("got res.StatusCode %d; expected %d", g, e)
+	}
+	bodyBytes, _ := ioutil.ReadAll(res.Body)
+	if g, e := string(bodyBytes), backendResponse; g != e {
+		t.Errorf("got body %q; expected %q", g, e)
+	}
+}
+
+var proxyQueryTests = []struct {
+	baseSuffix string // suffix to add to backend URL
+	reqSuffix  string // suffix to add to frontend's request URL
+	want       string // what backend should see for final request URL (without ?)
+}{
+	{"", "", ""},
+	{"?sta=tic", "?us=er", "sta=tic&us=er"},
+	{"", "?us=er", "us=er"},
+	{"?sta=tic", "", "sta=tic"},
+}
+
+func TestReverseProxyQuery(t *testing.T) {
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Got-Query", r.URL.RawQuery)
+		w.Write([]byte("hi"))
+	}))
+	defer backend.Close()
+
+	for i, tt := range proxyQueryTests {
+		backendURL, err := url.Parse(backend.URL + tt.baseSuffix)
+		if err != nil {
+			t.Fatal(err)
+		}
+		frontend := httptest.NewServer(NewSingleHostReverseProxy(backendURL))
+		req, _ := http.NewRequest("GET", frontend.URL+tt.reqSuffix, nil)
+		req.Close = true
+		res, err := http.DefaultClient.Do(req)
+		if err != nil {
+			t.Fatalf("%d. Get: %v", i, err)
+		}
+		if g, e := res.Header.Get("X-Got-Query"), tt.want; g != e {
+			t.Errorf("%d. got query %q; expected %q", i, g, e)
+		}
+		res.Body.Close()
+		frontend.Close()
+	}
+}
+
+func TestReverseProxyFlushInterval(t *testing.T) {
+	const expected = "hi"
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(expected))
+	}))
+	defer backend.Close()
+
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	proxyHandler.FlushInterval = time.Microsecond
+
+	done := make(chan bool)
+	onExitFlushLoop = func() { done <- true }
+	defer func() { onExitFlushLoop = nil }()
+
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+
+	req, _ := http.NewRequest("GET", frontend.URL, nil)
+	req.Close = true
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	defer res.Body.Close()
+	if bodyBytes, _ := ioutil.ReadAll(res.Body); string(bodyBytes) != expected {
+		t.Errorf("got body %q; expected %q", bodyBytes, expected)
+	}
+
+	select {
+	case <-done:
+		// OK
+	case <-time.After(5 * time.Second):
+		t.Error("maxLatencyWriter flushLoop() never exited")
+	}
+}