err = r.PipeReader.CloseWithError(err)
	r.wait()
	return err
}

// WaitPipe implements wait-group backend io.Pipe to provide
// synchronization between read() end with write() end.
func WaitPipe() (*PipeReader, *PipeWriter) {
	r, w := io.Pipe()
	var wg sync.WaitGroup
	wg.Add(1)
	return &PipeReader{
			PipeReader: r,
			wait:       wg.Wait,
		}, &PipeWriter{
			PipeWriter: w,

	// Race condition is because of io.PipeWriter implementation. i.e consider the following
	// sequent of operations:
	// 1) pipe.Write()
	// 2) pipe.Close()
	// Now pipe.Close() can return before the data is read on the other end of the pipe and written to the disk
	// Hence an immediate Read() on the file can return incorrect data.
	if b.canClose != nil {
		b.canClose.Wait()
	}
	return err
}

				}},
			},
			expect: true,
		},
		{
			desc: "listener-pipe",
			inFilter: &ListenerFilter{
				Address: "",
				Port:    0,
				Type:    "",
			},
			inListener: &listener.Listener{
				Address: &core.Address{
					Address: &core.Address_Pipe{
						Pipe: &core.Pipe{Path: "unix:///dev/shm/uds.socket"},
					},
				},
			},
			expect: true,
		},
	}

	askDisks := len(disks)
	readers := make([]*metacacheReader, askDisks)
	defer func() {
		for _, r := range readers {
			r.Close()
		}
	}()
	for i := range disks {
		r, w := io.Pipe()
		// Make sure we close the pipe so blocked writes doesn't stay around.
		defer r.CloseWithError(context.Canceled)

		readers[i] = newMetacacheReader(r)
		d := disks[i]

		// Send request to each disk.
		go func() {

	if err != nil {
		return nil, err
	}
	ok, err := clnt.BucketExists(r.Context(), bucket)
	if err != nil {
		return nil, err
	}
	if !ok {
		return nil, os.ErrNotExist
	}

	pr, pw := io.Pipe()

	wa := &writerAt{
		buffer: make(map[int64][]byte),
		w:      pw,
		r:      pr,
		wg:     &sync.WaitGroup{},
	}
	wa.wg.Add(1)
	go func() {

	return nil
}

func retrieveEndpointAddress(host *admin.HostStatus) string {
	addr := host.Address.GetSocketAddress()
	if addr != nil {
		return addr.Address
	}
	if pipe := host.Address.GetPipe(); pipe != nil {
		return "unix://" + pipe.Path
	}
	if internal := host.Address.GetEnvoyInternalAddress(); internal != nil {
		switch an := internal.GetAddressNameSpecifier().(type) {
		case *core.EnvoyInternalAddress_ServerListenerName:

	// passed on, the hanging adb subprocess will hold them open and
	// go test will hang forever.
	//
	// Avoid that by wrapping stderr, breaking the short circuit and
	// forcing cmd.Run to use another pipe and goroutine to pass
	// along stderr from adb.
	cmd.Stderr = struct{ io.Writer }{os.Stderr}
	err := cmd.Run()

	// Before we process err, flush any further output and get the exit code.
	exitCode, err2 := filter.Finish()

	}
	respBody, err := client.call(ctx, storageRESTMethodReadMultiple, nil, bytes.NewReader(body), int64(len(body)))
	if err != nil {
		return err
	}
	defer xhttp.DrainBody(respBody)

	pr, pw := io.Pipe()
	go func() {
		pw.CloseWithError(waitForHTTPStream(respBody, pw))
	}()
	mr := msgp.NewReader(pr)
	defer readMsgpReaderPoolPut(mr)
	for {
		var file ReadMultipleResp

	stop := make(chan struct{})
	defer close(stop)
	assert.NoError(t, logger.StartUDSLogServer(udsSock, stop))

	// Configure log to tee to UDS server
	stdout := os.Stdout
	r, w, _ := os.Pipe()
	os.Stdout = w
	loggingOptions := log.DefaultOptions()
	loggingOptions.WithTeeToUDS(udsSock, constants.UDSLogPath)
	assert.NoError(t, log.Configure(loggingOptions))
	log.FindScope("default").SetOutputLevel(log.DebugLevel)

}

func retrieveListenerAddress(l *listener.Listener) string {
	sockAddr := l.Address.GetSocketAddress()
	if sockAddr != nil {
		return sockAddr.Address
	}

	pipe := l.Address.GetPipe()
	if pipe != nil {
		return pipe.Path
	}

	return ""
}

func retrieveListenerAdditionalAddresses(l *listener.Listener) []string {
	var addrs []string
	socketAddresses := l.GetAdditionalAddresses()