return
	}
	if &wantConn.(*TCPConn).fd.pfd != gotFD {
		t.Error("internal.poll.SendFile called with unexpected FD")
	}
}

func TestSendfile(t *testing.T) {
	ln := newLocalListener(t, "tcp")
	defer ln.Close()

	errc := make(chan error, 1)
	go func(ln Listener) {
		// Wait for a connection.
		conn, err := ln.Accept()
		if err != nil {
			errc <- err
			close(errc)
			return

}

func TestDialTimeout(t *testing.T) {
	switch runtime.GOOS {
	case "plan9":
		t.Skipf("not supported on %s", runtime.GOOS)
	}

	t.Parallel()

	ln := newLocalListener(t, "tcp")
	defer func() {
		if err := ln.Close(); err != nil {
			t.Error(err)
		}
	}()

	for _, tt := range dialTimeoutTests {

	"net"
	"net/http/internal/testcert"
	"strings"
	"testing"
)

// Issue 15446: incorrect wrapping of errors when server closes an idle connection.
func TestTransportPersistConnReadLoopEOF(t *testing.T) {
	ln := newLocalListener(t)
	defer ln.Close()

	connc := make(chan net.Conn, 1)
	go func() {
		defer close(connc)
		c, err := ln.Accept()
		if err != nil {
			t.Error(err)
			return
		}
		connc <- c
	}()

		network := network
		t.Run(network, func(t *testing.T) {
			if !testableNetwork(network) {
				t.Skipf("network %s is not testable on the current platform", network)
			}
			t.Parallel()

			ln := newLocalListener(t, network)
			switch network {
			case "unix", "unixpacket":
				defer os.Remove(ln.Addr().String())
			}
			defer ln.Close()

			c, err := Dial(ln.Addr().Network(), ln.Addr().String())
			if err != nil {

	}

	handler := func(ls *localServer, ln Listener) {
		for {
			c, err := ln.Accept()
			if err != nil {
				return
			}
			c.Close()
		}
	}
	ln := newLocalListener(t, "tcp", &ListenConfig{
		KeepAlive: -1, // prevent calling hook from accepting
	})
	ls := (&streamListener{Listener: ln}).newLocalServer()
	defer ls.teardown()
	if err := ls.buildup(handler); err != nil {

			t.Fatalf("got %q; want %q", b[:n], data)
		}
	})
	t.Run("Deadline", func(t *testing.T) {
		switch runtime.GOOS {
		case "windows":
			t.Skipf("not supported on %s", runtime.GOOS)
		}

		ln := newLocalListener(t, "tcp")
		defer ln.Close()

		c, err := Dial(ln.Addr().Network(), ln.Addr().String())
		if err != nil {
			t.Fatal(err)
		}
		defer c.Close()

		cc, err := c.(*TCPConn).SyscallConn()

			t.Error(err)
		}
	})
	return filepath.Join(d, "sock")
}

func newLocalListener(t testing.TB, network string, lcOpt ...*ListenConfig) Listener {
	var lc *ListenConfig
	switch len(lcOpt) {
	case 0:
		lc = new(ListenConfig)
	case 1:
		lc = lcOpt[0]
	default:
		t.Helper()
		t.Fatal("too many ListenConfigs passed to newLocalListener: want 0 or 1")
	}

	listen := func(net, addr string) Listener {

		if address[0] == '@' && runtime.GOOS != "linux" {
			return false
		}
	}
	return true
}

// NewLocalListener returns a listener which listens to a loopback IP
// address or local file system path.
//
// The provided network must be "tcp", "tcp4", "tcp6", "unix" or
// "unixpacket".
func NewLocalListener(network string) (net.Listener, error) {
	stackOnce.Do(probeStack)
	switch network {
	case "tcp":

	if !*testTCPBig {
		t.Skip("test disabled; use -tcpbig to enable")
	}

	for _, writev := range []bool{false, true} {
		t.Run(fmt.Sprintf("writev=%v", writev), func(t *testing.T) {
			ln := newLocalListener(t, "tcp")
			defer ln.Close()

			x := int(1 << 30)
			x = x*5 + 1<<20 // just over 5 GB on 64-bit, just over 1GB on 32-bit
			done := make(chan int)
			go func() {
				defer close(done)

		c, err := Dial(tt.network, JoinHostPort(tt.address, port))
		if err == nil {
			c.Close()
			t.Errorf("#%d: %v", i, err)
		}
	}
}

func TestDialLocal(t *testing.T) {
	ln := newLocalListener(t, "tcp")
	defer ln.Close()
	_, port, err := SplitHostPort(ln.Addr().String())
	if err != nil {
		t.Fatal(err)
	}
	c, err := Dial("tcp", JoinHostPort("", port))
	if err != nil {
		t.Fatal(err)
	}