// Abstract unix domain sockets, a Linux-ism.
		if address[0] == '@' && runtime.GOOS != "linux" {
			return false
		}
	}
	return true
}

// testableListenArgs reports whether arguments are testable on the
// current platform configuration.
func testableListenArgs(network, address, client string) bool {
	if !testableNetwork(network) || !testableAddress(network, address) {
		return false
	}

	var err error
	var addr Addr

// TestTCPServer tests concurrent accept-read-write servers.
func TestTCPServer(t *testing.T) {
	const N = 3

	for i, tt := range tcpServerTests {
		t.Run(tt.snet+" "+tt.saddr+"<-"+tt.taddr, func(t *testing.T) {
			if !testableListenArgs(tt.snet, tt.saddr, tt.taddr) {
				t.Skip("not testable")
			}

			ln, err := Listen(tt.snet, tt.saddr)
			if err != nil {
				if perr := parseDialError(err); perr != nil {
					t.Error(perr)
				}

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

	for _, tt := range tcpListenerTests {
		if !testableListenArgs(tt.network, JoinHostPort(tt.address, "0"), "") {
			t.Logf("skipping %s test", tt.network+" "+tt.address)
			continue
		}

		ln1, err := Listen(tt.network, JoinHostPort(tt.address, "0"))
		if err != nil {