Function TestPacketConnConcurrentReadWriteUnicastUDP

ipv6/readwrite_test.go:221–326

(t *testing.T)

}

func TestPacketConnConcurrentReadWriteUnicastUDP(t *testing.T) {
	switch runtime.GOOS {
	case "fuchsia", "hurd", "js", "nacl", "plan9", "wasip1", "windows":
		t.Skipf("not supported on %s", runtime.GOOS)
	}
	ifi, err := nettest.RoutedInterface("ip6", net.FlagUp|net.FlagLoopback)
	if err != nil {
		t.Skip("ipv6 is not enabled for loopback interface")
	}
	c, err := nettest.NewLocalPacketListener("udp6")
	if err != nil {
		t.Fatal(err)
	}
	defer c.Close()
	p := ipv6.NewPacketConn(c)
	defer p.Close()

	dst := c.LocalAddr()
	cf := ipv6.FlagTrafficClass | ipv6.FlagHopLimit | ipv6.FlagSrc | ipv6.FlagDst | ipv6.FlagInterface | ipv6.FlagPathMTU
	wb := []byte("HELLO-R-U-THERE")

	if err := p.SetControlMessage(cf, true); err != nil { // probe before test
		if protocolNotSupported(err) {
			t.Skipf("not supported on %s", runtime.GOOS)
		}
		t.Fatal(err)
	}

	var firstError sync.Once
	fatalf := func(format string, args ...interface{}) {
		// On the first error, close the PacketConn to unblock the remaining
		// goroutines. Suppress any further errors, which may occur simply due to
		// closing the PacketConn.
		first := false
		firstError.Do(func() {
			first = true
			p.Close()
		})
		if first {
			t.Helper()
			t.Errorf(format, args...)
		}
		runtime.Goexit()
	}

	var wg sync.WaitGroup
	reader := func() {
		defer wg.Done()
		rb := make([]byte, 128)
		if n, cm, _, err := p.ReadFrom(rb); err != nil {
			fatalf("%v", err)
		} else if !bytes.Equal(rb[:n], wb) {
			fatalf("got %v; want %v", rb[:n], wb)
		} else {
			s := cm.String()
			if strings.Contains(s, ",") {
				t.Errorf("should be space-separated values: %s", s)
			}