package net

import (
	"context"
	"io"
	"os"
)

func (c *TCPConn) readFrom(r io.Reader) (int64, error) {
	return genericReadFrom(c, r)
}

func (c *TCPConn) writeTo(w io.Writer) (int64, error) {
	return genericWriteTo(c, w)
}

func (sd *sysDialer) dialTCP(ctx context.Context, laddr, raddr *TCPAddr) (*TCPConn, error) {
	if h := sd.testHookDialTCP; h != nil {
		return h(ctx, sd.network, laddr, raddr)
	}

	return &TCPAddr{loopbackIP(net), a.Port, a.Zone}
}

func (c *TCPConn) readFrom(r io.Reader) (int64, error) {
	if n, err, handled := spliceFrom(c.fd, r); handled {
		return n, err
	}
	if n, err, handled := sendFile(c.fd, r); handled {
		return n, err
	}
	return genericReadFrom(c, r)
}

func (c *TCPConn) writeTo(w io.Writer) (int64, error) {
	if n, err, handled := spliceTo(w, c.fd); handled {

	defer close(ch)

	if len(ls.cl) == 0 {
		ch <- errors.New("no accepted stream")
		return
	}

	c := ls.cl[0]

	tcp, ok := c.(*TCPConn)
	if !ok {
		ch <- errors.New("struct is not a TCPConn")
		return
	}

	mptcp, err := tcp.MultipathTCP()
	if err != nil {
		ch <- err
		return
	}

	if !mptcp {
		ch <- errors.New("incoming connection is not with MPTCP")

// Possibility raised in the discussion of https://golang.org/cl/71973.
func TestEndlessWrite(t *testing.T) {
	t.Parallel()
	c := make(chan bool)
	server := func(cs *TCPConn) error {
		cs.CloseWrite()
		<-c
		return nil
	}
	client := func(ss *TCPConn) error {
		// Tell the server to return when we return.
		defer close(c)

		// Loop writing to the server. The server is not reading

    def setup() {
        parent.add(type("typeOne"))
        parent.add(type("typeTwo"))
        parent.add(subtype("subTypeOne"))
        parent.add(subtype("subTypeTwo"))
        parent.add(otherSubtype("otherSubType"))

			t.Fatal(err)
		}

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

		cc, err := c.(*TCPConn).SyscallConn()
		if err != nil {
			t.Fatal(err)
		}
		data := []byte("HELLO-R-U-THERE")
		if err := writeRawConn(cc, data); err != nil {
			t.Fatal(err)
		}
		var b [32]byte
		n, err := readRawConn(cc, b[:])

			KeepAliveConfig: cfg}
		c, err := d.Dial("tcp", ls.Listener.Addr().String())
		if err != nil {
			t.Fatal(err)
		}
		defer c.Close()

		if errHook != nil {
			t.Fatal(errHook)
		}

		sc, err := c.(*TCPConn).SyscallConn()
		if err != nil {
			t.Fatal(err)
		}
		if err := sc.Control(func(fd uintptr) {
			verifyKeepAliveSettings(t, fdType(fd), oldCfg, cfg)
		}); err != nil {
			t.Fatal(err)
		}
	}
}

		log.Fatal(err)
	}
	wg.Add(2)
	go func() {
		defer wg.Done()
		defer ln.Close()
		c, err := ln.Accept()
		if err != nil {
			log.Fatal(err)
		}
		defer c.Close()
		cf, err := c.(*net.TCPConn).File()
		if err != nil {
			log.Fatal(err)
		}
		defer cf.Close()
		if err := syscall.SetNonblock(int(cf.Fd()), false); err != nil {
			log.Fatal(err)
		}
		// See comments in testPipe.

		t.Fatalf("failed to assert to net.TCPListener")
	}

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()

		tcpConn, terr := tcpListener.AcceptTCP()
		if terr != nil {
			t.Errorf("failed to accept new connection. %v", terr)
			return
		}
		deadlineconn := New(tcpConn)
		deadlineconn.WithReadDeadline(time.Second)
		deadlineconn.WithWriteDeadline(time.Second)
		defer deadlineconn.Close()

		// Read a line

The new type [KeepAliveConfig] permits fine-tuning the keep-alive
options for TCP connections, via a new [TCPConn.SetKeepAliveConfig]