runtime.KeepAlive(c.file)
	return err
}

func (c *rawConn) Write(f func(uintptr) bool) error {
	if err := c.file.checkValid("SyscallConn.Write"); err != nil {
		return err
	}
	err := c.file.pfd.RawWrite(f)
	runtime.KeepAlive(c.file)
	return err
}

func newRawConn(file *File) (*rawConn, error) {
	return &rawConn{file: file}, nil

	}
	return err
}

func (c *rawConn) Write(f func(uintptr) bool) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	err := c.fd.pfd.RawWrite(f)
	runtime.KeepAlive(c.fd)
	if err != nil {
		err = &OpError{Op: "raw-write", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	return err
}

}

// RawRead invokes the user-defined function f for a read operation.
func (fd *FD) RawRead(f func(uintptr) bool) error {
	return errors.New("not implemented")
}

// RawWrite invokes the user-defined function f for a write operation.
func (fd *FD) RawWrite(f func(uintptr) bool) error {
	return errors.New("not implemented")
}

func DupCloseOnExec(fd int) (int, string, error) {
	nfd, err := syscall.Dup(int(fd), -1)

	}
	for {
		if f(uintptr(fd.Sysfd)) {
			return nil
		}
		if err := fd.pd.waitRead(fd.isFile); err != nil {
			return err
		}
	}
}

// RawWrite invokes the user-defined function f for a write operation.
func (fd *FD) RawWrite(f func(uintptr) bool) error {
	if err := fd.writeLock(); err != nil {
		return err
	}
	defer fd.writeUnlock()
	if err := fd.pd.prepareWrite(fd.isFile); err != nil {

		})
		if err == windows.WSAEMSGSIZE {
			// expected with a 0-byte peek, ignore.
		} else if err != nil {
			return err
		}
	}
}

// RawWrite invokes the user-defined function f for a write operation.
func (fd *FD) RawWrite(f func(uintptr) bool) error {
	if err := fd.writeLock(); err != nil {
		return err
	}
	defer fd.writeUnlock()

	if f(uintptr(fd.Sysfd)) {
		return nil