c1.Close()

	if _, err := c1.Read(nil); err != io.ErrClosedPipe {
		t.Errorf("c1.Read() = %v, want io.ErrClosedPipe", err)
	}
	if _, err := c1.Write(nil); err != io.ErrClosedPipe {
		t.Errorf("c1.Write() = %v, want io.ErrClosedPipe", err)
	}
	if err := c1.SetDeadline(time.Time{}); err != io.ErrClosedPipe {
		t.Errorf("c1.SetDeadline() = %v, want io.ErrClosedPipe", err)
	}
	if _, err := c2.Read(nil); err != io.EOF {

			n += nw
		case <-p.localDone:
			return n, io.ErrClosedPipe
		case <-p.remoteDone:
			return n, io.ErrClosedPipe
		case <-p.writeDeadline.wait():
			return n, os.ErrDeadlineExceeded
		}
	}
	return n, nil
}

func (p *pipe) SetDeadline(t time.Time) error {
	if isClosedChan(p.localDone) || isClosedChan(p.remoteDone) {
		return io.ErrClosedPipe
	}
	p.readDeadline.set(t)
	p.writeDeadline.set(t)

	defer a.Unlock()
	if a.err != nil {
		return
	}
	a.err = err
}
func (a *onceError) Load() error {
	a.Lock()
	defer a.Unlock()
	return a.err
}

// ErrClosedPipe is the error used for read or write operations on a closed pipe.
var ErrClosedPipe = errors.New("io: read/write on closed pipe")

// A pipe is the shared pipe structure underlying PipeReader and PipeWriter.
type pipe struct {

	c := make(chan int, 1)
	r, _ := Pipe()
	go delayClose(t, r, c, pipeTest{})
	n, err := r.Read(make([]byte, 64))
	<-c
	if n != 0 || err != ErrClosedPipe {
		t.Errorf("read from closed pipe: %v, %v want %v, %v", n, err, 0, ErrClosedPipe)
	}
}

// Test write after/before reader close.

func TestPipeWriteClose(t *testing.T) {
	for _, tt := range pipeTests {
		c := make(chan int, 1)

		// gzipWriter, which feeds it to bodyReader.
		if _, err := io.Copy(gzipWriter, dataReader); err != nil && err != io.ErrClosedPipe {
			sendErr(err)
		}
		if err := gzipWriter.Close(); err != nil && err != io.ErrClosedPipe {
			sendErr(err)
		}
		if err := httpWriter.Close(); err != nil && err != io.ErrClosedPipe {
			sendErr(err)
		}
	}()

	// Send an HTTP request to the test server.

}

var errorWriterTests = []errorWriterTest{
	{0, 1, nil, io.ErrShortWrite},
	{1, 2, nil, io.ErrShortWrite},
	{1, 1, nil, nil},
	{0, 1, io.ErrClosedPipe, io.ErrClosedPipe},
	{1, 2, io.ErrClosedPipe, io.ErrClosedPipe},
	{1, 1, io.ErrClosedPipe, io.ErrClosedPipe},
}

func TestWriteErrors(t *testing.T) {
	for _, w := range errorWriterTests {
		buf := NewWriter(w)
		_, e := buf.Write([]byte("hello world"))

		}
	})
}

// errorWriter is a writer that fails after N writes.
type errorWriter struct {
	N int
}

func (e *errorWriter) Write(b []byte) (int, error) {
	if e.N <= 0 {
		return 0, io.ErrClosedPipe
	}
	e.N--
	return len(b), nil
}

// Test if errors from the underlying writer is passed upwards.
func TestWriteError(t *testing.T) {
	t.Parallel()
	buf := new(bytes.Buffer)
	n := 65536

		t.Errorf("r.Read at EOF = %d, %v want 0, EOF", n, err)
	}
	rb = bytes.NewBuffer(src)
	pr, pw := Pipe()
	pr.Close()
	r = TeeReader(rb, pw)
	if n, err := ReadFull(r, dst); n != 0 || err != ErrClosedPipe {
		t.Errorf("closed tee: ReadFull(r, dst) = %d, %v; want 0, EPIPE", n, err)
	}
}

func TestSectionReader_ReadAt(t *testing.T) {
	dat := "a long sample data, 1234567890"
	tests := []struct {

		{"ByteScanner", Type, 0},
		{"ByteWriter", Type, 1},
		{"Closer", Type, 0},
		{"Copy", Func, 0},
		{"CopyBuffer", Func, 5},
		{"CopyN", Func, 0},
		{"Discard", Var, 16},
		{"EOF", Var, 0},
		{"ErrClosedPipe", Var, 0},
		{"ErrNoProgress", Var, 1},
		{"ErrShortBuffer", Var, 0},
		{"ErrShortWrite", Var, 0},
		{"ErrUnexpectedEOF", Var, 0},
		{"LimitReader", Func, 0},
		{"LimitedReader", Type, 0},

pkg io, type WriterAt interface, WriteAt([]uint8, int64) (int, error)
pkg io, type WriterTo interface { WriteTo }
pkg io, type WriterTo interface, WriteTo(Writer) (int64, error)
pkg io, var EOF error
pkg io, var ErrClosedPipe error
pkg io, var ErrShortBuffer error
pkg io, var ErrShortWrite error
pkg io, var ErrUnexpectedEOF error
pkg io/ioutil, func NopCloser(io.Reader) io.ReadCloser