// goroutines: an event poller and an event waiter.
		time.Sleep(100 * time.Millisecond)

		var b [1]byte
		_, err = f.Read(b[:])
		if perr := parseReadError(err, isBadStateFileError); perr != nil {
			t.Fatal(perr)
		}
	})
}

func parseReadError(nestedErr error, verify func(error) (string, bool)) error {
	err := nestedErr
	if nerr, ok := err.(*net.OpError); ok {
		err = nerr.Err
	}

			t.Error(perr)
		}
		if !isDeadlineExceeded(err) {
			t.Errorf("got %v; want timeout", err)
		}
		if _, err = readRawConn(cc, b[:]); err == nil {
			t.Fatal("Read should fail")
		}
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}
		if !isDeadlineExceeded(err) {
			t.Errorf("got %v; want timeout", err)
		}

		c.SetReadDeadline(noDeadline)

	c.SetReadDeadline(time.Now().Add(someTimeout))
	c.SetWriteDeadline(time.Now().Add(someTimeout))

	b := make([]byte, 256)
	n, err := c.Read(b)
	if err != nil {
		if perr := parseReadError(err); perr != nil {
			ch <- perr
		}
		ch <- err
		return
	}
	if _, err := c.Write(b[:n]); err != nil {
		if perr := parseWriteError(err); perr != nil {
			ch <- perr
		}
		ch <- err

	max := <-maxch
	defer max.Stop()

	select {
	case err := <-ch:
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}
		t.Fatalf("expected Read to not return, but it returned with %v", err)
	case <-max.C:
		c.Close()
		err := <-ch // wait for tester goroutine to stop
		if perr := parseReadError(err); perr != nil {
			t.Error(perr)
		}

		}
		if err = parseDialError(err); err != nil {
			t.Errorf("%s: %v", network, err)
			continue
		}
	}
}

// parseReadError parses nestedErr and reports whether it is a valid
// error value from Read functions.
// It returns nil when nestedErr is valid.
func parseReadError(nestedErr error) error {
	if nestedErr == nil {
		return nil
	}

	switch err := nestedErr.(type) {
	case *OpError: