console: new mouse modes, request/response attempt

Thomas Wolff
Tue Apr 3 19:52:00 GMT 2012

Am 02.04.2012 22:40, schrieb Christopher Faylor:
> On Mon, Apr 02, 2012 at 09:50:17PM +0200, Thomas Wolff wrote:
>> Am 02.04.2012 20:50, schrieb Christopher Faylor:
>>> On Mon, Apr 02, 2012 at 08:46:31PM +0200, Thomas Wolff wrote:
>>>> ...
>>>> * semi-fix for missing terminal status responses
>>>> The fix tries to detect the proper fhandler for CONIO, which is then
>>>> used to queue the response.
>>>> Problem 1: I am not sure whether this detection is proper in all cases,
>>>> what e.g. if /dev/tty is reopened etc. I don't know where else a
>>>> relation between the handles for CONIN and CONOUT might be established.
>>>> Problem 2: While the response reaches the application with this patch,
>>>> only the first byte is read right-away. Further bytes are delayed until
>>>> other input is becoming present (typing a key). This may (or may not) be
>>>> related to other issues with select(), so maybe it's worth analyzing it.
>>>> Thomas
>>>> diff -rup sav/fhandler.h ./fhandler.h
>>>> --- sav/fhandler.h	2012-04-01 19:46:04.000000000 +0200
>>>> +++ ./fhandler.h	2012-04-02 15:47:22.385727000 +0200
>>>> @@ -1282,8 +1282,11 @@ class dev_console
>>>>     bool insert_mode;
>>>>     int use_mouse;
>>>> +  bool ext_mouse_mode6;
>>>> +  bool ext_mouse_mode15;
>>>>     bool use_focus;
>>>>     bool raw_win32_keyboard_mode;
>>>> +  fhandler_console * fh_tty;
>>>>     inline UINT get_console_cp ();
>>>>     DWORD con_to_str (char *d, int dlen, WCHAR w);
>>>> diff -rup sav/ ./
>>>> --- sav/	2012-04-02 00:28:55.000000000 +0200
>>>> +++ ./	2012-04-02 18:02:26.004016200 +0200
>>>> @@ -139,6 +139,8 @@ fhandler_console::set_unit ()
>>>>     if (shared_console_info)
>>>>       {
>>>>         fh_devices this_unit = dev ();
>>>> +      if (this_unit == FH_TTY)
>>>> +	dev_state.fh_tty = this;
>>> You *definitely* just can't squirrel away a pointer to a random fhandler
>>> here.
>> ...
> `this' is a pointer to a fhandler.  You can't just store it in a static
> location and use it whenever you want later.  You have no idea how long
> this fhandler will be around.  What happens if it's destroyed?
Yes, that's why I mentioned problem 1 above. The patch is experimental, 
and it revealed that even if the missing relation could be properly 
established, there's still the other problem... (see below).
>>> Do we really care about console mode that much now that mintty is the
>>> default?
>> Maybe not, but the fact that it works partially but subsequent
>> characters are postponed resembles the other problem that I have just reported
>>, which makes me wonder whether there is one common problem.
>> Also when I originally tweaked the mouse code, I couldn't completely
>> understand the code in (only got it to work by pattern
>> matching code...). I did notice, however, that select and read were
>> inconsistent in the sense that an application having called select()
>> with a positive response may not be able to get a byte with a subsequent
>> read(), because criteria were re-evaluated and could have different
>> results (esp. in border cases). I did fix it by strictly applying the
>> same guard routine for both cases, but only for the mouse code branch.
> If you have an example of actual failing code then please post it.
My point is: The function that doesn't work here, 
is also called in fhandler_pty_master::accept_input () (
and in fhandler_termios::line_edit () (,
and I remember pipe and/or pty problems being discussed recently.
Also there is the "input delay issue" in mintty/xterm I described (and 
by the way, I forgot to mention it does not happen anymore in the 
terminal after rlogin to another system) and somehow I suspect they 
might have a common cause, or similar causes.

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