Re: [Denemo-devel] Debug has become difficult

[Jeremiah Benham]

On Sun, May 17, 2009 at 05:25:44PM +0100, Richard Shann wrote:
> On Sun, 2009-05-17 at 09:39 -0500, Jeremiah Benham wrote:
> > On Sun, May 17, 2009 at 12:42:11PM +0100, Richard Shann wrote:
> > > It seems that debugging has just got a whole lot more difficult on my
> > > Lenny installation. Curiously, gdb was no longer on the machine after
> > > the upgrade & I had to download the package. And trying to use it to set
> > > breakpoints and inspect the program is failing - I was blaming this on
> > > JACK but occurs with the non jack build. gdb is complaining that  the
> > > program is not writable (someone else is running ptrace?).
> > > Jeremiah - can you use gdb on denemo - e.g. break on scorearea_keypress
> > > event and inspect variables?
> > 
> > yes. Do you want me to run a command and send the output to you. I just 
> > broke at scorearea_keypress_event.
> There's nothing specific, I just need to get gdb working.
> > (gdb) p *widget
> > $9 = {object = {parent_instance = {g_type_instance = {g_class = 0x92940c8}, 
> > ref_count = 5, qdata = 0x9197200}, 
> >     flags = 2170816}, private_flags = 3584, state = 0 '\0', saved_state = 0 
> > '\0', name = 0x0, style = 0x9295808, 
> >   requisition = {width = 0, height = 0}, allocation = {x = 2, y = 129, 
> > width = 1049, height = 527}, window = 0x92abe60, 
> >   parent = 0x918c728}
> > (gdb) p *event
> > $8 = {type = GDK_KEY_PRESS, window = 0x8fb7188, send_event = 0 '\0', time = 
> > 52511768, state = 0, keyval = 99, length = 1, 
> >   string = 0x9280e68 "c", hardware_keycode = 54, group = 0 '\0', 
> > is_modifier = 0}
> > 
> 
> This is a typical example of what I get:
> 
> Breakpoint 2, scorearea_keypress_event (widget=0x9e00920,
> event=0x9e7f458)
>     at ../../denemo/src/keyresponses.c:106
> 106     keymap *the_keymap = Denemo.map;
> (gdb) p widget
> $1 = (GtkWidget *) 0x9e00920
> (gdb) n
> 104   {
> (gdb) 
> PaHost_WatchDogProc: killing hung audio thread!
> Cannot remove breakpoints because program is no longer writable.
> It might be running in another process.
> Further execution is probably impossible.
> 104   {
> ptrace: No such process.
> 
> In this case it seems fairly clear that a portaudio thread woke up &
> upset things.
> Other times it breaks in some kernel system call and can't say where it
> was.
> In the past the portaudio complaining like this was ok, but it obviously
> is not so any more. Curiously, Lenny is still not V19, so it is not
> portaudio that is doing something different.
> In any case, it will be good to be able to switch portaudio off, as it
> is not doing anything useful on your jack build. Do you have another
> route for hearing what you are playing in via MIDI in?

Yes. I use my immagination. This is what I have been using so far. If I wanted 
to I can patch my midi controller into a softsynth as well as denemo if I 
wished to hear notes as entered. I figured that users would do the same. Users 
can just add it the softsynth into their lash session. The the user loads their 
project via lash and denemo, jack, softsynths, alsa connection, jackmidi stuff 
all get connected via lash. At least this was what I figured people would be 
doing. 
 
Jeremiah
 
> Richard
> 
> 
>