Re: [Gap-dev-discuss] Cynthiune crash (AO)

[Sebastian Reitenbach]

On Monday, May 7, 2012 08:17 CEST, Philippe Roussel <address@hidden> wrote:

> Le 07/05/2012 00:22, Riccardo Mottola a écrit :
> > Hi,
> >
> > things seem to proceed with Cynthiune. On my Debian laptop where I have
> > a handy way of installing all packages (x86, because it has more
> > diskspace than the iBook where I am very tight) I installed most
> > libraries and built so a full Cynthiune with OSS, ALSA and AO sound
> > backends. They all do play!
>
> Nice !
>
> > The endianness must be investigated... the ALSA backend on linux should
> > work on PPC. Perhaps I'll try OSS or AO too, I'll see.. Anyway, I think
> > there is smell for a release!

I found some example samples on the web for some AIFF and CAIFF, WAV and
.MOD files. The MOD file I downloaded, was working well with my patch, but
I got noise with some of the AIFF files. On i386, all files play nicely, but on
PPC, only those some produce noise, while the rest is fine.
So the patch is not perfect, but better than without. Not sure, whether
to back it out, or leave it in.


> >
> > While playing a bit, I got this Crash though. AO Backend.
> > ao_alsa WARNING: ao_plugin_close called with uninitialized
> > ao_device->internal
> > ao_alsa WARNING: ao_plugin_device_clear called with uninitialized
> > ao_device->internal
> > *** glibc detected *** Cynthiune: double free or corruption (!prev):
> > 0x085356c0
> > ***
> > ======= Backtrace: =========
> > /lib/i386-linux-gnu/i686/cmov/libc.so.6(+0x6e3e1)[0xb6d253e1]
> > /lib/i386-linux-gnu/i686/cmov/libc.so.6(+0x6fc48)[0xb6d26c48]
> > /lib/i386-linux-gnu/i686/cmov/libc.so.6(cfree+0x6d)[0xb6d29cfd]
> > /usr/lib/libao.so.4(ao_close+0xa1)[0xb29b02a1]
> > ======= Memory map: ========
> > 08048000-08072000 r-xp 00000000 08:01 245416
> > /usr/local/lib/GNUstep/Applications/Cynthiune.app/Cynthiune
> > 08072000-08083000 rw-p 00029000 08:01 245416
> > /usr/local/lib/GNUstep/Applications/Cynthiune.app/Cynthiune
> >
> > this is on x86 though, not ppc, where Sebastian wrote to have problems.

Has it happen while jumping from one song to the next? Did those songs

had different bit rate or number of channels?
If yes, maybe its a race condition in the prepareDevice... method
when closing the device, and the handle is already NULL.
For me, it crashed in ao_plugin_close and in ao_plugin_device_clear,
because those functions were called with the NULL as parameter.
PPC seems to be a bit more picky about NULL pointer dereferences.
After preventing to call those methods with NULL as parameter,
I also got the double free, and Cynthiune aborted. Maybe when I test
it more and longer on i386, I'd get the same problem.

On OpenBSD I have libao-1.1.0.

Sebastian
>
> I'll try to reproduce it.
>
> What version of libao do you have ?
>
> Philippe
>