[Openal-devel] Initializing openal/alut second time crashes.

[Joni Yrjana]

On Sat, 2006-02-25 at 20:33 +0200, Joni Yrjana wrote:
> I'm trying to make it possible in my application to turn sound on and
> off whenever user wants to. But after trying to initialize OpenAL/alut
> second time after closing it, the program crashes. As far as I can tell
> reading the manual, this should be possible to do.
<cut>

Hello,

I grabbed the current CVS source tree, configured with debug enabled and
made the attached patch which does seem to work.

Below is my debugging session with the debug-enabled openal library
before patching.

$ export LD_PRELOAD=/usr/local/lib/libopenal.so
$ gdb ./a.out
GNU gdb Red Hat Linux (6.3.0.0-1.84rh)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you
are
welcome to change it and/or distribute copies of it under certain
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Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for
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This GDB was configured as "i386-redhat-linux-gnu"...Using host
libthread_db library "/lib/libthread_db.so.1".

(gdb) r
Starting program: /tmp/a.out 
Reading symbols from shared object read from target memory...done.
Loaded system supplied DSO at 0x444000
[Thread debugging using libthread_db enabled]
[New Thread -1208416576 (LWP 24751)]
grab_native: (path /dev/dsp fd 6)
set_fd in: bufsiz 4096 fmt 0x10 speed 44100 channels 2
set_fd out: bufsiz 1024 fmt 0x10 speed 44100 channels 2
[New Thread -1208419408 (LWP 24754)]
[Thread -1208419408 (zombie) exited]
grab_native: (path /dev/dsp fd 6)
set_fd in: bufsiz 4096 fmt 0x10 speed 44100 channels 2
set_fd out: bufsiz 1024 fmt 0x10 speed 44100 channels 2
[New Thread -1208419408 (LWP 24755)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1208416576 (LWP 24751)]
_alcDeviceResume (dev=0x0) at alc/alc_device.c:239
239             dev->ops->resume( dev->privateData );
(gdb) print dev->privateData
Cannot access memory at address 0x8
(gdb) print dev
$1 = (AL_device *) 0x0
(gdb) bt
#0  _alcDeviceResume (dev=0x0) at alc/alc_device.c:239
#1  0x00c05bd2 in alcMakeContextCurrent (handle=0x0) at
alc/alc_context.c:240
#2  0x00000000 in ?? ()
(gdb)


Testing with the patched version looked like this:
$ ./a.out 
grab_native: (path /dev/dsp fd 3)
set_fd in: bufsiz 4096 fmt 0x10 speed 44100 channels 2
set_fd out: bufsiz 1024 fmt 0x10 speed 44100 channels 2
grab_native: (path /dev/dsp fd 3)
set_fd in: bufsiz 4096 fmt 0x10 speed 44100 channels 2
set_fd out: bufsiz 1024 fmt 0x10 speed 44100 channels 2
mutex 0x841f290 busy
$

The mutex couldn't be destroyed but it doesn't seem to have any effect.


Best regards,
 Joni Yrjana

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