Hi!
Apparently alsa-libs .15 is leaking memory when using snd_pcm_open() on some devices that cannot be opened.
On my USB wecam which has only a single mono audio stream, opening it as "front:3" (which of course fails) leaks a bit of memory. Consider this example:
<snip> #include <asoundlib.h> #include <assert.h>
int main(int argc, char *argv[]) { snd_pcm_t *pcm;
if (snd_pcm_open(&pcm, "front:3", SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK) == 0) { int r = snd_pcm_close(pcm); assert(r == 0); }
snd_config_update_free_global(); return 0; } </snip>
And there they are gone, the 10 bytes of memory. Here's a snippet from valgrinding this program:
==22198== 10 bytes in 1 blocks are definitely lost in loss record 1 of 3 ==22198== at 0x4023765: malloc (vg_replace_malloc.c:149) ==22198== by 0x417C44F: strdup (strdup.c:43) ==22198== by 0x4071954: snd_determine_driver (in /usr/lib/libasound.so.2.0.0) ==22198== by 0x406E80C: snd_config_hook_load_for_all_cards (in /usr/lib/libasound.so.2.0.0) ==22198== by 0x406EC7C: (within /usr/lib/libasound.so.2.0.0) ==22198== by 0x406F896: snd_config_searcha_hooks (in /usr/lib/libasound.so.2.0.0) ==22198== by 0x406FA74: snd_config_search_alias_hooks (in /usr/lib/libasound.so.2.0.0) ==22198== by 0x406FCD9: snd_config_search_definition (in /usr/lib/libasound.so.2.0.0) ==22198== by 0x40952FE: (within /usr/lib/libasound.so.2.0.0) ==22198== by 0x80484D7: main (in /home/lennart/alsa-test)
And there seem to be more. When PulseAudio starts up it probes for available audio devices. On my machine there are 5 sound cards, which are all probed with device strings like "surround51:0" and so on, and in the end some memory with a caller history like the one shown above is shown, and another one:
==22229== 235 (180 direct, 55 indirect) bytes in 5 blocks are definitely lost in loss record 6 of 6 ==22229== at 0x4023AA4: calloc (vg_replace_malloc.c:279) ==22229== by 0x46967B8: (within /usr/lib/libasound.so.2.0.0) ==22229== by 0x4696C48: snd_config_make (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x4696CD0: snd_config_imake_pointer (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46EA573: _snd_pcm_hook_ctl_elems_install (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46EAC10: (within /usr/lib/libasound.so.2.0.0) ==22229== by 0x46EB2BC: _snd_pcm_hooks_open (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46C0CD4: (within /usr/lib/libasound.so.2.0.0) ==22229== by 0x46C1467: snd_pcm_open_slave (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46D232B: _snd_pcm_route_open (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46C0CD4: (within /usr/lib/libasound.so.2.0.0) ==22229== by 0x46C1467: snd_pcm_open_slave (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46E47CC: _snd_pcm_empty_open (in /usr/lib/libasound.so.2.0.0) ==22229== by 0x46C0CD4: (within /usr/lib/libasound.so.2.0.0) ==22229== by 0x46C13D2: (within /usr/lib/libasound.so.2.0.0) ==22229== by 0x412E007: pa_alsa_open_by_device_id (alsa-util.c:529) ==22229== by 0x4135904: module_alsa_sink_LTX_pa__init (module-alsa-sink.c:781) ==22229== by 0x419CD2B: pa_module_load (module.c:115) ==22229== by 0x4164D33: hal_device_load_alsa (module-hal-detect.c:204) ==22229== by 0x4165313: hal_device_add (module-hal-detect.c:323)
Lennart