From: Timo Wischer twischer@de.adit-jv.com
Otherwise the ALSA thread could for example read a hw_ptr > buffer_size
Signed-off-by: Timo Wischer twischer@de.adit-jv.com
diff --git a/jack/pcm_jack.c b/jack/pcm_jack.c index 4468ede..3aed332 100644 --- a/jack/pcm_jack.c +++ b/jack/pcm_jack.c @@ -137,6 +137,7 @@ static int snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) { snd_pcm_jack_t *jack = io->private_data; + snd_pcm_uframes_t hw_ptr; const snd_pcm_channel_area_t *areas; snd_pcm_uframes_t xfer = 0; unsigned int channel; @@ -155,12 +156,13 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) return 0; } } - + + hw_ptr = jack->hw_ptr; areas = snd_pcm_ioplug_mmap_areas(io);
while (xfer < nframes) { snd_pcm_uframes_t frames = nframes - xfer; - snd_pcm_uframes_t offset = jack->hw_ptr; + snd_pcm_uframes_t offset = hw_ptr; snd_pcm_uframes_t cont = io->buffer_size - offset;
if (cont < frames) @@ -173,10 +175,11 @@ snd_pcm_jack_process_cb(jack_nframes_t nframes, snd_pcm_ioplug_t *io) snd_pcm_area_copy(&areas[channel], offset, &jack->areas[channel], xfer, frames, io->format); } - jack->hw_ptr += frames; - jack->hw_ptr %= io->buffer_size; + hw_ptr += frames; + hw_ptr %= io->buffer_size; xfer += frames; } + jack->hw_ptr = hw_ptr;
pcm_poll_unblock_check(io); /* unblock socket for polling if needed */