At Fri, 23 Nov 2007 14:41:43 +0100, I wrote:
Try the patch below. This should fix the problem. Now the multi plugin just shadows the slave buffers via mmap.
There was a minor bug in the last patch. The revised version is below.
Takashi
diff -r 3539f279ec38 src/pcm/pcm_multi.c --- a/src/pcm/pcm_multi.c Wed Nov 21 12:19:43 2007 +0100 +++ b/src/pcm/pcm_multi.c Fri Nov 23 15:34:16 2007 +0100 @@ -690,13 +690,44 @@ static snd_pcm_sframes_t snd_pcm_multi_m return size; }
-static int snd_pcm_multi_mmap(snd_pcm_t *pcm ATTRIBUTE_UNUSED) +static int snd_pcm_multi_munmap(snd_pcm_t *pcm) { + free(pcm->mmap_channels); + free(pcm->running_areas); + pcm->mmap_channels = NULL; + pcm->running_areas = NULL; return 0; }
-static int snd_pcm_multi_munmap(snd_pcm_t *pcm ATTRIBUTE_UNUSED) +static int snd_pcm_multi_mmap(snd_pcm_t *pcm) { + snd_pcm_multi_t *multi = pcm->private_data; + unsigned int c; + + pcm->mmap_channels = calloc(pcm->channels, + sizeof(pcm->mmap_channels[0])); + pcm->running_areas = calloc(pcm->channels, + sizeof(pcm->running_areas[0])); + if (!pcm->mmap_channels || !pcm->running_areas) { + snd_pcm_multi_munmap(pcm); + return -ENOMEM; + } + + /* Copy the slave mmapped buffer data */ + for (c = 0; c < pcm->channels; c++) { + snd_pcm_multi_channel_t *chan = &multi->channels[c]; + snd_pcm_t *slave; + if (chan->slave_idx < 0) { + snd_pcm_multi_munmap(pcm); + return -ENXIO; + } + slave = multi->slaves[chan->slave_idx].pcm; + pcm->mmap_channels[c] = + slave->mmap_channels[chan->slave_channel]; + pcm->mmap_channels[c].channel = c; + pcm->running_areas[c] = + slave->running_areas[chan->slave_channel]; + } return 0; }
@@ -850,6 +881,7 @@ int snd_pcm_multi_open(snd_pcm_t **pcmp, return err; } pcm->mmap_rw = 1; + pcm->mmap_shadow = 1; /* has own mmap method */ pcm->ops = &snd_pcm_multi_ops; pcm->fast_ops = &snd_pcm_multi_fast_ops; pcm->private_data = multi;