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Improved mmap emulation over write/read

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This commit is contained in:
Jaroslav Kysela 2001-12-08 21:00:21 +00:00
parent 437c96ef5f
commit 484c05ec36
1 changed files with 44 additions and 11 deletions
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55
src/pcm/pcm_hw.c
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@ -45,12 +45,19 @@ typedef struct {
int card, device, subdevice;
volatile struct sndrv_pcm_mmap_status *mmap_status;
struct sndrv_pcm_mmap_control *mmap_control;
int shadow_appl_ptr: 1, avail_update_flag: 1;
snd_pcm_uframes_t appl_ptr;
int shmid;
} snd_pcm_hw_t;
#define SNDRV_FILE_PCM_STREAM_PLAYBACK "/dev/snd/pcmC%iD%ip"
#define SNDRV_FILE_PCM_STREAM_CAPTURE "/dev/snd/pcmC%iD%ic"
#define SNDRV_PCM_VERSION_MAX SNDRV_PROTOCOL_VERSION(2, 0, 0)
#define SNDRV_PCM_VERSION_MAX SNDRV_PROTOCOL_VERSION(2, 0, 0)
/* update appl_ptr with driver */
#define UPDATE_SHADOW_PTR(hw) \
do { if (hw->shadow_appl_ptr && !hw->avail_update_flag) \
hw->appl_ptr = hw->mmap_control->appl_ptr; } while (0)
static int snd_pcm_hw_nonblock(snd_pcm_t *pcm, int nonblock)
{
@ -134,6 +141,16 @@ static int snd_pcm_hw_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params)
SYSERR("SNDRV_PCM_IOCTL_HW_PARAMS failed");
return -errno;
}
if (pcm->stream == SND_PCM_STREAM_CAPTURE) {
if (!(params->info & SNDRV_PCM_INFO_MMAP)) {
hw->shadow_appl_ptr = 1;
hw->appl_ptr = 0;
pcm->appl_ptr = &hw->appl_ptr;
} else {
hw->shadow_appl_ptr = 0;
pcm->appl_ptr = &hw->mmap_control->appl_ptr;
}
}
return 0;
}
@ -358,6 +375,7 @@ static snd_pcm_sframes_t snd_pcm_hw_readi(snd_pcm_t *pcm, void *buffer, snd_pcm_
result = ioctl(fd, SNDRV_PCM_IOCTL_READI_FRAMES, &xferi);
if (result < 0)
return -errno;
UPDATE_SHADOW_PTR(hw);
return xferi.result;
}
@ -372,6 +390,7 @@ static snd_pcm_sframes_t snd_pcm_hw_readn(snd_pcm_t *pcm, void **bufs, snd_pcm_u
result = ioctl(fd, SNDRV_PCM_IOCTL_READN_FRAMES, &xfern);
if (result < 0)
return -errno;
UPDATE_SHADOW_PTR(hw);
return xfern.result;
}
@ -467,28 +486,42 @@ static int snd_pcm_hw_close(snd_pcm_t *pcm)
return 0;
}
static snd_pcm_sframes_t snd_pcm_hw_mmap_commit(snd_pcm_t *pcm,
snd_pcm_uframes_t offset ATTRIBUTE_UNUSED,
snd_pcm_uframes_t size)
static int snd_pcm_hw_mmap_commit(snd_pcm_t *pcm,
snd_pcm_uframes_t offset ATTRIBUTE_UNUSED,
snd_pcm_uframes_t size)
{
if (!(pcm->info & SND_PCM_INFO_MMAP) &&
pcm->stream == SND_PCM_STREAM_PLAYBACK)
return snd_pcm_write_mmap(pcm, size);
if (!(pcm->info & SND_PCM_INFO_MMAP)) {
if (pcm->stream == SND_PCM_STREAM_PLAYBACK) {
snd_pcm_sframes_t res;
do {
res = snd_pcm_write_mmap(pcm, size);
if (res < 0)
return res;
size -= res;
} while (size > 0);
return 0;
} else {
snd_pcm_hw_t *hw = pcm->private_data;
assert(hw->shadow_appl_ptr);
}
}
snd_pcm_mmap_appl_forward(pcm, size);
return size;
return 0;
}
static snd_pcm_sframes_t snd_pcm_hw_avail_update(snd_pcm_t *pcm)
{
snd_pcm_uframes_t avail;
snd_pcm_sframes_t err;
if (pcm->stream == SND_PCM_STREAM_PLAYBACK) {
avail = snd_pcm_mmap_playback_avail(pcm);
} else {
avail = snd_pcm_mmap_capture_avail(pcm);
if (avail > 0 &&
!(pcm->info & SND_PCM_INFO_MMAP)) {
if (avail > 0 && !(pcm->info & SND_PCM_INFO_MMAP)) {
snd_pcm_sframes_t err;
snd_pcm_hw_t *hw = pcm->private_data;
hw->avail_update_flag = 1;
err = snd_pcm_read_mmap(pcm, avail);
hw->avail_update_flag = 0;
if (err < 0)
return err;
assert((snd_pcm_uframes_t)err == avail);