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Moved ring buffer pointers and added a mechanism to transfer them via shm

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This commit is contained in:
Jaroslav Kysela 2002-04-23 15:51:29 +00:00
parent f063381430
commit c941c548f8
26 changed files with 469 additions and 171 deletions
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38
src/pcm/pcm_mmap.c
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@ -36,48 +36,66 @@ size_t page_size(void)
size_t page_align(size_t size)
{
size_t r;
long psz = sysconf(_SC_PAGE_SIZE);
assert(psz > 0);
long psz = page_size();
r = size % psz;
if (r)
return size + psz - r;
return size;
}
size_t page_ptr(size_t object_offset, size_t object_size, size_t *offset, size_t *mmap_offset)
{
size_t r;
long psz = page_size();
assert(offset);
assert(mmap_offset);
*mmap_offset = object_offset;
object_offset %= psz;
*mmap_offset -= object_offset;
object_size += object_offset;
r = object_size % psz;
if (r)
r = object_size + psz - r;
else
r = object_size;
*offset = object_offset;
return r;
}
void snd_pcm_mmap_appl_backward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_sframes_t appl_ptr = *pcm->appl_ptr;
snd_pcm_sframes_t appl_ptr = *pcm->appl.ptr;
appl_ptr -= frames;
if (appl_ptr < 0)
appl_ptr += pcm->boundary;
*pcm->appl_ptr = appl_ptr;
*pcm->appl.ptr = appl_ptr;
}
void snd_pcm_mmap_appl_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_uframes_t appl_ptr = *pcm->appl_ptr;
snd_pcm_uframes_t appl_ptr = *pcm->appl.ptr;
appl_ptr += frames;
if (appl_ptr >= pcm->boundary)
appl_ptr -= pcm->boundary;
*pcm->appl_ptr = appl_ptr;
*pcm->appl.ptr = appl_ptr;
}
void snd_pcm_mmap_hw_backward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_sframes_t hw_ptr = *pcm->hw_ptr;
snd_pcm_sframes_t hw_ptr = *pcm->hw.ptr;
hw_ptr -= frames;
if (hw_ptr < 0)
hw_ptr += pcm->boundary;
*pcm->hw_ptr = hw_ptr;
*pcm->hw.ptr = hw_ptr;
}
void snd_pcm_mmap_hw_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
{
snd_pcm_uframes_t hw_ptr = *pcm->hw_ptr;
snd_pcm_uframes_t hw_ptr = *pcm->hw.ptr;
hw_ptr += frames;
if (hw_ptr >= pcm->boundary)
hw_ptr -= pcm->boundary;
*pcm->hw_ptr = hw_ptr;
*pcm->hw.ptr = hw_ptr;
}
static snd_pcm_sframes_t snd_pcm_mmap_write_areas(snd_pcm_t *pcm,