rework memory block management to be thread-safe and mostly lock-free.

pa_memblock is now an opaque structure. Access to its fields is now done
through various accessor functions in a thread-safe manner.

pa_memblock_acquire() and pa_memblock_release() are now used to access the
attached audio data. Why? To allow safe manipulation of the memory pointer
maintained by the memory block. Internally _acquire() and _release() maintain a
reference counter. Please do not confuse this reference counter whith the one
maintained by pa_memblock_ref()/_unref()!

As a side effect this patch removes all direct usages of AO_t and replaces it
with pa_atomic_xxx based code.

This stuff needs some serious testing love. Especially if threads are actively
used.



git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1404 fefdeb5f-60dc-0310-8127-8f9354f1896f
This commit is contained in:
Lennart Poettering 2006-09-26 23:50:56 +00:00
parent 5ad143b3ab
commit d210ebbb09
36 changed files with 991 additions and 500 deletions

View file

@ -113,6 +113,7 @@ static int do_read(struct connection *c) {
pa_memchunk chunk;
ssize_t r;
size_t l;
void *p;
if (!c->sink_input || !(l = pa_memblockq_missing(c->input_memblockq)))
return 0;
@ -121,7 +122,7 @@ static int do_read(struct connection *c) {
l = c->playback.fragment_size;
if (c->playback.current_memblock)
if (c->playback.current_memblock->length - c->playback.memblock_index < l) {
if (pa_memblock_get_length(c->playback.current_memblock) - c->playback.memblock_index < l) {
pa_memblock_unref(c->playback.current_memblock);
c->playback.current_memblock = NULL;
c->playback.memblock_index = 0;
@ -129,15 +130,20 @@ static int do_read(struct connection *c) {
if (!c->playback.current_memblock) {
c->playback.current_memblock = pa_memblock_new(c->protocol->core->mempool, c->playback.fragment_size*2);
assert(c->playback.current_memblock && c->playback.current_memblock->length >= l);
assert(c->playback.current_memblock);
assert(pa_memblock_get_length(c->playback.current_memblock) >= l);
c->playback.memblock_index = 0;
}
p = pa_memblock_acquire(c->playback.current_memblock);
if ((r = pa_iochannel_read(c->io, (uint8_t*) c->playback.current_memblock->data+c->playback.memblock_index, l)) <= 0) {
if ((r = pa_iochannel_read(c->io, (uint8_t*) p + c->playback.memblock_index, l)) <= 0) {
pa_memblock_release(c->playback.current_memblock);
pa_log_debug("read(): %s", r == 0 ? "EOF" : pa_cstrerror(errno));
return -1;
}
pa_memblock_release(c->playback.current_memblock);
chunk.memblock = c->playback.current_memblock;
chunk.index = c->playback.memblock_index;
chunk.length = r;
@ -156,7 +162,8 @@ static int do_read(struct connection *c) {
static int do_write(struct connection *c) {
pa_memchunk chunk;
ssize_t r;
void *p;
if (!c->source_output)
return 0;
@ -165,12 +172,17 @@ static int do_write(struct connection *c) {
return 0;
assert(chunk.memblock && chunk.length);
p = pa_memblock_acquire(chunk.memblock);
if ((r = pa_iochannel_write(c->io, (uint8_t*) chunk.memblock->data+chunk.index, chunk.length)) < 0) {
if ((r = pa_iochannel_write(c->io, (uint8_t*) p+chunk.index, chunk.length)) < 0) {
pa_memblock_release(chunk.memblock);
pa_memblock_unref(chunk.memblock);
pa_log("write(): %s", pa_cstrerror(errno));
return -1;
}
pa_memblock_release(chunk.memblock);
pa_memblockq_drop(c->output_memblockq, &chunk, r);
pa_memblock_unref(chunk.memblock);