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

@ -48,6 +48,7 @@
#include <pulsecore/creds.h>
#include <pulsecore/mutex.h>
#include <pulsecore/refcnt.h>
#include <pulsecore/anotify.h>
#include "pstream.h"
@ -113,10 +114,11 @@ struct pa_pstream {
PA_REFCNT_DECLARE;
pa_mainloop_api *mainloop;
pa_defer_event *defer_event;
pa_iochannel *io;
pa_queue *send_queue;
pa_mutex *mutex;
pa_mutex *mutex; /* only for access to the queue */
pa_anotify *anotify;
int dead;
@ -126,6 +128,7 @@ struct pa_pstream {
uint32_t shm_info[PA_PSTREAM_SHM_MAX];
void *data;
size_t index;
pa_memchunk memchunk;
} write;
struct {
@ -170,10 +173,6 @@ static void do_something(pa_pstream *p) {
pa_pstream_ref(p);
pa_mutex_lock(p->mutex);
p->mainloop->defer_enable(p->defer_event, 0);
if (!p->dead && pa_iochannel_is_readable(p->io)) {
if (do_read(p) < 0)
goto fail;
@ -185,8 +184,6 @@ static void do_something(pa_pstream *p) {
goto fail;
}
pa_mutex_unlock(p->mutex);
pa_pstream_unref(p);
return;
@ -197,8 +194,6 @@ fail:
if (p->die_callback)
p->die_callback(p, p->die_callback_userdata);
pa_mutex_unlock(p->mutex);
pa_pstream_unref(p);
}
@ -211,13 +206,10 @@ static void io_callback(pa_iochannel*io, void *userdata) {
do_something(p);
}
static void defer_callback(pa_mainloop_api *m, pa_defer_event *e, void*userdata) {
static void anotify_callback(uint8_t event, void *userdata) {
pa_pstream *p = userdata;
assert(p);
assert(p->defer_event == e);
assert(p->mainloop == m);
do_something(p);
}
@ -237,16 +229,16 @@ pa_pstream *pa_pstream_new(pa_mainloop_api *m, pa_iochannel *io, pa_mempool *poo
p->dead = 0;
p->mutex = pa_mutex_new(1);
p->anotify = pa_anotify_new(m, anotify_callback, p);
p->mainloop = m;
p->defer_event = m->defer_new(m, defer_callback, p);
m->defer_enable(p->defer_event, 0);
p->send_queue = pa_queue_new();
assert(p->send_queue);
p->write.current = NULL;
p->write.index = 0;
pa_memchunk_reset(&p->write.memchunk);
p->read.memblock = NULL;
p->read.packet = NULL;
p->read.index = 0;
@ -309,9 +301,15 @@ static void pstream_free(pa_pstream *p) {
if (p->read.packet)
pa_packet_unref(p->read.packet);
if (p->write.memchunk.memblock)
pa_memblock_unref(p->write.memchunk.memblock);
if (p->mutex)
pa_mutex_free(p->mutex);
if (p->anotify)
pa_anotify_free(p->anotify);
pa_xfree(p);
}
@ -322,11 +320,6 @@ void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet, const pa_creds *cre
assert(PA_REFCNT_VALUE(p) > 0);
assert(packet);
pa_mutex_lock(p->mutex);
if (p->dead)
goto finish;
i = pa_xnew(struct item_info, 1);
i->type = PA_PSTREAM_ITEM_PACKET;
i->packet = pa_packet_ref(packet);
@ -336,12 +329,11 @@ void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet, const pa_creds *cre
i->creds = *creds;
#endif
pa_mutex_lock(p->mutex);
pa_queue_push(p->send_queue, i);
p->mainloop->defer_enable(p->defer_event, 1);
finish:
pa_mutex_unlock(p->mutex);
pa_anotify_signal(p->anotify, 0);
}
void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, int64_t offset, pa_seek_mode_t seek_mode, const pa_memchunk *chunk) {
@ -352,12 +344,6 @@ void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, int64_t offset, pa
assert(channel != (uint32_t) -1);
assert(chunk);
pa_mutex_lock(p->mutex);
if (p->dead)
goto finish;
length = chunk->length;
idx = 0;
while (length > 0) {
@ -379,17 +365,15 @@ void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, int64_t offset, pa
i->with_creds = 0;
#endif
pa_mutex_lock(p->mutex);
pa_queue_push(p->send_queue, i);
pa_mutex_unlock(p->mutex);
idx += n;
length -= n;
}
p->mainloop->defer_enable(p->defer_event, 1);
finish:
pa_mutex_unlock(p->mutex);
pa_anotify_signal(p->anotify, 0);
}
static void memimport_release_cb(pa_memimport *i, uint32_t block_id, void *userdata) {
@ -399,11 +383,6 @@ static void memimport_release_cb(pa_memimport *i, uint32_t block_id, void *userd
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
if (p->dead)
goto finish;
/* pa_log("Releasing block %u", block_id); */
item = pa_xnew(struct item_info, 1);
@ -413,12 +392,11 @@ static void memimport_release_cb(pa_memimport *i, uint32_t block_id, void *userd
item->with_creds = 0;
#endif
pa_mutex_lock(p->mutex);
pa_queue_push(p->send_queue, item);
p->mainloop->defer_enable(p->defer_event, 1);
finish:
pa_mutex_unlock(p->mutex);
pa_anotify_signal(p->anotify, 0);
}
static void memexport_revoke_cb(pa_memexport *e, uint32_t block_id, void *userdata) {
@ -428,11 +406,6 @@ static void memexport_revoke_cb(pa_memexport *e, uint32_t block_id, void *userda
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
if (p->dead)
goto finish;
/* pa_log("Revoking block %u", block_id); */
item = pa_xnew(struct item_info, 1);
@ -442,23 +415,27 @@ static void memexport_revoke_cb(pa_memexport *e, uint32_t block_id, void *userda
item->with_creds = 0;
#endif
pa_mutex_lock(p->mutex);
pa_queue_push(p->send_queue, item);
p->mainloop->defer_enable(p->defer_event, 1);
finish:
pa_mutex_unlock(p->mutex);
pa_anotify_signal(p->anotify, 0);
}
static void prepare_next_write_item(pa_pstream *p) {
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
if (!(p->write.current = pa_queue_pop(p->send_queue)))
pa_mutex_lock(p->mutex);
p->write.current = pa_queue_pop(p->send_queue);
pa_mutex_unlock(p->mutex);
if (!p->write.current)
return;
p->write.index = 0;
p->write.data = NULL;
pa_memchunk_reset(&p->write.memchunk);
p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = 0;
p->write.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL] = htonl((uint32_t) -1);
@ -525,7 +502,9 @@ static void prepare_next_write_item(pa_pstream *p) {
if (send_payload) {
p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl(p->write.current->chunk.length);
p->write.data = (uint8_t*) p->write.current->chunk.memblock->data + p->write.current->chunk.index;
p->write.memchunk = p->write.current->chunk;
pa_memblock_ref(p->write.memchunk.memblock);
p->write.data = NULL;
}
p->write.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS] = htonl(flags);
@ -541,6 +520,7 @@ static int do_write(pa_pstream *p) {
void *d;
size_t l;
ssize_t r;
pa_memblock *release_memblock = NULL;
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
@ -555,9 +535,16 @@ static int do_write(pa_pstream *p) {
d = (uint8_t*) p->write.descriptor + p->write.index;
l = PA_PSTREAM_DESCRIPTOR_SIZE - p->write.index;
} else {
assert(p->write.data);
assert(p->write.data || p->write.memchunk.memblock);
if (p->write.data)
d = p->write.data;
else {
d = (uint8_t*) pa_memblock_acquire(p->write.memchunk.memblock) + p->write.memchunk.index;
release_memblock = p->write.memchunk.memblock;
}
d = (uint8_t*) p->write.data + p->write.index - PA_PSTREAM_DESCRIPTOR_SIZE;
d = (uint8_t*) d + p->write.index - PA_PSTREAM_DESCRIPTOR_SIZE;
l = ntohl(p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) - (p->write.index - PA_PSTREAM_DESCRIPTOR_SIZE);
}
@ -567,14 +554,17 @@ static int do_write(pa_pstream *p) {
if (p->send_creds_now) {
if ((r = pa_iochannel_write_with_creds(p->io, d, l, &p->write_creds)) < 0)
return -1;
goto fail;
p->send_creds_now = 0;
} else
#endif
if ((r = pa_iochannel_write(p->io, d, l)) < 0)
return -1;
goto fail;
if (release_memblock)
pa_memblock_release(release_memblock);
p->write.index += r;
@ -588,12 +578,20 @@ static int do_write(pa_pstream *p) {
}
return 0;
fail:
if (release_memblock)
pa_memblock_release(release_memblock);
return -1;
}
static int do_read(pa_pstream *p) {
void *d;
size_t l;
ssize_t r;
pa_memblock *release_memblock = NULL;
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
@ -602,8 +600,16 @@ static int do_read(pa_pstream *p) {
d = (uint8_t*) p->read.descriptor + p->read.index;
l = PA_PSTREAM_DESCRIPTOR_SIZE - p->read.index;
} else {
assert(p->read.data);
d = (uint8_t*) p->read.data + p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE;
assert(p->read.data || p->read.memblock);
if (p->read.data)
d = p->read.data;
else {
d = pa_memblock_acquire(p->read.memblock);
release_memblock = p->read.memblock;
}
d = (uint8_t*) d + p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE;
l = ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) - (p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE);
}
@ -612,14 +618,17 @@ static int do_read(pa_pstream *p) {
int b = 0;
if ((r = pa_iochannel_read_with_creds(p->io, d, l, &p->read_creds, &b)) <= 0)
return -1;
goto fail;
p->read_creds_valid = p->read_creds_valid || b;
}
#else
if ((r = pa_iochannel_read(p->io, d, l)) <= 0)
return -1;
goto fail;
#endif
if (release_memblock)
pa_memblock_release(release_memblock);
p->read.index += r;
@ -701,7 +710,7 @@ static int do_read(pa_pstream *p) {
/* Frame is a memblock frame */
p->read.memblock = pa_memblock_new(p->mempool, length);
p->read.data = p->read.memblock->data;
p->read.data = NULL;
} else {
pa_log_warn("Recieved memblock frame with invalid flags value.");
@ -788,7 +797,7 @@ static int do_read(pa_pstream *p) {
chunk.memblock = b;
chunk.index = 0;
chunk.length = b->length;
chunk.length = pa_memblock_get_length(b);
offset = (int64_t) (
(((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI])) << 32) |
@ -816,52 +825,51 @@ frame_done:
p->read.memblock = NULL;
p->read.packet = NULL;
p->read.index = 0;
p->read.data = NULL;
#ifdef HAVE_CREDS
p->read_creds_valid = 0;
#endif
return 0;
fail:
if (release_memblock)
pa_memblock_release(release_memblock);
return -1;
}
void pa_pstream_set_die_callback(pa_pstream *p, pa_pstream_notify_cb_t cb, void *userdata) {
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
p->die_callback = cb;
p->die_callback_userdata = userdata;
pa_mutex_unlock(p->mutex);
}
void pa_pstream_set_drain_callback(pa_pstream *p, pa_pstream_notify_cb_t cb, void *userdata) {
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
p->drain_callback = cb;
p->drain_callback_userdata = userdata;
pa_mutex_unlock(p->mutex);
}
void pa_pstream_set_recieve_packet_callback(pa_pstream *p, pa_pstream_packet_cb_t cb, void *userdata) {
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
p->recieve_packet_callback = cb;
p->recieve_packet_callback_userdata = userdata;
pa_mutex_unlock(p->mutex);
}
void pa_pstream_set_recieve_memblock_callback(pa_pstream *p, pa_pstream_memblock_cb_t cb, void *userdata) {
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
p->recieve_memblock_callback = cb;
p->recieve_memblock_callback_userdata = userdata;
pa_mutex_unlock(p->mutex);
}
int pa_pstream_is_pending(pa_pstream *p) {
@ -901,8 +909,6 @@ pa_pstream* pa_pstream_ref(pa_pstream*p) {
void pa_pstream_close(pa_pstream *p) {
assert(p);
pa_mutex_lock(p->mutex);
p->dead = 1;
if (p->import) {
@ -920,25 +926,16 @@ void pa_pstream_close(pa_pstream *p) {
p->io = NULL;
}
if (p->defer_event) {
p->mainloop->defer_free(p->defer_event);
p->defer_event = NULL;
}
p->die_callback = NULL;
p->drain_callback = NULL;
p->recieve_packet_callback = NULL;
p->recieve_memblock_callback = NULL;
pa_mutex_unlock(p->mutex);
}
void pa_pstream_use_shm(pa_pstream *p, int enable) {
assert(p);
assert(PA_REFCNT_VALUE(p) > 0);
pa_mutex_lock(p->mutex);
p->use_shm = enable;
if (enable) {
@ -953,6 +950,4 @@ void pa_pstream_use_shm(pa_pstream *p, int enable) {
p->export = NULL;
}
}
pa_mutex_unlock(p->mutex);
}