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authorwm4 <wm4@nowhere>2014-01-17 23:13:09 +0100
committerwm4 <wm4@nowhere>2014-01-17 23:21:17 +0100
commit92a9f11a0b4fda60c8880014be5920dcf3e95253 (patch)
tree790e1c362c0d23a12c03781c93183912f40edac3 /sub/dec_sub.c
parent49ebbce3e049c7f8fba0c001d1e70994e2473eee (diff)
downloadmpv-92a9f11a0b4fda60c8880014be5920dcf3e95253.tar.bz2
mpv-92a9f11a0b4fda60c8880014be5920dcf3e95253.tar.xz
sub: uglify sub decoder with locking
The plan is to make the whole OSD thread-safe, and we start with this. We just put locks on all entry points (fortunately, dec_sub.c and all sd_*.c decoders are very closed off, and only the entry points in dec_sub.h let you access it). I think this is pretty ugly, but at least it's very simple. There's a special case with sub_get_bitmaps(): this function returns pointers to decoder data (specifically, libass images). There's no way to synchronize this internally, so expose sub_lock/sub_unlock functions. To make things simpler, and especially because the lock is sort-of exposed to the outside world, make the locks recursive. Although the only case where this is actually needed (although trivial) is sub_set_extradata(). One corner case are ASS subtitles: for some reason, we keep a single ASS_Renderer instance for subtitles around (probably to avoid rescanning fonts with ordered chapters), and this ASS_Renderer instance is not synchronized. Also, demux_libass.c loads ASS_Track objects, which are directly passed to sd_ass.c. These things are not synchronized (and would be hard to synchronize), and basically we're out of luck. But I think for now, accesses happen reasonably serialized, so there is no actual problem yet, even if we start to access OSD from other threads.
Diffstat (limited to 'sub/dec_sub.c')
-rw-r--r--sub/dec_sub.c77
1 files changed, 71 insertions, 6 deletions
diff --git a/sub/dec_sub.c b/sub/dec_sub.c
index 102a048da3..64d285f568 100644
--- a/sub/dec_sub.c
+++ b/sub/dec_sub.c
@@ -21,6 +21,7 @@
#include <string.h>
#include <math.h>
#include <assert.h>
+#include <pthread.h>
#include "config.h"
#include "demux/demux.h"
@@ -57,6 +58,8 @@ static const struct sd_functions *sd_list[] = {
#define MAX_NUM_SD 3
struct dec_sub {
+ pthread_mutex_t lock;
+
struct mp_log *log;
struct MPOpts *opts;
struct sd init_sd;
@@ -73,11 +76,32 @@ struct packet_list {
int num_packets;
};
+
+void sub_lock(struct dec_sub *sub)
+{
+ pthread_mutex_lock(&sub->lock);
+}
+
+void sub_unlock(struct dec_sub *sub)
+{
+ pthread_mutex_unlock(&sub->lock);
+}
+
+// Thread-safety of the returned object: all functions are thread-safe,
+// except sub_get_bitmaps() and sub_get_text(). Decoder backends (sd_*)
+// do not need to acquire locks.
struct dec_sub *sub_create(struct mpv_global *global)
{
struct dec_sub *sub = talloc_zero(NULL, struct dec_sub);
sub->log = mp_log_new(sub, global->log, "sub");
sub->opts = global->opts;
+
+ pthread_mutexattr_t attr;
+ pthread_mutexattr_init(&attr);
+ pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+ pthread_mutex_init(&sub->lock, &attr);
+ pthread_mutexattr_destroy(&attr);
+
return sub;
}
@@ -97,12 +121,16 @@ void sub_destroy(struct dec_sub *sub)
if (!sub)
return;
sub_uninit(sub);
+ pthread_mutex_destroy(&sub->lock);
talloc_free(sub);
}
bool sub_is_initialized(struct dec_sub *sub)
{
- return !!sub->num_sd;
+ pthread_mutex_lock(&sub->lock);
+ bool r = !!sub->num_sd;
+ pthread_mutex_unlock(&sub->lock);
+ return r;
}
static struct sd *sub_get_last_sd(struct dec_sub *sub)
@@ -112,26 +140,34 @@ static struct sd *sub_get_last_sd(struct dec_sub *sub)
void sub_set_video_res(struct dec_sub *sub, int w, int h)
{
+ pthread_mutex_lock(&sub->lock);
sub->init_sd.sub_video_w = w;
sub->init_sd.sub_video_h = h;
+ pthread_mutex_unlock(&sub->lock);
}
void sub_set_video_fps(struct dec_sub *sub, double fps)
{
+ pthread_mutex_lock(&sub->lock);
sub->video_fps = fps;
+ pthread_mutex_unlock(&sub->lock);
}
void sub_set_extradata(struct dec_sub *sub, void *data, int data_len)
{
+ pthread_mutex_lock(&sub->lock);
sub->init_sd.extradata = data_len ? talloc_memdup(sub, data, data_len) : NULL;
sub->init_sd.extradata_len = data_len;
+ pthread_mutex_unlock(&sub->lock);
}
void sub_set_ass_renderer(struct dec_sub *sub, struct ass_library *ass_library,
struct ass_renderer *ass_renderer)
{
+ pthread_mutex_lock(&sub->lock);
sub->init_sd.ass_library = ass_library;
sub->init_sd.ass_renderer = ass_renderer;
+ pthread_mutex_unlock(&sub->lock);
}
static void print_chain(struct dec_sub *sub)
@@ -170,6 +206,8 @@ void sub_init_from_sh(struct dec_sub *sub, struct sh_stream *sh)
assert(!sub->num_sd);
assert(sh && sh->sub);
+ pthread_mutex_lock(&sub->lock);
+
if (sh->sub->extradata && !sub->init_sd.extradata)
sub_set_extradata(sub, sh->sub->extradata, sh->sub->extradata_len);
struct sd init_sd = sub->init_sd;
@@ -189,6 +227,7 @@ void sub_init_from_sh(struct dec_sub *sub, struct sh_stream *sh)
// Try adding new converters until a decoder is reached
if (sd->driver->get_bitmaps || sd->driver->get_text) {
print_chain(sub);
+ pthread_mutex_unlock(&sub->lock);
return;
}
init_sd = (struct sd) {
@@ -204,6 +243,7 @@ void sub_init_from_sh(struct dec_sub *sub, struct sh_stream *sh)
sub_uninit(sub);
MP_ERR(sub, "Could not find subtitle decoder for format '%s'.\n",
sh->codec ? sh->codec : "<unknown>");
+ pthread_mutex_unlock(&sub->lock);
}
static struct demux_packet *get_decoded_packet(struct sd *sd)
@@ -262,7 +302,9 @@ static void decode_chain_recode(struct dec_sub *sub, struct sd **sd, int num_sd,
void sub_decode(struct dec_sub *sub, struct demux_packet *packet)
{
+ pthread_mutex_lock(&sub->lock);
decode_chain_recode(sub, sub->sd, sub->num_sd, packet);
+ pthread_mutex_unlock(&sub->lock);
}
static const char *guess_sub_cp(struct mp_log *log, struct packet_list *subs,
@@ -373,8 +415,13 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_stream *sh)
assert(sh && sh->sub);
struct MPOpts *opts = sub->opts;
+ pthread_mutex_lock(&sub->lock);
+
if (!sub_accept_packets_in_advance(sub) || sh->sub->track || sub->num_sd < 1)
+ {
+ pthread_mutex_unlock(&sub->lock);
return false;
+ }
struct packet_list *subs = talloc_zero(NULL, struct packet_list);
@@ -446,17 +493,24 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_stream *sh)
add_sub_list(sub, preprocess, subs);
+ pthread_mutex_unlock(&sub->lock);
talloc_free(subs);
return true;
}
bool sub_accept_packets_in_advance(struct dec_sub *sub)
{
+ pthread_mutex_lock(&sub->lock);
// Converters are assumed to always accept packets in advance
struct sd *sd = sub_get_last_sd(sub);
- return sd && sd->driver->accept_packets_in_advance;
+ bool r = sd && sd->driver->accept_packets_in_advance;
+ pthread_mutex_unlock(&sub->lock);
+ return r;
}
+// You must call sub_lock/sub_unlock if more than 1 thread access sub.
+// The issue is that *res will contain decoder allocated data, which might
+// be deallocated on the next decoder access.
void sub_get_bitmaps(struct dec_sub *sub, struct mp_osd_res dim, double pts,
struct sub_bitmaps *res)
{
@@ -472,12 +526,17 @@ void sub_get_bitmaps(struct dec_sub *sub, struct mp_osd_res dim, double pts,
bool sub_has_get_text(struct dec_sub *sub)
{
+ pthread_mutex_lock(&sub->lock);
struct sd *sd = sub_get_last_sd(sub);
- return sd && sd->driver->get_text;
+ bool r = sd && sd->driver->get_text;
+ pthread_mutex_unlock(&sub->lock);
+ return r;
}
+// See sub_get_bitmaps() for locking requirements.
char *sub_get_text(struct dec_sub *sub, double pts)
{
+ pthread_mutex_lock(&sub->lock);
struct MPOpts *opts = sub->opts;
struct sd *sd = sub_get_last_sd(sub);
char *text = NULL;
@@ -485,27 +544,33 @@ char *sub_get_text(struct dec_sub *sub, double pts)
if (sd->driver->get_text)
text = sd->driver->get_text(sd, pts);
}
+ pthread_mutex_unlock(&sub->lock);
return text;
}
void sub_reset(struct dec_sub *sub)
{
+ pthread_mutex_lock(&sub->lock);
for (int n = 0; n < sub->num_sd; n++) {
if (sub->sd[n]->driver->reset)
sub->sd[n]->driver->reset(sub->sd[n]);
}
+ pthread_mutex_unlock(&sub->lock);
}
int sub_control(struct dec_sub *sub, enum sd_ctrl cmd, void *arg)
{
+ int r = CONTROL_UNKNOWN;
+ pthread_mutex_lock(&sub->lock);
for (int n = 0; n < sub->num_sd; n++) {
if (sub->sd[n]->driver->control) {
- int r = sub->sd[n]->driver->control(sub->sd[n], cmd, arg);
+ r = sub->sd[n]->driver->control(sub->sd[n], cmd, arg);
if (r != CONTROL_UNKNOWN)
- return r;
+ break;
}
}
- return CONTROL_UNKNOWN;
+ pthread_mutex_unlock(&sub->lock);
+ return r;
}
#define MAX_PACKETS 10