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Eliminate all uses of volatile in the alsa player and just lock reads instead

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Originally committed to SVN as r6496.
This commit is contained in:
Thomas Goyne 2012-02-20 18:22:37 +00:00
parent df73e15f0f
commit fb6d3daf8b
1 changed files with 41 additions and 38 deletions
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79
aegisub/src/audio_player_alsa.cpp
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@ -57,6 +57,7 @@ class PthreadMutexLocker {
PthreadMutexLocker(const PthreadMutexLocker &); // uncopyable
PthreadMutexLocker(); // no default
PthreadMutexLocker& operator=(PthreadMutexLocker const&);
public:
explicit PthreadMutexLocker(pthread_mutex_t &mutex) : mutex(mutex)
@ -85,13 +86,14 @@ public:
class ScopedAliveFlag {
volatile bool &flag;
bool &flag;
ScopedAliveFlag(const ScopedAliveFlag &); // uncopyable
ScopedAliveFlag(); // no default
ScopedAliveFlag& operator=(ScopedAliveFlag const&);
public:
explicit ScopedAliveFlag(volatile bool &var) : flag(var) { flag = true; }
explicit ScopedAliveFlag(bool &var) : flag(var) { flag = true; }
~ScopedAliveFlag() { flag = false; }
};
@ -100,17 +102,17 @@ struct PlaybackState {
pthread_mutex_t mutex;
pthread_cond_t cond;
volatile bool playing;
volatile bool alive;
bool playing;
bool alive;
volatile bool signal_start;
volatile bool signal_stop;
volatile bool signal_close;
volatile bool signal_volume;
bool signal_start;
bool signal_stop;
bool signal_close;
bool signal_volume;
volatile double volume;
volatile int64_t start_position;
volatile int64_t end_position;
double volume;
int64_t start_position;
int64_t end_position;
AudioProvider *provider;
std::string device_name;
@ -160,18 +162,18 @@ void *playback_thread(void *arg)
snd_pcm_t *pcm = 0;
if (snd_pcm_open(&pcm, ps.device_name.c_str(), SND_PCM_STREAM_PLAYBACK, 0) != 0)
return (void*)"snd_pcm_open";
printf("alsa_player: opened pcm\n");
LOG_D("audio/player/alsa") << "opened pcm";
do_setup:
snd_pcm_format_t pcm_format;
switch (ps.provider->GetBytesPerSample())
{
case 1:
printf("alsa_player: format U8\n");
LOG_D("audio/player/alsa") << "format U8";
pcm_format = SND_PCM_FORMAT_U8;
break;
case 2:
printf("alsa_player: format S16_LE\n");
LOG_D("audio/player/alsa") << "format S16_LE";
pcm_format = SND_PCM_FORMAT_S16_LE;
break;
default:
@ -187,7 +189,7 @@ do_setup:
100*1000 // 100 milliseconds latency
) != 0)
return (void*)"snd_pcm_set_params";
printf("alsa_player: set pcm params\n");
LOG_D("audio/player/alsa") << "set pcm params";
size_t framesize = ps.provider->GetChannels() * ps.provider->GetBytesPerSample();
@ -197,16 +199,16 @@ do_setup:
// Wait for condition to trigger
if (!ps.signal_start)
ml.WaitCondition(ps.cond);
printf("alsa_player: outer loop, condition happened\n");
LOG_D("audio/player/alsa") << "outer loop, condition happened";
if (ps.signal_start == false || ps.end_position <= ps.start_position)
{
printf("alsa_player: nothing to play, rewaiting\n");
LOG_D("audio/player/alsa") << "nothing to play, rewaiting";
ps.signal_start = false;
continue;
}
printf("alsa_player: starting playback\n");
LOG_D("audio/player/alsa") << "starting playback";
int64_t position = ps.start_position;
// Playback position
@ -229,7 +231,7 @@ do_setup:
{
delete[] buf;
snd_pcm_close(pcm);
printf("alsa_player: error filling buffer\n");
LOG_D("audio/player/alsa") << "error filling buffer";
return (void*)"snd_pcm_writei";
}
}
@ -237,7 +239,7 @@ do_setup:
position += written;
// Start playback
printf("alsa_player: initial buffer filled, hitting start\n");
LOG_D("audio/player/alsa") << "initial buffer filled, hitting start";
snd_pcm_start(pcm);
ps.signal_start = false;
@ -249,12 +251,12 @@ do_setup:
// Sleep a bit, or until an event
ml.WaitConditionTimeout(ps.cond, 50);
//printf("alsa_player: playback loop, out of wait\n");
//LOG_D("audio/player/alsa") << "playback loop, out of wait";
// Check for stop signal
if (ps.signal_stop == true)
{
printf("alsa_player: playback loop, stop signal\n");
LOG_D("audio/player/alsa") << "playback loop, stop signal";
snd_pcm_drop(pcm);
break;
}
@ -287,24 +289,24 @@ do_setup:
{
delete[] buf;
snd_pcm_close(pcm);
printf("alsa_player: error filling buffer, written=%d\n", (int)written);
LOG_D("audio/player/alsa") << "error filling buffer, written=" << written;
return (void*)"snd_pcm_writei";
}
}
delete[] buf;
position += written;
//printf("alsa_player: playback loop, filled buffer\n");
//LOG_D("audio/player/alsa") << "playback loop, filled buffer";
// Check for end of playback
if (position >= ps.end_position)
{
printf("alsa_player: playback loop, past end, draining\n");
LOG_D("audio/player/alsa") << "playback loop, past end, draining";
snd_pcm_drain(pcm);
break;
}
}
ps.signal_stop = false;
printf("alsa_player: out of playback loop\n");
LOG_D("audio/player/alsa") << "out of playback loop";
switch (snd_pcm_state(pcm))
{
@ -330,7 +332,7 @@ do_setup:
}
}
ps.signal_close = false;
printf("alsa_player: out of outer loop\n");
LOG_D("audio/player/alsa") << "out of outer loop";
snd_pcm_close(pcm);
@ -364,13 +366,9 @@ void AlsaPlayer::OpenStream()
ps->device_name = std::string(device_name.utf8_str());
if (pthread_create(&thread, 0, &playback_thread, ps.get()) == 0)
{
open = true;
}
else
{
throw agi::AudioPlayerOpenError("AlsaPlayer: Creating the playback thread failed", 0);
}
}
@ -382,7 +380,7 @@ void AlsaPlayer::CloseStream()
PthreadMutexLocker ml(ps->mutex);
ps->signal_stop = true;
ps->signal_close = true;
printf("AlsaPlayer: close stream, stop+close signal\n");
LOG_D("audio/player/alsa") << "close stream, stop+close signal";
pthread_cond_signal(&ps->cond);
}
@ -405,7 +403,8 @@ void AlsaPlayer::Play(int64_t start, int64_t count)
pthread_cond_signal(&ps->cond);
}
if (displayTimer && !displayTimer->IsRunning()) displayTimer->Start(15);
if (displayTimer && !displayTimer->IsRunning())
displayTimer->Start(15);
}
@ -416,17 +415,17 @@ void AlsaPlayer::Stop(bool timerToo)
{
PthreadMutexLocker ml(ps->mutex);
ps->signal_stop = true;
printf("AlsaPlayer: stop stream, stop signal\n");
LOG_D("audio/player/alsa") << "stop stream, stop signal";
pthread_cond_signal(&ps->cond);
}
if (timerToo && displayTimer) {
if (timerToo && displayTimer)
displayTimer->Stop();
}
}
bool AlsaPlayer::IsPlaying()
{
PthreadMutexLocker ml(ps->mutex);
return open && ps->playing;
}
@ -450,19 +449,21 @@ void AlsaPlayer::SetCurrentPosition(int64_t pos)
ps->start_position = pos;
ps->signal_start = true;
ps->signal_stop = true;
printf("AlsaPlayer: set position, stop+start signal\n");
LOG_D("audio/player/alsa") << "set position, stop+start signal";
pthread_cond_signal(&ps->cond);
}
int64_t AlsaPlayer::GetStartPosition()
{
if (!open) return 0;
PthreadMutexLocker ml(ps->mutex);
return ps->start_position;
}
int64_t AlsaPlayer::GetEndPosition()
{
if (!open) return 0;
PthreadMutexLocker ml(ps->mutex);
return ps->end_position;
}
@ -476,7 +477,7 @@ int64_t AlsaPlayer::GetCurrentPosition()
int64_t samplerate;
{
//PthreadMutexLocker ml(ps->mutex);
PthreadMutexLocker ml(ps->mutex);
lastpos = ps->last_position;
lasttime = ps->last_position_time;
samplerate = ps->provider->GetSampleRate();
@ -500,6 +501,7 @@ int64_t AlsaPlayer::GetCurrentPosition()
void AlsaPlayer::SetVolume(double vol)
{
if (!open) return;
PthreadMutexLocker ml(ps->mutex);
ps->volume = vol;
ps->signal_volume = true;
@ -510,6 +512,7 @@ void AlsaPlayer::SetVolume(double vol)
double AlsaPlayer::GetVolume()
{
if (!open) return 1.0;
PthreadMutexLocker ml(ps->mutex);
return ps->volume;
}