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am d6f50b4a: Merge "audio HAL: reverse mutex locking order" into mnc-dev

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* commit 'd6f50b4a46a706b59cfee9e2e72b5c9bedc6eba1':
  audio HAL: reverse mutex locking order
This commit is contained in:
Eric Laurent 2015-06-23 03:20:30 +00:00 committed by Android Git Automerger
commit 99741914d1
1 changed files with 51 additions and 26 deletions
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77
modules/usbaudio/audio_hal.c
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@ -80,6 +80,7 @@ struct stream_out {
struct audio_stream_out stream;
pthread_mutex_t lock; /* see note below on mutex acquisition order */
pthread_mutex_t pre_lock; /* acquire before lock to avoid DOS by playback thread */
bool standby;
struct audio_device *dev; /* hardware information - only using this for the lock */
@ -103,7 +104,8 @@ struct stream_out {
struct stream_in {
struct audio_stream_in stream;
pthread_mutex_t lock; /* see note below on mutex acquisition order */
pthread_mutex_t lock; /* see note below on mutex acquisition order */
pthread_mutex_t pre_lock; /* acquire before lock to avoid DOS by capture thread */
bool standby;
struct audio_device *dev; /* hardware information - only using this for the lock */
@ -125,6 +127,13 @@ struct stream_in {
size_t conversion_buffer_size; /* in bytes */
};
/*
* NOTE: when multiple mutexes have to be acquired, always take the
* stream_in or stream_out mutex first, followed by the audio_device mutex.
* stream pre_lock is always acquired before stream lock to prevent starvation of control thread by
* higher priority playback or capture thread.
*/
/*
* Extract the card and device numbers from the supplied key/value pairs.
* kvpairs A null-terminated string containing the key/value pairs or card and device.
@ -203,6 +212,20 @@ static char * device_get_parameters(alsa_device_profile * profile, const char *
return result_str;
}
void lock_input_stream(struct stream_in *in)
{
pthread_mutex_lock(&in->pre_lock);
pthread_mutex_lock(&in->lock);
pthread_mutex_unlock(&in->pre_lock);
}
void lock_output_stream(struct stream_out *out)
{
pthread_mutex_lock(&out->pre_lock);
pthread_mutex_lock(&out->lock);
pthread_mutex_unlock(&out->pre_lock);
}
/*
* HAl Functions
*/
@ -260,16 +283,14 @@ static int out_standby(struct audio_stream *stream)
{
struct stream_out *out = (struct stream_out *)stream;
pthread_mutex_lock(&out->dev->lock);
pthread_mutex_lock(&out->lock);
lock_output_stream(out);
if (!out->standby) {
pthread_mutex_lock(&out->dev->lock);
proxy_close(&out->proxy);
pthread_mutex_unlock(&out->dev->lock);
out->standby = true;
}
pthread_mutex_unlock(&out->lock);
pthread_mutex_unlock(&out->dev->lock);
return 0;
}
@ -295,9 +316,9 @@ static int out_set_parameters(struct audio_stream *stream, const char *kvpairs)
return ret_value;
}
lock_output_stream(out);
/* Lock the device because that is where the profile lives */
pthread_mutex_lock(&out->dev->lock);
pthread_mutex_lock(&out->lock);
if (!profile_is_cached_for(out->profile, card, device)) {
/* cannot read pcm device info if playback is active */
@ -316,8 +337,8 @@ static int out_set_parameters(struct audio_stream *stream, const char *kvpairs)
}
}
pthread_mutex_unlock(&out->lock);
pthread_mutex_unlock(&out->dev->lock);
pthread_mutex_unlock(&out->lock);
return ret_value;
}
@ -325,8 +346,8 @@ static int out_set_parameters(struct audio_stream *stream, const char *kvpairs)
static char * out_get_parameters(const struct audio_stream *stream, const char *keys)
{
struct stream_out *out = (struct stream_out *)stream;
lock_output_stream(out);
pthread_mutex_lock(&out->dev->lock);
pthread_mutex_lock(&out->lock);
char * params_str = device_get_parameters(out->profile, keys);
@ -360,17 +381,16 @@ static ssize_t out_write(struct audio_stream_out *stream, const void* buffer, si
int ret;
struct stream_out *out = (struct stream_out *)stream;
pthread_mutex_lock(&out->dev->lock);
pthread_mutex_lock(&out->lock);
lock_output_stream(out);
if (out->standby) {
pthread_mutex_lock(&out->dev->lock);
ret = start_output_stream(out);
pthread_mutex_unlock(&out->dev->lock);
if (ret != 0) {
pthread_mutex_unlock(&out->dev->lock);
goto err;
}
out->standby = false;
}
pthread_mutex_unlock(&out->dev->lock);
alsa_device_proxy* proxy = &out->proxy;
const void * write_buff = buffer;
@ -480,6 +500,9 @@ static int adev_open_output_stream(struct audio_hw_device *dev,
out->stream.get_presentation_position = out_get_presentation_position;
out->stream.get_next_write_timestamp = out_get_next_write_timestamp;
pthread_mutex_init(&out->lock, (const pthread_mutexattr_t *) NULL);
pthread_mutex_init(&out->pre_lock, (const pthread_mutexattr_t *) NULL);
out->dev = adev;
pthread_mutex_lock(&adev->lock);
out->profile = &adev->out_profile;
@ -639,16 +662,15 @@ static int in_standby(struct audio_stream *stream)
{
struct stream_in *in = (struct stream_in *)stream;
pthread_mutex_lock(&in->dev->lock);
pthread_mutex_lock(&in->lock);
lock_input_stream(in);
if (!in->standby) {
pthread_mutex_lock(&in->dev->lock);
proxy_close(&in->proxy);
pthread_mutex_unlock(&in->dev->lock);
in->standby = true;
}
pthread_mutex_unlock(&in->lock);
pthread_mutex_unlock(&in->dev->lock);
return 0;
}
@ -676,8 +698,8 @@ static int in_set_parameters(struct audio_stream *stream, const char *kvpairs)
return ret_value;
}
lock_input_stream(in);
pthread_mutex_lock(&in->dev->lock);
pthread_mutex_lock(&in->lock);
if (card >= 0 && device >= 0 && !profile_is_cached_for(in->profile, card, device)) {
/* cannot read pcm device info if playback is active */
@ -696,8 +718,8 @@ static int in_set_parameters(struct audio_stream *stream, const char *kvpairs)
}
}
pthread_mutex_unlock(&in->lock);
pthread_mutex_unlock(&in->dev->lock);
pthread_mutex_unlock(&in->lock);
return ret_value;
}
@ -706,13 +728,13 @@ static char * in_get_parameters(const struct audio_stream *stream, const char *k
{
struct stream_in *in = (struct stream_in *)stream;
lock_input_stream(in);
pthread_mutex_lock(&in->dev->lock);
pthread_mutex_lock(&in->lock);
char * params_str = device_get_parameters(in->profile, keys);
pthread_mutex_unlock(&in->lock);
pthread_mutex_unlock(&in->dev->lock);
pthread_mutex_unlock(&in->lock);
return params_str;
}
@ -750,16 +772,16 @@ static ssize_t in_read(struct audio_stream_in *stream, void* buffer, size_t byte
struct stream_in * in = (struct stream_in *)stream;
pthread_mutex_lock(&in->dev->lock);
pthread_mutex_lock(&in->lock);
lock_input_stream(in);
if (in->standby) {
if (start_input_stream(in) != 0) {
pthread_mutex_unlock(&in->dev->lock);
pthread_mutex_lock(&in->dev->lock);
ret = start_input_stream(in);
pthread_mutex_unlock(&in->dev->lock);
if (ret != 0) {
goto err;
}
in->standby = false;
}
pthread_mutex_unlock(&in->dev->lock);
alsa_device_profile * profile = in->profile;
@ -858,6 +880,9 @@ static int adev_open_input_stream(struct audio_hw_device *dev,
in->stream.read = in_read;
in->stream.get_input_frames_lost = in_get_input_frames_lost;
pthread_mutex_init(&in->lock, (const pthread_mutexattr_t *) NULL);
pthread_mutex_init(&in->pre_lock, (const pthread_mutexattr_t *) NULL);
in->dev = (struct audio_device *)dev;
pthread_mutex_lock(&in->dev->lock);