am a1478073: Revert "Revert "audio HAL: fix thread starvation""

* commit 'a1478073c18fbdecd6510452304270d2149ae5b6':
  Revert "Revert "audio HAL: fix thread starvation""

2 files changed, 39 insertions, 18 deletions

diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index 86072c0c..ca86d75b 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -849,6 +849,20 @@ error_config:
     return ret;
 }
 
+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);
+}
+
 /* must be called with out->lock locked */
 static int send_offload_cmd_l(struct stream_out* out, int command)
 {
@@ -889,7 +903,7 @@ static void *offload_thread_loop(void *context)
     prctl(PR_SET_NAME, (unsigned long)"Offload Callback", 0, 0, 0);
 
     ALOGV("%s", __func__);
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     for (;;) {
         struct offload_cmd *cmd = NULL;
         stream_callback_event_t event;
@@ -948,7 +962,7 @@ static void *offload_thread_loop(void *context)
             ALOGE("%s unknown command received: %d", __func__, cmd->cmd);
             break;
         }
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         out->offload_thread_blocked = false;
         pthread_cond_signal(&out->cond);
         if (send_callback) {
@@ -980,7 +994,7 @@ static int create_offload_callback_thread(struct stream_out *out)
 
 static int destroy_offload_callback_thread(struct stream_out *out)
 {
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     stop_compressed_output_l(out);
     send_offload_cmd_l(out, OFFLOAD_CMD_EXIT);
 
@@ -1315,7 +1329,7 @@ static int out_standby(struct audio_stream *stream)
     ALOGV("%s: enter: usecase(%d: %s)", __func__,
           out->usecase, use_case_table[out->usecase]);
 
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     if (!out->standby) {
         if (adev->adm_deregister_stream)
             adev->adm_deregister_stream(adev->adm_data, out->handle);
@@ -1404,7 +1418,7 @@ static int out_set_parameters(struct audio_stream *stream, const char *kvpairs)
     ret = str_parms_get_str(parms, AUDIO_PARAMETER_STREAM_ROUTING, value, sizeof(value));
     if (ret >= 0) {
         val = atoi(value);
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         pthread_mutex_lock(&adev->lock);
 
         /*
@@ -1568,7 +1582,7 @@ static ssize_t out_write_for_no_output(struct audio_stream_out *stream,
     /* No Output device supported other than BT for playback.
      * Sleep for the amount of buffer duration
      */
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     usleep(bytes * 1000000 / audio_stream_frame_size(&out->stream.common) /
             out_get_sample_rate(&out->stream.common));
     pthread_mutex_unlock(&out->lock);
@@ -1583,7 +1597,7 @@ static ssize_t out_write(struct audio_stream_out *stream, const void *buffer,
     struct audio_device *adev = out->dev;
     ssize_t ret = 0;
 
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     if (out->standby) {
         out->standby = false;
         pthread_mutex_lock(&adev->lock);
@@ -1660,7 +1674,7 @@ static int out_get_render_position(const struct audio_stream_out *stream,
     struct stream_out *out = (struct stream_out *)stream;
     *dsp_frames = 0;
     if ((out->usecase == USECASE_AUDIO_PLAYBACK_OFFLOAD) && (dsp_frames != NULL)) {
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (out->compr != NULL) {
             compress_get_tstamp(out->compr, (unsigned long *)dsp_frames,
                     &out->sample_rate);
@@ -1698,7 +1712,7 @@ static int out_get_presentation_position(const struct audio_stream_out *stream,
     int ret = -1;
     unsigned long dsp_frames;
 
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
 
     if (out->usecase == USECASE_AUDIO_PLAYBACK_OFFLOAD) {
         if (out->compr != NULL) {
@@ -1742,7 +1756,7 @@ static int out_set_callback(struct audio_stream_out *stream,
     struct stream_out *out = (struct stream_out *)stream;
 
     ALOGV("%s", __func__);
-    pthread_mutex_lock(&out->lock);
+    lock_output_stream(out);
     out->offload_callback = callback;
     out->offload_cookie = cookie;
     pthread_mutex_unlock(&out->lock);
@@ -1755,7 +1769,7 @@ static int out_pause(struct audio_stream_out* stream)
     int status = -ENOSYS;
     ALOGV("%s", __func__);
     if (out->usecase == USECASE_AUDIO_PLAYBACK_OFFLOAD) {
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (out->compr != NULL && out->offload_state == OFFLOAD_STATE_PLAYING) {
             status = compress_pause(out->compr);
             out->offload_state = OFFLOAD_STATE_PAUSED;
@@ -1772,7 +1786,7 @@ static int out_resume(struct audio_stream_out* stream)
     ALOGV("%s", __func__);
     if (out->usecase == USECASE_AUDIO_PLAYBACK_OFFLOAD) {
         status = 0;
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (out->compr != NULL && out->offload_state == OFFLOAD_STATE_PAUSED) {
             status = compress_resume(out->compr);
             out->offload_state = OFFLOAD_STATE_PLAYING;
@@ -1788,7 +1802,7 @@ static int out_drain(struct audio_stream_out* stream, audio_drain_type_t type )
     int status = -ENOSYS;
     ALOGV("%s", __func__);
     if (out->usecase == USECASE_AUDIO_PLAYBACK_OFFLOAD) {
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         if (type == AUDIO_DRAIN_EARLY_NOTIFY)
             status = send_offload_cmd_l(out, OFFLOAD_CMD_PARTIAL_DRAIN);
         else
@@ -1803,7 +1817,7 @@ static int out_flush(struct audio_stream_out* stream)
     struct stream_out *out = (struct stream_out *)stream;
     ALOGV("%s", __func__);
     if (out->usecase == USECASE_AUDIO_PLAYBACK_OFFLOAD) {
-        pthread_mutex_lock(&out->lock);
+        lock_output_stream(out);
         stop_compressed_output_l(out);
         pthread_mutex_unlock(&out->lock);
         return 0;
@@ -1855,7 +1869,8 @@ static int in_standby(struct audio_stream *stream)
     struct audio_device *adev = in->dev;
     int status = 0;
     ALOGV("%s: enter", __func__);
-    pthread_mutex_lock(&in->lock);
+
+    lock_input_stream(in);
 
     if (!in->standby && in->is_st_session) {
         ALOGD("%s: sound trigger pcm stop lab", __func__);
@@ -1903,7 +1918,8 @@ static int in_set_parameters(struct audio_stream *stream, const char *kvpairs)
 
     ret = str_parms_get_str(parms, AUDIO_PARAMETER_STREAM_INPUT_SOURCE, value, sizeof(value));
 
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
+
     pthread_mutex_lock(&adev->lock);
     if (ret >= 0) {
         val = atoi(value);
@@ -1951,7 +1967,8 @@ static ssize_t in_read(struct audio_stream_in *stream, void *buffer,
     struct audio_device *adev = in->dev;
     int i, ret = -1;
 
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
+
     if (in->is_st_session) {
         ALOGVV(" %s: reading on st session bytes=%d", __func__, bytes);
         /* Read from sound trigger HAL */
@@ -2023,7 +2040,7 @@ static int add_remove_audio_effect(const struct audio_stream *stream,
     if (status != 0)
         return status;
 
-    pthread_mutex_lock(&in->lock);
+    lock_input_stream(in);
     pthread_mutex_lock(&in->dev->lock);
     if ((in->source == AUDIO_SOURCE_VOICE_COMMUNICATION) &&
             in->enable_aec != enable &&
@@ -2274,6 +2291,7 @@ static int adev_open_output_stream(struct audio_hw_device *dev,
     /* out->written = 0; by calloc() */
 
     pthread_mutex_init(&out->lock, (const pthread_mutexattr_t *) NULL);
+    pthread_mutex_init(&out->pre_lock, (const pthread_mutexattr_t *) NULL);
     pthread_cond_init(&out->cond, (const pthread_condattr_t *) NULL);
 
     config->format = out->stream.common.get_format(&out->stream.common);
@@ -2521,6 +2539,7 @@ static int adev_open_input_stream(struct audio_hw_device *dev,
     in = (struct stream_in *)calloc(1, sizeof(struct stream_in));
 
     pthread_mutex_init(&in->lock, (const pthread_mutexattr_t *) NULL);
+    pthread_mutex_init(&in->pre_lock, (const pthread_mutexattr_t *) NULL);
 
     in->stream.common.get_sample_rate = in_get_sample_rate;
     in->stream.common.set_sample_rate = in_set_sample_rate;
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index e6ce5dcb..8c07b6d5 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -125,6 +125,7 @@ struct offload_cmd {
 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 */
     pthread_cond_t  cond;
     struct pcm_config config;
     struct compr_config compr_config;
@@ -163,6 +164,7 @@ 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 pre_lock; /* acquire before lock to avoid DOS by capture thread */
     struct pcm_config config;
     struct pcm *pcm;
     int standby;