Implement audio device callback

Add class AudioSystem::AudioDeviceCallback notifying
AudioSystem clients upon device selection change on a given
input or output thread.
Maintain a list of installed callback per I/O handle in AudioSystem
and call registered callbacks when an OPEN of CONFIG_CHANGED event
is received on IAudioFlingerClient::ioConfigChanged().
Add methods to AudioTrack and AudioRecord to add and remove device
change callbacks.
Add methods to AudioTrack and AudioRecord to query currently selected
device.
ioConfigChanged() events now convey the audio patch describing
the input or output thread routing.

Fix AudioRecord failure to start when invalidation is
handled by start().

Change-Id: I9e938adf025fa712337c63b1e02a8c18f2a20d39

2 files changed, 9 insertions, 0 deletions

diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 8b8dd78..2c4d801 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -500,6 +500,7 @@ AudioFlinger::ThreadBase::ThreadBase(const sp<AudioFlinger>& audioFlinger, audio
         // mName will be set by concrete (non-virtual) subclass
         mDeathRecipient(new PMDeathRecipient(this))
 {
+    memset(&mPatch, 0, sizeof(struct audio_patch));
 }
 
 AudioFlinger::ThreadBase::~ThreadBase()
@@ -1930,6 +1931,7 @@ void AudioFlinger::PlaybackThread::ioConfigChanged(audio_io_config_event event)
     switch (event) {
     case AUDIO_OUTPUT_OPENED:
     case AUDIO_OUTPUT_CONFIG_CHANGED:
+        desc->mPatch = mPatch;
         desc->mChannelMask = mChannelMask;
         desc->mSamplingRate = mSampleRate;
         desc->mFormat = mFormat;
@@ -3002,6 +3004,7 @@ status_t AudioFlinger::PlaybackThread::createAudioPatch_l(const struct audio_pat
         mEffectChains[i]->setDevice_l(type);
     }
     mOutDevice = type;
+    mPatch = *patch;
 
     if (mOutput->audioHwDev->version() >= AUDIO_DEVICE_API_VERSION_3_0) {
         audio_hw_device_t *hwDevice = mOutput->audioHwDev->hwDevice();
@@ -3028,6 +3031,7 @@ status_t AudioFlinger::PlaybackThread::createAudioPatch_l(const struct audio_pat
                 param.toString().string());
         *handle = AUDIO_PATCH_HANDLE_NONE;
     }
+    sendIoConfigEvent_l(AUDIO_OUTPUT_CONFIG_CHANGED);
     return status;
 }
 
@@ -6727,6 +6731,7 @@ void AudioFlinger::RecordThread::ioConfigChanged(audio_io_config_event event) {
     switch (event) {
     case AUDIO_INPUT_OPENED:
     case AUDIO_INPUT_CONFIG_CHANGED:
+        desc->mPatch = mPatch;
         desc->mChannelMask = mChannelMask;
         desc->mSamplingRate = mSampleRate;
         desc->mFormat = mFormat;
@@ -6884,6 +6889,7 @@ status_t AudioFlinger::RecordThread::createAudioPatch_l(const struct audio_patch
 
     // store new device and send to effects
     mInDevice = patch->sources[0].ext.device.type;
+    mPatch = *patch;
     for (size_t i = 0; i < mEffectChains.size(); i++) {
         mEffectChains[i]->setDevice_l(mInDevice);
     }
@@ -6936,6 +6942,8 @@ status_t AudioFlinger::RecordThread::createAudioPatch_l(const struct audio_patch
         *handle = AUDIO_PATCH_HANDLE_NONE;
     }
 
+    sendIoConfigEvent_l(AUDIO_INPUT_CONFIG_CHANGED);
+
     return status;
 }
 
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 8167bd1..0a5597f 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -426,6 +426,7 @@ protected:
                 bool                    mStandby;     // Whether thread is currently in standby.
                 audio_devices_t         mOutDevice;   // output device
                 audio_devices_t         mInDevice;    // input device
+                struct audio_patch      mPatch;
                 audio_source_t          mAudioSource;
 
                 const audio_io_handle_t mId;