Plumb the notification about audio HAL services update to APM

AudioFlinger registers a callback with libaudiohal to receive
notifications when new HAL services get registered. It relays
the notification to AudioPolicyManager via AudioSystem /
IAudioPolicyService interface.

Because AF / APM only interact via Binder interfaces and APM's
interface gets registered later than AF's, the notification
from AF is made asynchronous.

Bug: 149854039
Test: audio test on a regular phone configuration
      audio test on a phone with MSD audio HAL module
Change-Id: I158e941b8f75e2a4614b9d84ca798b0f1f47aa6a
Merged-In: I158e941b8f75e2a4614b9d84ca798b0f1f47aa6a
diff --git a/media/libaudioclient/AudioSystem.cpp b/media/libaudioclient/AudioSystem.cpp
index 480930b..481becc 100644
--- a/media/libaudioclient/AudioSystem.cpp
+++ b/media/libaudioclient/AudioSystem.cpp
@@ -783,6 +783,13 @@
 
 // ---------------------------------------------------------------------------
 
+void AudioSystem::onNewAudioModulesAvailable()
+{
+    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
+    if (aps == 0) return;
+    aps->onNewAudioModulesAvailable();
+}
+
 status_t AudioSystem::setDeviceConnectionState(audio_devices_t device,
                                                audio_policy_dev_state_t state,
                                                const char *device_address,
diff --git a/media/libaudioclient/IAudioPolicyService.cpp b/media/libaudioclient/IAudioPolicyService.cpp
index 0facaf8..24d7c92 100644
--- a/media/libaudioclient/IAudioPolicyService.cpp
+++ b/media/libaudioclient/IAudioPolicyService.cpp
@@ -108,6 +108,7 @@
     SET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY,
     REMOVE_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY,
     GET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY,
+    AUDIO_MODULES_UPDATED,  // oneway
 };
 
 #define MAX_ITEMS_PER_LIST 1024
@@ -1336,6 +1337,13 @@
         }
         return static_cast<status_t>(reply.readInt32());
     }
+
+    virtual void onNewAudioModulesAvailable()
+    {
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioPolicyService::getInterfaceDescriptor());
+        remote()->transact(AUDIO_MODULES_UPDATED, data, &reply, IBinder::FLAG_ONEWAY);
+    }
 };
 
 IMPLEMENT_META_INTERFACE(AudioPolicyService, "android.media.IAudioPolicyService");
@@ -1401,7 +1409,8 @@
         case SET_RTT_ENABLED:
         case SET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY:
         case REMOVE_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY:
-        case GET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY: {
+        case GET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY:
+        case AUDIO_MODULES_UPDATED: {
             if (!isServiceUid(IPCThreadState::self()->getCallingUid())) {
                 ALOGW("%s: transaction %d received from PID %d unauthorized UID %d",
                       __func__, code, IPCThreadState::self()->getCallingPid(),
@@ -2458,6 +2467,12 @@
             return NO_ERROR;
         }
 
+        case AUDIO_MODULES_UPDATED: {
+            CHECK_INTERFACE(IAudioPolicyService, data, reply);
+            onNewAudioModulesAvailable();
+            return NO_ERROR;
+        } break;
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/media/libaudioclient/include/media/AudioSystem.h b/media/libaudioclient/include/media/AudioSystem.h
index a86297d..925bc89 100644
--- a/media/libaudioclient/include/media/AudioSystem.h
+++ b/media/libaudioclient/include/media/AudioSystem.h
@@ -211,6 +211,7 @@
     //
     // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
     //
+    static void onNewAudioModulesAvailable();
     static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state,
                                              const char *device_address, const char *device_name,
                                              audio_format_t encodedFormat);
diff --git a/media/libaudioclient/include/media/IAudioPolicyService.h b/media/libaudioclient/include/media/IAudioPolicyService.h
index 9b91d6d..3edac33 100644
--- a/media/libaudioclient/include/media/IAudioPolicyService.h
+++ b/media/libaudioclient/include/media/IAudioPolicyService.h
@@ -42,6 +42,7 @@
     //
     // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
     //
+    virtual void onNewAudioModulesAvailable() = 0;
     virtual status_t setDeviceConnectionState(audio_devices_t device,
                                               audio_policy_dev_state_t state,
                                               const char *device_address,
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 10a9c63..9e36f77 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -29,6 +29,7 @@
 #include <string>
 #include <sys/time.h>
 #include <sys/resource.h>
+#include <thread>
 
 #include <android/os/IExternalVibratorService.h>
 #include <binder/IPCThreadState.h>
@@ -143,6 +144,19 @@
     return sExternalVibratorService;
 }
 
+class DevicesFactoryHalCallbackImpl : public DevicesFactoryHalCallback {
+  public:
+    void onNewDevicesAvailable() override {
+        // Start a detached thread to execute notification in parallel.
+        // This is done to prevent mutual blocking of audio_flinger and
+        // audio_policy services during system initialization.
+        std::thread notifier([]() {
+            AudioSystem::onNewAudioModulesAvailable();
+        });
+        notifier.detach();
+    }
+};
+
 // ----------------------------------------------------------------------------
 
 std::string formatToString(audio_format_t format) {
@@ -221,6 +235,9 @@
     mMode = AUDIO_MODE_NORMAL;
 
     gAudioFlinger = this;
+
+    mDevicesFactoryHalCallback = new DevicesFactoryHalCallbackImpl;
+    mDevicesFactoryHal->setCallbackOnce(mDevicesFactoryHalCallback);
 }
 
 status_t AudioFlinger::setAudioHalPids(const std::vector<pid_t>& pids) {
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index a43a6dc..115bbb8 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -103,6 +103,7 @@
 class AudioBuffer;
 class AudioResampler;
 class DeviceHalInterface;
+class DevicesFactoryHalCallback;
 class DevicesFactoryHalInterface;
 class EffectsFactoryHalInterface;
 class FastMixer;
@@ -827,6 +828,7 @@
                 DefaultKeyedVector<audio_module_handle_t, AudioHwDevice*>  mAudioHwDevs;
 
                 sp<DevicesFactoryHalInterface> mDevicesFactoryHal;
+                sp<DevicesFactoryHalCallback> mDevicesFactoryHalCallback;
 
     // for dump, indicates which hardware operation is currently in progress (but not stream ops)
     enum hardware_call_state {
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index c1190be..227adc7 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -28,6 +28,14 @@
 
 // ----------------------------------------------------------------------------
 
+void AudioPolicyService::doOnNewAudioModulesAvailable()
+{
+    if (mAudioPolicyManager == NULL) return;
+    Mutex::Autolock _l(mLock);
+    AutoCallerClear acc;
+    mAudioPolicyManager->onNewAudioModulesAvailable();
+}
+
 status_t AudioPolicyService::setDeviceConnectionState(audio_devices_t device,
                                                   audio_policy_dev_state_t state,
                                                   const char *device_address,
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp
index 90939ce..3d9278b 100644
--- a/services/audiopolicy/service/AudioPolicyService.cpp
+++ b/services/audiopolicy/service/AudioPolicyService.cpp
@@ -1278,6 +1278,16 @@
                         mLock.lock();
                     }
                     } break;
+                case AUDIO_MODULES_UPDATE: {
+                    ALOGV("AudioCommandThread() processing audio modules update");
+                    svc = mService.promote();
+                    if (svc == 0) {
+                        break;
+                    }
+                    mLock.unlock();
+                    svc->doOnNewAudioModulesAvailable();
+                    mLock.lock();
+                    } break;
 
                 default:
                     ALOGW("AudioCommandThread() unknown command %d", command->mCommand);
@@ -1567,6 +1577,13 @@
     sendCommand(command);
 }
 
+void AudioPolicyService::AudioCommandThread::audioModulesUpdateCommand()
+{
+    sp<AudioCommand> command = new AudioCommand();
+    command->mCommand = AUDIO_MODULES_UPDATE;
+    sendCommand(command);
+}
+
 status_t AudioPolicyService::AudioCommandThread::sendCommand(sp<AudioCommand>& command, int delayMs)
 {
     {
@@ -1814,6 +1831,11 @@
     mAudioCommandThread->setEffectSuspendedCommand(effectId, sessionId, suspended);
 }
 
+void AudioPolicyService::onNewAudioModulesAvailable()
+{
+    mAudioCommandThread->audioModulesUpdateCommand();
+}
+
 
 extern "C" {
 audio_module_handle_t aps_load_hw_module(void *service __unused,
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 7b72dc1..0370438 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -60,6 +60,7 @@
     // BnAudioPolicyService (see AudioPolicyInterface for method descriptions)
     //
 
+    void onNewAudioModulesAvailable() override;
     virtual status_t setDeviceConnectionState(audio_devices_t device,
                                               audio_policy_dev_state_t state,
                                               const char *device_address,
@@ -268,6 +269,7 @@
 
     virtual status_t setRttEnabled(bool enabled);
 
+            void doOnNewAudioModulesAvailable();
             status_t doStopOutput(audio_port_handle_t portId);
             void doReleaseOutput(audio_port_handle_t portId);
 
@@ -450,6 +452,7 @@
             DYN_POLICY_MIX_STATE_UPDATE,
             RECORDING_CONFIGURATION_UPDATE,
             SET_EFFECT_SUSPENDED,
+            AUDIO_MODULES_UPDATE,
         };
 
         AudioCommandThread (String8 name, const wp<AudioPolicyService>& service);
@@ -495,6 +498,7 @@
                     void        setEffectSuspendedCommand(int effectId,
                                                           audio_session_t sessionId,
                                                           bool suspended);
+                    void        audioModulesUpdateCommand();
                     void        insertCommand_l(AudioCommand *command, int delayMs = 0);
     private:
         class AudioCommandData;