AudioPolicyManager: update getDevicesForAttributes

Add forVolume parameter to enable special volume handling.
This is the first step to remove getDevicesForStream.

Test: volume changes; adb shell dumpsys audio
Bug: 219974551
Merged-In: If0886e6e885a06d927befadb02830cead421fabd
Change-Id: If0886e6e885a06d927befadb02830cead421fabd
diff --git a/media/libaudioclient/AudioSystem.cpp b/media/libaudioclient/AudioSystem.cpp
index 4c2284b..dd729c4 100644
--- a/media/libaudioclient/AudioSystem.cpp
+++ b/media/libaudioclient/AudioSystem.cpp
@@ -1270,7 +1270,8 @@
 }
 
 status_t AudioSystem::getDevicesForAttributes(const AudioAttributes& aa,
-                                              AudioDeviceTypeAddrVector* devices) {
+                                              AudioDeviceTypeAddrVector* devices,
+                                              bool forVolume) {
     if (devices == nullptr) {
         return BAD_VALUE;
     }
@@ -1281,7 +1282,7 @@
             legacy2aidl_AudioAttributes_AudioAttributesEx(aa));
     std::vector<AudioDevice> retAidl;
     RETURN_STATUS_IF_ERROR(
-            statusTFromBinderStatus(aps->getDevicesForAttributes(aaAidl, &retAidl)));
+            statusTFromBinderStatus(aps->getDevicesForAttributes(aaAidl, forVolume, &retAidl)));
     *devices = VALUE_OR_RETURN_STATUS(
             convertContainer<AudioDeviceTypeAddrVector>(
                     retAidl,
diff --git a/media/libaudioclient/aidl/android/media/IAudioPolicyService.aidl b/media/libaudioclient/aidl/android/media/IAudioPolicyService.aidl
index f10c5d0..748a10b 100644
--- a/media/libaudioclient/aidl/android/media/IAudioPolicyService.aidl
+++ b/media/libaudioclient/aidl/android/media/IAudioPolicyService.aidl
@@ -139,7 +139,7 @@
 
     AudioDeviceDescription[] getDevicesForStream(AudioStreamType stream);
 
-    AudioDevice[] getDevicesForAttributes(in AudioAttributesEx attr);
+    AudioDevice[] getDevicesForAttributes(in AudioAttributesEx attr, boolean forVolume);
 
     int /* audio_io_handle_t */ getOutputForEffect(in EffectDescriptor desc);
 
diff --git a/media/libaudioclient/include/media/AudioSystem.h b/media/libaudioclient/include/media/AudioSystem.h
index a1fb125..f1fcd3f 100644
--- a/media/libaudioclient/include/media/AudioSystem.h
+++ b/media/libaudioclient/include/media/AudioSystem.h
@@ -330,7 +330,8 @@
     static product_strategy_t getStrategyForStream(audio_stream_type_t stream);
     static DeviceTypeSet getDevicesForStream(audio_stream_type_t stream);
     static status_t getDevicesForAttributes(const AudioAttributes &aa,
-                                            AudioDeviceTypeAddrVector *devices);
+                                            AudioDeviceTypeAddrVector *devices,
+                                            bool forVolume);
 
     static audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc);
     static status_t registerEffect(const effect_descriptor_t *desc,
diff --git a/services/audiopolicy/AudioPolicyInterface.h b/services/audiopolicy/AudioPolicyInterface.h
index 5b2b87e..0ccc963 100644
--- a/services/audiopolicy/AudioPolicyInterface.h
+++ b/services/audiopolicy/AudioPolicyInterface.h
@@ -215,7 +215,8 @@
 
     // retrieves the list of enabled output devices for the given audio attributes
     virtual status_t getDevicesForAttributes(const audio_attributes_t &attr,
-                                             AudioDeviceTypeAddrVector *devices) = 0;
+                                             AudioDeviceTypeAddrVector *devices,
+                                             bool forVolume) = 0;
 
     // Audio effect management
     virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc) = 0;
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index fd42229..f981b26 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -3919,7 +3919,7 @@
 status_t AudioPolicyManager::getDirectProfilesForAttributes(const audio_attributes_t* attr,
                                                 AudioProfileVector& audioProfilesVector) {
     AudioDeviceTypeAddrVector devices;
-    status_t status = getDevicesForAttributes(*attr, &devices);
+    status_t status = getDevicesForAttributes(*attr, &devices, false /* forVolume */);
     if (status != OK) {
         return status;
     }
@@ -6472,24 +6472,69 @@
 
 // TODO - consider MSD routes b/214971780
 status_t AudioPolicyManager::getDevicesForAttributes(
-        const audio_attributes_t &attr, AudioDeviceTypeAddrVector *devices) {
+        const audio_attributes_t &attr, AudioDeviceTypeAddrVector *devices, bool forVolume) {
     if (devices == nullptr) {
         return BAD_VALUE;
     }
+
+    // Devices are determined in the following precedence:
+    //
+    // 1) Devices associated with a dynamic policy matching the attributes.  This is often
+    //    a remote submix from MIX_ROUTE_FLAG_LOOP_BACK.
+    //
+    // If no such dynamic policy then
+    // 2) Devices containing an active client using setPreferredDevice
+    //    with same strategy as the attributes.
+    //    (from the default Engine::getOutputDevicesForAttributes() implementation).
+    //
+    // If no corresponding active client with setPreferredDevice then
+    // 3) Devices associated with the strategy determined by the attributes
+    //    (from the default Engine::getOutputDevicesForAttributes() implementation).
+    //
+    // See related getOutputForAttrInt().
+
     // check dynamic policies but only for primary descriptors (secondary not used for audible
     // audio routing, only used for duplication for playback capture)
     sp<AudioPolicyMix> policyMix;
     status_t status = mPolicyMixes.getOutputForAttr(attr, 0 /*uid unknown here*/,
-            AUDIO_OUTPUT_FLAG_NONE, policyMix, nullptr);
+            AUDIO_OUTPUT_FLAG_NONE, policyMix, nullptr /* secondaryMixes */);
     if (status != OK) {
         return status;
     }
-    if (policyMix != nullptr && policyMix->getOutput() != nullptr) {
-        AudioDeviceTypeAddr device(policyMix->mDeviceType, policyMix->mDeviceAddress.c_str());
-        devices->push_back(device);
-        return NO_ERROR;
+
+    DeviceVector curDevices;
+    if (policyMix != nullptr && policyMix->getOutput() != nullptr &&
+            // For volume control, skip LOOPBACK mixes which use AUDIO_DEVICE_OUT_REMOTE_SUBMIX
+            // as they are unaffected by device/stream volume
+            // (per SwAudioOutputDescriptor::isFixedVolume()).
+            (!forVolume || policyMix->mDeviceType != AUDIO_DEVICE_OUT_REMOTE_SUBMIX)
+            ) {
+        sp<DeviceDescriptor> deviceDesc = mAvailableOutputDevices.getDevice(
+                policyMix->mDeviceType, policyMix->mDeviceAddress, AUDIO_FORMAT_DEFAULT);
+        curDevices.add(deviceDesc);
+    } else {
+        // The default Engine::getOutputDevicesForAttributes() uses findPreferredDevice()
+        // which selects setPreferredDevice if active.  This means forVolume call
+        // will take an active setPreferredDevice, if such exists.
+
+        curDevices = mEngine->getOutputDevicesForAttributes(
+                attr, nullptr /* preferredDevice */, false /* fromCache */);
     }
-    DeviceVector curDevices = mEngine->getOutputDevicesForAttributes(attr, nullptr, false);
+
+    if (forVolume) {
+        // We alias the device AUDIO_DEVICE_OUT_SPEAKER_SAFE to AUDIO_DEVICE_OUT_SPEAKER
+        // for single volume control in AudioService (such relationship should exist if
+        // SPEAKER_SAFE is present).
+        //
+        // (This is unrelated to a different device grouping as Volume::getDeviceCategory)
+        DeviceVector speakerSafeDevices =
+                curDevices.getDevicesFromType(AUDIO_DEVICE_OUT_SPEAKER_SAFE);
+        if (!speakerSafeDevices.isEmpty()) {
+            curDevices.merge(
+                    mAvailableOutputDevices.getDevicesFromType(AUDIO_DEVICE_OUT_SPEAKER));
+            curDevices.remove(speakerSafeDevices);
+        }
+    }
     for (const auto& device : curDevices) {
         devices->push_back(device->getDeviceTypeAddr());
     }
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.h b/services/audiopolicy/managerdefault/AudioPolicyManager.h
index daa4faf..ac8b625 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.h
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.h
@@ -193,9 +193,37 @@
         // return the enabled output devices for the given stream type
         virtual DeviceTypeSet getDevicesForStream(audio_stream_type_t stream);
 
+        /**
+         * Returns a vector of devices associated with attributes.
+         *
+         * An AudioTrack opened with specified attributes should play on the returned devices.
+         * If forVolume is set to true, the caller is AudioService, determining the proper
+         * device volume to adjust.
+         *
+         * Devices are determined in the following precedence:
+         * 1) Devices associated with a dynamic policy matching the attributes.  This is often
+         *    a remote submix from MIX_ROUTE_FLAG_LOOP_BACK.  Secondary mixes from a
+         *    dynamic policy are not included.
+         *
+         * If no such dynamic policy then
+         * 2) Devices containing an active client using setPreferredDevice
+         *    with same strategy as the attributes.
+         *    (from the default Engine::getOutputDevicesForAttributes() implementation).
+         *
+         * If no corresponding active client with setPreferredDevice then
+         * 3) Devices associated with the strategy determined by the attributes
+         *    (from the default Engine::getOutputDevicesForAttributes() implementation).
+         *
+         * @param attributes to be considered
+         * @param devices    an AudioDeviceTypeAddrVector container passed in that
+         *                   will be filled on success.
+         * @param forVolume  true if the devices are to be associated with current device volume.
+         * @return           NO_ERROR on success.
+         */
         virtual status_t getDevicesForAttributes(
                 const audio_attributes_t &attributes,
-                AudioDeviceTypeAddrVector *devices);
+                AudioDeviceTypeAddrVector *devices,
+                bool forVolume);
 
         virtual audio_io_handle_t getOutputForEffect(const effect_descriptor_t *desc = NULL);
         virtual status_t registerEffect(const effect_descriptor_t *desc,
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index 391d60a..82d28ca 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -1184,6 +1184,7 @@
 }
 
 Status AudioPolicyService::getDevicesForAttributes(const media::AudioAttributesEx& attrAidl,
+                                                   bool forVolume,
                                                    std::vector<AudioDevice>* _aidl_return)
 {
     AudioAttributes aa = VALUE_OR_RETURN_BINDER_STATUS(
@@ -1196,7 +1197,8 @@
     Mutex::Autolock _l(mLock);
     AutoCallerClear acc;
     RETURN_IF_BINDER_ERROR(binderStatusFromStatusT(
-            mAudioPolicyManager->getDevicesForAttributes(aa.getAttributes(), &devices)));
+            mAudioPolicyManager->getDevicesForAttributes(
+                    aa.getAttributes(), &devices, forVolume)));
     *_aidl_return = VALUE_OR_RETURN_BINDER_STATUS(
             convertContainer<std::vector<AudioDevice>>(devices,
                                                        legacy2aidl_AudioDeviceTypeAddress));
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 0a01b7b..f482886 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -138,6 +138,7 @@
             AudioStreamType stream,
             std::vector<AudioDeviceDescription>* _aidl_return) override;
     binder::Status getDevicesForAttributes(const media::AudioAttributesEx& attr,
+                                           bool forVolume,
                                            std::vector<AudioDevice>* _aidl_return) override;
     binder::Status getOutputForEffect(const media::EffectDescriptor& desc,
                                       int32_t* _aidl_return) override;