Convert getDevicesForStream to return a DeviceTypeSet

As a pre-requisite for switching from 'int' to
'AudioDeviceDescription' in the framework AIDL interfaces,
get rid of the usage of 'int' as a mask of 'audio_devices_t'
values. This is needed because 'AudioDeviceDescription'
can't be coerced into an int directly, and interpreting
a mask of multiple 'audio_devices_t' values is ambiguous
due to presence of multi-bit device types.

Note that at the Java layer the returned DeviceTypeSet
is still collapsed into a single integer value. This needs
to be addressed separately.

Bug: 188932434
Test: check audio on device
Change-Id: I1bc2a28ac2e1037a38b7be7967349b33845f88de
diff --git a/services/audiopolicy/AudioPolicyInterface.h b/services/audiopolicy/AudioPolicyInterface.h
index 2e49e71..a8bb7da 100644
--- a/services/audiopolicy/AudioPolicyInterface.h
+++ b/services/audiopolicy/AudioPolicyInterface.h
@@ -18,6 +18,7 @@
 #define ANDROID_AUDIOPOLICY_INTERFACE_H
 
 #include <media/AudioCommonTypes.h>
+#include <media/AudioContainers.h>
 #include <media/AudioDeviceTypeAddr.h>
 #include <media/AudioSystem.h>
 #include <media/AudioPolicy.h>
@@ -198,7 +199,7 @@
     virtual product_strategy_t getStrategyForStream(audio_stream_type_t stream) = 0;
 
     // return the enabled output devices for the given stream type
-    virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream) = 0;
+    virtual DeviceTypeSet getDevicesForStream(audio_stream_type_t stream) = 0;
 
     // retrieves the list of enabled output devices for the given audio attributes
     virtual status_t getDevicesForAttributes(const audio_attributes_t &attr,
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index 49db0d1..18bc7bd 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -5917,13 +5917,13 @@
     return (stream1 == stream2);
 }
 
-audio_devices_t AudioPolicyManager::getDevicesForStream(audio_stream_type_t stream) {
+DeviceTypeSet AudioPolicyManager::getDevicesForStream(audio_stream_type_t stream) {
     // By checking the range of stream before calling getStrategy, we avoid
     // getOutputDevicesForStream's behavior for invalid streams.
     // engine's getOutputDevicesForStream would fallback on its default behavior (most probably
     // device for music stream), but we want to return the empty set.
     if (stream < AUDIO_STREAM_MIN || stream >= AUDIO_STREAM_PUBLIC_CNT) {
-        return AUDIO_DEVICE_NONE;
+        return DeviceTypeSet{};
     }
     DeviceVector activeDevices;
     DeviceVector devices;
@@ -5954,8 +5954,7 @@
         devices.merge(mAvailableOutputDevices.getDevicesFromType(AUDIO_DEVICE_OUT_SPEAKER));
         devices.remove(speakerSafeDevices);
     }
-    // FIXME: use DeviceTypeSet when Java layer is ready for it.
-    return deviceTypesToBitMask(devices.types());
+    return devices.types();
 }
 
 status_t AudioPolicyManager::getDevicesForAttributes(
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.h b/services/audiopolicy/managerdefault/AudioPolicyManager.h
index 98f96d1..8534923 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.h
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.h
@@ -193,7 +193,7 @@
         }
 
         // return the enabled output devices for the given stream type
-        virtual audio_devices_t getDevicesForStream(audio_stream_type_t stream);
+        virtual DeviceTypeSet getDevicesForStream(audio_stream_type_t stream);
 
         virtual status_t getDevicesForAttributes(
                 const audio_attributes_t &attributes,
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index 90332af..4183fd8 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -1076,13 +1076,12 @@
 //audio policy: use audio_device_t appropriately
 
 Status AudioPolicyService::getDevicesForStream(media::AudioStreamType streamAidl,
-                                               int32_t* _aidl_return) {
+                                               std::vector<int32_t>* _aidl_return) {
     audio_stream_type_t stream = VALUE_OR_RETURN_BINDER_STATUS(
             aidl2legacy_AudioStreamType_audio_stream_type_t(streamAidl));
 
     if (uint32_t(stream) >= AUDIO_STREAM_PUBLIC_CNT) {
-        *_aidl_return = VALUE_OR_RETURN_BINDER_STATUS(
-                legacy2aidl_audio_devices_t_int32_t(AUDIO_DEVICE_NONE));
+        *_aidl_return = std::vector<int32_t>{};
         return Status::ok();
     }
     if (mAudioPolicyManager == NULL) {
@@ -1091,7 +1090,9 @@
     Mutex::Autolock _l(mLock);
     AutoCallerClear acc;
     *_aidl_return = VALUE_OR_RETURN_BINDER_STATUS(
-            legacy2aidl_audio_devices_t_int32_t(mAudioPolicyManager->getDevicesForStream(stream)));
+            convertContainer<std::vector<int32_t>>(
+                    mAudioPolicyManager->getDevicesForStream(stream),
+                    legacy2aidl_audio_devices_t_int32_t));
     return Status::ok();
 }
 
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index ed9f44e..11212f6 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -118,7 +118,7 @@
     binder::Status getStrategyForStream(media::AudioStreamType stream,
                                         int32_t* _aidl_return) override;
     binder::Status getDevicesForStream(media::AudioStreamType stream,
-                                       int32_t* _aidl_return) override;
+                                       std::vector<int32_t>* _aidl_return) override;
     binder::Status getDevicesForAttributes(const media::AudioAttributesEx& attr,
                                            std::vector<media::AudioDevice>* _aidl_return) override;
     binder::Status getOutputForEffect(const media::EffectDescriptor& desc,