audiopolicy: Add AudioSessionInfo API

 * This patch introduces a new API which allows applications to
   query the state of the audio effects system, and receive
   callbacks with the necessary information to attach effects
   to any stream.
 * In the future, this may come as part of the AudioPort system,
   but since that's an active area of development by Google, we
   will dodge it for now.
 * The policy now simply keeps a refcounted list of objects which
   hold various bits of stream metadata. Callbacks are sent on
   stream open/close to applications which might be listening
   for them.

Change-Id: I2d554d36e1378f4eb7b276010a3bfe8345c22ecd

5 files changed, 86 insertions, 0 deletions

diff --git a/include/media/AudioPolicy.h b/include/media/AudioPolicy.h
index feed402..7e33df7 100644
--- a/include/media/AudioPolicy.h
+++ b/include/media/AudioPolicy.h
@@ -23,6 +23,7 @@
 #include <binder/Parcel.h>
 #include <utils/String8.h>
 #include <utils/Vector.h>
+#include <media/AudioSession.h>
 
 namespace android {
 
@@ -42,6 +43,7 @@ namespace android {
 //   AudioSystem's implementation of the AudioPolicyClient interface
 // keep in sync with AudioSystem.java
 #define DYNAMIC_POLICY_EVENT_MIX_STATE_UPDATE 0
+#define AUDIO_OUTPUT_SESSION_EFFECTS_UPDATE 10
 
 #define MIX_STATE_DISABLED -1
 #define MIX_STATE_IDLE 0
diff --git a/include/media/AudioSession.h b/include/media/AudioSession.h
new file mode 100644
index 0000000..d9658cc
--- /dev/null
+++ b/include/media/AudioSession.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2016 The CyanogenMod Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_AUDIOSESSION_H
+#define ANDROID_AUDIOSESSION_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <system/audio.h>
+
+#include <utils/RefBase.h>
+#include <utils/Errors.h>
+#include <binder/Parcel.h>
+
+namespace android {
+
+// class to store streaminfo
+class AudioSessionInfo : public RefBase {
+public:
+    AudioSessionInfo(int session, audio_stream_type_t stream, audio_output_flags_t flags,
+            audio_channel_mask_t channelMask, uid_t uid) :
+        mSessionId(session), mStream(stream), mFlags(flags), mChannelMask(channelMask),
+        mUid(uid), mRefCount(0) {}
+
+    AudioSessionInfo() : mSessionId(0), mStream(AUDIO_STREAM_DEFAULT), mFlags(AUDIO_OUTPUT_FLAG_NONE), mChannelMask(AUDIO_CHANNEL_NONE), mUid(0) {}
+
+    /*virtual*/ ~AudioSessionInfo() {}
+
+    int mSessionId;
+    audio_stream_type_t mStream;
+    audio_output_flags_t mFlags;
+    audio_channel_mask_t mChannelMask;
+    uid_t mUid;
+
+    // AudioPolicyManager keeps mLock, no need for lock on reference count here
+    int mRefCount;
+
+    void readFromParcel(const Parcel &parcel)  {
+        mSessionId = parcel.readInt32();
+        mStream = static_cast<audio_stream_type_t>(parcel.readInt32());
+        mFlags = static_cast<audio_output_flags_t>(parcel.readInt32());
+        mChannelMask = static_cast<audio_channel_mask_t>(parcel.readInt32());
+        mUid = static_cast<uid_t>(parcel.readInt32());
+    }
+
+    void writeToParcel(Parcel *parcel) const {
+        parcel->writeInt32(mSessionId);
+        parcel->writeInt32(mStream);
+        parcel->writeInt32(mFlags);
+        parcel->writeInt32(mChannelMask);
+        parcel->writeInt32(mUid);
+    }
+};
+
+}; // namespace android
+
+#endif // ANDROID_AUDIOSESSION_H
diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 26a0bb2..3f4a610 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -31,6 +31,8 @@ namespace android {
 
 typedef void (*audio_error_callback)(status_t err);
 typedef void (*dynamic_policy_callback)(int event, String8 regId, int val);
+typedef void (*audio_session_callback)(int event,
+        sp<AudioSessionInfo>& session, bool added);
 
 class IAudioFlinger;
 class IAudioPolicyService;
@@ -92,6 +94,7 @@ public:
 
     static void setErrorCallback(audio_error_callback cb);
     static void setDynPolicyCallback(dynamic_policy_callback cb);
+    static status_t setAudioSessionCallback(audio_session_callback cb);
 
     // helper function to obtain AudioFlinger service handle
     static const sp<IAudioFlinger> get_audio_flinger();
@@ -319,6 +322,8 @@ public:
                                       audio_io_handle_t *handle);
     static status_t stopAudioSource(audio_io_handle_t handle);
 
+    static status_t listAudioSessions(audio_stream_type_t streams,
+                                      Vector< sp<AudioSessionInfo>> &sessions);
 
     // ----------------------------------------------------------------------------
 
@@ -419,6 +424,7 @@ private:
         virtual void onAudioPortListUpdate();
         virtual void onAudioPatchListUpdate();
         virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state);
+        virtual void onOutputSessionEffectsUpdate(sp<AudioSessionInfo>& info, bool added);
 
     private:
         Mutex                               mLock;
@@ -438,6 +444,7 @@ private:
     static sp<IAudioFlinger> gAudioFlinger;
     static audio_error_callback gAudioErrorCallback;
     static dynamic_policy_callback gDynPolicyCallback;
+    static audio_session_callback gAudioSessionCallback;
 
     static size_t gInBuffSize;
     // previous parameters for recording buffer size queries
diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index 6b93f6f..1df91ee 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -165,6 +165,9 @@ public:
                                       const audio_attributes_t *attributes,
                                       audio_io_handle_t *handle) = 0;
     virtual status_t stopAudioSource(audio_io_handle_t handle) = 0;
+
+    virtual status_t listAudioSessions(audio_stream_type_t streams,
+                                       Vector< sp<AudioSessionInfo>> &sessions) = 0;
 };
 
 
diff --git a/include/media/IAudioPolicyServiceClient.h b/include/media/IAudioPolicyServiceClient.h
index a7f2cc3..ec38157 100644
--- a/include/media/IAudioPolicyServiceClient.h
+++ b/include/media/IAudioPolicyServiceClient.h
@@ -21,6 +21,7 @@
 #include <utils/RefBase.h>
 #include <binder/IInterface.h>
 #include <system/audio.h>
+#include <media/AudioSession.h>
 
 namespace android {
 
@@ -37,6 +38,8 @@ public:
     virtual void onAudioPatchListUpdate() = 0;
     // Notifies a change in the mixing state of a specific mix in a dynamic audio policy
     virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state) = 0;
+    // Notifies when a default effect set is attached to a session/stream
+    virtual void onOutputSessionEffectsUpdate(sp<AudioSessionInfo>& info, bool added) = 0;
 };