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

1 files changed, 71 insertions, 0 deletions

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