Make AudioTrack control block volume field private

This is part of the process of abstracting the control block
to make it easier to maintain.

Change-Id: Idb8f461e68dab3bcf268159cc0781651c6fb7094

3 files changed, 20 insertions, 8 deletions

diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h
index ffc546ee6cf8..dd97ce48d23e 100644
--- a/include/private/media/AudioTrackShared.h
+++ b/include/private/media/AudioTrackShared.h
@@ -76,7 +76,9 @@ struct audio_track_cblk_t
                 // Left channel is in [0:15], right channel is in [16:31].
                 // Always read and write the combined pair atomically.
                 // For AudioTrack only, not used by AudioRecord.
-                uint32_t    volumeLR;
+private:
+                uint32_t    mVolumeLR;
+public:
 
                 uint32_t    sampleRate;
                 // NOTE: audio_track_cblk_t::frameSize is not equal to AudioTrack::frameSize() for
@@ -116,6 +118,17 @@ public:
                 uint16_t    getSendLevel_U4_12() const {
                     return mSendLevel;
                 }
+
+                // for AudioTrack client only, caller must limit to 0 <= volumeLR <= 0x10001000
+                void        setVolumeLR(uint32_t volumeLR) {
+                    mVolumeLR = volumeLR;
+                }
+
+                // for AudioFlinger only; the return value must be validated by the caller
+                uint32_t    getVolumeLR() const {
+                    return mVolumeLR;
+                }
+
 };
 
 
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 17e3d4b440aa..90a67dbaf8e1 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -501,7 +501,7 @@ status_t AudioTrack::setVolume(float left, float right)
     mVolume[LEFT] = left;
     mVolume[RIGHT] = right;
 
-    mCblk->volumeLR = (uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000);
+    mCblk->setVolumeLR((uint32_t(uint16_t(right * 0x1000)) << 16) | uint16_t(left * 0x1000));
 
     return NO_ERROR;
 }
@@ -837,7 +837,7 @@ status_t AudioTrack::createTrack_l(
         mCblk->stepUser(mCblk->frameCount);
     }
 
-    mCblk->volumeLR = (uint32_t(uint16_t(mVolume[RIGHT] * 0x1000)) << 16) | uint16_t(mVolume[LEFT] * 0x1000);
+    mCblk->setVolumeLR((uint32_t(uint16_t(mVolume[RIGHT] * 0x1000)) << 16) | uint16_t(mVolume[LEFT] * 0x1000));
     mCblk->setSendLevel(mSendLevel);
     mAudioTrack->attachAuxEffect(mAuxEffectId);
     mCblk->bufferTimeoutMs = MAX_STARTUP_TIMEOUT_MS;
@@ -1320,7 +1320,7 @@ void AudioTrack::AudioTrackThread::onFirstRef()
 audio_track_cblk_t::audio_track_cblk_t()
     : lock(Mutex::SHARED), cv(Condition::SHARED), user(0), server(0),
     userBase(0), serverBase(0), buffers(0), frameCount(0),
-    loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), volumeLR(0),
+    loopStart(UINT_MAX), loopEnd(UINT_MAX), loopCount(0), mVolumeLR(0x10001000),
     mSendLevel(0), flags(0)
 {
 }
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index c6a9c7770fc4..d9f419bde277 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -2191,7 +2191,7 @@ uint32_t AudioFlinger::MixerThread::prepareTracks_l(const SortedVector< wp<Track
                 // read original volumes with volume control
                 float typeVolume = mStreamTypes[track->type()].volume;
                 float v = masterVolume * typeVolume;
-                uint32_t vlr = cblk->volumeLR;
+                uint32_t vlr = cblk->getVolumeLR();
                 vl = vlr & 0xFFFF;
                 vr = vlr >> 16;
                 // track volumes come from shared memory, so can't be trusted and must be clamped
@@ -2727,7 +2727,7 @@ bool AudioFlinger::DirectOutputThread::threadLoop()
                     } else {
                         float typeVolume = mStreamTypes[track->type()].volume;
                         float v = mMasterVolume * typeVolume;
-                        uint32_t vlr = cblk->volumeLR;
+                        uint32_t vlr = cblk->getVolumeLR();
                         float v_clamped = v * (vlr & 0xFFFF);
                         if (v_clamped > MAX_GAIN) v_clamped = MAX_GAIN;
                         left = v_clamped/MAX_GAIN;
@@ -3466,7 +3466,7 @@ void AudioFlinger::PlaybackThread::Track::destroy()
 
 void AudioFlinger::PlaybackThread::Track::dump(char* buffer, size_t size)
 {
-    uint32_t vlr = mCblk->volumeLR;
+    uint32_t vlr = mCblk->getVolumeLR();
     snprintf(buffer, size, "   %05d %05d %03u %03u 0x%08x %05u   %04u %1d %1d %1d %05u %05u %05u  0x%08x 0x%08x 0x%08x 0x%08x\n",
             mName - AudioMixer::TRACK0,
             (mClient == NULL) ? getpid() : mClient->pid(),
@@ -3825,7 +3825,6 @@ AudioFlinger::PlaybackThread::OutputTrack::OutputTrack(
     if (mCblk != NULL) {
         mCblk->flags |= CBLK_DIRECTION_OUT;
         mCblk->buffers = (char*)mCblk + sizeof(audio_track_cblk_t);
-        mCblk->volumeLR = (MAX_GAIN_INT << 16) | MAX_GAIN_INT;
         mOutBuffer.frameCount = 0;
         playbackThread->mTracks.add(this);
         ALOGV("OutputTrack constructor mCblk %p, mBuffer %p, mCblk->buffers %p, " \