diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index 2436248..0af4c7b 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -148,14 +148,6 @@
     void                setFinalVolume(float volume);
     float               getFinalVolume() const { return mFinalVolume; }
 
-    /** @return true if the track has changed (metadata or volume) since
-     *          the last time this function was called,
-     *          true if this function was never called since the track creation,
-     *          false otherwise.
-     *  Thread safe.
-     */
-    bool            readAndClearHasChanged() { return !mChangeNotified.test_and_set(); }
-
     using SourceMetadatas = std::vector<playback_track_metadata_v7_t>;
     using MetadataInserter = std::back_insert_iterator<SourceMetadatas>;
     /** Copy the track metadata in the provided iterator. Thread safe. */
@@ -234,8 +226,6 @@
     bool presentationComplete(int64_t framesWritten, size_t audioHalFrames);
     void signalClientFlag(int32_t flag);
 
-    /** Set that a metadata has changed and needs to be notified to backend. Thread safe. */
-    void setMetadataHasChanged() { mChangeNotified.clear(); }
 public:
     void triggerEvents(AudioSystem::sync_event_t type);
     virtual void invalidate();
@@ -320,8 +310,6 @@
     bool                mFlushHwPending; // track requests for thread flush
     bool                mPauseHwPending = false; // direct/offload track request for thread pause
     audio_output_flags_t mFlags;
-    // If the last track change was notified to the client with readAndClearHasChanged
-    std::atomic_flag     mChangeNotified = ATOMIC_FLAG_INIT;
     TeePatches  mTeePatches;
 };  // end of Track
 
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index d42a6ca..d878611 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -1798,8 +1798,14 @@
 
 template <typename T>
 bool AudioFlinger::ThreadBase::ActiveTracks<T>::readAndClearHasChanged() {
-    const bool hasChanged = mHasChanged;
+    bool hasChanged = mHasChanged;
     mHasChanged = false;
+
+    for (const sp<T> &track : mActiveTracks) {
+        // Do not short-circuit as all hasChanged states must be reset
+        // as all the metadata are going to be sent
+        hasChanged |= track->readAndClearHasChanged();
+    }
     return hasChanged;
 }
 
@@ -1986,7 +1992,7 @@
 
 void AudioFlinger::PlaybackThread::onFirstRef()
 {
-    if (mOutput == nullptr || mOutput->stream == nullptr) {
+    if (!isStreamInitialized()) {
         ALOGE("The stream is not open yet"); // This should not happen.
     } else {
         // setEventCallback will need a strong pointer as a parameter. Calling it
@@ -2695,7 +2701,7 @@
 
 status_t AudioFlinger::DirectOutputThread::selectPresentation(int presentationId, int programId) {
     Mutex::Autolock _l(mLock);
-    if (mOutput == nullptr || mOutput->stream == nullptr) {
+    if (!isStreamInitialized()) {
         return NO_INIT;
     }
     return mOutput->stream->selectPresentation(presentationId, programId);
@@ -2992,16 +2998,7 @@
 
 void AudioFlinger::PlaybackThread::updateMetadata_l()
 {
-    if (mOutput == nullptr || mOutput->stream == nullptr ) {
-        return; // That should not happen
-    }
-    bool hasChanged = mActiveTracks.readAndClearHasChanged();
-    for (const sp<Track> &track : mActiveTracks) {
-        // Do not short-circuit as all hasChanged states must be reset
-        // as all the metadata are going to be sent
-        hasChanged |= track->readAndClearHasChanged();
-    }
-    if (!hasChanged) {
+    if (!isStreamInitialized() || !mActiveTracks.readAndClearHasChanged()) {
         return; // nothing to do
     }
     StreamOutHalInterface::SourceMetadata metadata;
@@ -8186,7 +8183,7 @@
 {
     ALOGV("RecordThread::getActiveMicrophones");
     AutoMutex _l(mLock);
-    if (mInput == nullptr || mInput->stream == nullptr) {
+    if (!isStreamInitialized()) {
         return NO_INIT;
     }
     status_t status = mInput->stream->getActiveMicrophones(activeMicrophones);
@@ -8198,7 +8195,7 @@
 {
     ALOGV("setPreferredMicrophoneDirection(%d)", direction);
     AutoMutex _l(mLock);
-    if (mInput == nullptr || mInput->stream == nullptr) {
+    if (!isStreamInitialized()) {
         return NO_INIT;
     }
     return mInput->stream->setPreferredMicrophoneDirection(direction);
@@ -8208,7 +8205,7 @@
 {
     ALOGV("setPreferredMicrophoneFieldDimension(%f)", zoom);
     AutoMutex _l(mLock);
-    if (mInput == nullptr || mInput->stream == nullptr) {
+    if (!isStreamInitialized()) {
         return NO_INIT;
     }
     return mInput->stream->setPreferredMicrophoneFieldDimension(zoom);
@@ -8259,9 +8256,8 @@
 
 void AudioFlinger::RecordThread::updateMetadata_l()
 {
-    if (mInput == nullptr || mInput->stream == nullptr ||
-            !mActiveTracks.readAndClearHasChanged()) {
-        return;
+    if (!isStreamInitialized() || !mActiveTracks.readAndClearHasChanged()) {
+        return; // nothing to do
     }
     StreamInHalInterface::SinkMetadata metadata;
     for (const sp<RecordTrack> &track : mActiveTracks) {
@@ -9959,14 +9955,16 @@
                 }
             }
         }
+        for (const sp<MmapTrack> &track : mActiveTracks) {
+            track->setMetadataHasChanged();
+        }
     }
 }
 
 void AudioFlinger::MmapPlaybackThread::updateMetadata_l()
 {
-    if (mOutput == nullptr || mOutput->stream == nullptr ||
-            !mActiveTracks.readAndClearHasChanged()) {
-        return;
+    if (!isStreamInitialized() || !mActiveTracks.readAndClearHasChanged()) {
+        return; // nothing to do
     }
     StreamOutHalInterface::SourceMetadata metadata;
     for (const sp<MmapTrack> &track : mActiveTracks) {
@@ -10093,9 +10091,8 @@
 
 void AudioFlinger::MmapCaptureThread::updateMetadata_l()
 {
-    if (mInput == nullptr || mInput->stream == nullptr ||
-            !mActiveTracks.readAndClearHasChanged()) {
-        return;
+    if (!isStreamInitialized() || !mActiveTracks.readAndClearHasChanged()) {
+        return; // nothing to do
     }
     StreamInHalInterface::SinkMetadata metadata;
     for (const sp<MmapTrack> &track : mActiveTracks) {
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 65db986..17acb16 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -527,6 +527,8 @@
                     }
                 }
 
+    virtual     bool isStreamInitialized() = 0;
+
 protected:
 
                 // entry describing an effect being suspended in mSuspendedSessions keyed vector
@@ -741,7 +743,9 @@
                     void            updatePowerState(sp<ThreadBase> thread, bool force = false);
 
                     /** @return true if one or move active tracks was added or removed since the
-                     *          last time this function was called or the vector was created. */
+                     *          last time this function was called or the vector was created.
+                     *          true if volume of one of active tracks was changed.
+                     */
                     bool            readAndClearHasChanged();
 
                 private:
@@ -993,6 +997,10 @@
                                         && outDeviceTypes().count(mTimestampCorrectedDevice) != 0;
                             }
 
+    virtual     bool        isStreamInitialized() {
+                                return !(mOutput == nullptr || mOutput->stream == nullptr);
+                            }
+
                 audio_channel_mask_t hapticChannelMask() const override {
                                          return mHapticChannelMask;
                                      }
@@ -1780,6 +1788,10 @@
                                           audio_session_t sharedSessionId = AUDIO_SESSION_NONE,
                                           int64_t sharedAudioStartMs = -1);
 
+    virtual bool        isStreamInitialized() {
+                            return !(mInput == nullptr || mInput->stream == nullptr);
+                        }
+
 protected:
             void        dumpInternals_l(int fd, const Vector<String16>& args) override;
             void        dumpTracks_l(int fd, const Vector<String16>& args) override;
@@ -1949,6 +1961,8 @@
     virtual     void        setRecordSilenced(audio_port_handle_t portId __unused,
                                               bool silenced __unused) {}
 
+    virtual     bool        isStreamInitialized() { return false; }
+
  protected:
                 void        dumpInternals_l(int fd, const Vector<String16>& args) override;
                 void        dumpTracks_l(int fd, const Vector<String16>& args) override;
@@ -2011,6 +2025,10 @@
 
                 status_t    getExternalPosition(uint64_t *position, int64_t *timeNanos) override;
 
+    virtual     bool        isStreamInitialized() {
+                                return !(mOutput == nullptr || mOutput->stream == nullptr);
+                            }
+
 protected:
                 void        dumpInternals_l(int fd, const Vector<String16>& args) override;
 
@@ -2043,6 +2061,10 @@
 
                 status_t       getExternalPosition(uint64_t *position, int64_t *timeNanos) override;
 
+    virtual     bool           isStreamInitialized() {
+                                   return !(mInput == nullptr || mInput->stream == nullptr);
+                               }
+
 protected:
 
                 AudioStreamIn*  mInput;
diff --git a/services/audioflinger/TrackBase.h b/services/audioflinger/TrackBase.h
index 38dab5b..92f129c 100644
--- a/services/audioflinger/TrackBase.h
+++ b/services/audioflinger/TrackBase.h
@@ -255,6 +255,17 @@
 
     audio_channel_mask_t channelMask() const { return mChannelMask; }
 
+    /** @return true if the track has changed (metadata or volume) since
+     *          the last time this function was called,
+     *          true if this function was never called since the track creation,
+     *          false otherwise.
+     *  Thread safe.
+     */
+    bool readAndClearHasChanged() { return !mChangeNotified.test_and_set(); }
+
+    /** Set that a metadata has changed and needs to be notified to backend. Thread safe. */
+    void setMetadataHasChanged() { mChangeNotified.clear(); }
+
 protected:
     DISALLOW_COPY_AND_ASSIGN(TrackBase);
 
@@ -391,6 +402,9 @@
     std::atomic<FrameTime> mKernelFrameTime{};     // last frame time on kernel side.
     const pid_t         mCreatorPid;  // can be different from mclient->pid() for instance
                                       // when created by NuPlayer on behalf of a client
+
+    // If the last track change was notified to the client with readAndClearHasChanged
+    std::atomic_flag    mChangeNotified = ATOMIC_FLAG_INIT;
 };
 
 // PatchProxyBufferProvider interface is implemented by PatchTrack and PatchRecord.