diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index e440ac7..f784be8 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -685,9 +685,9 @@
         //      mWaitWorkCV.wait(...);
         //      // now thread is hung
         //  }
-        AutoMutex lock(mLock);
+        audio_utils::lock_guard lock(mutex());
         requestExit();
-        mWaitWorkCV.broadcast();
+        mWaitWorkCV.notify_all();
     }
     // When Thread::requestExitAndWait is made virtual and this method is renamed to
     // "virtual status_t requestExitAndWait()", replace by "return Thread::requestExitAndWait();"
@@ -697,7 +697,7 @@
 status_t ThreadBase::setParameters(const String8& keyValuePairs)
 {
     ALOGV("ThreadBase::setParameters() %s", keyValuePairs.c_str());
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
 
     return sendSetParameterConfigEvent_l(keyValuePairs);
 }
@@ -716,30 +716,31 @@
     }
     mConfigEvents.add(event);
     ALOGV("sendConfigEvent_l() num events %zu event %d", mConfigEvents.size(), event->mType);
-    mWaitWorkCV.signal();
-    mLock.unlock();
+    mWaitWorkCV.notify_one();
+    mutex().unlock();
     {
-        Mutex::Autolock _l(event->mLock);
+        audio_utils::unique_lock _l(event->mutex());
         while (event->mWaitStatus) {
-            if (event->mCond.waitRelative(event->mLock, kConfigEventTimeoutNs) != NO_ERROR) {
+            if (event->mCondition.wait_for(_l, std::chrono::nanoseconds(kConfigEventTimeoutNs))
+                        == std::cv_status::timeout) {
                 event->mStatus = TIMED_OUT;
                 event->mWaitStatus = false;
             }
         }
         status = event->mStatus;
     }
-    mLock.lock();
+    mutex().lock();
     return status;
 }
 
 void ThreadBase::sendIoConfigEvent(audio_io_config_event_t event, pid_t pid,
                                                  audio_port_handle_t portId)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     sendIoConfigEvent_l(event, pid, portId);
 }
 
-// sendIoConfigEvent_l() must be called with ThreadBase::mLock held
+// sendIoConfigEvent_l() must be called with ThreadBase::mutex() held
 void ThreadBase::sendIoConfigEvent_l(audio_io_config_event_t event, pid_t pid,
                                                    audio_port_handle_t portId)
 {
@@ -759,11 +760,11 @@
 
 void ThreadBase::sendPrioConfigEvent(pid_t pid, pid_t tid, int32_t prio, bool forApp)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     sendPrioConfigEvent_l(pid, tid, prio, forApp);
 }
 
-// sendPrioConfigEvent_l() must be called with ThreadBase::mLock held
+// sendPrioConfigEvent_l() must be called with ThreadBase::mutex() held
 void ThreadBase::sendPrioConfigEvent_l(
         pid_t pid, pid_t tid, int32_t prio, bool forApp)
 {
@@ -771,7 +772,7 @@
     sendConfigEvent_l(configEvent);
 }
 
-// sendSetParameterConfigEvent_l() must be called with ThreadBase::mLock held
+// sendSetParameterConfigEvent_l() must be called with ThreadBase::mutex() held
 status_t ThreadBase::sendSetParameterConfigEvent_l(const String8& keyValuePair)
 {
     sp<ConfigEvent> configEvent;
@@ -794,7 +795,7 @@
                                                         const struct audio_patch *patch,
                                                         audio_patch_handle_t *handle)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     sp<ConfigEvent> configEvent = (ConfigEvent *)new CreateAudioPatchConfigEvent(*patch, *handle);
     status_t status = sendConfigEvent_l(configEvent);
     if (status == NO_ERROR) {
@@ -808,7 +809,7 @@
 status_t ThreadBase::sendReleaseAudioPatchConfigEvent(
                                                                 const audio_patch_handle_t handle)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     sp<ConfigEvent> configEvent = (ConfigEvent *)new ReleaseAudioPatchConfigEvent(handle);
     return sendConfigEvent_l(configEvent);
 }
@@ -820,7 +821,7 @@
         // The update out device operation is only for record thread.
         return INVALID_OPERATION;
     }
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     sp<ConfigEvent> configEvent = (ConfigEvent *)new UpdateOutDevicesConfigEvent(outDevices);
     return sendConfigEvent_l(configEvent);
 }
@@ -835,7 +836,7 @@
 
 void ThreadBase::sendCheckOutputStageEffectsEvent()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     sendCheckOutputStageEffectsEvent_l();
 }
 
@@ -930,10 +931,10 @@
             break;
         }
         {
-            Mutex::Autolock _l(event->mLock);
+           audio_utils::lock_guard _l(event->mutex());
             if (event->mWaitStatus) {
                 event->mWaitStatus = false;
-                event->mCond.signal();
+                event->mCondition.notify_one();
             }
         }
         ALOGV_IF(mConfigEvents.isEmpty(), "processConfigEvents_l() DONE thread %p", this);
@@ -1026,7 +1027,7 @@
     dprintf(fd, "\n%s thread %p, name %s, tid %d, type %d (%s):\n", isOutput() ? "Output" : "Input",
             this, mThreadName, getTid(), type(), threadTypeToString(type()));
 
-    const bool locked = afutils::dumpTryLock(mLock);
+    const bool locked = afutils::dumpTryLock(mutex());
     if (!locked) {
         dprintf(fd, "  Thread may be deadlocked\n");
     }
@@ -1037,7 +1038,7 @@
     dumpEffectChains_l(fd, args);
 
     if (locked) {
-        mLock.unlock();
+        mutex().unlock();
     }
 
     dprintf(fd, "  Local log:\n");
@@ -1152,7 +1153,7 @@
 
 void ThreadBase::acquireWakeLock()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     acquireWakeLock_l();
 }
 
@@ -1206,7 +1207,7 @@
 
 void ThreadBase::releaseWakeLock()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     releaseWakeLock_l();
 }
 
@@ -1265,7 +1266,7 @@
 
 void ThreadBase::clearPowerManager()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     releaseWakeLock_l();
     mPowerManager.clear();
 }
@@ -1396,7 +1397,7 @@
 NO_THREAD_SAFETY_ANALYSIS  // manual locking
 {
     if (!threadLocked) {
-        mLock.lock();
+        mutex().lock();
     }
 
     if (mType != RECORD) {
@@ -1411,11 +1412,11 @@
     }
 
     if (!threadLocked) {
-        mLock.unlock();
+        mutex().unlock();
     }
 }
 
-// checkEffectCompatibility_l() must be called with ThreadBase::mLock held
+// checkEffectCompatibility_l() must be called with ThreadBase::mutex() held
 status_t RecordThread::checkEffectCompatibility_l(
         const effect_descriptor_t *desc, audio_session_t sessionId)
 {
@@ -1459,7 +1460,7 @@
     return NO_ERROR;
 }
 
-// checkEffectCompatibility_l() must be called with ThreadBase::mLock held
+// checkEffectCompatibility_l() must be called with ThreadBase::mutex() held
 status_t PlaybackThread::checkEffectCompatibility_l(
         const effect_descriptor_t *desc, audio_session_t sessionId)
 {
@@ -1614,7 +1615,7 @@
     return NO_ERROR;
 }
 
-// ThreadBase::createEffect_l() must be called with AudioFlinger::mLock held
+// ThreadBase::createEffect_l() must be called with AudioFlinger::mutex() held
 sp<IAfEffectHandle> ThreadBase::createEffect_l(
         const sp<Client>& client,
         const sp<IEffectClient>& effectClient,
@@ -1643,8 +1644,8 @@
 
     ALOGV("createEffect_l() thread %p effect %s on session %d", this, desc->name, sessionId);
 
-    { // scope for mLock
-        Mutex::Autolock _l(mLock);
+    { // scope for mutex()
+       audio_utils::lock_guard _l(mutex());
 
         lStatus = checkEffectCompatibility_l(desc, sessionId);
         if (probe || lStatus != NO_ERROR) {
@@ -1706,7 +1707,7 @@
 
 Exit:
     if (!probe && lStatus != NO_ERROR && lStatus != ALREADY_EXISTS) {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         if (effectCreated) {
             chain->removeEffect_l(effect);
         }
@@ -1726,7 +1727,7 @@
     bool remove = false;
     sp<IAfEffectModule> effect;
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         sp<IAfEffectBase> effectBase = handle->effect().promote();
         if (effectBase == nullptr) {
             return;
@@ -1752,7 +1753,7 @@
 
 void ThreadBase::onEffectEnable(const sp<IAfEffectModule>& effect) {
     if (isOffloadOrMmap()) {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         broadcast_l();
     }
     if (!effect->isOffloadable()) {
@@ -1768,7 +1769,7 @@
 
 void ThreadBase::onEffectDisable() {
     if (isOffloadOrMmap()) {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         broadcast_l();
     }
 }
@@ -1776,7 +1777,7 @@
 sp<IAfEffectModule> ThreadBase::getEffect(audio_session_t sessionId,
         int effectId) const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return getEffect_l(sessionId, effectId);
 }
 
@@ -1793,8 +1794,8 @@
     return chain != nullptr ? chain->getEffectIds() : std::vector<int>{};
 }
 
-// PlaybackThread::addEffect_l() must be called with AudioFlinger::mLock and
-// PlaybackThread::mLock held
+// PlaybackThread::addEffect_l() must be called with AudioFlinger::mutex() and
+// PlaybackThread::mutex() held
 status_t ThreadBase::addEffect_l(const sp<IAfEffectModule>& effect)
 {
     // check for existing effect chain with the requested audio session
@@ -1880,7 +1881,7 @@
 
 sp<IAfEffectChain> ThreadBase::getEffectChain(audio_session_t sessionId) const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return getEffectChain_l(sessionId);
 }
 
@@ -1898,7 +1899,7 @@
 
 void ThreadBase::setMode(audio_mode_t mode)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     size_t size = mEffectChains.size();
     for (size_t i = 0; i < size; i++) {
         mEffectChains[i]->setMode_l(mode);
@@ -1918,7 +1919,7 @@
 
 void ThreadBase::systemReady()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (mSystemReady) {
         return;
     }
@@ -2016,7 +2017,7 @@
     // If threadLoop is currently unlocked a signal of mWaitWorkCV will
     // be lost so we also flag to prevent it blocking on mWaitWorkCV
     mSignalPending = true;
-    mWaitWorkCV.broadcast();
+    mWaitWorkCV.notify_all();
 }
 
 // Call only from threadLoop() or when it is idle.
@@ -2092,7 +2093,7 @@
     return AudioSystem::getStrategyForStream(stream);
 }
 
-// startMelComputation_l() must be called with AudioFlinger::mLock held
+// startMelComputation_l() must be called with AudioFlinger::mutex() held
 void ThreadBase::startMelComputation_l(
         const sp<audio_utils::MelProcessor>& /*processor*/)
 {
@@ -2100,7 +2101,7 @@
     ALOGW("%s: ThreadBase does not support CSD", __func__);
 }
 
-// stopMelComputation_l() must be called with AudioFlinger::mLock held
+// stopMelComputation_l() must be called with AudioFlinger::mutex() held
 void ThreadBase::stopMelComputation_l()
 {
     // Do nothing
@@ -2156,7 +2157,7 @@
     snprintf(mThreadName, kThreadNameLength, "AudioOut_%X", id);
     mNBLogWriter = afThreadCallback->newWriter_l(kLogSize, mThreadName);
 
-    // Assumes constructor is called by AudioFlinger with it's mLock held, but
+    // Assumes constructor is called by AudioFlinger with its mutex() held, but
     // it would be safer to explicitly pass initial masterVolume/masterMute as
     // parameter.
     //
@@ -2356,7 +2357,7 @@
     }
 }
 
-// PlaybackThread::createTrack_l() must be called with AudioFlinger::mLock held
+// PlaybackThread::createTrack_l() must be called with AudioFlinger::mutex() held
 sp<IAfTrack> PlaybackThread::createTrack_l(
         const sp<Client>& client,
         audio_stream_type_t streamType,
@@ -2461,8 +2462,8 @@
         }
 
         // check compatibility with audio effects.
-        { // scope for mLock
-            Mutex::Autolock _l(mLock);
+        { // scope for mutex()
+           audio_utils::lock_guard _l(mutex());
             for (audio_session_t session : {
                     AUDIO_SESSION_DEVICE,
                     AUDIO_SESSION_OUTPUT_STAGE,
@@ -2668,8 +2669,8 @@
         goto Exit;
     }
 
-    { // scope for mLock
-        Mutex::Autolock _l(mLock);
+    { // scope for mutex()
+       audio_utils::lock_guard _l(mutex());
 
         // all tracks in same audio session must share the same routing strategy otherwise
         // conflicts will happen when tracks are moved from one output to another by audio policy
@@ -2714,7 +2715,7 @@
         }
         mTracks.add(track);
         {
-            Mutex::Autolock _atCbL(mAudioTrackCbLock);
+           audio_utils::lock_guard _atCbL(audioTrackCbMutex());
             if (callback.get() != nullptr) {
                 mAudioTrackCallbacks.emplace(track, callback);
             }
@@ -2766,7 +2767,7 @@
 
 uint32_t PlaybackThread::latency() const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return latency_l();
 }
 uint32_t PlaybackThread::latency_l() const
@@ -2780,7 +2781,7 @@
 
 void PlaybackThread::setMasterVolume(float value)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // Don't apply master volume in SW if our HAL can do it for us.
     if (mOutput && mOutput->audioHwDev &&
         mOutput->audioHwDev->canSetMasterVolume()) {
@@ -2800,7 +2801,7 @@
     if (isDuplicating()) {
         return;
     }
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // Don't apply master mute in SW if our HAL can do it for us.
     if (mOutput && mOutput->audioHwDev &&
         mOutput->audioHwDev->canSetMasterMute()) {
@@ -2812,21 +2813,21 @@
 
 void PlaybackThread::setStreamVolume(audio_stream_type_t stream, float value)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mStreamTypes[stream].volume = value;
     broadcast_l();
 }
 
 void PlaybackThread::setStreamMute(audio_stream_type_t stream, bool muted)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mStreamTypes[stream].mute = muted;
     broadcast_l();
 }
 
 float PlaybackThread::streamVolume(audio_stream_type_t stream) const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return mStreamTypes[stream].volume;
 }
 
@@ -2835,9 +2836,9 @@
     mOutput->stream->setVolume(left, right);
 }
 
-// addTrack_l() must be called with ThreadBase::mLock held
+// addTrack_l() must be called with ThreadBase::mutex() held
 status_t PlaybackThread::addTrack_l(const sp<IAfTrack>& track)
-NO_THREAD_SAFETY_ANALYSIS  // release and re-acquire mLock
+NO_THREAD_SAFETY_ANALYSIS  // release and re-acquire mutex()
 {
     status_t status = ALREADY_EXISTS;
 
@@ -2847,15 +2848,15 @@
         // effectively get the latency it requested.
         if (track->isExternalTrack()) {
             IAfTrackBase::track_state state = track->state();
-            mLock.unlock();
+            mutex().unlock();
             status = AudioSystem::startOutput(track->portId());
-            mLock.lock();
+            mutex().lock();
             // abort track was stopped/paused while we released the lock
             if (state != track->state()) {
                 if (status == NO_ERROR) {
-                    mLock.unlock();
+                    mutex().unlock();
                     AudioSystem::stopOutput(track->portId());
-                    mLock.lock();
+                    mutex().lock();
                 }
                 return INVALID_OPERATION;
             }
@@ -2894,7 +2895,7 @@
                         || (chain != nullptr && chain->containsHapticGeneratingEffect_l()))) {
             // Unlock due to VibratorService will lock for this call and will
             // call Tracks.mute/unmute which also require thread's lock.
-            mLock.unlock();
+            mutex().unlock();
             const os::HapticScale intensity = afutils::onExternalVibrationStart(
                     track->getExternalVibration());
             std::optional<media::AudioVibratorInfo> vibratorInfo;
@@ -2904,7 +2905,7 @@
                 audio_utils::lock_guard _l(mAfThreadCallback->mutex());
                 vibratorInfo = std::move(mAfThreadCallback->getDefaultVibratorInfo_l());
             }
-            mLock.lock();
+            mutex().lock();
             track->setHapticIntensity(intensity);
             if (vibratorInfo) {
                 track->setHapticMaxAmplitude(vibratorInfo->maxAmplitude);
@@ -2970,7 +2971,7 @@
 
     mTracks.remove(track);
     {
-        Mutex::Autolock _atCbL(mAudioTrackCbLock);
+       audio_utils::lock_guard _atCbL(audioTrackCbMutex());
         mAudioTrackCallbacks.erase(track);
     }
     if (track->isFastTrack()) {
@@ -2989,7 +2990,7 @@
 
 String8 PlaybackThread::getParameters(const String8& keys)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     String8 out_s8;
     if (initCheck() == NO_ERROR && mOutput->stream->getParameters(keys, &out_s8) == OK) {
         return out_s8;
@@ -2998,7 +2999,7 @@
 }
 
 status_t DirectOutputThread::selectPresentation(int presentationId, int programId) {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (!isStreamInitialized()) {
         return NO_INIT;
     }
@@ -3068,7 +3069,7 @@
             audio_utils::metadata::ByteString metaDataStr =
                     audio_utils::metadata::byteStringFromData(metadata);
             std::vector metadataVec(metaDataStr.begin(), metaDataStr.end());
-            Mutex::Autolock _l(mAudioTrackCbLock);
+           audio_utils::lock_guard _l(audioTrackCbMutex());
             for (const auto& callbackPair : mAudioTrackCallbacks) {
                 callbackPair.second->onCodecFormatChanged(metadataVec);
             }
@@ -3077,17 +3078,17 @@
 
 void PlaybackThread::resetWriteBlocked(uint32_t sequence)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // reject out of sequence requests
     if ((mWriteAckSequence & 1) && (sequence == mWriteAckSequence)) {
         mWriteAckSequence &= ~1;
-        mWaitWorkCV.signal();
+        mWaitWorkCV.notify_one();
     }
 }
 
 void PlaybackThread::resetDraining(uint32_t sequence)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // reject out of sequence requests
     if ((mDrainSequence & 1) && (sequence == mDrainSequence)) {
         // Register discontinuity when HW drain is completed because that can cause
@@ -3096,7 +3097,7 @@
         // elsewhere, e.g. in flush).
         mTimestampVerifier.discontinuity(mTimestampVerifier.DISCONTINUITY_MODE_ZERO);
         mDrainSequence &= ~1;
-        mWaitWorkCV.signal();
+        mWaitWorkCV.notify_one();
     }
 }
 
@@ -3265,7 +3266,7 @@
 
     // force reconfiguration of effect chains and engines to take new buffer size and audio
     // parameters into account
-    // Note that mLock is not held when readOutputParameters_l() is called from the constructor
+    // Note that mutex() is not held when readOutputParameters_l() is called from the constructor
     // but in this case nothing is done below as no audio sessions have effect yet so it doesn't
     // matter.
     // create a copy of mEffectChains as calling moveEffectChain_l() can reorder some effect chains
@@ -3329,7 +3330,7 @@
     if (halFrames == NULL || dspFrames == NULL) {
         return BAD_VALUE;
     }
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (initCheck() != NO_ERROR) {
         return INVALID_OPERATION;
     }
@@ -3370,13 +3371,13 @@
 
 AudioStreamOut* PlaybackThread::getOutput() const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return mOutput;
 }
 
 AudioStreamOut* PlaybackThread::clearOutput()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     AudioStreamOut *output = mOutput;
     mOutput = NULL;
     // FIXME FastMixer might also have a raw ptr to mOutputSink;
@@ -3387,7 +3388,7 @@
     return output;
 }
 
-// this method must always be called either with ThreadBase mLock held or inside the thread loop
+// this method must always be called either with ThreadBase mutex() held or inside the thread loop
 sp<StreamHalInterface> PlaybackThread::stream() const
 {
     if (mOutput == NULL) {
@@ -3407,7 +3408,7 @@
         return BAD_VALUE;
     }
 
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
 
     for (size_t i = 0; i < mTracks.size(); ++i) {
         sp<IAfTrack> track = mTracks[i];
@@ -3537,7 +3538,7 @@
     return bytesWritten;
 }
 
-// startMelComputation_l() must be called with AudioFlinger::mLock held
+// startMelComputation_l() must be called with AudioFlinger::mutex() held
 void PlaybackThread::startMelComputation_l(
         const sp<audio_utils::MelProcessor>& processor)
 {
@@ -3547,7 +3548,7 @@
     }
 }
 
-// stopMelComputation_l() must be called with AudioFlinger::mLock held
+// stopMelComputation_l() must be called with AudioFlinger::mutex() held
 void PlaybackThread::stopMelComputation_l()
 {
     auto outputSink = static_cast<AudioStreamOutSink*>(mOutputSink.get());
@@ -3575,7 +3576,7 @@
 void PlaybackThread::threadLoop_exit()
 {
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         for (size_t i = 0; i < mTracks.size(); i++) {
             sp<IAfTrack> track = mTracks[i];
             track->invalidate();
@@ -3643,12 +3644,12 @@
 
 void PlaybackThread::invalidateTracks(audio_stream_type_t streamType)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     invalidateTracks_l(streamType);
 }
 
 void PlaybackThread::invalidateTracks(std::set<audio_port_handle_t>& portIds) {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     invalidateTracks_l(portIds);
 }
 
@@ -3852,7 +3853,7 @@
 status_t PlaybackThread::attachAuxEffect(
         const sp<IAfTrack>& track, int EffectId)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return attachAuxEffect_l(track, EffectId);
 }
 
@@ -3953,7 +3954,7 @@
 
         // If the device is AUDIO_DEVICE_OUT_BUS, check for downstream latency.
         //
-        // Note: we access outDeviceTypes() outside of mLock.
+        // Note: we access outDeviceTypes() outside of mutex().
         if (isMsdDevice() && outDeviceTypes().count(AUDIO_DEVICE_OUT_BUS) != 0) {
             // Here, we try for the AF lock, but do not block on it as the latency
             // is more informational.
@@ -3999,16 +4000,16 @@
         }
 
         MetadataUpdate metadataUpdate;
-        { // scope for mLock
+        { // scope for mutex()
 
-            Mutex::Autolock _l(mLock);
+            audio_utils::unique_lock _l(mutex());
 
             processConfigEvents_l();
             if (mCheckOutputStageEffects.load()) {
                 continue;
             }
 
-            // See comment at declaration of logString for why this is done under mLock
+            // See comment at declaration of logString for why this is done under mutex()
             if (logString != NULL) {
                 mNBLogWriter->logTimestamp();
                 mNBLogWriter->log(logString);
@@ -4033,8 +4034,9 @@
 
                 const int64_t waitNs = computeWaitTimeNs_l();
                 ALOGV("wait async completion (wait time: %lld)", (long long)waitNs);
-                status_t status = mWaitWorkCV.waitRelative(mLock, waitNs);
-                if (status == TIMED_OUT) {
+                std::cv_status cvstatus =
+                        mWaitWorkCV.wait_for(_l, std::chrono::nanoseconds(waitNs));
+                if (cvstatus == std::cv_status::timeout) {
                     mSignalPending = true; // if timeout recheck everything
                 }
                 ALOGV("async completion/wake");
@@ -4076,7 +4078,7 @@
                     releaseWakeLock_l();
                     // wait until we have something to do...
                     ALOGV("%s going to sleep", myName.c_str());
-                    mWaitWorkCV.wait(mLock);
+                    mWaitWorkCV.wait(_l);
                     ALOGV("%s waking up", myName.c_str());
                     acquireWakeLock_l();
 
@@ -4149,9 +4151,9 @@
                     && (mKernelPositionOnStandby
                             != mTimestamp.mPosition[ExtendedTimestamp::LOCATION_KERNEL])))) {
                 mHalStarted = true;
-                mWaitHalStartCV.broadcast();
+                mWaitHalStartCV.notify_all();
             }
-        } // mLock scope ends
+        } // mutex() scope ends
 
         if (mBytesRemaining == 0) {
             mCurrentWriteLength = 0;
@@ -4382,7 +4384,7 @@
                                 const double processMs =
                                        (lastIoBeginNs - mLastIoEndNs) * 1e-6;
 
-                                Mutex::Autolock _l(mLock);
+                               audio_utils::lock_guard _l(mutex());
                                 mIoJitterMs.add(jitterMs);
                                 mProcessTimeMs.add(processMs);
 
@@ -4483,7 +4485,7 @@
 
             } else {
                 ATRACE_BEGIN("sleep");
-                Mutex::Autolock _l(mLock);
+                audio_utils::unique_lock _l(mutex());
                 // suspended requires accurate metering of sleep time.
                 if (isSuspended()) {
                     // advance by expected sleepTime
@@ -4508,7 +4510,7 @@
                     mSleepTimeUs = deltaNs / 1000;
                 }
                 if (!mSignalPending && mConfigEvents.isEmpty() && !exitPending()) {
-                    mWaitWorkCV.waitRelative(mLock, microseconds((nsecs_t)mSleepTimeUs));
+                    mWaitWorkCV.wait_for(_l, std::chrono::microseconds(mSleepTimeUs));
                 }
                 ATRACE_END();
             }
@@ -4681,9 +4683,9 @@
 #endif
 }
 
-// removeTracks_l() must be called with ThreadBase::mLock held
+// removeTracks_l() must be called with ThreadBase::mutex() held
 void PlaybackThread::removeTracks_l(const Vector<sp<IAfTrack>>& tracksToRemove)
-NO_THREAD_SAFETY_ANALYSIS  // release and re-acquire mLock
+NO_THREAD_SAFETY_ANALYSIS  // release and re-acquire mutex()
 {
     for (const auto& track : tracksToRemove) {
         mActiveTracks.remove(track);
@@ -4709,11 +4711,11 @@
         if (mHapticChannelCount > 0 &&
                 ((track->channelMask() & AUDIO_CHANNEL_HAPTIC_ALL) != AUDIO_CHANNEL_NONE
                         || (chain != nullptr && chain->containsHapticGeneratingEffect_l()))) {
-            mLock.unlock();
+            mutex().unlock();
             // Unlock due to VibratorService will lock for this call and will
             // call Tracks.mute/unmute which also require thread's lock.
             afutils::onExternalVibrationStop(track->getExternalVibration());
-            mLock.lock();
+            mutex().lock();
 
             // When the track is stop, set the haptic intensity as MUTE
             // for the HapticGenerator effect.
@@ -4911,13 +4913,13 @@
 
 void PlaybackThread::addPatchTrack(const sp<IAfPatchTrack>& track)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mTracks.add(track);
 }
 
 void PlaybackThread::deletePatchTrack(const sp<IAfPatchTrack>& track)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     destroyTrack_l(track);
 }
 
@@ -5167,7 +5169,7 @@
 void MixerThread::onFirstRef() {
     PlaybackThread::onFirstRef();
 
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (mOutput != nullptr && mOutput->stream != nullptr) {
         status_t status = mOutput->stream->setLatencyModeCallback(this);
         if (status != INVALID_OPERATION) {
@@ -5282,7 +5284,7 @@
 
 bool PlaybackThread::waitingAsyncCallback()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return waitingAsyncCallback_l();
 }
 
@@ -5387,7 +5389,7 @@
     // TODO add standby time extension fct of effect tail
 }
 
-// prepareTracks_l() must be called with ThreadBase::mLock held
+// prepareTracks_l() must be called with ThreadBase::mutex() held
 PlaybackThread::mixer_state MixerThread::prepareTracks_l(
         Vector<sp<IAfTrack>>* tracksToRemove)
 {
@@ -6183,7 +6185,7 @@
     return mixerStatus;
 }
 
-// trackCountForUid_l() must be called with ThreadBase::mLock held
+// trackCountForUid_l() must be called with ThreadBase::mutex() held
 uint32_t PlaybackThread::trackCountForUid_l(uid_t uid) const
 {
     uint32_t trackCount = 0;
@@ -6226,7 +6228,7 @@
     mPreviousNs = 0;
 }
 
-// isTrackAllowed_l() must be called with ThreadBase::mLock held
+// isTrackAllowed_l() must be called with ThreadBase::mutex() held
 bool MixerThread::isTrackAllowed_l(
         audio_channel_mask_t channelMask, audio_format_t format,
         audio_session_t sessionId, uid_t uid) const
@@ -6246,7 +6248,7 @@
     return true;
 }
 
-// checkForNewParameter_l() must be called with ThreadBase::mLock held
+// checkForNewParameter_l() must be called with ThreadBase::mutex() held
 bool MixerThread::checkForNewParameter_l(const String8& keyValuePair,
                                                        status_t& status)
 {
@@ -6464,14 +6466,14 @@
     if (modes == nullptr) {
         return BAD_VALUE;
     }
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     *modes = mSupportedLatencyModes;
     return NO_ERROR;
 }
 
 void MixerThread::onRecommendedLatencyModeChanged(
         std::vector<audio_latency_mode_t> modes) {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (modes != mSupportedLatencyModes) {
         ALOGD("%s: thread(%d) supported latency modes: %s",
             __func__, mId, toString(modes).c_str());
@@ -6522,7 +6524,7 @@
 
 void DirectOutputThread::setMasterBalance(float balance)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (mMasterBalance != balance) {
         mMasterBalance.store(balance);
         mBalance.computeStereoBalance(balance, &mMasterBalanceLeft, &mMasterBalanceRight);
@@ -6903,7 +6905,7 @@
 void DirectOutputThread::threadLoop_exit()
 {
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         for (size_t i = 0; i < mTracks.size(); i++) {
             if (mTracks[i]->isFlushPending()) {
                 mTracks[i]->flushAck();
@@ -6934,7 +6936,7 @@
     return !mStandby && !(trackPaused || (mHwPaused && !trackStopped));
 }
 
-// checkForNewParameter_l() must be called with ThreadBase::mLock held
+// checkForNewParameter_l() must be called with ThreadBase::mutex() held
 bool DirectOutputThread::checkForNewParameter_l(const String8& keyValuePair,
                                                               status_t& status)
 {
@@ -7069,12 +7071,12 @@
         bool asyncError;
 
         {
-            Mutex::Autolock _l(mLock);
+            audio_utils::unique_lock _l(mutex());
             while (!((mWriteAckSequence & 1) ||
                      (mDrainSequence & 1) ||
                      mAsyncError ||
                      exitPending())) {
-                mWaitWorkCV.wait(mLock);
+                mWaitWorkCV.wait(_l);
             }
 
             if (exitPending()) {
@@ -7110,50 +7112,50 @@
 void AsyncCallbackThread::exit()
 {
     ALOGV("AsyncCallbackThread::exit");
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     requestExit();
-    mWaitWorkCV.broadcast();
+    mWaitWorkCV.notify_all();
 }
 
 void AsyncCallbackThread::setWriteBlocked(uint32_t sequence)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // bit 0 is cleared
     mWriteAckSequence = sequence << 1;
 }
 
 void AsyncCallbackThread::resetWriteBlocked()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // ignore unexpected callbacks
     if (mWriteAckSequence & 2) {
         mWriteAckSequence |= 1;
-        mWaitWorkCV.signal();
+        mWaitWorkCV.notify_one();
     }
 }
 
 void AsyncCallbackThread::setDraining(uint32_t sequence)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // bit 0 is cleared
     mDrainSequence = sequence << 1;
 }
 
 void AsyncCallbackThread::resetDraining()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // ignore unexpected callbacks
     if (mDrainSequence & 2) {
         mDrainSequence |= 1;
-        mWaitWorkCV.signal();
+        mWaitWorkCV.notify_one();
     }
 }
 
 void AsyncCallbackThread::setAsyncError()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mAsyncError = true;
-    mWaitWorkCV.signal();
+    mWaitWorkCV.notify_one();
 }
 
 
@@ -7449,7 +7451,7 @@
 
 bool OffloadThread::waitingAsyncCallback()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return waitingAsyncCallback_l();
 }
 
@@ -7476,14 +7478,14 @@
 
 void OffloadThread::invalidateTracks(audio_stream_type_t streamType)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (PlaybackThread::invalidateTracks_l(streamType)) {
         mFlushPending = true;
     }
 }
 
 void OffloadThread::invalidateTracks(std::set<audio_port_handle_t>& portIds) {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (PlaybackThread::invalidateTracks_l(portIds)) {
         mFlushPending = true;
     }
@@ -7625,7 +7627,7 @@
 
 void DuplicatingThread::addOutputTrack(IAfPlaybackThread* thread)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // The downstream MixerThread consumes thread->frameCount() amount of frames per mix pass.
     // Adjust for thread->sampleRate() to determine minimum buffer frame count.
     // Then triple buffer because Threads do not run synchronously and may not be clock locked.
@@ -7662,7 +7664,7 @@
 
 void DuplicatingThread::removeOutputTrack(IAfPlaybackThread* thread)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     for (size_t i = 0; i < mOutputTracks.size(); i++) {
         if (mOutputTracks[i]->thread() == thread) {
             mOutputTracks[i]->destroy();
@@ -7677,7 +7679,7 @@
     ALOGV("removeOutputTrack(): unknown thread: %p", thread);
 }
 
-// caller must hold mLock
+// caller must hold mutex()
 void DuplicatingThread::updateWaitTime_l()
 {
     mWaitTimeMs = UINT_MAX;
@@ -7811,7 +7813,7 @@
     if (mode != AUDIO_LATENCY_MODE_LOW && mode != AUDIO_LATENCY_MODE_FREE) {
         return BAD_VALUE;
     }
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mRequestedLatencyMode = mode;
     return NO_ERROR;
 }
@@ -7822,7 +7824,7 @@
     bool hasDownMixer = false;
     sp<IAfEffectHandle> finalDownMixer;
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         sp<IAfEffectChain> chain = getEffectChain_l(AUDIO_SESSION_OUTPUT_STAGE);
         if (chain != 0) {
             hasVirtualizer = chain->getEffectFromType_l(FX_IID_SPATIALIZER) != nullptr;
@@ -7863,7 +7865,7 @@
     }
 
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         mFinalDownMixer = finalDownMixer;
     }
 }
@@ -8069,13 +8071,13 @@
 void RecordThread::preExit()
 {
     ALOGV("  preExit()");
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     for (size_t i = 0; i < mTracks.size(); i++) {
         sp<IAfRecordTrack> track = mTracks[i];
         track->invalidate();
     }
     mActiveTracks.clear();
-    mStartStopCond.broadcast();
+    mStartStopCV.notify_all();
 }
 
 bool RecordThread::threadLoop()
@@ -8087,7 +8089,7 @@
 reacquire_wakelock:
     sp<IAfRecordTrack> activeTrack;
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         acquireWakeLock_l();
     }
 
@@ -8111,13 +8113,13 @@
 
         bool silenceFastCapture = false;
 
-        { // scope for mLock
-            Mutex::Autolock _l(mLock);
+        { // scope for mutex()
+            audio_utils::unique_lock _l(mutex());
 
             processConfigEvents_l();
 
             // check exitPending here because checkForNewParameters_l() and
-            // checkForNewParameters_l() can temporarily release mLock
+            // checkForNewParameters_l() can temporarily release mutex()
             if (exitPending()) {
                 break;
             }
@@ -8125,7 +8127,7 @@
             // sleep with mutex unlocked
             if (sleepUs > 0) {
                 ATRACE_BEGIN("sleepC");
-                mWaitWorkCV.waitRelative(mLock, microseconds((nsecs_t)sleepUs));
+                (void)mWaitWorkCV.wait_for(_l, std::chrono::microseconds(sleepUs));
                 ATRACE_END();
                 sleepUs = 0;
                 continue;
@@ -8139,7 +8141,7 @@
                 releaseWakeLock_l();
                 ALOGV("RecordThread: loop stopping");
                 // go to sleep
-                mWaitWorkCV.wait(mLock);
+                mWaitWorkCV.wait(_l);
                 ALOGV("RecordThread: loop starting");
                 goto reacquire_wakelock;
             }
@@ -8246,7 +8248,7 @@
                 standbyIfNotAlreadyInStandby();
             }
             if (doBroadcast) {
-                mStartStopCond.broadcast();
+                mStartStopCV.notify_all();
             }
 
             // sleep if there are no active tracks to process
@@ -8615,7 +8617,7 @@
                     {0, 0} /* lastTimestamp */, mSampleRate);
             const double processMs = (lastIoBeginNs - mLastIoEndNs) * 1e-6;
 
-            Mutex::Autolock _l(mLock);
+           audio_utils::lock_guard _l(mutex());
             mIoJitterMs.add(jitterMs);
             mProcessTimeMs.add(processMs);
         }
@@ -8628,13 +8630,13 @@
     standbyIfNotAlreadyInStandby();
 
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         for (size_t i = 0; i < mTracks.size(); i++) {
             sp<IAfRecordTrack> track = mTracks[i];
             track->invalidate();
         }
         mActiveTracks.clear();
-        mStartStopCond.broadcast();
+        mStartStopCV.notify_all();
     }
 
     releaseWakeLock();
@@ -8693,7 +8695,7 @@
     }
 }
 
-// RecordThread::createRecordTrack_l() must be called with AudioFlinger::mLock held
+// RecordThread::createRecordTrack_l() must be called with AudioFlinger::mutex() held
 sp<IAfRecordTrack> RecordThread::createRecordTrack_l(
         const sp<Client>& client,
         const audio_attributes_t& attr,
@@ -8785,7 +8787,7 @@
             mFastTrackAvail
         ) {
           // check compatibility with audio effects.
-          Mutex::Autolock _l(mLock);
+         audio_utils::lock_guard _l(mutex());
           // Do not accept FAST flag if the session has software effects
           sp<IAfEffectChain> chain = getEffectChain_l(sessionId);
           if (chain != 0) {
@@ -8849,8 +8851,8 @@
     *pFrameCount = frameCount;
     *pNotificationFrameCount = notificationFrameCount;
 
-    { // scope for mLock
-        Mutex::Autolock _l(mLock);
+    { // scope for mutex()
+       audio_utils::lock_guard _l(mutex());
         int32_t startFrames = -1;
         if (!mSharedAudioPackageName.empty()
                 && mSharedAudioPackageName == attributionSource.packageName
@@ -8911,7 +8913,7 @@
 
     {
         // This section is a rendezvous between binder thread executing start() and RecordThread
-        AutoMutex lock(mLock);
+        audio_utils::lock_guard lock(mutex());
         if (recordTrack->isInvalid()) {
             recordTrack->clearSyncStartEvent();
             ALOGW("%s track %d: invalidated before startInput", __func__, recordTrack->portId());
@@ -8935,9 +8937,9 @@
         recordTrack->setState(IAfTrackBase::STARTING_1);
         mActiveTracks.add(recordTrack);
         if (recordTrack->isExternalTrack()) {
-            mLock.unlock();
+            mutex().unlock();
             status = AudioSystem::startInput(recordTrack->portId());
-            mLock.lock();
+            mutex().lock();
             if (recordTrack->isInvalid()) {
                 recordTrack->clearSyncStartEvent();
                 if (status == NO_ERROR && recordTrack->state() == IAfTrackBase::STARTING_1) {
@@ -8983,7 +8985,7 @@
         }
         recordTrack->setState(IAfTrackBase::STARTING_2);
         // signal thread to start
-        mWaitWorkCV.broadcast();
+        mWaitWorkCV.notify_all();
         return status;
     }
 }
@@ -9004,7 +9006,7 @@
 
 bool RecordThread::stop(IAfRecordTrack* recordTrack) {
     ALOGV("RecordThread::stop");
-    AutoMutex _l(mLock);
+    audio_utils::unique_lock _l(mutex());
     // if we're invalid, we can't be on the ActiveTracks.
     if (mActiveTracks.indexOf(recordTrack) < 0 || recordTrack->state() == IAfTrackBase::PAUSING) {
         return false;
@@ -9015,8 +9017,8 @@
     // NOTE: Waiting here is important to keep stop synchronous.
     // This is needed for proper patchRecord peer release.
     while (recordTrack->state() == IAfTrackBase::PAUSING && !recordTrack->isInvalid()) {
-        mWaitWorkCV.broadcast(); // signal thread to stop
-        mStartStopCond.wait(mLock);
+        mWaitWorkCV.notify_all(); // signal thread to stop
+        mStartStopCV.wait(_l);
     }
 
     if (recordTrack->state() == IAfTrackBase::PAUSED) { // successful stop
@@ -9045,7 +9047,7 @@
     audio_session_t eventSession = event->triggerSession();
     status_t ret = NAME_NOT_FOUND;
 
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
 
     for (size_t i = 0; i < mTracks.size(); i++) {
         sp<IAfRecordTrack> track = mTracks[i];
@@ -9064,7 +9066,7 @@
         std::vector<media::MicrophoneInfoFw>* activeMicrophones) const
 {
     ALOGV("RecordThread::getActiveMicrophones");
-    AutoMutex _l(mLock);
+    audio_utils::lock_guard _l(mutex());
     if (!isStreamInitialized()) {
         return NO_INIT;
     }
@@ -9076,7 +9078,7 @@
             audio_microphone_direction_t direction)
 {
     ALOGV("setPreferredMicrophoneDirection(%d)", direction);
-    AutoMutex _l(mLock);
+    audio_utils::lock_guard _l(mutex());
     if (!isStreamInitialized()) {
         return NO_INIT;
     }
@@ -9086,7 +9088,7 @@
 status_t RecordThread::setPreferredMicrophoneFieldDimension(float zoom)
 {
     ALOGV("setPreferredMicrophoneFieldDimension(%f)", zoom);
-    AutoMutex _l(mLock);
+    audio_utils::lock_guard _l(mutex());
     if (!isStreamInitialized()) {
         return NO_INIT;
     }
@@ -9096,7 +9098,7 @@
 status_t RecordThread::shareAudioHistory(
         const std::string& sharedAudioPackageName, audio_session_t sharedSessionId,
         int64_t sharedAudioStartMs) {
-    AutoMutex _l(mLock);
+    audio_utils::lock_guard _l(mutex());
     return shareAudioHistory_l(sharedAudioPackageName, sharedSessionId, sharedAudioStartMs);
 }
 
@@ -9162,7 +9164,7 @@
     return change;
 }
 
-// destroyTrack_l() must be called with ThreadBase::mLock held
+// destroyTrack_l() must be called with ThreadBase::mutex() held
 void RecordThread::destroyTrack_l(const sp<IAfRecordTrack>& track)
 {
     track->terminate();
@@ -9262,7 +9264,7 @@
 
 void RecordThread::setRecordSilenced(audio_port_handle_t portId, bool silenced)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     for (size_t i = 0; i < mTracks.size() ; i++) {
         sp<IAfRecordTrack> track = mTracks[i];
         if (track != 0 && track->portId() == portId) {
@@ -9387,7 +9389,7 @@
 
 void RecordThread::checkBtNrec()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     checkBtNrec_l();
 }
 
@@ -9496,7 +9498,7 @@
 
 String8 RecordThread::getParameters(const String8& keys)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (initCheck() == NO_ERROR) {
         String8 out_s8;
         if (mInput->stream->getParameters(keys, &out_s8) == OK) {
@@ -9572,7 +9574,7 @@
 
 uint32_t RecordThread::getInputFramesLost() const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     uint32_t result;
     if (initCheck() == NO_ERROR && mInput->stream->getInputFramesLost(&result) == OK) {
         return result;
@@ -9583,7 +9585,7 @@
 KeyedVector<audio_session_t, bool> RecordThread::sessionIds() const
 {
     KeyedVector<audio_session_t, bool> ids;
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     for (size_t j = 0; j < mTracks.size(); ++j) {
         sp<IAfRecordTrack> track = mTracks[j];
         audio_session_t sessionId = track->sessionId();
@@ -9596,13 +9598,13 @@
 
 AudioStreamIn* RecordThread::clearInput()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     AudioStreamIn *input = mInput;
     mInput = NULL;
     return input;
 }
 
-// this method must always be called either with ThreadBase mLock held or inside the thread loop
+// this method must always be called either with ThreadBase mutex() held or inside the thread loop
 sp<StreamHalInterface> RecordThread::stream() const
 {
     if (mInput == NULL) {
@@ -9720,7 +9722,7 @@
 
 void RecordThread::updateOutDevices(const DeviceDescriptorBaseVector& outDevices)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mOutDevices = outDevices;
     mOutDeviceTypeAddrs = deviceTypeAddrsFromDescriptors(mOutDevices);
     for (size_t i = 0; i < mEffectChains.size(); i++) {
@@ -9857,7 +9859,7 @@
 
 void RecordThread::addPatchTrack(const sp<IAfPatchRecord>& record)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mTracks.add(record);
     if (record->getSource()) {
         mSource = record->getSource();
@@ -9866,7 +9868,7 @@
 
 void RecordThread::deletePatchTrack(const sp<IAfPatchRecord>& record)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (mSource == record->getSource()) {
         mSource = mInput;
     }
@@ -9991,7 +9993,7 @@
 {
     ActiveTracks<IAfMmapTrack> activeTracks;
     {
-        Mutex::Autolock _l(mLock);
+       audio_utils::lock_guard _l(mutex());
         for (const sp<IAfMmapTrack>& t : mActiveTracks) {
             activeTracks.add(t);
         }
@@ -10135,24 +10137,24 @@
         {
             // Add the track record before starting input so that the silent status for the
             // client can be cached.
-            Mutex::Autolock _l(mLock);
+           audio_utils::lock_guard _l(mutex());
             setClientSilencedState_l(portId, false /*silenced*/);
         }
         ret = AudioSystem::startInput(portId);
     }
 
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // abort if start is rejected by audio policy manager
     if (ret != NO_ERROR) {
         ALOGE("%s: error start rejected by AudioPolicyManager = %d", __FUNCTION__, ret);
         if (!mActiveTracks.isEmpty()) {
-            mLock.unlock();
+            mutex().unlock();
             if (isOutput()) {
                 AudioSystem::releaseOutput(portId);
             } else {
                 AudioSystem::releaseInput(portId);
             }
-            mLock.lock();
+            mutex().lock();
         } else {
             mHalStream->stop();
         }
@@ -10217,7 +10219,7 @@
         return NO_ERROR;
     }
 
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
 
     sp<IAfMmapTrack> track;
     for (const sp<IAfMmapTrack>& t : mActiveTracks) {
@@ -10233,7 +10235,7 @@
     mActiveTracks.remove(track);
     eraseClientSilencedState_l(track->portId());
 
-    mLock.unlock();
+    mutex().unlock();
     if (isOutput()) {
         AudioSystem::stopOutput(track->portId());
         AudioSystem::releaseOutput(track->portId());
@@ -10241,7 +10243,7 @@
         AudioSystem::stopInput(track->portId());
         AudioSystem::releaseInput(track->portId());
     }
-    mLock.lock();
+    mutex().lock();
 
     sp<IAfEffectChain> chain = getEffectChain_l(track->sessionId());
     if (chain != 0) {
@@ -10330,7 +10332,7 @@
         Vector<sp<IAfEffectChain>> effectChains;
 
         { // under Thread lock
-        Mutex::Autolock _l(mLock);
+        audio_utils::unique_lock _l(mutex());
 
         if (mSignalPending) {
             // A signal was raised while we were unlocked
@@ -10346,7 +10348,7 @@
 
                 // wait until we have something to do...
                 ALOGV("%s going to sleep", myName.c_str());
-                mWaitWorkCV.wait(mLock);
+                mWaitWorkCV.wait(_l);
                 ALOGV("%s waking up", myName.c_str());
 
                 checkSilentMode_l();
@@ -10389,7 +10391,7 @@
     return false;
 }
 
-// checkForNewParameter_l() must be called with ThreadBase::mLock held
+// checkForNewParameter_l() must be called with ThreadBase::mutex() held
 bool MmapThread::checkForNewParameter_l(const String8& keyValuePair,
                                                               status_t& status)
 {
@@ -10410,7 +10412,7 @@
 
 String8 MmapThread::getParameters(const String8& keys)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     String8 out_s8;
     if (initCheck() == NO_ERROR && mHalStream->getParameters(keys, &out_s8) == OK) {
         return out_s8;
@@ -10445,7 +10447,7 @@
 
 status_t MmapThread::createAudioPatch_l(const struct audio_patch* patch,
                                                           audio_patch_handle_t *handle)
-NO_THREAD_SAFETY_ANALYSIS  // elease and re-acquire mLock
+NO_THREAD_SAFETY_ANALYSIS  // elease and re-acquire mutex()
 {
     status_t status = NO_ERROR;
 
@@ -10521,9 +10523,9 @@
         }
         sp<MmapStreamCallback> callback = mCallback.promote();
         if (mDeviceId != deviceId && callback != 0) {
-            mLock.unlock();
+            mutex().unlock();
             callback->onRoutingChanged(deviceId);
-            mLock.lock();
+            mutex().lock();
         }
         mPatch = *patch;
         mDeviceId = deviceId;
@@ -10674,7 +10676,7 @@
 }
 
 void MmapThread::checkInvalidTracks_l()
-NO_THREAD_SAFETY_ANALYSIS  // release and re-acquire mLock
+NO_THREAD_SAFETY_ANALYSIS  // release and re-acquire mutex()
 {
     sp<MmapStreamCallback> callback;
     for (const sp<IAfMmapTrack>& track : mActiveTracks) {
@@ -10688,9 +10690,9 @@
         }
     }
     if (callback != 0) {
-        mLock.unlock();
+        mutex().unlock();
         callback->onRoutingChanged(AUDIO_PORT_HANDLE_NONE);
-        mLock.lock();
+        mutex().lock();
     }
 }
 
@@ -10778,7 +10780,7 @@
 
 AudioStreamOut* MmapPlaybackThread::clearOutput()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     AudioStreamOut *output = mOutput;
     mOutput = NULL;
     return output;
@@ -10786,7 +10788,7 @@
 
 void MmapPlaybackThread::setMasterVolume(float value)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // Don't apply master volume in SW if our HAL can do it for us.
     if (mAudioHwDev &&
             mAudioHwDev->canSetMasterVolume()) {
@@ -10798,7 +10800,7 @@
 
 void MmapPlaybackThread::setMasterMute(bool muted)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     // Don't apply master mute in SW if our HAL can do it for us.
     if (mAudioHwDev && mAudioHwDev->canSetMasterMute()) {
         mMasterMute = false;
@@ -10809,7 +10811,7 @@
 
 void MmapPlaybackThread::setStreamVolume(audio_stream_type_t stream, float value)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mStreamTypes[stream].volume = value;
     if (stream == mStreamType) {
         broadcast_l();
@@ -10818,13 +10820,13 @@
 
 float MmapPlaybackThread::streamVolume(audio_stream_type_t stream) const
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     return mStreamTypes[stream].volume;
 }
 
 void MmapPlaybackThread::setStreamMute(audio_stream_type_t stream, bool muted)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     mStreamTypes[stream].mute = muted;
     if (stream == mStreamType) {
         broadcast_l();
@@ -10833,7 +10835,7 @@
 
 void MmapPlaybackThread::invalidateTracks(audio_stream_type_t streamType)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     if (streamType == mStreamType) {
         for (const sp<IAfMmapTrack>& track : mActiveTracks) {
             track->invalidate();
@@ -10844,7 +10846,7 @@
 
 void MmapPlaybackThread::invalidateTracks(std::set<audio_port_handle_t>& portIds)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     bool trackMatch = false;
     for (const sp<IAfMmapTrack>& track : mActiveTracks) {
         if (portIds.find(track->portId()) != portIds.end()) {
@@ -10892,9 +10894,9 @@
             if (callback != 0) {
                 mHalVolFloat = volume; // SW volume control worked, so update value.
                 mNoCallbackWarningCount = 0;
-                mLock.unlock();
+                mutex().unlock();
                 callback->onVolumeChanged(volume);
-                mLock.lock();
+                mutex().lock();
             } else {
                 if (mNoCallbackWarningCount < kMaxNoCallbackWarnings) {
                     ALOGW("Could not set MMAP stream volume: no volume callback!");
@@ -10991,7 +10993,7 @@
     return NO_ERROR;
 }
 
-// startMelComputation_l() must be called with AudioFlinger::mLock held
+// startMelComputation_l() must be called with AudioFlinger::mutex() held
 void MmapPlaybackThread::startMelComputation_l(
         const sp<audio_utils::MelProcessor>& processor)
 {
@@ -11005,7 +11007,7 @@
     // assigned constant for each thread
 }
 
-// stopMelComputation_l() must be called with AudioFlinger::mLock held
+// stopMelComputation_l() must be called with AudioFlinger::mutex() held
 void MmapPlaybackThread::stopMelComputation_l()
 {
     ALOGV("%s: pausing mel processor for thread %d", __func__, id());
@@ -11054,7 +11056,7 @@
 
 AudioStreamIn* MmapCaptureThread::clearInput()
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     AudioStreamIn *input = mInput;
     mInput = NULL;
     return input;
@@ -11112,7 +11114,7 @@
 
 void MmapCaptureThread::setRecordSilenced(audio_port_handle_t portId, bool silenced)
 {
-    Mutex::Autolock _l(mLock);
+   audio_utils::lock_guard _l(mutex());
     for (size_t i = 0; i < mActiveTracks.size() ; i++) {
         if (mActiveTracks[i]->portId() == portId) {
             mActiveTracks[i]->setSilenced_l(silenced);