diff --git a/camera/ndk/impl/ACameraCaptureSession.cpp b/camera/ndk/impl/ACameraCaptureSession.cpp
index 68db233..110d47a 100644
--- a/camera/ndk/impl/ACameraCaptureSession.cpp
+++ b/camera/ndk/impl/ACameraCaptureSession.cpp
@@ -23,7 +23,11 @@
 
 ACameraCaptureSession::~ACameraCaptureSession() {
     ALOGV("~ACameraCaptureSession: %p notify device end of life", this);
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev != nullptr && !dev->isClosed()) {
         dev->lockDeviceForSessionOps();
         {
@@ -50,7 +54,11 @@
         mClosedByApp = true;
     }
 
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev != nullptr) {
         dev->lockDeviceForSessionOps();
     }
@@ -75,7 +83,11 @@
 
 camera_status_t
 ACameraCaptureSession::stopRepeating() {
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev == nullptr) {
         ALOGE("Error: Device associated with session %p has been closed!", this);
         return ACAMERA_ERROR_SESSION_CLOSED;
@@ -93,7 +105,11 @@
 
 camera_status_t
 ACameraCaptureSession::abortCaptures() {
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev == nullptr) {
         ALOGE("Error: Device associated with session %p has been closed!", this);
         return ACAMERA_ERROR_SESSION_CLOSED;
@@ -110,7 +126,11 @@
 }
 
 camera_status_t ACameraCaptureSession::updateOutputConfiguration(ACaptureSessionOutput *output) {
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev == nullptr) {
         ALOGE("Error: Device associated with session %p has been closed!", this);
         return ACAMERA_ERROR_SESSION_CLOSED;
@@ -129,7 +149,11 @@
 ACameraDevice*
 ACameraCaptureSession::getDevice() {
     Mutex::Autolock _l(mSessionLock);
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev == nullptr) {
         ALOGE("Error: Device associated with session %p has been closed!", this);
         return nullptr;
@@ -143,6 +167,17 @@
     mIsClosed = true;
 }
 
+#ifdef __ANDROID_VNDK__
+std::shared_ptr<acam::CameraDevice>
+ACameraCaptureSession::getDevicePtr() {
+    std::shared_ptr<acam::CameraDevice> device = mDevice.lock();
+    if (device == nullptr || device->isClosed()) {
+        ALOGW("Device is closed but session %d is not notified", mId);
+        return nullptr;
+    }
+    return device;
+}
+#else
 sp<acam::CameraDevice>
 ACameraCaptureSession::getDeviceSp() {
     sp<acam::CameraDevice> device = mDevice.promote();
@@ -152,5 +187,4 @@
     }
     return device;
 }
-
-
+#endif
diff --git a/camera/ndk/impl/ACameraCaptureSession.h b/camera/ndk/impl/ACameraCaptureSession.h
index 08a9226..cd65e8c 100644
--- a/camera/ndk/impl/ACameraCaptureSession.h
+++ b/camera/ndk/impl/ACameraCaptureSession.h
@@ -47,6 +47,21 @@
         return mWindow > other.mWindow;
     }
 
+    inline bool isWindowEqual(ACameraWindowType* window) const {
+        return mWindow == window;
+    }
+
+    // returns true if the window was successfully added, false otherwise.
+    inline bool addSharedWindow(ACameraWindowType* window) {
+        auto ret = mSharedWindows.insert(window);
+        return ret.second;
+    }
+
+    // returns the number of elements removed.
+    inline size_t removeSharedWindow(ACameraWindowType* window) {
+        return mSharedWindows.erase(window);
+    }
+
     ACameraWindowType* mWindow;
     std::set<ACameraWindowType *> mSharedWindows;
     bool           mIsShared;
@@ -65,6 +80,15 @@
  */
 struct ACameraCaptureSession : public RefBase {
   public:
+#ifdef __ANDROID_VNDK__
+    ACameraCaptureSession(
+            int id,
+            const ACaptureSessionOutputContainer* outputs,
+            const ACameraCaptureSession_stateCallbacks* cb,
+            std::weak_ptr<android::acam::CameraDevice> device) :
+            mId(id), mOutput(*outputs), mUserSessionCallback(*cb),
+            mDevice(std::move(device)) {}
+#else
     ACameraCaptureSession(
             int id,
             const ACaptureSessionOutputContainer* outputs,
@@ -72,6 +96,7 @@
             android::acam::CameraDevice* device) :
             mId(id), mOutput(*outputs), mUserSessionCallback(*cb),
             mDevice(device) {}
+#endif
 
     // This can be called in app calling close() or after some app callback is finished
     // Make sure the caller does not hold device or session lock!
@@ -114,12 +139,21 @@
     // or a new session is replacing this session.
     void closeByDevice();
 
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<android::acam::CameraDevice> getDevicePtr();
+#else
     sp<android::acam::CameraDevice> getDeviceSp();
+#endif
 
     const int mId;
     const ACaptureSessionOutputContainer mOutput;
     const ACameraCaptureSession_stateCallbacks mUserSessionCallback;
+#ifdef __ANDROID_VNDK__
+    const std::weak_ptr<android::acam::CameraDevice> mDevice;
+#else
     const wp<android::acam::CameraDevice> mDevice;
+#endif
+
     bool  mIsClosed = false;
     bool  mClosedByApp = false;
     Mutex mSessionLock;
diff --git a/camera/ndk/impl/ACameraCaptureSession.inc b/camera/ndk/impl/ACameraCaptureSession.inc
index 86bf8a5..da535f8 100644
--- a/camera/ndk/impl/ACameraCaptureSession.inc
+++ b/camera/ndk/impl/ACameraCaptureSession.inc
@@ -15,9 +15,8 @@
  */
 
 #include "ACameraCaptureSession.h"
-
 #ifdef __ANDROID_VNDK__
-#include "ndk_vendor/impl/ACameraDeviceVendor.inc"
+#include <ndk_vendor/impl/ACameraDeviceVendor.inc>
 #else
 #include "ACameraDevice.inc"
 #endif
@@ -30,7 +29,11 @@
         /*optional*/T* cbs,
         int numRequests, ACaptureRequest** requests,
         /*optional*/int* captureSequenceId) {
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev == nullptr) {
         ALOGE("Error: Device associated with session %p has been closed!", this);
         return ACAMERA_ERROR_SESSION_CLOSED;
@@ -52,7 +55,11 @@
         /*optional*/T* cbs,
         int numRequests, ACaptureRequest** requests,
         /*optional*/int* captureSequenceId) {
+#ifdef __ANDROID_VNDK__
+    std::shared_ptr<acam::CameraDevice> dev = getDevicePtr();
+#else
     sp<acam::CameraDevice> dev = getDeviceSp();
+#endif
     if (dev == nullptr) {
         ALOGE("Error: Device associated with session %p has been closed!", this);
         return ACAMERA_ERROR_SESSION_CLOSED;
diff --git a/camera/ndk/impl/ACameraDevice.cpp b/camera/ndk/impl/ACameraDevice.cpp
index 7997768..536055b 100644
--- a/camera/ndk/impl/ACameraDevice.cpp
+++ b/camera/ndk/impl/ACameraDevice.cpp
@@ -1412,7 +1412,6 @@
     while (it != mSequenceLastFrameNumberMap.end()) {
         int sequenceId = it->first;
         int64_t lastFrameNumber = it->second.lastFrameNumber;
-        bool hasCallback = true;
 
         if (mRemote == nullptr) {
             ALOGW("Camera %s closed while checking sequence complete", getId());
@@ -1425,7 +1424,6 @@
             // This should not happen because we always register callback (with nullptr inside)
             if (mSequenceCallbackMap.count(sequenceId) == 0) {
                 ALOGW("No callback found for sequenceId %d", sequenceId);
-                hasCallback = false;
             }
 
             if (lastFrameNumber <= completedFrameNumber) {
diff --git a/camera/ndk/impl/ACameraManager.cpp b/camera/ndk/impl/ACameraManager.cpp
index 23d90cc..9dc262f 100644
--- a/camera/ndk/impl/ACameraManager.cpp
+++ b/camera/ndk/impl/ACameraManager.cpp
@@ -38,17 +38,16 @@
 const char* CameraManagerGlobal::kContextKey    = "CallbackContext";
 const nsecs_t CameraManagerGlobal::kCallbackDrainTimeout = 5000000; // 5 ms
 Mutex                CameraManagerGlobal::sLock;
-CameraManagerGlobal* CameraManagerGlobal::sInstance = nullptr;
+wp<CameraManagerGlobal> CameraManagerGlobal::sInstance = nullptr;
 
-CameraManagerGlobal&
-CameraManagerGlobal::getInstance() {
+sp<CameraManagerGlobal> CameraManagerGlobal::getInstance() {
     Mutex::Autolock _l(sLock);
-    CameraManagerGlobal* instance = sInstance;
+    sp<CameraManagerGlobal> instance = sInstance.promote();
     if (instance == nullptr) {
         instance = new CameraManagerGlobal();
         sInstance = instance;
     }
-    return *instance;
+    return instance;
 }
 
 CameraManagerGlobal::~CameraManagerGlobal() {
@@ -637,7 +636,7 @@
     Mutex::Autolock _l(mLock);
 
     std::vector<String8> idList;
-    CameraManagerGlobal::getInstance().getCameraIdList(&idList);
+    CameraManagerGlobal::getInstance()->getCameraIdList(&idList);
 
     int numCameras = idList.size();
     ACameraIdList *out = new ACameraIdList;
@@ -687,7 +686,7 @@
         const char* cameraIdStr, sp<ACameraMetadata>* characteristics) {
     Mutex::Autolock _l(mLock);
 
-    sp<hardware::ICameraService> cs = CameraManagerGlobal::getInstance().getCameraService();
+    sp<hardware::ICameraService> cs = CameraManagerGlobal::getInstance()->getCameraService();
     if (cs == nullptr) {
         ALOGE("%s: Cannot reach camera service!", __FUNCTION__);
         return ACAMERA_ERROR_CAMERA_DISCONNECTED;
@@ -733,7 +732,7 @@
 
     ACameraDevice* device = new ACameraDevice(cameraId, callback, chars);
 
-    sp<hardware::ICameraService> cs = CameraManagerGlobal::getInstance().getCameraService();
+    sp<hardware::ICameraService> cs = CameraManagerGlobal::getInstance()->getCameraService();
     if (cs == nullptr) {
         ALOGE("%s: Cannot reach camera service!", __FUNCTION__);
         delete device;
diff --git a/camera/ndk/impl/ACameraManager.h b/camera/ndk/impl/ACameraManager.h
index d53d809..0dd79da 100644
--- a/camera/ndk/impl/ACameraManager.h
+++ b/camera/ndk/impl/ACameraManager.h
@@ -46,7 +46,7 @@
  */
 class CameraManagerGlobal final : public RefBase {
   public:
-    static CameraManagerGlobal& getInstance();
+    static sp<CameraManagerGlobal> getInstance();
     sp<hardware::ICameraService> getCameraService();
 
     void registerAvailabilityCallback(
@@ -257,7 +257,7 @@
 
     // For the singleton instance
     static Mutex sLock;
-    static CameraManagerGlobal* sInstance;
+    static wp<CameraManagerGlobal> sInstance;
     CameraManagerGlobal() {};
     ~CameraManagerGlobal();
 };
@@ -271,7 +271,7 @@
  */
 struct ACameraManager {
     ACameraManager() :
-            mGlobalManager(&(android::acam::CameraManagerGlobal::getInstance())) {}
+            mGlobalManager(android::acam::CameraManagerGlobal::getInstance()) {}
     ~ACameraManager();
     camera_status_t getCameraIdList(ACameraIdList** cameraIdList);
     static void     deleteCameraIdList(ACameraIdList* cameraIdList);