diff --git a/camera/ndk/impl/ACameraCaptureSession.cpp b/camera/ndk/impl/ACameraCaptureSession.cpp
new file mode 100644
index 0000000..7f1b75d
--- /dev/null
+++ b/camera/ndk/impl/ACameraCaptureSession.cpp
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2016 The Android Open Source 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.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "ACameraCaptureSession"
+
+#include "ACameraCaptureSession.h"
+
+using namespace android;
+
+ACameraCaptureSession::~ACameraCaptureSession() {
+    ALOGV("~ACameraCaptureSession: %p notify device end of life", this);
+    sp<CameraDevice> dev = getDeviceSp();
+    if (dev != nullptr && !dev->isClosed()) {
+        dev->lockDeviceForSessionOps();
+        {
+            Mutex::Autolock _l(mSessionLock);
+            dev->notifySessionEndOfLifeLocked(this);
+        }
+        dev->unlockDevice();
+    }
+    // Fire onClosed callback
+    (*mUserSessionCallback.onClosed)(mUserSessionCallback.context, this);
+    ALOGV("~ACameraCaptureSession: %p is deleted", this);
+}
+
+void
+ACameraCaptureSession::closeByApp() {
+    sp<CameraDevice> dev = getDeviceSp();
+    if (dev != nullptr) {
+        dev->lockDeviceForSessionOps();
+    }
+
+    {
+        Mutex::Autolock _l(mSessionLock);
+
+        if (!mIsClosed && dev != nullptr) {
+            camera_status_t ret = dev->stopRepeatingLocked();
+            if (ret != ACAMERA_OK) {
+                ALOGE("Stop repeating request failed while closing session %p", this);
+            }
+        }
+        mIsClosed = true;
+    }
+
+    if (dev != nullptr) {
+        dev->unlockDevice();
+    }
+    this->decStrong((void*) ACameraDevice_createCaptureSession);
+}
+
+camera_status_t
+ACameraCaptureSession::stopRepeating() {
+    sp<CameraDevice> dev = getDeviceSp();
+    if (dev == nullptr) {
+        ALOGE("Error: Device associated with session %p has been closed!", this);
+        return ACAMERA_ERROR_SESSION_CLOSED;
+    }
+
+    camera_status_t ret;
+    dev->lockDeviceForSessionOps();
+    {
+        Mutex::Autolock _l(mSessionLock);
+        ret = dev->stopRepeatingLocked();
+    }
+    dev->unlockDevice();
+    return ret;
+}
+
+camera_status_t
+ACameraCaptureSession::setRepeatingRequest(
+        /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+        int numRequests, ACaptureRequest** requests,
+        /*optional*/int* captureSequenceId) {
+    sp<CameraDevice> dev = getDeviceSp();
+    if (dev == nullptr) {
+        ALOGE("Error: Device associated with session %p has been closed!", this);
+        return ACAMERA_ERROR_SESSION_CLOSED;
+    }
+
+    camera_status_t ret;
+    dev->lockDeviceForSessionOps();
+    {
+        Mutex::Autolock _l(mSessionLock);
+        ret = dev->setRepeatingRequestsLocked(
+                this, cbs, numRequests, requests, captureSequenceId);
+    }
+    dev->unlockDevice();
+    return ret;
+}
+
+camera_status_t ACameraCaptureSession::capture(
+        /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+        int numRequests, ACaptureRequest** requests,
+        /*optional*/int* captureSequenceId) {
+    sp<CameraDevice> dev = getDeviceSp();
+    if (dev == nullptr) {
+        ALOGE("Error: Device associated with session %p has been closed!", this);
+        return ACAMERA_ERROR_SESSION_CLOSED;
+    }
+    camera_status_t ret;
+    dev->lockDeviceForSessionOps();
+    {
+        Mutex::Autolock _l(mSessionLock);
+        ret = dev->captureLocked(this, cbs, numRequests, requests, captureSequenceId);
+    }
+    dev->unlockDevice();
+    return ret;
+}
+
+ACameraDevice*
+ACameraCaptureSession::getDevice() {
+    Mutex::Autolock _l(mSessionLock);
+    sp<CameraDevice> dev = getDeviceSp();
+    if (dev == nullptr) {
+        ALOGE("Error: Device associated with session %p has been closed!", this);
+        return nullptr;
+    }
+    return dev->getWrapper();
+}
+
+void
+ACameraCaptureSession::closeByDevice() {
+    Mutex::Autolock _l(mSessionLock);
+    mIsClosed = true;
+}
+
+sp<CameraDevice>
+ACameraCaptureSession::getDeviceSp() {
+    sp<CameraDevice> device = mDevice.promote();
+    if (device == nullptr || device->isClosed()) {
+        ALOGW("Device is closed but session %d is not notified", mId);
+        return nullptr;
+    }
+    return device;
+}
+
+
diff --git a/camera/ndk/impl/ACameraCaptureSession.h b/camera/ndk/impl/ACameraCaptureSession.h
new file mode 100644
index 0000000..1db1b21
--- /dev/null
+++ b/camera/ndk/impl/ACameraCaptureSession.h
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2016 The Android Open Source 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 _ACAMERA_CAPTURE_SESSION_H
+#define _ACAMERA_CAPTURE_SESSION_H
+
+#include <set>
+#include <hardware/camera3.h>
+#include <NdkCameraDevice.h>
+#include "ACameraDevice.h"
+
+using namespace android;
+
+struct ACaptureSessionOutput {
+    ACaptureSessionOutput(ANativeWindow* window) : mWindow(window) {};
+
+    bool operator == (const ACaptureSessionOutput& other) const {
+        return mWindow == other.mWindow;
+    }
+    bool operator != (const ACaptureSessionOutput& other) const {
+        return mWindow != other.mWindow;
+    }
+    bool operator < (const ACaptureSessionOutput& other) const {
+        return mWindow < other.mWindow;
+    }
+    bool operator > (const ACaptureSessionOutput& other) const {
+        return mWindow > other.mWindow;
+    }
+
+    ANativeWindow* mWindow;
+    int            mRotation = CAMERA3_STREAM_ROTATION_0;
+};
+
+struct ACaptureSessionOutputContainer {
+    std::set<ACaptureSessionOutput> mOutputs;
+};
+
+/**
+ * ACameraCaptureSession opaque struct definition
+ * Leave outside of android namespace because it's NDK struct
+ */
+struct ACameraCaptureSession : public RefBase {
+  public:
+    ACameraCaptureSession(
+            int id,
+            const ACaptureSessionOutputContainer* outputs,
+            const ACameraCaptureSession_stateCallbacks* cb,
+            CameraDevice* device) :
+            mId(id), mOutput(*outputs), mUserSessionCallback(*cb),
+            mDevice(device) {}
+
+    // 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!
+    ~ACameraCaptureSession();
+
+    // No API except Session_Close will work if device is closed
+    // A session will enter closed state when one of the following happens:
+    //     1. Explicitly closed by app
+    //     2. Replaced by a newer session
+    //     3. Device is closed
+    bool isClosed() { Mutex::Autolock _l(mSessionLock); return mIsClosed; }
+
+    // Close the session and mark app no longer need this session.
+    void closeByApp();
+
+    camera_status_t stopRepeating();
+
+    camera_status_t setRepeatingRequest(
+            /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+            int numRequests, ACaptureRequest** requests,
+            /*optional*/int* captureSequenceId);
+
+    camera_status_t capture(
+            /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+            int numRequests, ACaptureRequest** requests,
+            /*optional*/int* captureSequenceId);
+
+    ACameraDevice* getDevice();
+
+  private:
+    friend class CameraDevice;
+
+    // Close session because app close camera device, camera device got ERROR_DISCONNECTED,
+    // or a new session is replacing this session.
+    void closeByDevice();
+
+    sp<CameraDevice> getDeviceSp();
+
+    const int mId;
+    const ACaptureSessionOutputContainer mOutput;
+    const ACameraCaptureSession_stateCallbacks mUserSessionCallback;
+    const wp<CameraDevice> mDevice;
+    bool  mIsClosed = false;
+    bool  mIdle = true;
+    Mutex mSessionLock;
+};
+
+#endif // _ACAMERA_CAPTURE_SESSION_H
diff --git a/camera/ndk/impl/ACameraDevice.cpp b/camera/ndk/impl/ACameraDevice.cpp
index 0c6f8af..5f89fa3 100644
--- a/camera/ndk/impl/ACameraDevice.cpp
+++ b/camera/ndk/impl/ACameraDevice.cpp
@@ -17,19 +17,30 @@
 //#define LOG_NDEBUG 0
 #define LOG_TAG "ACameraDevice"
 
+#include <vector>
+#include <utility>
 #include <inttypes.h>
+#include <gui/Surface.h>
 #include "ACameraDevice.h"
 #include "ACameraMetadata.h"
 #include "ACaptureRequest.h"
+#include "ACameraCaptureSession.h"
 
 using namespace android;
 
 namespace android {
 // Static member definitions
-const char* CameraDevice::kContextKey   = "Context";
-const char* CameraDevice::kDeviceKey    = "Device";
-const char* CameraDevice::kErrorCodeKey = "ErrorCode";
-const char* CameraDevice::kCallbackKey  = "Callback";
+const char* CameraDevice::kContextKey        = "Context";
+const char* CameraDevice::kDeviceKey         = "Device";
+const char* CameraDevice::kErrorCodeKey      = "ErrorCode";
+const char* CameraDevice::kCallbackFpKey     = "Callback";
+const char* CameraDevice::kSessionSpKey      = "SessionSp";
+const char* CameraDevice::kCaptureRequestKey = "CaptureRequest";
+const char* CameraDevice::kTimeStampKey      = "TimeStamp";
+const char* CameraDevice::kCaptureResultKey  = "CaptureResult";
+const char* CameraDevice::kCaptureFailureKey = "CaptureFailure";
+const char* CameraDevice::kSequenceIdKey     = "SequenceId";
+const char* CameraDevice::kFrameNumberKey    = "FrameNumber";
 
 /**
  * CameraDevice Implementation
@@ -54,22 +65,42 @@
     status_t ret = mCbLooper->start(
             /*runOnCallingThread*/false,
             /*canCallJava*/       true,
-            PRIORITY_FOREGROUND);
+            PRIORITY_DEFAULT);
     mHandler = new CallbackHandler();
     mCbLooper->registerHandler(mHandler);
+
+    CameraMetadata metadata = mChars->mData;
+    camera_metadata_entry entry = metadata.find(ANDROID_REQUEST_PARTIAL_RESULT_COUNT);
+    if (entry.count != 1) {
+        ALOGW("%s: bad count %zu for partial result count", __FUNCTION__, entry.count);
+        mPartialResultCount = 1;
+    } else {
+        mPartialResultCount = entry.data.i32[0];
+    }
+
+    entry = metadata.find(ANDROID_LENS_INFO_SHADING_MAP_SIZE);
+    if (entry.count != 2) {
+        ALOGW("%s: bad count %zu for shading map size", __FUNCTION__, entry.count);
+        mShadingMapSize[0] = 0;
+        mShadingMapSize[1] = 0;
+    } else {
+        mShadingMapSize[0] = entry.data.i32[0];
+        mShadingMapSize[1] = entry.data.i32[1];
+    }
 }
 
+// Device close implementaiton
 CameraDevice::~CameraDevice() {
     Mutex::Autolock _l(mDeviceLock);
+    if (!isClosed()) {
+        disconnectLocked();
+    }
     if (mCbLooper != nullptr) {
         mCbLooper->unregisterHandler(mHandler->id());
         mCbLooper->stop();
     }
     mCbLooper.clear();
     mHandler.clear();
-    if (!isClosed()) {
-        disconnectLocked();
-    }
 }
 
 // TODO: cached created request?
@@ -102,6 +133,213 @@
     return ACAMERA_OK;
 }
 
+camera_status_t
+CameraDevice::createCaptureSession(
+        const ACaptureSessionOutputContainer*       outputs,
+        const ACameraCaptureSession_stateCallbacks* callbacks,
+        /*out*/ACameraCaptureSession** session) {
+    Mutex::Autolock _l(mDeviceLock);
+    camera_status_t ret = checkCameraClosedOrErrorLocked();
+    if (ret != ACAMERA_OK) {
+        return ret;
+    }
+
+    if (mCurrentSession != nullptr) {
+        mCurrentSession->closeByDevice();
+        stopRepeatingLocked();
+    }
+
+    // Create new session
+    ret = configureStreamsLocked(outputs);
+    if (ret != ACAMERA_OK) {
+        ALOGE("Fail to create new session. cannot configure streams");
+        return ret;
+    }
+
+    ACameraCaptureSession* newSession = new ACameraCaptureSession(
+            mNextSessionId++, outputs, callbacks, this);
+
+    bool configureSucceeded = (ret == ACAMERA_OK);
+
+    // set new session as current session
+    newSession->incStrong((void *) ACameraDevice_createCaptureSession);
+    mCurrentSession = newSession;
+    *session = newSession;
+    return ACAMERA_OK;
+}
+
+camera_status_t
+CameraDevice::captureLocked(
+        sp<ACameraCaptureSession> session,
+        /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+        int numRequests, ACaptureRequest** requests,
+        /*optional*/int* captureSequenceId) {
+    return submitRequestsLocked(
+            session, cbs, numRequests, requests, captureSequenceId, /*isRepeating*/false);
+}
+
+camera_status_t
+CameraDevice::setRepeatingRequestsLocked(
+        sp<ACameraCaptureSession> session,
+        /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+        int numRequests, ACaptureRequest** requests,
+        /*optional*/int* captureSequenceId) {
+    return submitRequestsLocked(
+            session, cbs, numRequests, requests, captureSequenceId, /*isRepeating*/true);
+}
+
+camera_status_t
+CameraDevice::submitRequestsLocked(
+        sp<ACameraCaptureSession> session,
+        /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+        int numRequests, ACaptureRequest** requests,
+        /*optional*/int* captureSequenceId,
+        bool isRepeating) {
+    camera_status_t ret = checkCameraClosedOrErrorLocked();
+    if (ret != ACAMERA_OK) {
+        ALOGE("Camera %s submit capture request failed! ret %d", getId(), ret);
+        return ret;
+    }
+
+    // Form List/Vector of capture request
+    List<sp<CaptureRequest> > requestList;
+    Vector<sp<CaptureRequest> > requestsV;
+    requestsV.setCapacity(numRequests);
+    for (int i = 0; i < numRequests; i++) {
+        sp<CaptureRequest> req;
+        ret = allocateCaptureRequest(requests[i], req);
+        if (ret != ACAMERA_OK) {
+            ALOGE("Convert capture request to internal format failure! ret %d", ret);
+            return ret;
+        }
+        if (req->mSurfaceList.empty()) {
+            ALOGE("Capture request without output target cannot be submitted!");
+            return ACAMERA_ERROR_INVALID_PARAMETER;
+        }
+        requestList.push_back(req);
+        requestsV.push_back(req);
+    }
+
+    if (isRepeating) {
+        ret = stopRepeatingLocked();
+        if (ret != ACAMERA_OK) {
+            ALOGE("Camera %s stop repeating failed! ret %d", getId(), ret);
+            return ret;
+        }
+    }
+
+    int sequenceId;
+    int64_t lastFrameNumber;
+
+    sequenceId = mRemote->submitRequestList(requestList, isRepeating, &lastFrameNumber);
+    if (sequenceId < 0) {
+        ALOGE("Camera %s submit request remote failure: ret %d", getId(), sequenceId);
+        return ACAMERA_ERROR_UNKNOWN;
+    }
+
+    CallbackHolder cbHolder(session, requestsV, isRepeating, cbs);
+    mSequenceCallbackMap.insert(std::make_pair(sequenceId, cbHolder));
+
+    if (isRepeating) {
+        // stopRepeating above should have cleanup repeating sequence id
+        if (mRepeatingSequenceId != REQUEST_ID_NONE) {
+            setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_DEVICE);
+            return ACAMERA_ERROR_CAMERA_DEVICE;
+        }
+        mRepeatingSequenceId = sequenceId;
+    } else {
+        mSequenceLastFrameNumberMap.insert(std::make_pair(sequenceId, lastFrameNumber));
+    }
+
+    if (mIdle) {
+        sp<AMessage> msg = new AMessage(kWhatSessionStateCb, mHandler);
+        msg->setPointer(kContextKey, session->mUserSessionCallback.context);
+        msg->setObject(kSessionSpKey, session);
+        msg->setPointer(kCallbackFpKey, (void*) session->mUserSessionCallback.onActive);
+        msg->post();
+    }
+    mIdle = false;
+    mBusySession = session;
+
+    if (captureSequenceId) {
+        *captureSequenceId = sequenceId;
+    }
+    return ACAMERA_OK;
+}
+
+camera_status_t
+CameraDevice::allocateCaptureRequest(
+        const ACaptureRequest* request, /*out*/sp<CaptureRequest>& outReq) {
+    camera_status_t ret;
+    sp<CaptureRequest> req(new CaptureRequest());
+    req->mMetadata = request->settings->mData;
+    req->mIsReprocess = false; // NDK does not support reprocessing yet
+
+    for (auto outputTarget : request->targets->mOutputs) {
+        ANativeWindow* anw = outputTarget.mWindow;
+        sp<Surface> surface;
+        ret = getSurfaceFromANativeWindow(anw, surface);
+        if (ret != ACAMERA_OK) {
+            ALOGE("Bad output target in capture request! ret %d", ret);
+            return ret;
+        }
+        req->mSurfaceList.push_back(surface);
+    }
+    outReq = req;
+    return ACAMERA_OK;
+}
+
+ACaptureRequest*
+CameraDevice::allocateACaptureRequest(sp<CaptureRequest>& req) {
+    ACaptureRequest* pRequest = new ACaptureRequest();
+    CameraMetadata clone = req->mMetadata;
+    pRequest->settings = new ACameraMetadata(clone.release(), ACameraMetadata::ACM_REQUEST);
+    pRequest->targets  = new ACameraOutputTargets();
+    for (size_t i = 0; i < req->mSurfaceList.size(); i++) {
+        ANativeWindow* anw = static_cast<ANativeWindow*>(req->mSurfaceList[i].get());
+        ACameraOutputTarget outputTarget(anw);
+        pRequest->targets->mOutputs.insert(outputTarget);
+    }
+    return pRequest;
+}
+
+void
+CameraDevice::freeACaptureRequest(ACaptureRequest* req) {
+    if (req == nullptr) {
+        return;
+    }
+    delete req->settings;
+    delete req->targets;
+    delete req;
+}
+
+void
+CameraDevice::notifySessionEndOfLifeLocked(ACameraCaptureSession* session) {
+    if (isClosed()) {
+        // Device is closing already. do nothing
+        return;
+    }
+
+    if (session != mCurrentSession) {
+        // Session has been replaced by other seesion or device is closed
+        return;
+    }
+    mCurrentSession = nullptr;
+
+    // Should not happen
+    if (!session->mIsClosed) {
+        ALOGE("Error: unclosed session %p reaches end of life!", session);
+        setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_DEVICE);
+        return;
+    }
+
+    // No new session, unconfigure now
+    camera_status_t ret = configureStreamsLocked(nullptr);
+    if (ret != ACAMERA_OK) {
+        ALOGE("Unconfigure stream failed. Device might still be configured! ret %d", ret);
+    }
+}
+
 void
 CameraDevice::disconnectLocked() {
     if (mClosing.exchange(true)) {
@@ -114,6 +352,199 @@
         mRemote->disconnect();
     }
     mRemote = nullptr;
+
+    if (mCurrentSession != nullptr) {
+        mCurrentSession->closeByDevice();
+        mCurrentSession = nullptr;
+    }
+}
+
+camera_status_t
+CameraDevice::stopRepeatingLocked() {
+    camera_status_t ret = checkCameraClosedOrErrorLocked();
+    if (ret != ACAMERA_OK) {
+        ALOGE("Camera %s stop repeating failed! ret %d", getId(), ret);
+        return ret;
+    }
+    if (mRepeatingSequenceId != REQUEST_ID_NONE) {
+        int repeatingSequenceId = mRepeatingSequenceId;
+        mRepeatingSequenceId = REQUEST_ID_NONE;
+
+        int64_t lastFrameNumber;
+        status_t remoteRet = mRemote->cancelRequest(repeatingSequenceId, &lastFrameNumber);
+        if (remoteRet != OK) {
+            ALOGE("Stop repeating request fails in remote! ret %d", remoteRet);
+            return ACAMERA_ERROR_UNKNOWN;
+        }
+        checkRepeatingSequenceCompleteLocked(repeatingSequenceId, lastFrameNumber);
+    }
+    return ACAMERA_OK;
+}
+
+camera_status_t
+CameraDevice::waitUntilIdleLocked() {
+    camera_status_t ret = checkCameraClosedOrErrorLocked();
+    if (ret != ACAMERA_OK) {
+        ALOGE("Wait until camera %s idle failed! ret %d", getId(), ret);
+        return ret;
+    }
+
+    if (mRepeatingSequenceId != REQUEST_ID_NONE) {
+        ALOGE("Camera device %s won't go to idle when there is repeating request!", getId());
+        return ACAMERA_ERROR_INVALID_OPERATION;
+    }
+
+    status_t remoteRet = mRemote->waitUntilIdle();
+    if (remoteRet != OK) {
+        ALOGE("Camera device %s waitUntilIdle failed! ret %d", getId(), remoteRet);
+        // TODO: define a function to convert status_t -> camera_status_t
+        return ACAMERA_ERROR_UNKNOWN;
+    }
+
+    return ACAMERA_OK;
+}
+
+camera_status_t
+CameraDevice::getIGBPfromSessionOutput(
+        const ACaptureSessionOutput& config,
+        sp<IGraphicBufferProducer>& out) {
+    ANativeWindow* anw = config.mWindow;
+    if (anw == nullptr) {
+        ALOGE("Error: output ANativeWindow is null");
+        return ACAMERA_ERROR_INVALID_PARAMETER;
+    }
+    int value;
+    int err = (*anw->query)(anw, NATIVE_WINDOW_CONCRETE_TYPE, &value);
+    if (value != NATIVE_WINDOW_SURFACE) {
+        ALOGE("Error: ANativeWindow is not backed by Surface!");
+        return ACAMERA_ERROR_INVALID_PARAMETER;
+    }
+    const sp<Surface> surface(static_cast<Surface*>(anw));
+    out = surface->getIGraphicBufferProducer();
+    return ACAMERA_OK;
+}
+
+camera_status_t
+CameraDevice::getSurfaceFromANativeWindow(
+        ANativeWindow* anw, sp<Surface>& out) {
+    if (anw == nullptr) {
+        ALOGE("Error: output ANativeWindow is null");
+        return ACAMERA_ERROR_INVALID_PARAMETER;
+    }
+    int value;
+    int err = (*anw->query)(anw, NATIVE_WINDOW_CONCRETE_TYPE, &value);
+    if (value != NATIVE_WINDOW_SURFACE) {
+        ALOGE("Error: ANativeWindow is not backed by Surface!");
+        return ACAMERA_ERROR_INVALID_PARAMETER;
+    }
+    sp<Surface> surface(static_cast<Surface*>(anw));
+    out = surface;
+    return ACAMERA_OK;
+}
+
+camera_status_t
+CameraDevice::configureStreamsLocked(const ACaptureSessionOutputContainer* outputs) {
+    ACaptureSessionOutputContainer emptyOutput;
+    if (outputs == nullptr) {
+        outputs = &emptyOutput;
+    }
+
+    bool success = false;
+    camera_status_t ret = checkCameraClosedOrErrorLocked();
+    if (ret != ACAMERA_OK) {
+        return ret;
+    }
+
+    std::set<OutputConfiguration> outputSet;
+    for (auto outConfig : outputs->mOutputs) {
+        sp<IGraphicBufferProducer> iGBP(nullptr);
+        ret = getIGBPfromSessionOutput(outConfig, iGBP);
+        if (ret != ACAMERA_OK) {
+            return ret;
+        }
+        outputSet.insert(OutputConfiguration(iGBP, outConfig.mRotation));
+    }
+    std::set<OutputConfiguration> addSet = outputSet;
+    std::vector<int> deleteList;
+
+    // Determine which streams need to be created, which to be deleted
+    for (auto& kvPair : mConfiguredOutputs) {
+        int streamId = kvPair.first;
+        OutputConfiguration& outConfig = kvPair.second;
+        if (outputSet.count(outConfig) == 0) {
+            deleteList.push_back(streamId); // Need to delete a no longer needed stream
+        } else {
+            addSet.erase(outConfig);        // No need to add already existing stream
+        }
+    }
+
+    ret = stopRepeatingLocked();
+    if (ret != ACAMERA_OK) {
+        ALOGE("Camera device %s stop repeating failed, ret %d", getId(), ret);
+        return ret;
+    }
+
+    ret = waitUntilIdleLocked();
+    if (ret != ACAMERA_OK) {
+        ALOGE("Camera device %s wait until idle failed, ret %d", getId(), ret);
+        return ret;
+    }
+
+    // Send onReady to previous session
+    // CurrentSession will be updated after configureStreamLocked, so here
+    // mCurrentSession is the session to be replaced by a new session
+    if (!mIdle && mCurrentSession != nullptr) {
+        if (mBusySession != mCurrentSession) {
+            ALOGE("Current session != busy session");
+            setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_DEVICE);
+            return ACAMERA_ERROR_CAMERA_DEVICE;
+        }
+        sp<AMessage> msg = new AMessage(kWhatSessionStateCb, mHandler);
+        msg->setPointer(kContextKey, mBusySession->mUserSessionCallback.context);
+        msg->setObject(kSessionSpKey, mBusySession);
+        msg->setPointer(kCallbackFpKey, (void*) mBusySession->mUserSessionCallback.onReady);
+        mBusySession.clear();
+        msg->post();
+    }
+    mIdle = true;
+
+    status_t remoteRet = mRemote->beginConfigure();
+    if (remoteRet != ACAMERA_OK) {
+        ALOGE("Camera device %s begin configure failed, ret %d", getId(), remoteRet);
+        return ACAMERA_ERROR_UNKNOWN;
+    }
+
+    // delete to-be-deleted streams
+    for (auto streamId : deleteList) {
+        remoteRet = mRemote->deleteStream(streamId);
+        if (remoteRet != ACAMERA_OK) {
+            ALOGE("Camera device %s fails to remove stream %d", getId(), streamId);
+            return ACAMERA_ERROR_UNKNOWN;
+        }
+        mConfiguredOutputs.erase(streamId);
+    }
+
+    // add new streams
+    for (auto outConfig : addSet) {
+        remoteRet = mRemote->createStream(outConfig);
+        if (remoteRet < 0) {
+            ALOGE("Camera device %s fails to create stream", getId());
+            return ACAMERA_ERROR_UNKNOWN;
+        }
+        int streamId = remoteRet; // Weird, right?
+        mConfiguredOutputs.insert(std::make_pair(streamId, outConfig));
+    }
+
+    remoteRet = mRemote->endConfigure();
+    if (remoteRet == BAD_VALUE) {
+        ALOGE("Camera device %s cannnot support app output configuration", getId());
+        return ACAMERA_ERROR_STREAM_CONFIGURE_FAIL;
+    } else if (remoteRet != ACAMERA_OK) {
+        ALOGE("Camera device %s end configure failed, ret %d", getId(), remoteRet);
+        return ACAMERA_ERROR_UNKNOWN;
+    }
+
+    return ACAMERA_OK;
 }
 
 void
@@ -136,10 +567,99 @@
 }
 
 void
+CameraDevice::setCameraDeviceErrorLocked(camera_status_t error) {
+    mInError = true;
+    mError = error;
+    return;
+}
+
+void
+CameraDevice::FrameNumberTracker::updateTracker(int64_t frameNumber, bool isError) {
+    ALOGV("updateTracker frame %" PRId64 " isError %d", frameNumber, isError);
+    if (isError) {
+        mFutureErrorSet.insert(frameNumber);
+    } else if (frameNumber <= mCompletedFrameNumber) {
+        ALOGE("Frame number %" PRId64 " decreased! current fn %" PRId64,
+                frameNumber, mCompletedFrameNumber);
+        return;
+    } else {
+        if (frameNumber != mCompletedFrameNumber + 1) {
+            ALOGE("Frame number out of order. Expect %" PRId64 " but get %" PRId64,
+                    mCompletedFrameNumber + 1, frameNumber);
+            // Do not assert as in java implementation
+        }
+        mCompletedFrameNumber = frameNumber;
+    }
+    update();
+}
+
+void
+CameraDevice::FrameNumberTracker::update() {
+    for (auto it = mFutureErrorSet.begin(); it != mFutureErrorSet.end();) {
+        int64_t errorFrameNumber = *it;
+        if (errorFrameNumber == mCompletedFrameNumber + 1) {
+            mCompletedFrameNumber++;
+            it = mFutureErrorSet.erase(it);
+        } else if (errorFrameNumber <= mCompletedFrameNumber) {
+            // This should not happen, but deal with it anyway
+            ALOGE("Completd frame number passed through current frame number!");
+            // erase the old error since it's no longer useful
+            it = mFutureErrorSet.erase(it);
+        } else {
+            // Normal requests hasn't catched up error frames, just break
+            break;
+        }
+    }
+    ALOGV("Update complete frame %" PRId64, mCompletedFrameNumber);
+}
+
+void
 CameraDevice::onCaptureErrorLocked(
         ICameraDeviceCallbacks::CameraErrorCode errorCode,
         const CaptureResultExtras& resultExtras) {
-    // TODO: implement!
+    int sequenceId = resultExtras.requestId;
+    int64_t frameNumber = resultExtras.frameNumber;
+    int32_t burstId = resultExtras.burstId;
+
+    // No way to report buffer error now
+    if (errorCode == ICameraDeviceCallbacks::CameraErrorCode::ERROR_CAMERA_BUFFER) {
+        ALOGE("Camera %s Lost output buffer for frame %" PRId64,
+                getId(), frameNumber);
+        return;
+    }
+    // Fire capture failure callback if there is one registered
+    auto it = mSequenceCallbackMap.find(sequenceId);
+    if (it != mSequenceCallbackMap.end()) {
+        CallbackHolder cbh = (*it).second;
+        ACameraCaptureSession_captureCallback_failed onError = cbh.mCallbacks.onCaptureFailed;
+        sp<ACameraCaptureSession> session = cbh.mSession;
+        if ((size_t) burstId >= cbh.mRequests.size()) {
+            ALOGE("%s: Error: request index %d out of bound (size %zu)",
+                    __FUNCTION__, burstId, cbh.mRequests.size());
+            setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_SERVICE);
+            return;
+        }
+        sp<CaptureRequest> request = cbh.mRequests[burstId];
+        sp<CameraCaptureFailure> failure(new CameraCaptureFailure());
+        failure->frameNumber = frameNumber;
+        // TODO: refine this when implementing flush
+        failure->reason      = CAPTURE_FAILURE_REASON_ERROR;
+        failure->sequenceId  = sequenceId;
+        failure->wasImageCaptured = (errorCode ==
+                ICameraDeviceCallbacks::CameraErrorCode::ERROR_CAMERA_RESULT);
+
+        sp<AMessage> msg = new AMessage(kWhatCaptureFail, mHandler);
+        msg->setPointer(kContextKey, cbh.mCallbacks.context);
+        msg->setObject(kSessionSpKey, session);
+        msg->setPointer(kCallbackFpKey, (void*) onError);
+        msg->setObject(kCaptureRequestKey, request);
+        msg->setObject(kCaptureFailureKey, failure);
+        msg->post();
+    }
+
+    // Update tracker
+    mFrameNumberTracker.updateTracker(frameNumber, /*isError*/true);
+    checkAndFireSequenceCompleteLocked();
 }
 
 void CameraDevice::CallbackHandler::onMessageReceived(
@@ -147,6 +667,13 @@
     switch (msg->what()) {
         case kWhatOnDisconnected:
         case kWhatOnError:
+        case kWhatSessionStateCb:
+        case kWhatCaptureStart:
+        case kWhatCaptureResult:
+        case kWhatCaptureFail:
+        case kWhatCaptureSeqEnd:
+        case kWhatCaptureSeqAbort:
+            ALOGV("%s: Received msg %d", __FUNCTION__, msg->what());
             break;
         default:
             ALOGE("%s:Error: unknown device callback %d", __FUNCTION__, msg->what());
@@ -159,28 +686,37 @@
         ALOGE("%s: Cannot find callback context!", __FUNCTION__);
         return;
     }
-    ACameraDevice* dev;
-    found = msg->findPointer(kDeviceKey, (void**) &dev);
-    if (!found) {
-        ALOGE("%s: Cannot find device pointer!", __FUNCTION__);
-        return;
-    }
     switch (msg->what()) {
         case kWhatOnDisconnected:
         {
+            ACameraDevice* dev;
+            found = msg->findPointer(kDeviceKey, (void**) &dev);
+            if (!found || dev == nullptr) {
+                ALOGE("%s: Cannot find device pointer!", __FUNCTION__);
+                return;
+            }
             ACameraDevice_StateCallback onDisconnected;
-            found = msg->findPointer(kCallbackKey, (void**) &onDisconnected);
+            found = msg->findPointer(kCallbackFpKey, (void**) &onDisconnected);
             if (!found) {
                 ALOGE("%s: Cannot find onDisconnected!", __FUNCTION__);
                 return;
             }
+            if (onDisconnected == nullptr) {
+                return;
+            }
             (*onDisconnected)(context, dev);
             break;
         }
         case kWhatOnError:
         {
+            ACameraDevice* dev;
+            found = msg->findPointer(kDeviceKey, (void**) &dev);
+            if (!found || dev == nullptr) {
+                ALOGE("%s: Cannot find device pointer!", __FUNCTION__);
+                return;
+            }
             ACameraDevice_ErrorStateCallback onError;
-            found = msg->findPointer(kCallbackKey, (void**) &onError);
+            found = msg->findPointer(kCallbackFpKey, (void**) &onError);
             if (!found) {
                 ALOGE("%s: Cannot find onError!", __FUNCTION__);
                 return;
@@ -191,7 +727,271 @@
                 ALOGE("%s: Cannot find error code!", __FUNCTION__);
                 return;
             }
+            if (onError == nullptr) {
+                return;
+            }
             (*onError)(context, dev, errorCode);
+            break;
+        }
+        case kWhatSessionStateCb:
+        case kWhatCaptureStart:
+        case kWhatCaptureResult:
+        case kWhatCaptureFail:
+        case kWhatCaptureSeqEnd:
+        case kWhatCaptureSeqAbort:
+        {
+            sp<RefBase> obj;
+            found = msg->findObject(kSessionSpKey, &obj);
+            if (!found || obj == nullptr) {
+                ALOGE("%s: Cannot find session pointer!", __FUNCTION__);
+                return;
+            }
+            sp<ACameraCaptureSession> session(static_cast<ACameraCaptureSession*>(obj.get()));
+            sp<CaptureRequest> requestSp = nullptr;
+            switch (msg->what()) {
+                case kWhatCaptureStart:
+                case kWhatCaptureResult:
+                case kWhatCaptureFail:
+                    found = msg->findObject(kCaptureRequestKey, &obj);
+                    if (!found) {
+                        ALOGE("%s: Cannot find capture request!", __FUNCTION__);
+                        return;
+                    }
+                    requestSp = static_cast<CaptureRequest*>(obj.get());
+                    break;
+            }
+
+            switch (msg->what()) {
+                case kWhatSessionStateCb:
+                {
+                    ACameraCaptureSession_stateCallback onState;
+                    found = msg->findPointer(kCallbackFpKey, (void**) &onState);
+                    if (!found) {
+                        ALOGE("%s: Cannot find state callback!", __FUNCTION__);
+                        return;
+                    }
+                    if (onState == nullptr) {
+                        return;
+                    }
+                    (*onState)(context, session.get());
+                    break;
+                }
+                case kWhatCaptureStart:
+                {
+                    ACameraCaptureSession_captureCallback_start onStart;
+                    found = msg->findPointer(kCallbackFpKey, (void**) &onStart);
+                    if (!found) {
+                        ALOGE("%s: Cannot find capture start callback!", __FUNCTION__);
+                        return;
+                    }
+                    if (onStart == nullptr) {
+                        return;
+                    }
+                    int64_t timestamp;
+                    found = msg->findInt64(kTimeStampKey, &timestamp);
+                    if (!found) {
+                        ALOGE("%s: Cannot find timestamp!", __FUNCTION__);
+                        return;
+                    }
+                    ACaptureRequest* request = allocateACaptureRequest(requestSp);
+                    (*onStart)(context, session.get(), request, timestamp);
+                    freeACaptureRequest(request);
+                    break;
+                }
+                case kWhatCaptureResult:
+                {
+                    ACameraCaptureSession_captureCallback_result onResult;
+                    found = msg->findPointer(kCallbackFpKey, (void**) &onResult);
+                    if (!found) {
+                        ALOGE("%s: Cannot find capture result callback!", __FUNCTION__);
+                        return;
+                    }
+                    if (onResult == nullptr) {
+                        return;
+                    }
+
+                    found = msg->findObject(kCaptureResultKey, &obj);
+                    if (!found) {
+                        ALOGE("%s: Cannot find capture result!", __FUNCTION__);
+                        return;
+                    }
+                    sp<ACameraMetadata> result(static_cast<ACameraMetadata*>(obj.get()));
+                    ACaptureRequest* request = allocateACaptureRequest(requestSp);
+                    (*onResult)(context, session.get(), request, result.get());
+                    freeACaptureRequest(request);
+                    break;
+                }
+                case kWhatCaptureFail:
+                {
+                    ACameraCaptureSession_captureCallback_failed onFail;
+                    found = msg->findPointer(kCallbackFpKey, (void**) &onFail);
+                    if (!found) {
+                        ALOGE("%s: Cannot find capture fail callback!", __FUNCTION__);
+                        return;
+                    }
+                    if (onFail == nullptr) {
+                        return;
+                    }
+
+                    found = msg->findObject(kCaptureFailureKey, &obj);
+                    if (!found) {
+                        ALOGE("%s: Cannot find capture failure!", __FUNCTION__);
+                        return;
+                    }
+                    sp<CameraCaptureFailure> failureSp(
+                            static_cast<CameraCaptureFailure*>(obj.get()));
+                    ACameraCaptureFailure* failure =
+                            static_cast<ACameraCaptureFailure*>(failureSp.get());
+                    ACaptureRequest* request = allocateACaptureRequest(requestSp);
+                    (*onFail)(context, session.get(), request, failure);
+                    freeACaptureRequest(request);
+                    delete failure;
+                    break;
+                }
+                case kWhatCaptureSeqEnd:
+                {
+                    ACameraCaptureSession_captureCallback_sequenceEnd onSeqEnd;
+                    found = msg->findPointer(kCallbackFpKey, (void**) &onSeqEnd);
+                    if (!found) {
+                        ALOGE("%s: Cannot find sequence end callback!", __FUNCTION__);
+                        return;
+                    }
+                    if (onSeqEnd == nullptr) {
+                        return;
+                    }
+                    int seqId;
+                    found = msg->findInt32(kSequenceIdKey, &seqId);
+                    if (!found) {
+                        ALOGE("%s: Cannot find frame number!", __FUNCTION__);
+                        return;
+                    }
+                    int64_t frameNumber;
+                    found = msg->findInt64(kFrameNumberKey, &frameNumber);
+                    if (!found) {
+                        ALOGE("%s: Cannot find frame number!", __FUNCTION__);
+                        return;
+                    }
+                    (*onSeqEnd)(context, session.get(), seqId, frameNumber);
+                    break;
+                }
+                case kWhatCaptureSeqAbort:
+                {
+                    ACameraCaptureSession_captureCallback_sequenceAbort onSeqAbort;
+                    found = msg->findPointer(kCallbackFpKey, (void**) &onSeqAbort);
+                    if (!found) {
+                        ALOGE("%s: Cannot find sequence end callback!", __FUNCTION__);
+                        return;
+                    }
+                    if (onSeqAbort == nullptr) {
+                        return;
+                    }
+                    int seqId;
+                    found = msg->findInt32(kSequenceIdKey, &seqId);
+                    if (!found) {
+                        ALOGE("%s: Cannot find frame number!", __FUNCTION__);
+                        return;
+                    }
+                    (*onSeqAbort)(context, session.get(), seqId);
+                    break;
+                }
+            }
+            break;
+        }
+    }
+}
+
+CameraDevice::CallbackHolder::CallbackHolder(
+    sp<ACameraCaptureSession>          session,
+    const Vector<sp<CaptureRequest> >& requests,
+    bool                               isRepeating,
+    ACameraCaptureSession_captureCallbacks* cbs) :
+    mSession(session), mRequests(requests),
+    mIsRepeating(isRepeating), mCallbacks(fillCb(cbs)) {}
+
+void
+CameraDevice::checkRepeatingSequenceCompleteLocked(
+    const int sequenceId, const int64_t lastFrameNumber) {
+    ALOGV("Repeating seqId %d lastFrameNumer %" PRId64, sequenceId, lastFrameNumber);
+    if (lastFrameNumber == NO_FRAMES_CAPTURED) {
+        if (mSequenceCallbackMap.count(sequenceId) == 0) {
+            ALOGW("No callback found for sequenceId %d", sequenceId);
+            return;
+        }
+        // remove callback holder from callback map
+        auto cbIt = mSequenceCallbackMap.find(sequenceId);
+        CallbackHolder cbh = cbIt->second;
+        mSequenceCallbackMap.erase(cbIt);
+        // send seq aborted callback
+        sp<AMessage> msg = new AMessage(kWhatCaptureSeqAbort, mHandler);
+        msg->setPointer(kContextKey, cbh.mCallbacks.context);
+        msg->setObject(kSessionSpKey, cbh.mSession);
+        msg->setPointer(kCallbackFpKey, (void*) cbh.mCallbacks.onCaptureSequenceAborted);
+        msg->setInt32(kSequenceIdKey, sequenceId);
+        msg->post();
+    } else {
+        // Use mSequenceLastFrameNumberMap to track
+        mSequenceLastFrameNumberMap.insert(std::make_pair(sequenceId, lastFrameNumber));
+
+        // Last frame might have arrived. Check now
+        checkAndFireSequenceCompleteLocked();
+    }
+}
+
+void
+CameraDevice::checkAndFireSequenceCompleteLocked() {
+    int64_t completedFrameNumber = mFrameNumberTracker.getCompletedFrameNumber();
+    //std::map<int, int64_t> mSequenceLastFrameNumberMap;
+    auto it = mSequenceLastFrameNumberMap.begin();
+    while (it != mSequenceLastFrameNumberMap.end()) {
+        int sequenceId = it->first;
+        int64_t lastFrameNumber = it->second;
+        bool seqCompleted = false;
+        bool hasCallback  = true;
+
+        if (mRemote == nullptr) {
+            ALOGW("Camera %s closed while checking sequence complete", getId());
+            return;
+        }
+
+        // Check if there is callback for this sequence
+        // 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) {
+            ALOGV("seq %d reached last frame %" PRId64 ", completed %" PRId64,
+                    sequenceId, lastFrameNumber, completedFrameNumber);
+            seqCompleted = true;
+        }
+
+        if (seqCompleted && hasCallback) {
+            // remove callback holder from callback map
+            auto cbIt = mSequenceCallbackMap.find(sequenceId);
+            CallbackHolder cbh = cbIt->second;
+            mSequenceCallbackMap.erase(cbIt);
+            // send seq complete callback
+            sp<AMessage> msg = new AMessage(kWhatCaptureSeqEnd, mHandler);
+            msg->setPointer(kContextKey, cbh.mCallbacks.context);
+            msg->setObject(kSessionSpKey, cbh.mSession);
+            msg->setPointer(kCallbackFpKey, (void*) cbh.mCallbacks.onCaptureSequenceCompleted);
+            msg->setInt32(kSequenceIdKey, sequenceId);
+            msg->setInt64(kFrameNumberKey, lastFrameNumber);
+
+            // Clear the session sp before we send out the message
+            // This will guarantee the rare case where the message is processed
+            // before cbh goes out of scope and causing we call the session
+            // destructor while holding device lock
+            cbh.mSession.clear();
+            msg->post();
+        }
+
+        // No need to track sequence complete if there is no callback registered
+        if (seqCompleted || !hasCallback) {
+            it = mSequenceLastFrameNumberMap.erase(it);
+        } else {
+            ++it;
         }
     }
 }
@@ -213,17 +1013,20 @@
 
     Mutex::Autolock _l(dev->mDeviceLock);
     if (dev->mRemote == nullptr) {
-        return; // device has been disconnected
+        return; // device has been closed
     }
     switch (errorCode) {
         case ERROR_CAMERA_DISCONNECTED:
         {
-            // should be clear mRemote here?
-            // TODO: close current session
+            // Camera is disconnected, close the session and expect no more callbacks
+            if (dev->mCurrentSession != nullptr) {
+                dev->mCurrentSession->closeByDevice();
+                dev->mCurrentSession = nullptr;
+            }
             sp<AMessage> msg = new AMessage(kWhatOnDisconnected, dev->mHandler);
             msg->setPointer(kContextKey, dev->mAppCallbacks.context);
             msg->setPointer(kDeviceKey, (void*) dev->getWrapper());
-            msg->setPointer(kCallbackKey, (void*) dev->mAppCallbacks.onDisconnected);
+            msg->setPointer(kCallbackFpKey, (void*) dev->mAppCallbacks.onDisconnected);
             msg->post();
             break;
         }
@@ -233,22 +1036,21 @@
         case ERROR_CAMERA_DEVICE:
         case ERROR_CAMERA_SERVICE:
         {
-            dev->mInError = true;
             switch (errorCode) {
                 case ERROR_CAMERA_DEVICE:
-                    dev->mError = ACAMERA_ERROR_CAMERA_DEVICE;
+                    dev->setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_DEVICE);
                     break;
                 case ERROR_CAMERA_SERVICE:
-                    dev->mError = ACAMERA_ERROR_CAMERA_SERVICE;
+                    dev->setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_SERVICE);
                     break;
                 default:
-                    dev->mError = ACAMERA_ERROR_UNKNOWN;
+                    dev->setCameraDeviceErrorLocked(ACAMERA_ERROR_UNKNOWN);
                     break;
             }
             sp<AMessage> msg = new AMessage(kWhatOnError, dev->mHandler);
             msg->setPointer(kContextKey, dev->mAppCallbacks.context);
             msg->setPointer(kDeviceKey, (void*) dev->getWrapper());
-            msg->setPointer(kCallbackKey, (void*) dev->mAppCallbacks.onError);
+            msg->setPointer(kCallbackFpKey, (void*) dev->mAppCallbacks.onError);
             msg->setInt32(kErrorCodeKey, errorCode);
             msg->post();
             break;
@@ -270,11 +1072,30 @@
     }
 
     Mutex::Autolock _l(dev->mDeviceLock);
-    if (dev->mRemote == nullptr) {
-        return; // device has been disconnected
+    if (dev->isClosed() || dev->mRemote == nullptr) {
+        return;
     }
-    if (!dev->mIdle) {
-        // TODO: send idle callback to current session
+
+    if (dev->mIdle) {
+        // Already in idle state. Possibly other thread did waitUntilIdle
+        return;
+    }
+
+    if (dev->mCurrentSession != nullptr) {
+        ALOGE("onDeviceIdle sending state cb");
+        if (dev->mBusySession != dev->mCurrentSession) {
+            ALOGE("Current session != busy session");
+            dev->setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_DEVICE);
+            return;
+        }
+        sp<AMessage> msg = new AMessage(kWhatSessionStateCb, dev->mHandler);
+        msg->setPointer(kContextKey, dev->mBusySession->mUserSessionCallback.context);
+        msg->setObject(kSessionSpKey, dev->mBusySession);
+        msg->setPointer(kCallbackFpKey, (void*) dev->mBusySession->mUserSessionCallback.onReady);
+        // Make sure we clear the sp first so the session destructor can
+        // only happen on handler thread (where we don't hold device/session lock)
+        dev->mBusySession.clear();
+        msg->post();
     }
     dev->mIdle = true;
 }
@@ -283,12 +1104,103 @@
 CameraDevice::ServiceCallback::onCaptureStarted(
         const CaptureResultExtras& resultExtras,
         int64_t timestamp) {
+    sp<CameraDevice> dev = mDevice.promote();
+    if (dev == nullptr) {
+        return; // device has been closed
+    }
+    Mutex::Autolock _l(dev->mDeviceLock);
+    if (dev->isClosed() || dev->mRemote == nullptr) {
+        return;
+    }
+
+    int sequenceId = resultExtras.requestId;
+    int64_t frameNumber = resultExtras.frameNumber;
+    int32_t burstId = resultExtras.burstId;
+
+    auto it = dev->mSequenceCallbackMap.find(sequenceId);
+    if (it != dev->mSequenceCallbackMap.end()) {
+        CallbackHolder cbh = (*it).second;
+        ACameraCaptureSession_captureCallback_start onStart = cbh.mCallbacks.onCaptureStarted;
+        sp<ACameraCaptureSession> session = cbh.mSession;
+        if ((size_t) burstId >= cbh.mRequests.size()) {
+            ALOGE("%s: Error: request index %d out of bound (size %zu)",
+                    __FUNCTION__, burstId, cbh.mRequests.size());
+            dev->setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_SERVICE);
+        }
+        sp<CaptureRequest> request = cbh.mRequests[burstId];
+        sp<AMessage> msg = new AMessage(kWhatCaptureStart, dev->mHandler);
+        msg->setPointer(kContextKey, cbh.mCallbacks.context);
+        msg->setObject(kSessionSpKey, session);
+        msg->setPointer(kCallbackFpKey, (void*) onStart);
+        msg->setObject(kCaptureRequestKey, request);
+        msg->setInt64(kTimeStampKey, timestamp);
+        msg->post();
+    }
 }
 
 void
 CameraDevice::ServiceCallback::onResultReceived(
         const CameraMetadata& metadata,
         const CaptureResultExtras& resultExtras) {
+    sp<CameraDevice> dev = mDevice.promote();
+    if (dev == nullptr) {
+        return; // device has been closed
+    }
+    int sequenceId = resultExtras.requestId;
+    int64_t frameNumber = resultExtras.frameNumber;
+    int32_t burstId = resultExtras.burstId;
+    bool    isPartialResult = (resultExtras.partialResultCount < dev->mPartialResultCount);
+
+    if (!isPartialResult) {
+        ALOGV("SeqId %d frame %" PRId64 " result arrive.", sequenceId, frameNumber);
+    }
+
+    Mutex::Autolock _l(dev->mDeviceLock);
+    if (dev->mRemote == nullptr) {
+        return; // device has been disconnected
+    }
+
+    if (dev->isClosed()) {
+        if (!isPartialResult) {
+            dev->mFrameNumberTracker.updateTracker(frameNumber, /*isError*/false);
+        }
+        // early return to avoid callback sent to closed devices
+        return;
+    }
+
+    CameraMetadata metadataCopy = metadata;
+    // Copied from java implmentation. Why do we need this?
+    metadataCopy.update(ANDROID_LENS_INFO_SHADING_MAP_SIZE, dev->mShadingMapSize, /*data_count*/2);
+
+    auto it = dev->mSequenceCallbackMap.find(sequenceId);
+    if (it != dev->mSequenceCallbackMap.end()) {
+        CallbackHolder cbh = (*it).second;
+        ACameraCaptureSession_captureCallback_result onResult = isPartialResult ?
+                cbh.mCallbacks.onCaptureProgressed :
+                cbh.mCallbacks.onCaptureCompleted;
+        sp<ACameraCaptureSession> session = cbh.mSession;
+        if ((size_t) burstId >= cbh.mRequests.size()) {
+            ALOGE("%s: Error: request index %d out of bound (size %zu)",
+                    __FUNCTION__, burstId, cbh.mRequests.size());
+            dev->setCameraDeviceErrorLocked(ACAMERA_ERROR_CAMERA_SERVICE);
+        }
+        sp<CaptureRequest> request = cbh.mRequests[burstId];
+        sp<ACameraMetadata> result(new ACameraMetadata(
+                metadataCopy.release(), ACameraMetadata::ACM_RESULT));
+
+        sp<AMessage> msg = new AMessage(kWhatCaptureResult, dev->mHandler);
+        msg->setPointer(kContextKey, cbh.mCallbacks.context);
+        msg->setObject(kSessionSpKey, session);
+        msg->setPointer(kCallbackFpKey, (void*) onResult);
+        msg->setObject(kCaptureRequestKey, request);
+        msg->setObject(kCaptureResultKey, result);
+        msg->post();
+    }
+
+    if (!isPartialResult) {
+        dev->mFrameNumberTracker.updateTracker(frameNumber, /*isError*/false);
+        dev->checkAndFireSequenceCompleteLocked();
+    }
 }
 
 void
diff --git a/camera/ndk/impl/ACameraDevice.h b/camera/ndk/impl/ACameraDevice.h
index 061175c..b73e621 100644
--- a/camera/ndk/impl/ACameraDevice.h
+++ b/camera/ndk/impl/ACameraDevice.h
@@ -17,26 +17,35 @@
 #define _ACAMERA_DEVICE_H
 
 #include <memory>
+#include <map>
+#include <set>
 #include <atomic>
 #include <utils/StrongPointer.h>
 #include <utils/Mutex.h>
 #include <utils/String8.h>
+#include <utils/List.h>
+#include <utils/Vector.h>
 
 #include <media/stagefright/foundation/ALooper.h>
 #include <media/stagefright/foundation/AHandler.h>
 #include <media/stagefright/foundation/AMessage.h>
+#include <camera/CaptureResult.h>
 #include <camera/camera2/ICameraDeviceCallbacks.h>
 #include <camera/camera2/ICameraDeviceUser.h>
+#include <camera/camera2/OutputConfiguration.h>
+#include <camera/camera2/CaptureRequest.h>
 
 #include <NdkCameraDevice.h>
 #include "ACameraMetadata.h"
 
-
 using namespace android;
 
 namespace android {
 
-struct CameraDevice final : public RefBase {
+// Wrap ACameraCaptureFailure so it can be ref-counter
+struct CameraCaptureFailure : public RefBase, public ACameraCaptureFailure {};
+
+class CameraDevice final : public RefBase {
   public:
     CameraDevice(const char* id, ACameraDevice_StateCallbacks* cb,
                   std::unique_ptr<ACameraMetadata> chars,
@@ -49,6 +58,11 @@
             ACameraDevice_request_template templateId,
             ACaptureRequest** request) const;
 
+    camera_status_t createCaptureSession(
+            const ACaptureSessionOutputContainer*       outputs,
+            const ACameraCaptureSession_stateCallbacks* callbacks,
+            /*out*/ACameraCaptureSession** session);
+
     // Callbacks from camera service
     class ServiceCallback : public BnCameraDeviceCallbacks {
       public:
@@ -69,10 +83,60 @@
     // Camera device is only functional after remote being set
     void setRemoteDevice(sp<ICameraDeviceUser> remote);
 
+    inline ACameraDevice* getWrapper() const { return mWrapper; };
+
   private:
-    void disconnectLocked(); // disconnect from camera service
+    friend ACameraCaptureSession;
     camera_status_t checkCameraClosedOrErrorLocked() const;
 
+    // device goes into fatal error state after this
+    void setCameraDeviceErrorLocked(camera_status_t error);
+
+    void disconnectLocked(); // disconnect from camera service
+
+    camera_status_t stopRepeatingLocked();
+
+    camera_status_t waitUntilIdleLocked();
+
+
+    camera_status_t captureLocked(sp<ACameraCaptureSession> session,
+            /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+            int numRequests, ACaptureRequest** requests,
+            /*optional*/int* captureSequenceId);
+
+    camera_status_t setRepeatingRequestsLocked(sp<ACameraCaptureSession> session,
+            /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+            int numRequests, ACaptureRequest** requests,
+            /*optional*/int* captureSequenceId);
+
+    camera_status_t submitRequestsLocked(
+            sp<ACameraCaptureSession> session,
+            /*optional*/ACameraCaptureSession_captureCallbacks* cbs,
+            int numRequests, ACaptureRequest** requests,
+            /*out*/int* captureSequenceId,
+            bool isRepeating);
+
+    static camera_status_t allocateCaptureRequest(
+            const ACaptureRequest* request, sp<CaptureRequest>& outReq);
+
+    static ACaptureRequest* allocateACaptureRequest(sp<CaptureRequest>& req);
+    static void freeACaptureRequest(ACaptureRequest*);
+
+    // only For session to hold device lock
+    // Always grab device lock before grabbing session lock
+    void lockDeviceForSessionOps() const { mDeviceLock.lock(); };
+    void unlockDevice() const { mDeviceLock.unlock(); };
+
+    // For capture session to notify its end of life
+    void notifySessionEndOfLifeLocked(ACameraCaptureSession* session);
+
+    camera_status_t configureStreamsLocked(const ACaptureSessionOutputContainer* outputs);
+
+    static camera_status_t getIGBPfromSessionOutput(
+            const ACaptureSessionOutput& config, sp<IGraphicBufferProducer>& out);
+
+    static camera_status_t getSurfaceFromANativeWindow(
+            ANativeWindow* anw, sp<Surface>& out);
 
     mutable Mutex mDeviceLock;
     const String8 mCameraId;                          // Camera ID
@@ -81,6 +145,9 @@
     const sp<ServiceCallback> mServiceCallback;
     ACameraDevice* mWrapper;
 
+    // stream id -> OutputConfiguration map
+    std::map<int, OutputConfiguration> mConfiguredOutputs;
+
     // TODO: maybe a bool will suffice for synchronous implementation?
     std::atomic_bool mClosing;
     inline bool isClosed() { return mClosing; }
@@ -92,6 +159,8 @@
             const CaptureResultExtras& resultExtras);
 
     bool mIdle;
+    // This will avoid a busy session being deleted before it's back to idle state
+    sp<ACameraCaptureSession> mBusySession;
 
     sp<ICameraDeviceUser> mRemote;
 
@@ -99,13 +168,29 @@
     sp<ALooper> mCbLooper;
     // definition of handler and message
     enum {
-        kWhatOnDisconnected,
-        kWhatOnError
+        // Device state callbacks
+        kWhatOnDisconnected, // onDisconnected
+        kWhatOnError,        // onError
+        // Session state callbacks
+        kWhatSessionStateCb, // onReady, onActive
+        // Capture callbacks
+        kWhatCaptureStart,   // onCaptureStarted
+        kWhatCaptureResult,  // onCaptureProgressed, onCaptureCompleted
+        kWhatCaptureFail,    // onCaptureFailed
+        kWhatCaptureSeqEnd,  // onCaptureSequenceCompleted
+        kWhatCaptureSeqAbort // onCaptureSequenceAborted
     };
     static const char* kContextKey;
     static const char* kDeviceKey;
     static const char* kErrorCodeKey;
-    static const char* kCallbackKey;
+    static const char* kCallbackFpKey;
+    static const char* kSessionSpKey;
+    static const char* kCaptureRequestKey;
+    static const char* kTimeStampKey;
+    static const char* kCaptureResultKey;
+    static const char* kCaptureFailureKey;
+    static const char* kSequenceIdKey;
+    static const char* kFrameNumberKey;
     class CallbackHandler : public AHandler {
       public:
         CallbackHandler() {}
@@ -113,10 +198,65 @@
     };
     sp<CallbackHandler> mHandler;
 
-    inline ACameraDevice* getWrapper() { return mWrapper; };
+    /***********************************
+     * Capture session related members *
+     ***********************************/
+    // The current active session
+    ACameraCaptureSession* mCurrentSession = nullptr;
 
+    int mNextSessionId = 0;
     // TODO: might need another looper/handler to handle callbacks from service
 
+    static const int REQUEST_ID_NONE = -1;
+    int mRepeatingSequenceId = REQUEST_ID_NONE;
+
+    // sequence id -> last frame number map
+    std::map<int, int64_t> mSequenceLastFrameNumberMap;
+
+    struct CallbackHolder {
+        CallbackHolder(sp<ACameraCaptureSession>          session,
+                       const Vector<sp<CaptureRequest> >& requests,
+                       bool                               isRepeating,
+                       ACameraCaptureSession_captureCallbacks* cbs);
+
+        static ACameraCaptureSession_captureCallbacks fillCb(
+                ACameraCaptureSession_captureCallbacks* cbs) {
+            if (cbs != nullptr) {
+                return *cbs;
+            }
+            return { nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr };
+        }
+
+        sp<ACameraCaptureSession>   mSession;
+        Vector<sp<CaptureRequest> > mRequests;
+        const bool                  mIsRepeating;
+        ACameraCaptureSession_captureCallbacks mCallbacks;
+    };
+    // sequence id -> callbacks map
+    std::map<int, CallbackHolder> mSequenceCallbackMap;
+
+    static const int64_t NO_FRAMES_CAPTURED = -1;
+    class FrameNumberTracker {
+      public:
+        // TODO: Called in onResultReceived and onCaptureErrorLocked
+        void updateTracker(int64_t frameNumber, bool isError);
+        inline int64_t getCompletedFrameNumber() { return mCompletedFrameNumber; }
+      private:
+        void update();
+        void updateCompletedFrameNumber(int64_t frameNumber);
+
+        int64_t mCompletedFrameNumber = NO_FRAMES_CAPTURED;
+        List<int64_t> mSkippedFrameNumbers;
+        std::set<int64_t> mFutureErrorSet;
+    };
+    FrameNumberTracker mFrameNumberTracker;
+
+    void checkRepeatingSequenceCompleteLocked(const int sequenceId, const int64_t lastFrameNumber);
+    void checkAndFireSequenceCompleteLocked();
+
+    // Misc variables
+    int32_t mShadingMapSize[2];   // const after constructor
+    int32_t mPartialResultCount;  // const after constructor
 
 };
 
@@ -133,6 +273,9 @@
 
     ~ACameraDevice() {};
 
+    /*******************
+     * NDK public APIs *
+     *******************/
     inline const char* getId() const { return mDevice->getId(); }
 
     camera_status_t createCaptureRequest(
@@ -141,6 +284,16 @@
         return mDevice->createCaptureRequest(templateId, request);
     }
 
+    camera_status_t createCaptureSession(
+            const ACaptureSessionOutputContainer*       outputs,
+            const ACameraCaptureSession_stateCallbacks* callbacks,
+            /*out*/ACameraCaptureSession** session) {
+        return mDevice->createCaptureSession(outputs, callbacks, session);
+    }
+
+    /***********************
+     * Device interal APIs *
+     ***********************/
     inline sp<ICameraDeviceCallbacks> getServiceCallback() {
         return mDevice->getServiceCallback();
     };
@@ -151,7 +304,6 @@
     }
 
   private:
-    // TODO: might need an API to give wp of mDevice to capture session
     sp<CameraDevice> mDevice;
 };
 
diff --git a/camera/ndk/impl/ACameraManager.cpp b/camera/ndk/impl/ACameraManager.cpp
index 4014fd2..ed5c3ba 100644
--- a/camera/ndk/impl/ACameraManager.cpp
+++ b/camera/ndk/impl/ACameraManager.cpp
@@ -58,6 +58,7 @@
     Mutex::Autolock _l(mLock);
     if (mCameraService != nullptr) {
         IInterface::asBinder(mCameraService)->unlinkToDeath(mDeathNotifier);
+        mCameraService->removeListener(mCameraServiceListener);
     }
     mDeathNotifier.clear();
     if (mCbLooper != nullptr) {
@@ -96,7 +97,7 @@
             status_t ret = mCbLooper->start(
                     /*runOnCallingThread*/false,
                     /*canCallJava*/       true,
-                    PRIORITY_FOREGROUND);
+                    PRIORITY_DEFAULT);
             if (mHandler == nullptr) {
                 mHandler = new CallbackHandler();
             }
@@ -242,7 +243,7 @@
         Status status, int32_t cameraId) {
     sp<CameraManagerGlobal> cm = mCameraManager.promote();
     if (cm == nullptr) {
-        ALOGE("Cannot deliver status change. Camera service died");
+        ALOGE("Cannot deliver status change. Global camera manager died");
         return;
     }
     cm->onStatusChanged(status, cameraId);
diff --git a/camera/ndk/impl/ACameraMetadata.cpp b/camera/ndk/impl/ACameraMetadata.cpp
index 25571c5..f121391 100644
--- a/camera/ndk/impl/ACameraMetadata.cpp
+++ b/camera/ndk/impl/ACameraMetadata.cpp
@@ -27,7 +27,10 @@
  */
 ACameraMetadata::ACameraMetadata(camera_metadata_t* buffer, ACAMERA_METADATA_TYPE type) :
         mData(buffer), mType(type) {
-    filterUnsupportedFeatures();
+    if (mType == ACM_CHARACTERISTICS) {
+        filterUnsupportedFeatures();
+    }
+    // TODO: filter request/result keys
 }
 
 bool
diff --git a/camera/ndk/impl/ACameraMetadata.h b/camera/ndk/impl/ACameraMetadata.h
index 36a9a9a..fa0149a 100644
--- a/camera/ndk/impl/ACameraMetadata.h
+++ b/camera/ndk/impl/ACameraMetadata.h
@@ -17,6 +17,7 @@
 #define _ACAMERA_METADATA_H
 
 #include <sys/types.h>
+#include <utils/RefBase.h>
 #include <camera/CameraMetadata.h>
 
 #include "NdkCameraMetadata.h"
@@ -27,7 +28,7 @@
  * ACameraMetadata opaque struct definition
  * Leave outside of android namespace because it's NDK struct
  */
-struct ACameraMetadata {
+struct ACameraMetadata : public RefBase {
   public:
     typedef enum {
         ACM_CHARACTERISTICS, // Read only
@@ -50,7 +51,6 @@
     camera_status_t update(uint32_t tag, uint32_t count, const int64_t* data);
     camera_status_t update(uint32_t tag, uint32_t count, const ACameraMetadata_rational* data);
 
-  private:
     bool isNdkSupportedCapability(const int32_t capability);
     inline bool isVendorTag(const uint32_t tag);
     bool isCaptureRequestTag(const uint32_t tag);