diff --git a/camera/device/1.0/types.hal b/camera/device/1.0/types.hal
index 4e5683a..83c0be4 100644
--- a/camera/device/1.0/types.hal
+++ b/camera/device/1.0/types.hal
@@ -89,7 +89,7 @@
  * 4. 0x07 is enabling a callback with frame copied out only once. A typical
  *    use case is the Barcode scanner application.
  */
-enum FrameCallbackFlags : uint32_t {
+enum FrameCallbackFlag : uint32_t {
     ENABLE_MASK = 0x01,
     ONE_SHOT_MASK = 0x02,
     COPY_OUT_MASK = 0x04,
@@ -100,6 +100,8 @@
     BARCODE_SCANNER = 0x07
 };
 
+typedef bitfield<FrameCallbackFlag> FrameCallbackFlags;
+
 /**
  * Subset of commands in /system/core/include/system/camera.h relevant for
  * ICameraDevice@1.0::sendCommand()
diff --git a/vehicle/2.0/default/tests/SubscriptionManager_test.cpp b/vehicle/2.0/default/tests/SubscriptionManager_test.cpp
index 19b11e6..171a692 100644
--- a/vehicle/2.0/default/tests/SubscriptionManager_test.cpp
+++ b/vehicle/2.0/default/tests/SubscriptionManager_test.cpp
@@ -19,9 +19,6 @@
 
 #include <gtest/gtest.h>
 
-#include <vehicle_hal_manager/VehiclePropConfigIndex.h>
-#include <VehicleHal.h>
-#include <vehicle_hal_manager/VehicleHalManager.h>
 #include "vehicle_hal_manager/SubscriptionManager.h"
 
 #include "VehicleHalTestUtils.h"
diff --git a/vehicle/2.0/default/tests/VehicleHalManager_test.cpp b/vehicle/2.0/default/tests/VehicleHalManager_test.cpp
index 6ef1205..d06f6f4 100644
--- a/vehicle/2.0/default/tests/VehicleHalManager_test.cpp
+++ b/vehicle/2.0/default/tests/VehicleHalManager_test.cpp
@@ -17,13 +17,11 @@
 #include <unordered_map>
 #include <iostream>
 
+#include <utils/SystemClock.h>
+
 #include <gtest/gtest.h>
 
-#include <vehicle_hal_manager/VehiclePropConfigIndex.h>
-#include <VehicleHal.h>
-#include <vehicle_hal_manager/VehicleHalManager.h>
-#include <utils/SystemClock.h>
-#include "vehicle_hal_manager/SubscriptionManager.h"
+#include "vehicle_hal_manager/VehicleHalManager.h"
 
 #include "VehicleHalTestUtils.h"
 
@@ -429,11 +427,11 @@
     clients.addOrUpdate(c2);
     ASSERT_EQ(2u, clients.size());
     ASSERT_FALSE(clients.isEmpty());
-    ASSERT_GE(0, clients.indexOf(c1));
-    ASSERT_GE(0, clients.remove(c1));
-    ASSERT_GE(0, clients.indexOf(c1));
-    ASSERT_GE(0, clients.remove(c1));
-    ASSERT_GE(0, clients.remove(c2));
+    ASSERT_LE(0, clients.indexOf(c1));
+    ASSERT_LE(0, clients.remove(c1));
+    ASSERT_GT(0, clients.indexOf(c1));  // c1 was already removed
+    ASSERT_GT(0, clients.remove(c1));   // attempt to remove c1 again
+    ASSERT_LE(0, clients.remove(c2));
 
     ASSERT_TRUE(clients.isEmpty());
 }
diff --git a/vehicle/2.0/default/tests/VehicleObjectPool_test.cpp b/vehicle/2.0/default/tests/VehicleObjectPool_test.cpp
index 88b1be0..135f9fa 100644
--- a/vehicle/2.0/default/tests/VehicleObjectPool_test.cpp
+++ b/vehicle/2.0/default/tests/VehicleObjectPool_test.cpp
@@ -18,9 +18,10 @@
 
 #include <gtest/gtest.h>
 
-#include <vehicle_hal_manager/VehicleObjectPool.h>
 #include <utils/SystemClock.h>
 
+#include "vehicle_hal_manager/VehicleObjectPool.h"
+
 namespace android {
 namespace hardware {
 namespace vehicle {
diff --git a/vehicle/2.0/default/tests/VehiclePropConfigIndex_test.cpp b/vehicle/2.0/default/tests/VehiclePropConfigIndex_test.cpp
index aae7e62..28cdcbb 100644
--- a/vehicle/2.0/default/tests/VehiclePropConfigIndex_test.cpp
+++ b/vehicle/2.0/default/tests/VehiclePropConfigIndex_test.cpp
@@ -16,7 +16,7 @@
 
 #include <gtest/gtest.h>
 
-#include <vehicle_hal_manager/VehiclePropConfigIndex.h>
+#include "vehicle_hal_manager/VehiclePropConfigIndex.h"
 
 #include "VehicleHalTestUtils.h"
 
diff --git a/vehicle/2.0/default/vehicle_hal_manager/ConcurrentQueue.h b/vehicle/2.0/default/vehicle_hal_manager/ConcurrentQueue.h
index 485f3dc..8f575dc 100644
--- a/vehicle/2.0/default/vehicle_hal_manager/ConcurrentQueue.h
+++ b/vehicle/2.0/default/vehicle_hal_manager/ConcurrentQueue.h
@@ -108,20 +108,17 @@
         mQueue = queue;
         mBatchInterval = batchInterval;
 
-        std::thread(&BatchingConsumer<T>::runInternal, this, func).detach();
+        mWorkerThread = std::thread(
+            &BatchingConsumer<T>::runInternal, this, func);
     }
 
     void requestStop() {
-        if (mState.exchange(State::STOP_REQUESTED) != State::RUNNING) {
-            mState = State::STOPPED;
-            mCondStopped.notify_one();
-        }
+        mState = State::STOP_REQUESTED;
     }
 
     void waitStopped() {
-        std::unique_lock<std::mutex> g(mLock);
-        while (State::STOPPED != mState) {
-            mCondStopped.wait(g);
+        if (mWorkerThread.joinable()) {
+            mWorkerThread.join();
         }
     }
 
@@ -144,12 +141,10 @@
         }
 
         mState = State::STOPPED;
-        mCondStopped.notify_one();
     }
 
 private:
-    std::mutex mLock;
-    std::condition_variable mCondStopped;
+    std::thread mWorkerThread;
 
     std::atomic<State> mState;
     std::chrono::nanoseconds mBatchInterval;