diff --git a/sensors/2.0/multihal/HalProxy.cpp b/sensors/2.0/multihal/HalProxy.cpp
index d667218..fe2b98b 100644
--- a/sensors/2.0/multihal/HalProxy.cpp
+++ b/sensors/2.0/multihal/HalProxy.cpp
@@ -65,15 +65,7 @@
 }
 
 HalProxy::~HalProxy() {
-    mThreadsRun.store(false);
-    mWakelockCV.notify_one();
-    mEventQueueWriteCV.notify_one();
-    if (mPendingWritesThread.joinable()) {
-        mPendingWritesThread.join();
-    }
-    if (mWakelockThread.joinable()) {
-        mWakelockThread.join();
-    }
+    stopThreads();
 }
 
 Return<void> HalProxy::getSensorsList(getSensorsList_cb _hidl_cb) {
@@ -119,8 +111,18 @@
         const sp<ISensorsCallback>& sensorsCallback) {
     Result result = Result::OK;
 
-    // TODO: clean up sensor requests, if not already done elsewhere through a death recipient, and
-    // clean up any other resources that exist (FMQs, flags, threads, etc.)
+    stopThreads();
+    resetSharedWakelock();
+
+    // So that the pending write events queue can be cleared safely and when we start threads
+    // again we do not get new events until after initialize resets the subhals.
+    disableAllSensors();
+
+    // Clears the queue if any events were pending write before.
+    mPendingWriteEventsQueue = std::queue<std::pair<std::vector<Event>, size_t>>();
+
+    // Clears previously connected dynamic sensors
+    mDynamicSensors.clear();
 
     mDynamicSensorsCallback = sensorsCallback;
 
@@ -128,21 +130,29 @@
     mEventQueue =
             std::make_unique<EventMessageQueue>(eventQueueDescriptor, true /* resetPointers */);
 
-    // Create the EventFlag that is used to signal to the framework that sensor events have been
-    // written to the Event FMQ
-    if (EventFlag::createEventFlag(mEventQueue->getEventFlagWord(), &mEventQueueFlag) != OK) {
-        result = Result::BAD_VALUE;
-    }
-
     // Create the Wake Lock FMQ that is used by the framework to communicate whenever WAKE_UP
     // events have been successfully read and handled by the framework.
     mWakeLockQueue =
             std::make_unique<WakeLockMessageQueue>(wakeLockDescriptor, true /* resetPointers */);
 
+    if (mEventQueueFlag != nullptr) {
+        EventFlag::deleteEventFlag(&mEventQueueFlag);
+    }
+    if (mWakelockQueueFlag != nullptr) {
+        EventFlag::deleteEventFlag(&mWakelockQueueFlag);
+    }
+    if (EventFlag::createEventFlag(mEventQueue->getEventFlagWord(), &mEventQueueFlag) != OK) {
+        result = Result::BAD_VALUE;
+    }
+    if (EventFlag::createEventFlag(mWakeLockQueue->getEventFlagWord(), &mWakelockQueueFlag) != OK) {
+        result = Result::BAD_VALUE;
+    }
     if (!mDynamicSensorsCallback || !mEventQueue || !mWakeLockQueue || mEventQueueFlag == nullptr) {
         result = Result::BAD_VALUE;
     }
 
+    mThreadsRun.store(true);
+
     mPendingWritesThread = std::thread(startPendingWritesThread, this);
     mWakelockThread = std::thread(startWakelockThread, this);
 
@@ -157,6 +167,8 @@
         }
     }
 
+    mCurrentOperationMode = OperationMode::NORMAL;
+
     return result;
 }
 
@@ -331,6 +343,41 @@
     initializeSensorList();
 }
 
+void HalProxy::stopThreads() {
+    mThreadsRun.store(false);
+    if (mEventQueueFlag != nullptr && mEventQueue != nullptr) {
+        size_t numToRead = mEventQueue->availableToRead();
+        std::vector<Event> events(numToRead);
+        mEventQueue->read(events.data(), numToRead);
+        mEventQueueFlag->wake(static_cast<uint32_t>(EventQueueFlagBits::EVENTS_READ));
+    }
+    if (mWakelockQueueFlag != nullptr && mWakeLockQueue != nullptr) {
+        uint32_t kZero = 0;
+        mWakeLockQueue->write(&kZero);
+        mWakelockQueueFlag->wake(static_cast<uint32_t>(WakeLockQueueFlagBits::DATA_WRITTEN));
+    }
+    mWakelockCV.notify_one();
+    mEventQueueWriteCV.notify_one();
+    if (mPendingWritesThread.joinable()) {
+        mPendingWritesThread.join();
+    }
+    if (mWakelockThread.joinable()) {
+        mWakelockThread.join();
+    }
+}
+
+void HalProxy::disableAllSensors() {
+    for (const auto& sensorEntry : mSensors) {
+        int32_t sensorHandle = sensorEntry.first;
+        activate(sensorHandle, false /* enabled */);
+    }
+    std::lock_guard<std::mutex> dynamicSensorsLock(mDynamicSensorsMutex);
+    for (const auto& sensorEntry : mDynamicSensors) {
+        int32_t sensorHandle = sensorEntry.first;
+        activate(sensorHandle, false /* enabled */);
+    }
+}
+
 void HalProxy::startPendingWritesThread(HalProxy* halProxy) {
     halProxy->handlePendingWrites();
 }
@@ -347,8 +394,6 @@
             size_t eventQueueSize = mEventQueue->getQuantumCount();
             size_t numToWrite = std::min(pendingWriteEvents.size(), eventQueueSize);
             lock.unlock();
-            // TODO: Find a way to interrup writeBlocking if the thread should exit
-            // so we don't have to wait for timeout on framework restarts.
             if (!mEventQueue->writeBlocking(
                         pendingWriteEvents.data(), numToWrite,
                         static_cast<uint32_t>(EventQueueFlagBits::EVENTS_READ),
diff --git a/sensors/2.0/multihal/include/HalProxy.h b/sensors/2.0/multihal/include/HalProxy.h
index 6592afe..26bc644 100644
--- a/sensors/2.0/multihal/include/HalProxy.h
+++ b/sensors/2.0/multihal/include/HalProxy.h
@@ -149,9 +149,13 @@
     std::unique_ptr<WakeLockMessageQueue> mWakeLockQueue;
 
     /**
-     * Event Flag to signal to the framework when sensor events are available to be read
+     * Event Flag to signal to the framework when sensor events are available to be read and to
+     * interrupt event queue blocking write.
      */
-    EventFlag* mEventQueueFlag;
+    EventFlag* mEventQueueFlag = nullptr;
+
+    //! Event Flag to signal internally that the wakelock queue should stop its blocking read.
+    EventFlag* mWakelockQueueFlag = nullptr;
 
     /**
      * Callback to the sensors framework to inform it that new sensors have been added or removed.
@@ -254,6 +258,16 @@
     void init();
 
     /**
+     * Stops all threads by setting the threads running flag to false and joining to them.
+     */
+    void stopThreads();
+
+    /**
+     * Disable all the sensors observed by the HalProxy.
+     */
+    void disableAllSensors();
+
+    /**
      * Starts the thread that handles pending writes to event fmq.
      *
      * @param halProxy The HalProxy object pointer.
diff --git a/sensors/2.0/multihal/include/SubHal.h b/sensors/2.0/multihal/include/SubHal.h
index e7eedaa..92ae3a6 100644
--- a/sensors/2.0/multihal/include/SubHal.h
+++ b/sensors/2.0/multihal/include/SubHal.h
@@ -130,11 +130,13 @@
     virtual const std::string getName() = 0;
 
     /**
-     * First method invoked on the sub-HAL after it's allocated through sensorsHalGetSubHal() by the
-     * HalProxy. Sub-HALs should use this to initialize any state and retain the callback given in
-     * order to communicate with the HalProxy. Method will be called anytime the sensors framework
-     * restarts. Therefore, this method will be responsible for reseting the state of the subhal and
-     * cleaning up and reallocating any previously allocated data.
+     * This is the first method invoked on the sub-HAL after it's allocated through
+     * sensorsHalGetSubHal() by the HalProxy. Sub-HALs should use this to initialize any state and
+     * retain the callback given in order to communicate with the HalProxy. Method will be called
+     * anytime the sensors framework restarts. Therefore, this method will be responsible for
+     * reseting the state of the subhal and cleaning up and reallocating any previously allocated
+     * data. Initialize should ensure that the subhal has reset its operation mode to NORMAL state
+     * as well.
      *
      * @param halProxyCallback callback used to inform the HalProxy when a dynamic sensor's state
      *     changes, new sensor events should be sent to the framework, and when a new ScopedWakelock
diff --git a/sensors/2.0/multihal/tests/HalProxy_test.cpp b/sensors/2.0/multihal/tests/HalProxy_test.cpp
index fa527c9..040e8c2 100644
--- a/sensors/2.0/multihal/tests/HalProxy_test.cpp
+++ b/sensors/2.0/multihal/tests/HalProxy_test.cpp
@@ -432,7 +432,7 @@
     EXPECT_EQ(eventQueue->availableToRead(), kNumEvents * 2);
 }
 
-TEST(HalProxyTest, DestructingWithEventsPendingOnBackgroundThreadTest) {
+TEST(HalProxyTest, DestructingWithEventsPendingOnBackgroundThread) {
     constexpr size_t kQueueSize = 5;
     constexpr size_t kNumEvents = 6;
     AllSensorsSubHal subHal;
@@ -447,13 +447,145 @@
     std::vector<Event> events = makeMultipleAccelerometerEvents(kNumEvents);
     subHal.postEvents(events, false /* wakeup */);
 
-    // Sleep for a half second so that background thread has time to attempt it's blocking write
-    std::this_thread::sleep_for(std::chrono::milliseconds(500));
+    // Destructing HalProxy object with events on the background thread
+}
 
-    // Should see a 5 second wait for blocking write timeout here
+TEST(HalProxyTest, DestructingWithUnackedWakeupEventsPosted) {
+    constexpr size_t kQueueSize = 5;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
 
-    // Should be one events left on pending writes queue here and proxy will destruct
-    // If this TEST completes then it was a success, if it hangs we will see a crash
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events{makeProximityEvent()};
+    subHal.postEvents(events, true /* wakeup */);
+
+    // Not sending any acks back through wakeLockQueue
+
+    // Destructing HalProxy object with unacked wakeup events posted
+}
+
+TEST(HalProxyTest, ReinitializeWithEventsPendingOnBackgroundThread) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 10;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events = makeMultipleAccelerometerEvents(kNumEvents);
+    subHal.postEvents(events, false /* wakeup */);
+
+    eventQueue = makeEventFMQ(kQueueSize);
+    wakeLockQueue = makeWakelockFMQ(kQueueSize);
+
+    Result secondInitResult =
+            proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+    EXPECT_EQ(secondInitResult, Result::OK);
+    // Small sleep so that pending writes thread has a change to hit writeBlocking call.
+    std::this_thread::sleep_for(std::chrono::milliseconds(5));
+    Event eventOut;
+    EXPECT_FALSE(eventQueue->read(&eventOut));
+}
+
+TEST(HalProxyTest, ReinitializingWithUnackedWakeupEventsPosted) {
+    constexpr size_t kQueueSize = 5;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events{makeProximityEvent()};
+    subHal.postEvents(events, true /* wakeup */);
+
+    // Not sending any acks back through wakeLockQueue
+
+    eventQueue = makeEventFMQ(kQueueSize);
+    wakeLockQueue = makeWakelockFMQ(kQueueSize);
+
+    Result secondInitResult =
+            proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+    EXPECT_EQ(secondInitResult, Result::OK);
+}
+
+TEST(HalProxyTest, InitializeManyTimesInARow) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumTimesToInit = 100;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+
+    for (size_t i = 0; i < kNumTimesToInit; i++) {
+        Result secondInitResult =
+                proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+        EXPECT_EQ(secondInitResult, Result::OK);
+    }
+}
+
+TEST(HalProxyTest, OperationModeResetOnInitialize) {
+    constexpr size_t kQueueSize = 5;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+    proxy.setOperationMode(OperationMode::DATA_INJECTION);
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+    Event event = makeAccelerometerEvent();
+    // Should not be able to inject a non AdditionInfo type event because operation mode should
+    // have been reset to NORMAL
+    EXPECT_EQ(proxy.injectSensorData(event), Result::BAD_VALUE);
+}
+
+TEST(HalProxyTest, DynamicSensorsDiscardedOnInitialize) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumSensors = 5;
+    AddAndRemoveDynamicSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    HalProxy proxy(subHals);
+
+    std::vector<SensorInfo> sensorsToConnect;
+    std::vector<int32_t> sensorHandlesToAttemptToRemove;
+    makeSensorsAndSensorHandlesStartingAndOfSize(1, kNumSensors, sensorsToConnect,
+                                                 sensorHandlesToAttemptToRemove);
+
+    std::vector<int32_t> nonDynamicSensorHandles;
+    for (int32_t sensorHandle = 1; sensorHandle < 10; sensorHandle++) {
+        nonDynamicSensorHandles.push_back(sensorHandle);
+    }
+
+    TestSensorsCallback* callback = new TestSensorsCallback();
+    ::android::sp<ISensorsCallback> callbackPtr = callback;
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callbackPtr);
+    subHal.addDynamicSensors(sensorsToConnect);
+
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callbackPtr);
+    subHal.removeDynamicSensors(sensorHandlesToAttemptToRemove);
+
+    std::vector<int32_t> sensorHandlesActuallyRemoved = callback->getSensorHandlesDisconnected();
+
+    // Should not have received the sensorHandles for any dynamic sensors that were removed since
+    // all of them should have been removed in the second initialize call.
+    EXPECT_TRUE(sensorHandlesActuallyRemoved.empty());
 }
 
 TEST(HalProxyTest, DynamicSensorsConnectedTest) {
diff --git a/sensors/2.0/multihal/tests/fake_subhal/SensorsSubHal.cpp b/sensors/2.0/multihal/tests/fake_subhal/SensorsSubHal.cpp
index cf3ae75..0da4246 100644
--- a/sensors/2.0/multihal/tests/fake_subhal/SensorsSubHal.cpp
+++ b/sensors/2.0/multihal/tests/fake_subhal/SensorsSubHal.cpp
@@ -158,6 +158,7 @@
 
 Return<Result> SensorsSubHal::initialize(const sp<IHalProxyCallback>& halProxyCallback) {
     mCallback = halProxyCallback;
+    setOperationMode(OperationMode::NORMAL);
     return Result::OK;
 }