Merge "Add Sensors Multihal support for Hal 2.0"

sensors/2.0/multihal/Android.bp

@@ -0,0 +1,73 @@
+//
+// Copyright (C) 2019 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.
+
+cc_defaults {
+    name: "android.hardware.sensors@2.0-multihal-defaults",
+    header_libs: [
+        "android.hardware.sensors@2.0-multihal.header",
+    ],
+    shared_libs: [
+        "android.hardware.sensors@1.0",
+        "android.hardware.sensors@2.0",
+        "libbase",
+        "libcutils",
+        "libfmq",
+        "libhidlbase",
+        "liblog",
+        "libpower",
+        "libutils",
+    ],
+    cflags: ["-DLOG_TAG=\"SensorsMultiHal\""],
+}
+
+cc_binary {
+    name: "android.hardware.sensors@2.0-service.multihal",
+    defaults: [
+        "hidl_defaults",
+        "android.hardware.sensors@2.0-multihal-defaults",
+    ],
+    vendor: true,
+    relative_install_path: "hw",
+    srcs: [
+        "service.cpp",
+        "HalProxy.cpp",
+        "ScopedWakelock.cpp",
+    ],
+    init_rc: ["android.hardware.sensors@2.0-service-multihal.rc"],
+    vintf_fragments: ["android.hardware.sensors@2.0-multihal.xml"],
+}
+
+cc_library_headers {
+    name: "android.hardware.sensors@2.0-multihal.header",
+    vendor_available: true,
+    export_include_dirs: ["include"],
+}
+
+// The below targets should only be used for testing.
+cc_test_library {
+    name: "android.hardware.sensors@2.0-HalProxy",
+    defaults: ["android.hardware.sensors@2.0-multihal-defaults"],
+    vendor_available: true,
+    srcs: [
+        "HalProxy.cpp",
+        "ScopedWakelock.cpp",
+    ],
+    export_header_lib_headers: [
+        "android.hardware.sensors@2.0-multihal.header",
+    ],
+    shared_libs: [
+        "libutils",
+    ],
+}

sensors/2.0/multihal/HalProxy.cpp

@@ -0,0 +1,686 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include "HalProxy.h"
+
+#include "SubHal.h"
+
+#include <android/hardware/sensors/2.0/types.h>
+
+#include <android-base/file.h>
+#include "hardware_legacy/power.h"
+
+#include <dlfcn.h>
+
+#include <cinttypes>
+#include <cmath>
+#include <fstream>
+#include <functional>
+#include <thread>
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::hardware::sensors::V2_0::EventQueueFlagBits;
+using ::android::hardware::sensors::V2_0::WakeLockQueueFlagBits;
+using ::android::hardware::sensors::V2_0::implementation::getTimeNow;
+using ::android::hardware::sensors::V2_0::implementation::kWakelockTimeoutNs;
+
+typedef ISensorsSubHal*(SensorsHalGetSubHalFunc)(uint32_t*);
+
+static constexpr int32_t kBitsAfterSubHalIndex = 24;
+
+/**
+ * Set the subhal index as first byte of sensor handle and return this modified version.
+ *
+ * @param sensorHandle The sensor handle to modify.
+ * @param subHalIndex The index in the hal proxy of the sub hal this sensor belongs to.
+ *
+ * @return The modified sensor handle.
+ */
+int32_t setSubHalIndex(int32_t sensorHandle, size_t subHalIndex) {
+    return sensorHandle | (static_cast<int32_t>(subHalIndex) << kBitsAfterSubHalIndex);
+}
+
+/**
+ * Extract the subHalIndex from sensorHandle.
+ *
+ * @param sensorHandle The sensorHandle to extract from.
+ *
+ * @return The subhal index.
+ */
+size_t extractSubHalIndex(int32_t sensorHandle) {
+    return static_cast<size_t>(sensorHandle >> kBitsAfterSubHalIndex);
+}
+
+/**
+ * Convert nanoseconds to milliseconds.
+ *
+ * @param nanos The nanoseconds input.
+ *
+ * @return The milliseconds count.
+ */
+int64_t msFromNs(int64_t nanos) {
+    constexpr int64_t nanosecondsInAMillsecond = 1000000;
+    return nanos / nanosecondsInAMillsecond;
+}
+
+HalProxy::HalProxy() {
+    const char* kMultiHalConfigFile = "/vendor/etc/sensors/hals.conf";
+    initializeSubHalListFromConfigFile(kMultiHalConfigFile);
+    init();
+}
+
+HalProxy::HalProxy(std::vector<ISensorsSubHal*>& subHalList) : mSubHalList(subHalList) {
+    init();
+}
+
+HalProxy::~HalProxy() {
+    stopThreads();
+}
+
+Return<void> HalProxy::getSensorsList(getSensorsList_cb _hidl_cb) {
+    std::vector<SensorInfo> sensors;
+    for (const auto& iter : mSensors) {
+        sensors.push_back(iter.second);
+    }
+    _hidl_cb(sensors);
+    return Void();
+}
+
+Return<Result> HalProxy::setOperationMode(OperationMode mode) {
+    Result result = Result::OK;
+    size_t subHalIndex;
+    for (subHalIndex = 0; subHalIndex < mSubHalList.size(); subHalIndex++) {
+        ISensorsSubHal* subHal = mSubHalList[subHalIndex];
+        result = subHal->setOperationMode(mode);
+        if (result != Result::OK) {
+            ALOGE("setOperationMode failed for SubHal: %s", subHal->getName().c_str());
+            break;
+        }
+    }
+    if (result != Result::OK) {
+        // Reset the subhal operation modes that have been flipped
+        for (size_t i = 0; i < subHalIndex; i++) {
+            ISensorsSubHal* subHal = mSubHalList[i];
+            subHal->setOperationMode(mCurrentOperationMode);
+        }
+    } else {
+        mCurrentOperationMode = mode;
+    }
+    return result;
+}
+
+Return<Result> HalProxy::activate(int32_t sensorHandle, bool enabled) {
+    if (!isSubHalIndexValid(sensorHandle)) {
+        return Result::BAD_VALUE;
+    }
+    return getSubHalForSensorHandle(sensorHandle)
+            ->activate(clearSubHalIndex(sensorHandle), enabled);
+}
+
+Return<Result> HalProxy::initialize(
+        const ::android::hardware::MQDescriptorSync<Event>& eventQueueDescriptor,
+        const ::android::hardware::MQDescriptorSync<uint32_t>& wakeLockDescriptor,
+        const sp<ISensorsCallback>& sensorsCallback) {
+    Result result = Result::OK;
+
+    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;
+
+    // Create the Event FMQ from the eventQueueDescriptor. Reset the read/write positions.
+    mEventQueue =
+            std::make_unique<EventMessageQueue>(eventQueueDescriptor, true /* resetPointers */);
+
+    // 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);
+
+    for (size_t i = 0; i < mSubHalList.size(); i++) {
+        auto subHal = mSubHalList[i];
+        const auto& subHalCallback = mSubHalCallbacks[i];
+        Result currRes = subHal->initialize(subHalCallback);
+        if (currRes != Result::OK) {
+            result = currRes;
+            ALOGE("Subhal '%s' failed to initialize.", subHal->getName().c_str());
+            break;
+        }
+    }
+
+    mCurrentOperationMode = OperationMode::NORMAL;
+
+    return result;
+}
+
+Return<Result> HalProxy::batch(int32_t sensorHandle, int64_t samplingPeriodNs,
+                               int64_t maxReportLatencyNs) {
+    if (!isSubHalIndexValid(sensorHandle)) {
+        return Result::BAD_VALUE;
+    }
+    return getSubHalForSensorHandle(sensorHandle)
+            ->batch(clearSubHalIndex(sensorHandle), samplingPeriodNs, maxReportLatencyNs);
+}
+
+Return<Result> HalProxy::flush(int32_t sensorHandle) {
+    if (!isSubHalIndexValid(sensorHandle)) {
+        return Result::BAD_VALUE;
+    }
+    return getSubHalForSensorHandle(sensorHandle)->flush(clearSubHalIndex(sensorHandle));
+}
+
+Return<Result> HalProxy::injectSensorData(const Event& event) {
+    Result result = Result::OK;
+    if (mCurrentOperationMode == OperationMode::NORMAL &&
+        event.sensorType != V1_0::SensorType::ADDITIONAL_INFO) {
+        ALOGE("An event with type != ADDITIONAL_INFO passed to injectSensorData while operation"
+              " mode was NORMAL.");
+        result = Result::BAD_VALUE;
+    }
+    if (result == Result::OK) {
+        Event subHalEvent = event;
+        if (!isSubHalIndexValid(event.sensorHandle)) {
+            return Result::BAD_VALUE;
+        }
+        subHalEvent.sensorHandle = clearSubHalIndex(event.sensorHandle);
+        result = getSubHalForSensorHandle(event.sensorHandle)->injectSensorData(subHalEvent);
+    }
+    return result;
+}
+
+Return<void> HalProxy::registerDirectChannel(const SharedMemInfo& mem,
+                                             registerDirectChannel_cb _hidl_cb) {
+    if (mDirectChannelSubHal == nullptr) {
+        _hidl_cb(Result::INVALID_OPERATION, -1 /* channelHandle */);
+    } else {
+        mDirectChannelSubHal->registerDirectChannel(mem, _hidl_cb);
+    }
+    return Return<void>();
+}
+
+Return<Result> HalProxy::unregisterDirectChannel(int32_t channelHandle) {
+    Result result;
+    if (mDirectChannelSubHal == nullptr) {
+        result = Result::INVALID_OPERATION;
+    } else {
+        result = mDirectChannelSubHal->unregisterDirectChannel(channelHandle);
+    }
+    return result;
+}
+
+Return<void> HalProxy::configDirectReport(int32_t sensorHandle, int32_t channelHandle,
+                                          RateLevel rate, configDirectReport_cb _hidl_cb) {
+    if (mDirectChannelSubHal == nullptr) {
+        _hidl_cb(Result::INVALID_OPERATION, -1 /* reportToken */);
+    } else {
+        mDirectChannelSubHal->configDirectReport(clearSubHalIndex(sensorHandle), channelHandle,
+                                                 rate, _hidl_cb);
+    }
+    return Return<void>();
+}
+
+Return<void> HalProxy::debug(const hidl_handle& fd, const hidl_vec<hidl_string>& /*args*/) {
+    if (fd.getNativeHandle() == nullptr || fd->numFds < 1) {
+        ALOGE("%s: missing fd for writing", __FUNCTION__);
+        return Void();
+    }
+
+    android::base::borrowed_fd writeFd = dup(fd->data[0]);
+
+    std::ostringstream stream;
+    stream << "===HalProxy===" << std::endl;
+    stream << "Internal values:" << std::endl;
+    stream << "  Threads are running: " << (mThreadsRun.load() ? "true" : "false") << std::endl;
+    int64_t now = getTimeNow();
+    stream << "  Wakelock timeout start time: " << msFromNs(now - mWakelockTimeoutStartTime)
+           << " ms ago" << std::endl;
+    stream << "  Wakelock timeout reset time: " << msFromNs(now - mWakelockTimeoutResetTime)
+           << " ms ago" << std::endl;
+    // TODO(b/142969448): Add logging for history of wakelock acquisition per subhal.
+    stream << "  Wakelock ref count: " << mWakelockRefCount << std::endl;
+    stream << "  Size of pending write events queue: " << mPendingWriteEventsQueue.size()
+           << std::endl;
+    if (!mPendingWriteEventsQueue.empty()) {
+        stream << "  Size of events list on front of pending writes queue: "
+               << mPendingWriteEventsQueue.front().first.size() << std::endl;
+    }
+    stream << "  # of non-dynamic sensors across all subhals: " << mSensors.size() << std::endl;
+    stream << "  # of dynamic sensors across all subhals: " << mDynamicSensors.size() << std::endl;
+    stream << "SubHals (" << mSubHalList.size() << "):" << std::endl;
+    for (ISensorsSubHal* subHal : mSubHalList) {
+        stream << "  Name: " << subHal->getName() << std::endl;
+        stream << "  Debug dump: " << std::endl;
+        android::base::WriteStringToFd(stream.str(), writeFd);
+        subHal->debug(fd, {});
+        stream.str("");
+        stream << std::endl;
+    }
+    android::base::WriteStringToFd(stream.str(), writeFd);
+    return Return<void>();
+}
+
+Return<void> HalProxy::onDynamicSensorsConnected(const hidl_vec<SensorInfo>& dynamicSensorsAdded,
+                                                 int32_t subHalIndex) {
+    std::vector<SensorInfo> sensors;
+    {
+        std::lock_guard<std::mutex> lock(mDynamicSensorsMutex);
+        for (SensorInfo sensor : dynamicSensorsAdded) {
+            if (!subHalIndexIsClear(sensor.sensorHandle)) {
+                ALOGE("Dynamic sensor added %s had sensorHandle with first byte not 0.",
+                      sensor.name.c_str());
+            } else {
+                sensor.sensorHandle = setSubHalIndex(sensor.sensorHandle, subHalIndex);
+                mDynamicSensors[sensor.sensorHandle] = sensor;
+                sensors.push_back(sensor);
+            }
+        }
+    }
+    mDynamicSensorsCallback->onDynamicSensorsConnected(sensors);
+    return Return<void>();
+}
+
+Return<void> HalProxy::onDynamicSensorsDisconnected(
+        const hidl_vec<int32_t>& dynamicSensorHandlesRemoved, int32_t subHalIndex) {
+    // TODO(b/143302327): Block this call until all pending events are flushed from queue
+    std::vector<int32_t> sensorHandles;
+    {
+        std::lock_guard<std::mutex> lock(mDynamicSensorsMutex);
+        for (int32_t sensorHandle : dynamicSensorHandlesRemoved) {
+            if (!subHalIndexIsClear(sensorHandle)) {
+                ALOGE("Dynamic sensorHandle removed had first byte not 0.");
+            } else {
+                sensorHandle = setSubHalIndex(sensorHandle, subHalIndex);
+                if (mDynamicSensors.find(sensorHandle) != mDynamicSensors.end()) {
+                    mDynamicSensors.erase(sensorHandle);
+                    sensorHandles.push_back(sensorHandle);
+                }
+            }
+        }
+    }
+    mDynamicSensorsCallback->onDynamicSensorsDisconnected(sensorHandles);
+    return Return<void>();
+}
+
+void HalProxy::initializeSubHalListFromConfigFile(const char* configFileName) {
+    std::ifstream subHalConfigStream(configFileName);
+    if (!subHalConfigStream) {
+        ALOGE("Failed to load subHal config file: %s", configFileName);
+    } else {
+        std::string subHalLibraryFile;
+        while (subHalConfigStream >> subHalLibraryFile) {
+            void* handle = dlopen(subHalLibraryFile.c_str(), RTLD_NOW);
+            if (handle == nullptr) {
+                ALOGE("dlopen failed for library: %s", subHalLibraryFile.c_str());
+            } else {
+                SensorsHalGetSubHalFunc* sensorsHalGetSubHalPtr =
+                        (SensorsHalGetSubHalFunc*)dlsym(handle, "sensorsHalGetSubHal");
+                if (sensorsHalGetSubHalPtr == nullptr) {
+                    ALOGE("Failed to locate sensorsHalGetSubHal function for library: %s",
+                          subHalLibraryFile.c_str());
+                } else {
+                    std::function<SensorsHalGetSubHalFunc> sensorsHalGetSubHal =
+                            *sensorsHalGetSubHalPtr;
+                    uint32_t version;
+                    ISensorsSubHal* subHal = sensorsHalGetSubHal(&version);
+                    if (version != SUB_HAL_2_0_VERSION) {
+                        ALOGE("SubHal version was not 2.0 for library: %s",
+                              subHalLibraryFile.c_str());
+                    } else {
+                        ALOGV("Loaded SubHal from library: %s", subHalLibraryFile.c_str());
+                        mSubHalList.push_back(subHal);
+                    }
+                }
+            }
+        }
+    }
+}
+
+void HalProxy::initializeSubHalCallbacks() {
+    for (size_t subHalIndex = 0; subHalIndex < mSubHalList.size(); subHalIndex++) {
+        sp<IHalProxyCallback> callback = new HalProxyCallback(this, subHalIndex);
+        mSubHalCallbacks.push_back(callback);
+    }
+}
+
+void HalProxy::initializeSensorList() {
+    for (size_t subHalIndex = 0; subHalIndex < mSubHalList.size(); subHalIndex++) {
+        ISensorsSubHal* subHal = mSubHalList[subHalIndex];
+        auto result = subHal->getSensorsList([&](const auto& list) {
+            for (SensorInfo sensor : list) {
+                if (!subHalIndexIsClear(sensor.sensorHandle)) {
+                    ALOGE("SubHal sensorHandle's first byte was not 0");
+                } else {
+                    ALOGV("Loaded sensor: %s", sensor.name.c_str());
+                    sensor.sensorHandle = setSubHalIndex(sensor.sensorHandle, subHalIndex);
+                    setDirectChannelFlags(&sensor, subHal);
+                    mSensors[sensor.sensorHandle] = sensor;
+                }
+            }
+        });
+        if (!result.isOk()) {
+            ALOGE("getSensorsList call failed for SubHal: %s", subHal->getName().c_str());
+        }
+    }
+}
+
+void HalProxy::init() {
+    initializeSubHalCallbacks();
+    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();
+}
+
+void HalProxy::handlePendingWrites() {
+    // TODO(b/143302327): Find a way to optimize locking strategy maybe using two mutexes instead of
+    // one.
+    std::unique_lock<std::mutex> lock(mEventQueueWriteMutex);
+    while (mThreadsRun.load()) {
+        mEventQueueWriteCV.wait(
+                lock, [&] { return !mPendingWriteEventsQueue.empty() || !mThreadsRun.load(); });
+        if (mThreadsRun.load()) {
+            std::vector<Event>& pendingWriteEvents = mPendingWriteEventsQueue.front().first;
+            size_t numWakeupEvents = mPendingWriteEventsQueue.front().second;
+            size_t eventQueueSize = mEventQueue->getQuantumCount();
+            size_t numToWrite = std::min(pendingWriteEvents.size(), eventQueueSize);
+            lock.unlock();
+            if (!mEventQueue->writeBlocking(
+                        pendingWriteEvents.data(), numToWrite,
+                        static_cast<uint32_t>(EventQueueFlagBits::EVENTS_READ),
+                        static_cast<uint32_t>(EventQueueFlagBits::READ_AND_PROCESS),
+                        kPendingWriteTimeoutNs, mEventQueueFlag)) {
+                ALOGE("Dropping %zu events after blockingWrite failed.", numToWrite);
+                if (numWakeupEvents > 0) {
+                    if (pendingWriteEvents.size() > eventQueueSize) {
+                        decrementRefCountAndMaybeReleaseWakelock(
+                                countNumWakeupEvents(pendingWriteEvents, eventQueueSize));
+                    } else {
+                        decrementRefCountAndMaybeReleaseWakelock(numWakeupEvents);
+                    }
+                }
+            }
+            lock.lock();
+            if (pendingWriteEvents.size() > eventQueueSize) {
+                // TODO(b/143302327): Check if this erase operation is too inefficient. It will copy
+                // all the events ahead of it down to fill gap off array at front after the erase.
+                pendingWriteEvents.erase(pendingWriteEvents.begin(),
+                                         pendingWriteEvents.begin() + eventQueueSize);
+            } else {
+                mPendingWriteEventsQueue.pop();
+            }
+        }
+    }
+}
+
+void HalProxy::startWakelockThread(HalProxy* halProxy) {
+    halProxy->handleWakelocks();
+}
+
+void HalProxy::handleWakelocks() {
+    std::unique_lock<std::recursive_mutex> lock(mWakelockMutex);
+    while (mThreadsRun.load()) {
+        mWakelockCV.wait(lock, [&] { return mWakelockRefCount > 0 || !mThreadsRun.load(); });
+        if (mThreadsRun.load()) {
+            int64_t timeLeft;
+            if (sharedWakelockDidTimeout(&timeLeft)) {
+                resetSharedWakelock();
+            } else {
+                uint32_t numWakeLocksProcessed;
+                lock.unlock();
+                bool success = mWakeLockQueue->readBlocking(
+                        &numWakeLocksProcessed, 1, 0,
+                        static_cast<uint32_t>(WakeLockQueueFlagBits::DATA_WRITTEN), timeLeft);
+                lock.lock();
+                if (success) {
+                    decrementRefCountAndMaybeReleaseWakelock(
+                            static_cast<size_t>(numWakeLocksProcessed));
+                }
+            }
+        }
+    }
+    resetSharedWakelock();
+}
+
+bool HalProxy::sharedWakelockDidTimeout(int64_t* timeLeft) {
+    bool didTimeout;
+    int64_t duration = getTimeNow() - mWakelockTimeoutStartTime;
+    if (duration > kWakelockTimeoutNs) {
+        didTimeout = true;
+    } else {
+        didTimeout = false;
+        *timeLeft = kWakelockTimeoutNs - duration;
+    }
+    return didTimeout;
+}
+
+void HalProxy::resetSharedWakelock() {
+    std::lock_guard<std::recursive_mutex> lockGuard(mWakelockMutex);
+    decrementRefCountAndMaybeReleaseWakelock(mWakelockRefCount);
+    mWakelockTimeoutResetTime = getTimeNow();
+}
+
+void HalProxy::postEventsToMessageQueue(const std::vector<Event>& events, size_t numWakeupEvents,
+                                        ScopedWakelock wakelock) {
+    size_t numToWrite = 0;
+    std::lock_guard<std::mutex> lock(mEventQueueWriteMutex);
+    if (wakelock.isLocked()) {
+        incrementRefCountAndMaybeAcquireWakelock(numWakeupEvents);
+    }
+    if (mPendingWriteEventsQueue.empty()) {
+        numToWrite = std::min(events.size(), mEventQueue->availableToWrite());
+        if (numToWrite > 0) {
+            if (mEventQueue->write(events.data(), numToWrite)) {
+                // TODO(b/143302327): While loop if mEventQueue->avaiableToWrite > 0 to possibly fit
+                // in more writes immediately
+                mEventQueueFlag->wake(static_cast<uint32_t>(EventQueueFlagBits::READ_AND_PROCESS));
+            } else {
+                numToWrite = 0;
+            }
+        }
+    }
+    if (numToWrite < events.size()) {
+        // TODO(b/143302327): Bound the mPendingWriteEventsQueue so that we do not trigger OOMs if
+        // framework stalls
+        std::vector<Event> eventsLeft(events.begin() + numToWrite, events.end());
+        mPendingWriteEventsQueue.push({eventsLeft, numWakeupEvents});
+        mEventQueueWriteCV.notify_one();
+    }
+}
+
+bool HalProxy::incrementRefCountAndMaybeAcquireWakelock(size_t delta,
+                                                        int64_t* timeoutStart /* = nullptr */) {
+    if (!mThreadsRun.load()) return false;
+    std::lock_guard<std::recursive_mutex> lockGuard(mWakelockMutex);
+    if (mWakelockRefCount == 0) {
+        acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakelockName);
+        mWakelockCV.notify_one();
+    }
+    mWakelockTimeoutStartTime = getTimeNow();
+    mWakelockRefCount += delta;
+    if (timeoutStart != nullptr) {
+        *timeoutStart = mWakelockTimeoutStartTime;
+    }
+    return true;
+}
+
+void HalProxy::decrementRefCountAndMaybeReleaseWakelock(size_t delta,
+                                                        int64_t timeoutStart /* = -1 */) {
+    if (!mThreadsRun.load()) return;
+    std::lock_guard<std::recursive_mutex> lockGuard(mWakelockMutex);
+    if (timeoutStart == -1) timeoutStart = mWakelockTimeoutResetTime;
+    if (mWakelockRefCount == 0 || timeoutStart < mWakelockTimeoutResetTime) return;
+    mWakelockRefCount -= std::min(mWakelockRefCount, delta);
+    if (mWakelockRefCount == 0) {
+        release_wake_lock(kWakelockName);
+    }
+}
+
+void HalProxy::setDirectChannelFlags(SensorInfo* sensorInfo, ISensorsSubHal* subHal) {
+    bool sensorSupportsDirectChannel =
+            (sensorInfo->flags & (V1_0::SensorFlagBits::MASK_DIRECT_REPORT |
+                                  V1_0::SensorFlagBits::MASK_DIRECT_CHANNEL)) != 0;
+    if (mDirectChannelSubHal == nullptr && sensorSupportsDirectChannel) {
+        mDirectChannelSubHal = subHal;
+    } else if (mDirectChannelSubHal != nullptr && subHal != mDirectChannelSubHal) {
+        // disable direct channel capability for sensors in subHals that are not
+        // the only one we will enable
+        sensorInfo->flags &= ~(V1_0::SensorFlagBits::MASK_DIRECT_REPORT |
+                               V1_0::SensorFlagBits::MASK_DIRECT_CHANNEL);
+    }
+}
+
+ISensorsSubHal* HalProxy::getSubHalForSensorHandle(int32_t sensorHandle) {
+    return mSubHalList[extractSubHalIndex(sensorHandle)];
+}
+
+bool HalProxy::isSubHalIndexValid(int32_t sensorHandle) {
+    return extractSubHalIndex(sensorHandle) < mSubHalList.size();
+}
+
+size_t HalProxy::countNumWakeupEvents(const std::vector<Event>& events, size_t n) {
+    size_t numWakeupEvents = 0;
+    for (size_t i = 0; i < n; i++) {
+        int32_t sensorHandle = events[i].sensorHandle;
+        if (mSensors[sensorHandle].flags & static_cast<uint32_t>(V1_0::SensorFlagBits::WAKE_UP)) {
+            numWakeupEvents++;
+        }
+    }
+    return numWakeupEvents;
+}
+
+int32_t HalProxy::clearSubHalIndex(int32_t sensorHandle) {
+    return sensorHandle & (~kSensorHandleSubHalIndexMask);
+}
+
+bool HalProxy::subHalIndexIsClear(int32_t sensorHandle) {
+    return (sensorHandle & kSensorHandleSubHalIndexMask) == 0;
+}
+
+void HalProxyCallback::postEvents(const std::vector<Event>& events, ScopedWakelock wakelock) {
+    if (events.empty() || !mHalProxy->areThreadsRunning()) return;
+    size_t numWakeupEvents;
+    std::vector<Event> processedEvents = processEvents(events, &numWakeupEvents);
+    if (numWakeupEvents > 0) {
+        ALOG_ASSERT(wakelock.isLocked(),
+                    "Wakeup events posted while wakelock unlocked for subhal"
+                    " w/ index %zu.",
+                    mSubHalIndex);
+    } else {
+        ALOG_ASSERT(!wakelock.isLocked(),
+                    "No Wakeup events posted but wakelock locked for subhal"
+                    " w/ index %zu.",
+                    mSubHalIndex);
+    }
+    mHalProxy->postEventsToMessageQueue(processedEvents, numWakeupEvents, std::move(wakelock));
+}
+
+ScopedWakelock HalProxyCallback::createScopedWakelock(bool lock) {
+    ScopedWakelock wakelock(mHalProxy, lock);
+    return wakelock;
+}
+
+std::vector<Event> HalProxyCallback::processEvents(const std::vector<Event>& events,
+                                                   size_t* numWakeupEvents) const {
+    *numWakeupEvents = 0;
+    std::vector<Event> eventsOut;
+    for (Event event : events) {
+        event.sensorHandle = setSubHalIndex(event.sensorHandle, mSubHalIndex);
+        eventsOut.push_back(event);
+        const SensorInfo& sensor = mHalProxy->getSensorInfo(event.sensorHandle);
+        if ((sensor.flags & V1_0::SensorFlagBits::WAKE_UP) != 0) {
+            (*numWakeupEvents)++;
+        }
+    }
+    return eventsOut;
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/OWNERS

@@ -0,0 +1,3 @@
+arthuri@google.com
+bduddie@google.com
+stange@google.com

sensors/2.0/multihal/ScopedWakelock.cpp

@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include "ScopedWakelock.h"
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace implementation {
+
+int64_t getTimeNow() {
+    return std::chrono::duration_cast<std::chrono::nanoseconds>(
+                   std::chrono::system_clock::now().time_since_epoch())
+            .count();
+}
+
+ScopedWakelock::ScopedWakelock(IScopedWakelockRefCounter* refCounter, bool locked)
+    : mRefCounter(refCounter), mLocked(locked) {
+    if (mLocked) {
+        mLocked = mRefCounter->incrementRefCountAndMaybeAcquireWakelock(1, &mCreatedAtTimeNs);
+    }
+}
+
+ScopedWakelock::~ScopedWakelock() {
+    if (mLocked) {
+        mRefCounter->decrementRefCountAndMaybeReleaseWakelock(1, mCreatedAtTimeNs);
+    }
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/android.hardware.sensors@2.0-multihal.xml

@@ -0,0 +1,11 @@
+<manifest version="1.0" type="device">
+    <hal format="hidl">
+        <name>android.hardware.sensors</name>
+        <transport>hwbinder</transport>
+        <version>2.0</version>
+        <interface>
+            <name>ISensors</name>
+            <instance>multihal</instance>
+        </interface>
+    </hal>
+</manifest>

sensors/2.0/multihal/android.hardware.sensors@2.0-service-multihal.rc

@@ -0,0 +1,7 @@
+service vendor.sensors-hal-2-0-multihal /vendor/bin/hw/android.hardware.sensors@2.0-service.multihal
+    class hal
+    user system
+    group system wakelock
+    writepid /dev/cpuset/system-background/tasks
+    capabilities BLOCK_SUSPEND
+    rlimit rtprio 10 10

sensors/2.0/multihal/include/HalProxy.h

@@ -0,0 +1,396 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include "ScopedWakelock.h"
+#include "SubHal.h"
+
+#include <android/hardware/sensors/2.0/ISensors.h>
+#include <android/hardware/sensors/2.0/types.h>
+#include <fmq/MessageQueue.h>
+#include <hardware_legacy/power.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+
+#include <atomic>
+#include <condition_variable>
+#include <map>
+#include <mutex>
+#include <queue>
+#include <thread>
+#include <utility>
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::EventFlag;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::MQDescriptor;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+class HalProxy : public ISensors, public IScopedWakelockRefCounter {
+  public:
+    using Event = ::android::hardware::sensors::V1_0::Event;
+    using OperationMode = ::android::hardware::sensors::V1_0::OperationMode;
+    using RateLevel = ::android::hardware::sensors::V1_0::RateLevel;
+    using Result = ::android::hardware::sensors::V1_0::Result;
+    using SensorInfo = ::android::hardware::sensors::V1_0::SensorInfo;
+    using SharedMemInfo = ::android::hardware::sensors::V1_0::SharedMemInfo;
+    using ISensorsSubHal = ::android::hardware::sensors::V2_0::implementation::ISensorsSubHal;
+
+    explicit HalProxy();
+    // Test only constructor.
+    explicit HalProxy(std::vector<ISensorsSubHal*>& subHalList);
+    ~HalProxy();
+
+    // Methods from ::android::hardware::sensors::V2_0::ISensors follow.
+    Return<void> getSensorsList(getSensorsList_cb _hidl_cb) override;
+
+    Return<Result> setOperationMode(OperationMode mode) override;
+
+    Return<Result> activate(int32_t sensorHandle, bool enabled) override;
+
+    Return<Result> initialize(
+            const ::android::hardware::MQDescriptorSync<Event>& eventQueueDescriptor,
+            const ::android::hardware::MQDescriptorSync<uint32_t>& wakeLockDescriptor,
+            const sp<ISensorsCallback>& sensorsCallback) override;
+
+    Return<Result> batch(int32_t sensorHandle, int64_t samplingPeriodNs,
+                         int64_t maxReportLatencyNs) override;
+
+    Return<Result> flush(int32_t sensorHandle) override;
+
+    Return<Result> injectSensorData(const Event& event) override;
+
+    Return<void> registerDirectChannel(const SharedMemInfo& mem,
+                                       registerDirectChannel_cb _hidl_cb) override;
+
+    Return<Result> unregisterDirectChannel(int32_t channelHandle) override;
+
+    Return<void> configDirectReport(int32_t sensorHandle, int32_t channelHandle, RateLevel rate,
+                                    configDirectReport_cb _hidl_cb) override;
+
+    Return<void> debug(const hidl_handle& fd, const hidl_vec<hidl_string>& args) override;
+
+    // Below methods from ::android::hardware::sensors::V2_0::ISensorsCallback with a minor change
+    // to pass in the sub-HAL index. While the above methods are invoked from the sensors framework
+    // via the binder, these methods are invoked from a callback provided to sub-HALs inside the
+    // same process as the HalProxy, but potentially running on different threads.
+    Return<void> onDynamicSensorsConnected(const hidl_vec<SensorInfo>& dynamicSensorsAdded,
+                                           int32_t subHalIndex);
+
+    Return<void> onDynamicSensorsDisconnected(const hidl_vec<int32_t>& dynamicSensorHandlesRemoved,
+                                              int32_t subHalIndex);
+
+    // Below methods are for HalProxyCallback
+
+    /**
+     * Post events to the event message queue if there is room to write them. Otherwise post the
+     * remaining events to a background thread for a blocking write with a kPendingWriteTimeoutNs
+     * timeout.
+     *
+     * @param events The list of events to post to the message queue.
+     * @param numWakeupEvents The number of wakeup events in events.
+     * @param wakelock The wakelock associated with this post of events.
+     */
+    void postEventsToMessageQueue(const std::vector<Event>& events, size_t numWakeupEvents,
+                                  ScopedWakelock wakelock);
+
+    /**
+     * Get the sensor info associated with that sensorHandle.
+     *
+     * @param sensorHandle The sensor handle.
+     *
+     * @return The sensor info object in the mapping.
+     */
+    const SensorInfo& getSensorInfo(int32_t sensorHandle) { return mSensors[sensorHandle]; }
+
+    bool areThreadsRunning() { return mThreadsRun.load(); }
+
+    // Below methods are from IScopedWakelockRefCounter interface
+    bool incrementRefCountAndMaybeAcquireWakelock(size_t delta,
+                                                  int64_t* timeoutStart = nullptr) override;
+
+    void decrementRefCountAndMaybeReleaseWakelock(size_t delta, int64_t timeoutStart = -1) override;
+
+  private:
+    using EventMessageQueue = MessageQueue<Event, kSynchronizedReadWrite>;
+    using WakeLockMessageQueue = MessageQueue<uint32_t, kSynchronizedReadWrite>;
+
+    /**
+     * The Event FMQ where sensor events are written
+     */
+    std::unique_ptr<EventMessageQueue> mEventQueue;
+
+    /**
+     * The Wake Lock FMQ that is read to determine when the framework has handled WAKE_UP events
+     */
+    std::unique_ptr<WakeLockMessageQueue> mWakeLockQueue;
+
+    /**
+     * Event Flag to signal to the framework when sensor events are available to be read and to
+     * interrupt event queue blocking write.
+     */
+    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.
+     */
+    sp<ISensorsCallback> mDynamicSensorsCallback;
+
+    /**
+     * SubHal object pointers that have been saved from vendor dynamic libraries.
+     */
+    std::vector<ISensorsSubHal*> mSubHalList;
+
+    //! The list of subhal callbacks for each subhal where the indices correlate with mSubHalList
+    std::vector<const sp<IHalProxyCallback>> mSubHalCallbacks;
+
+    /**
+     * Map of sensor handles to SensorInfo objects that contains the sensor info from subhals as
+     * well as the modified sensor handle for the framework.
+     *
+     * The subhal index is encoded in the first byte of the sensor handle and the remaining
+     * bytes are generated by the subhal to identify the sensor.
+     */
+    std::map<int32_t, SensorInfo> mSensors;
+
+    //! Map of the dynamic sensors that have been added to halproxy.
+    std::map<int32_t, SensorInfo> mDynamicSensors;
+
+    //! The current operation mode for all subhals.
+    OperationMode mCurrentOperationMode = OperationMode::NORMAL;
+
+    //! The single subHal that supports directChannel reporting.
+    ISensorsSubHal* mDirectChannelSubHal = nullptr;
+
+    //! The timeout for each pending write on background thread for events.
+    static const int64_t kPendingWriteTimeoutNs = 5 * INT64_C(1000000000) /* 5 seconds */;
+
+    //! The bit mask used to get the subhal index from a sensor handle.
+    static constexpr int32_t kSensorHandleSubHalIndexMask = 0xFF000000;
+
+    /**
+     * A FIFO queue of pairs of vector of events and the number of wakeup events in that vector
+     * which are waiting to be written to the events fmq in the background thread.
+     */
+    std::queue<std::pair<std::vector<Event>, size_t>> mPendingWriteEventsQueue;
+
+    //! The mutex protecting writing to the fmq and the pending events queue
+    std::mutex mEventQueueWriteMutex;
+
+    //! The condition variable waiting on pending write events to stack up
+    std::condition_variable mEventQueueWriteCV;
+
+    //! The thread object ptr that handles pending writes
+    std::thread mPendingWritesThread;
+
+    //! The thread object that handles wakelocks
+    std::thread mWakelockThread;
+
+    //! The bool indicating whether to end the threads started in initialize
+    std::atomic_bool mThreadsRun = true;
+
+    //! The mutex protecting access to the dynamic sensors added and removed methods.
+    std::mutex mDynamicSensorsMutex;
+
+    // WakelockRefCount membar vars below
+
+    //! The mutex protecting the wakelock refcount and subsequent wakelock releases and
+    //! acquisitions
+    std::recursive_mutex mWakelockMutex;
+
+    std::condition_variable_any mWakelockCV;
+
+    //! The refcount of how many ScopedWakelocks and pending wakeup events are active
+    size_t mWakelockRefCount = 0;
+
+    int64_t mWakelockTimeoutStartTime = getTimeNow();
+
+    int64_t mWakelockTimeoutResetTime = getTimeNow();
+
+    const char* kWakelockName = "SensorsHAL_WAKEUP";
+
+    /**
+     * Initialize the list of SubHal objects in mSubHalList by reading from dynamic libraries
+     * listed in a config file.
+     */
+    void initializeSubHalListFromConfigFile(const char* configFileName);
+
+    /**
+     * Initialize the HalProxyCallback vector using the list of subhals.
+     */
+    void initializeSubHalCallbacks();
+
+    /**
+     * Initialize the list of SensorInfo objects in mSensorList by getting sensors from each
+     * subhal.
+     */
+    void initializeSensorList();
+
+    /**
+     * Calls the helper methods that all ctors use.
+     */
+    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.
+     */
+    static void startPendingWritesThread(HalProxy* halProxy);
+
+    //! Handles the pending writes on events to eventqueue.
+    void handlePendingWrites();
+
+    /**
+     * Starts the thread that handles decrementing the ref count on wakeup events processed by the
+     * framework and timing out wakelocks.
+     *
+     * @param halProxy The HalProxy object pointer.
+     */
+    static void startWakelockThread(HalProxy* halProxy);
+
+    //! Handles the wakelocks.
+    void handleWakelocks();
+
+    /**
+     * @param timeLeft The variable that should be set to the timeleft before timeout will occur or
+     * unmodified if timeout occurred.
+     *
+     * @return true if the shared wakelock has been held passed the timeout and should be released
+     */
+    bool sharedWakelockDidTimeout(int64_t* timeLeft);
+
+    /**
+     * Reset all the member variables associated with the wakelock ref count and maybe release
+     * the shared wakelock.
+     */
+    void resetSharedWakelock();
+
+    /**
+     * Clear direct channel flags if the HalProxy has already chosen a subhal as its direct channel
+     * subhal. Set the directChannelSubHal pointer to the subHal passed in if this is the first
+     * direct channel enabled sensor seen.
+     *
+     * @param sensorInfo The SensorInfo object that may be altered to have direct channel support
+     *    disabled.
+     * @param subHal The subhal pointer that the current sensorInfo object came from.
+     */
+    void setDirectChannelFlags(SensorInfo* sensorInfo, ISensorsSubHal* subHal);
+
+    /*
+     * Get the subhal pointer which can be found by indexing into the mSubHalList vector
+     * using the index from the first byte of sensorHandle.
+     *
+     * @param sensorHandle The handle used to identify a sensor in one of the subhals.
+     */
+    ISensorsSubHal* getSubHalForSensorHandle(int32_t sensorHandle);
+
+    /**
+     * Checks that sensorHandle's subhal index byte is within bounds of mSubHalList.
+     *
+     * @param sensorHandle The sensor handle to check.
+     *
+     * @return true if sensorHandles's subhal index byte is valid.
+     */
+    bool isSubHalIndexValid(int32_t sensorHandle);
+
+    /**
+     * Count the number of wakeup events in the first n events of the vector.
+     *
+     * @param events The vector of Event objects.
+     * @param n The end index not inclusive of events to consider.
+     *
+     * @return The number of wakeup events of the considered events.
+     */
+    size_t countNumWakeupEvents(const std::vector<Event>& events, size_t n);
+
+    /*
+     * Clear out the subhal index bytes from a sensorHandle.
+     *
+     * @param sensorHandle The sensor handle to modify.
+     *
+     * @return The modified version of the sensor handle.
+     */
+    static int32_t clearSubHalIndex(int32_t sensorHandle);
+
+    /**
+     * @param sensorHandle The sensor handle to modify.
+     *
+     * @return true if subHalIndex byte of sensorHandle is zeroed.
+     */
+    static bool subHalIndexIsClear(int32_t sensorHandle);
+};
+
+/**
+ * Callback class used to provide the HalProxy with the index of which subHal is invoking
+ */
+class HalProxyCallback : public IHalProxyCallback {
+    using SensorInfo = ::android::hardware::sensors::V1_0::SensorInfo;
+
+  public:
+    HalProxyCallback(HalProxy* halProxy, int32_t subHalIndex)
+        : mHalProxy(halProxy), mSubHalIndex(subHalIndex) {}
+
+    Return<void> onDynamicSensorsConnected(
+            const hidl_vec<SensorInfo>& dynamicSensorsAdded) override {
+        return mHalProxy->onDynamicSensorsConnected(dynamicSensorsAdded, mSubHalIndex);
+    }
+
+    Return<void> onDynamicSensorsDisconnected(
+            const hidl_vec<int32_t>& dynamicSensorHandlesRemoved) override {
+        return mHalProxy->onDynamicSensorsDisconnected(dynamicSensorHandlesRemoved, mSubHalIndex);
+    }
+
+    void postEvents(const std::vector<Event>& events, ScopedWakelock wakelock);
+
+    ScopedWakelock createScopedWakelock(bool lock);
+
+  private:
+    HalProxy* mHalProxy;
+    int32_t mSubHalIndex;
+
+    std::vector<Event> processEvents(const std::vector<Event>& events,
+                                     size_t* numWakeupEvents) const;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/include/ScopedWakelock.h

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include <android/hardware/sensors/2.0/types.h>
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::hardware::sensors::V2_0::SensorTimeout;
+
+const int64_t kWakelockTimeoutNs =
+        static_cast<int64_t>(SensorTimeout::WAKE_LOCK_SECONDS) * INT64_C(1000000000);
+
+int64_t getTimeNow();
+
+class IScopedWakelockRefCounter : public RefBase {
+  public:
+    /**
+     * Increment the wakelock ref count and maybe acquire the shared wakelock if incrementing
+     * from 0 then return the time of incrementing back to caller.
+     *
+     * @param delta The amount to change ref count by.
+     * @param timeoutStart The ptr to the timestamp in ns that the increment occurred which will be
+     *        set in the function or nullptr if not specified.
+     *
+     * @return true if successfully incremented the wakelock ref count.
+     */
+    virtual bool incrementRefCountAndMaybeAcquireWakelock(size_t delta,
+                                                          int64_t* timeoutStart = nullptr) = 0;
+    /**
+     * Decrement the wakelock ref count and maybe release wakelock if ref count ends up 0.
+     *
+     * @param delta The amount to change ref count by.
+     * @param timeoutStart The timestamp in ns that the calling context kept track of when
+     *        incrementing the ref count or -1 by default
+     */
+    virtual void decrementRefCountAndMaybeReleaseWakelock(size_t delta,
+                                                          int64_t timeoutStart = -1) = 0;
+    // Virtual dtor needed for compilation success
+    virtual ~IScopedWakelockRefCounter(){};
+};
+
+/**
+ * Wrapper around wake lock acquisition functions (acquire/release_wake_lock) that provides a
+ * RAII-style mechanism for keeping a wake lock held for the duration of a scoped block.
+ * When a ScopedWakelock is created, it increments the reference count stored in the HalProxy
+ * for the sub-HALs specific wake lock, acquiring the wake lock if necessary. When the object goes
+ * out of scope, the ref count is decremented, potentially releasing the wake lock if no other
+ * references to the wake lock exist.
+ *
+ * This class is allocated through the createScopedWakelock callback inside the IHalProxyCallback
+ * provided to sub-HALs during initialization and should be used for all wake lock acquisition
+ * inside of the sub-HAL to ensure wake locks are not held indefinitely.
+ *
+ * The most prevalent use case for this class will be for posting events to the framework through
+ * the postEvents HalProxy callback. The expectation is that sub-HALs will create this
+ * ScopedWakelock through the createScopedWakelock upon receiving a sensor events. The lock boolean
+ * provided to createScopedWakelock will be set the according to whether the sensor events are
+ * from wakeup sensors. Then, the sub-HAL will perform any processing necessary before invoking the
+ * postEvents callback passing in the previously created ScopedWakelock. At this point, ownership
+ * of the object will be passed to the HalProxy that will then be responsible for ensuring any
+ * wake locks continue to be held, if necessary.
+ */
+class ScopedWakelock {
+  public:
+    ScopedWakelock(ScopedWakelock&&) = default;
+    ScopedWakelock& operator=(ScopedWakelock&&) = default;
+    virtual ~ScopedWakelock();
+
+    bool isLocked() const { return mLocked; }
+
+  private:
+    friend class HalProxyCallback;
+    IScopedWakelockRefCounter* mRefCounter;
+    int64_t mCreatedAtTimeNs;
+    bool mLocked;
+    ScopedWakelock(IScopedWakelockRefCounter* refCounter, bool locked);
+    ScopedWakelock(const ScopedWakelock&) = delete;
+    ScopedWakelock& operator=(const ScopedWakelock&) = delete;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/include/SubHal.h

@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include "ScopedWakelock.h"
+
+#include <android/hardware/sensors/1.0/types.h>
+#include <android/hardware/sensors/2.0/ISensors.h>
+
+#include <vector>
+
+// Indicates the current version of the multiHAL interface formatted as (HAL major version) << 24 |
+// (HAL minor version) << 16 | (multiHAL version)
+#define SUB_HAL_2_0_VERSION 0x02000000
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace implementation {
+
+using ::android::hardware::sensors::V1_0::Event;
+using ::android::hardware::sensors::V1_0::Result;
+using ::android::hardware::sensors::V1_0::SensorInfo;
+
+/**
+ * Interface that contains several callbacks into the HalProxy class to communicate dynamic sensor
+ * changes and sensor events to the framework and acquire wake locks. The HalProxy will ensure
+ * callbacks occurring at the same time from multiple sub-HALs are synchronized in a safe, efficient
+ * manner.
+ */
+class IHalProxyCallback : public ISensorsCallback {
+  public:
+    /**
+     * Thread-safe callback used to post events to the HalProxy. Sub-HALs should invoke this
+     * whenever new sensor events need to be delivered to the sensors framework. Once invoked, the
+     * HalProxy will attempt to send events to the sensors framework using a blocking write with a
+     * 5 second timeout. This write may be done asynchronously if the queue used to communicate
+     * with the framework is full to avoid blocking sub-HALs for the length of the timeout. If the
+     * write fails, the events will be dropped and any wake locks held will be released.
+     *
+     * The provided ScopedWakelock must be locked if the events are from wakeup sensors. If it's
+     * not locked accordingly, the HalProxy will crash as this indicates the sub-HAL isn't compliant
+     * with the sensors HAL 2.0 specification. Additionally, since ScopedWakelock isn't copyable,
+     * the HalProxy will take ownership of the wake lock given when this method is invoked. Once the
+     * method returns, the HalProxy will handle holding the wake lock, if necessary, until the
+     * framework has successfully processed any wakeup events.
+     *
+     * No return type is used for this callback to avoid sub-HALs trying to resend events when
+     * writes fail. Writes should only fail when the framework is under inordinate stress which will
+     * likely result in a framework restart so retrying will likely only result in overloading the
+     * HalProxy. Sub-HALs should always assume that the write was a success and perform any
+     * necessary cleanup. Additionally, the HalProxy will ensure it logs any errors (through ADB and
+     * bug reports) it encounters during delivery to ensure it's obvious that a failure occurred.
+     *
+     * @param events the events that should be sent to the sensors framework
+     * @param wakelock ScopedWakelock that should be locked to send events from wake sensors and
+     *     unlocked otherwise.
+     */
+    virtual void postEvents(const std::vector<Event>& events, ScopedWakelock wakelock) = 0;
+
+    /**
+     * Initializes a ScopedWakelock on the stack that, when locked, will increment the reference
+     * count for the sub-HAL's wake lock managed inside the HalProxy. See the ScopedWakelock class
+     * definition for how it should be used.
+     *
+     * @param lock whether the ScopedWakelock should be locked before it's returned.
+     * @return the created ScopedWakelock
+     */
+    virtual ScopedWakelock createScopedWakelock(bool lock) = 0;
+};
+
+/**
+ * ISensorsSubHal is an interface that sub-HALs must implement in order to be compliant with
+ * multihal 2.0 and in order for the HalProxy to successfully load and communicate with the sub-HAL.
+ *
+ * Any vendor wishing to implement this interface and support multihal 2.0 will need to create a
+ * dynamic library that exposes sensorsHalGetSubHal (defined below). This library will be loaded by
+ * the HalProxy when the sensors HAL is initialized and then the HalProxy will retrieve the vendor's
+ * implementation of sensorsHalGetSubHal.
+ *
+ * With the exception of the initialize method, ISensorsSubHal will implement the ISensors.hal spec.
+ * Any sensor handles given to the HalProxy, either through getSensorsList() or the
+ * onDynamicSensors(Dis)Connected callbacks, will be translated to avoid clashing with other sub-HAL
+ * handles. To achieve this, the HalProxy will use the upper byte to store the sub-HAL index and
+ * sub-HALs can continue to use the lower 3 bytes of the handle.
+ */
+class ISensorsSubHal : public ISensors {
+  public:
+    // The ISensors version of initialize isn't used for multihal. Instead, sub-HALs must implement
+    // the version below to allow communciation logic to centralized in the HalProxy
+    Return<Result> initialize(
+            const ::android::hardware::MQDescriptorSync<Event>& /* eventQueueDescriptor */,
+            const ::android::hardware::MQDescriptorSync<uint32_t>& /* wakeLockDescriptor */,
+            const sp<ISensorsCallback>& /* sensorsCallback */) final {
+        return Result::INVALID_OPERATION;
+    }
+
+    /**
+     * Method defined in ::android::hidl::base::V1_0::IBase.
+     *
+     * This method should write debug information to hidl_handle that is useful for debugging
+     * issues. Suggestions include:
+     * - Sensor info including handle values and any other state available in the SensorInfo class
+     * - List of active sensors and their current sampling period and reporting latency
+     * - Information about pending flush requests
+     * - Current operating mode
+     * - Currently registered direct channel info
+     * - A history of any of the above
+     */
+    virtual Return<void> debug(const hidl_handle& fd, const hidl_vec<hidl_string>& args) = 0;
+
+    /**
+     * @return A human-readable name for use in wake locks and logging.
+     */
+    virtual const std::string getName() = 0;
+
+    /**
+     * 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
+     *     should be created.
+     * @return result OK on success
+     */
+    virtual Return<Result> initialize(const sp<IHalProxyCallback>& halProxyCallback) = 0;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android
+
+using ::android::hardware::sensors::V2_0::implementation::ISensorsSubHal;
+
+/**
+ * Function that must be exported so the HalProxy class can invoke it on the sub-HAL dynamic
+ * library. This function will only be invoked once at initialization time.
+ *
+ * NOTE: The supported sensors HAL version must match SUB_HAL_2_0_VERSION exactly or the HalProxy
+ * will fail to initialize.
+ *
+ * @param uint32_t when this function returns, this parameter must contain the HAL version that
+ *     this sub-HAL supports. To support this version of multi-HAL, this must be set to
+ *     SUB_HAL_2_0_VERSION.
+ * @return A statically allocated, valid ISensorsSubHal implementation.
+ */
+__attribute__((visibility("default"))) extern "C" ISensorsSubHal* sensorsHalGetSubHal(
+        uint32_t* version);

sensors/2.0/multihal/service.cpp

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include <android/hardware/sensors/2.0/ISensors.h>
+#include <hidl/HidlTransportSupport.h>
+#include <log/log.h>
+#include <utils/StrongPointer.h>
+#include "HalProxy.h"
+
+using android::hardware::configureRpcThreadpool;
+using android::hardware::joinRpcThreadpool;
+using android::hardware::sensors::V2_0::ISensors;
+using android::hardware::sensors::V2_0::implementation::HalProxy;
+
+int main(int /* argc */, char** /* argv */) {
+    configureRpcThreadpool(1, true);
+
+    android::sp<ISensors> halProxy = new HalProxy();
+    if (halProxy->registerAsService() != ::android::OK) {
+        ALOGE("Failed to register Sensors HAL instance");
+        return -1;
+    }
+
+    joinRpcThreadpool();
+    return 1;  // joinRpcThreadpool shouldn't exit
+}

sensors/2.0/multihal/tests/Android.bp

@@ -0,0 +1,99 @@
+//
+// Copyright (C) 2019 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.
+
+cc_defaults {
+    name: "android.hardware.sensors@2.0-fakesubhal-defaults",
+    srcs: [
+        "fake_subhal/*.cpp",
+    ],
+    header_libs: [
+        "android.hardware.sensors@2.0-multihal.header",
+    ],
+    export_include_dirs: ["fake_subhal"],
+    shared_libs: [
+        "android.hardware.sensors@1.0",
+        "android.hardware.sensors@2.0",
+        "libcutils",
+        "libfmq",
+        "libhardware",
+        "libhidlbase",
+        "liblog",
+        "libpower",
+        "libutils",
+    ],
+    static_libs: [
+        "android.hardware.sensors@2.0-HalProxy",
+    ],
+    cflags: [
+        "-DLOG_TAG=\"FakeSubHal\""
+    ],
+}
+
+cc_library {
+    name: "android.hardware.sensors@2.0-fakesubhal-config1",
+    vendor: true,
+    defaults: ["android.hardware.sensors@2.0-fakesubhal-defaults"],
+    cflags: [
+        "-DSUPPORT_CONTINUOUS_SENSORS",
+        "-DSUB_HAL_NAME=\"FakeSubHal-Continuous\"",
+    ],
+}
+
+cc_library {
+    name: "android.hardware.sensors@2.0-fakesubhal-config2",
+    vendor: true,
+    defaults: ["android.hardware.sensors@2.0-fakesubhal-defaults"],
+    cflags: [
+        "-DSUPPORT_ON_CHANGE_SENSORS",
+        "-DSUB_HAL_NAME=\"FakeSubHal-OnChange\"",
+    ],
+}
+
+cc_test_library {
+    name: "android.hardware.sensors@2.0-fakesubhal-unittest",
+    vendor_available: true,
+    defaults: ["android.hardware.sensors@2.0-fakesubhal-defaults"],
+    cflags: [
+        "-DSUPPORT_ON_CHANGE_SENSORS",
+        "-DSUPPORT_CONTINUOUS_SENSORS",
+        "-DSUB_HAL_NAME=\"FakeSubHal-Test\"",
+    ],
+}
+
+cc_test {
+    name: "android.hardware.sensors@2.0-halproxy-unit-tests",
+    srcs: ["HalProxy_test.cpp"],
+    vendor: true,
+    static_libs: [
+        "android.hardware.sensors@2.0-HalProxy",
+        "android.hardware.sensors@2.0-fakesubhal-unittest",
+    ],
+    shared_libs: [
+        "android.hardware.sensors@1.0",
+        "android.hardware.sensors@2.0",
+        "libbase",
+        "libcutils",
+        "libfmq",
+        "libhardware",
+        "libhidlbase",
+        "liblog",
+        "libpower",
+        "libutils",
+    ],
+    test_suites: ["device-tests"],
+    cflags: [
+        "-DLOG_TAG=\"HalProxyUnitTests\"",
+    ],
+}

sensors/2.0/multihal/tests/HalProxy_test.cpp

@@ -0,0 +1,833 @@
+//
+// Copyright (C) 2019 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.
+
+#include <gtest/gtest.h>
+
+#include <android/hardware/sensors/2.0/types.h>
+#include <fmq/MessageQueue.h>
+
+#include "HalProxy.h"
+#include "ScopedWakelock.h"
+#include "SensorsSubHal.h"
+
+#include <chrono>
+#include <set>
+#include <thread>
+#include <vector>
+
+namespace {
+
+using ::android::hardware::EventFlag;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::MessageQueue;
+using ::android::hardware::Return;
+using ::android::hardware::sensors::V1_0::EventPayload;
+using ::android::hardware::sensors::V1_0::SensorFlagBits;
+using ::android::hardware::sensors::V1_0::SensorInfo;
+using ::android::hardware::sensors::V1_0::SensorType;
+using ::android::hardware::sensors::V2_0::EventQueueFlagBits;
+using ::android::hardware::sensors::V2_0::ISensorsCallback;
+using ::android::hardware::sensors::V2_0::WakeLockQueueFlagBits;
+using ::android::hardware::sensors::V2_0::implementation::HalProxy;
+using ::android::hardware::sensors::V2_0::implementation::HalProxyCallback;
+using ::android::hardware::sensors::V2_0::subhal::implementation::AddAndRemoveDynamicSensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::AllSensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::
+        AllSupportDirectChannelSensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::ContinuousSensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::
+        DoesNotSupportDirectChannelSensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::OnChangeSensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::SensorsSubHal;
+using ::android::hardware::sensors::V2_0::subhal::implementation::
+        SetOperationModeFailingSensorsSubHal;
+
+using EventMessageQueue = MessageQueue<Event, ::android::hardware::kSynchronizedReadWrite>;
+using WakeupMessageQueue = MessageQueue<uint32_t, ::android::hardware::kSynchronizedReadWrite>;
+
+// The barebones sensors callback class passed into halproxy initialize calls
+class SensorsCallback : public ISensorsCallback {
+  public:
+    Return<void> onDynamicSensorsConnected(
+            const hidl_vec<SensorInfo>& /*dynamicSensorsAdded*/) override {
+        // Nothing yet
+        return Return<void>();
+    }
+
+    Return<void> onDynamicSensorsDisconnected(
+            const hidl_vec<int32_t>& /*dynamicSensorHandlesRemoved*/) override {
+        // Nothing yet
+        return Return<void>();
+    }
+};
+
+// The sensors callback that expects a variable list of sensors to be added
+class TestSensorsCallback : public ISensorsCallback {
+  public:
+    Return<void> onDynamicSensorsConnected(
+            const hidl_vec<SensorInfo>& dynamicSensorsAdded) override {
+        mSensorsConnected.insert(mSensorsConnected.end(), dynamicSensorsAdded.begin(),
+                                 dynamicSensorsAdded.end());
+        return Return<void>();
+    }
+
+    Return<void> onDynamicSensorsDisconnected(
+            const hidl_vec<int32_t>& dynamicSensorHandlesRemoved) override {
+        mSensorHandlesDisconnected.insert(mSensorHandlesDisconnected.end(),
+                                          dynamicSensorHandlesRemoved.begin(),
+                                          dynamicSensorHandlesRemoved.end());
+        return Return<void>();
+    }
+
+    const std::vector<SensorInfo>& getSensorsConnected() const { return mSensorsConnected; }
+    const std::vector<int32_t>& getSensorHandlesDisconnected() const {
+        return mSensorHandlesDisconnected;
+    }
+
+  private:
+    std::vector<SensorInfo> mSensorsConnected;
+    std::vector<int32_t> mSensorHandlesDisconnected;
+};
+
+// Helper declarations follow
+
+/**
+ * Tests that for each SensorInfo object from a proxy getSensorsList call each corresponding
+ * object from a subhal getSensorsList call has the same type and its last 3 bytes are the
+ * same for sensorHandle field.
+ *
+ * @param proxySensorsList The list of SensorInfo objects from the proxy.getSensorsList callback.
+ * @param subHalSenosrsList The list of SensorInfo objects from the subHal.getSensorsList callback.
+ */
+void testSensorsListFromProxyAndSubHal(const std::vector<SensorInfo>& proxySensorsList,
+                                       const std::vector<SensorInfo>& subHalSensorsList);
+
+/**
+ * Tests that there is exactly one subhal that allows its sensors to have direct channel enabled.
+ * Therefore, all SensorInfo objects that are not from the enabled subhal should be disabled for
+ * direct channel.
+ *
+ * @param sensorsList The SensorInfo object list from proxy.getSensorsList call.
+ * @param enabledSubHalIndex The index of the subhal in the halproxy that is expected to be
+ *     enabled.
+ */
+void testSensorsListForOneDirectChannelEnabledSubHal(const std::vector<SensorInfo>& sensorsList,
+                                                     size_t enabledSubHalIndex);
+
+void ackWakeupEventsToHalProxy(size_t numEvents, std::unique_ptr<WakeupMessageQueue>& wakelockQueue,
+                               EventFlag* wakelockQueueFlag);
+
+bool readEventsOutOfQueue(size_t numEvents, std::unique_ptr<EventMessageQueue>& eventQueue,
+                          EventFlag* eventQueueFlag);
+
+std::unique_ptr<EventMessageQueue> makeEventFMQ(size_t size);
+
+std::unique_ptr<WakeupMessageQueue> makeWakelockFMQ(size_t size);
+
+/**
+ * Construct and return a HIDL Event type thats sensorHandle refers to a proximity sensor
+ *    which is a wakeup type sensor.
+ *
+ * @return A proximity event.
+ */
+Event makeProximityEvent();
+
+/**
+ * Construct and return a HIDL Event type thats sensorHandle refers to a proximity sensor
+ *    which is a wakeup type sensor.
+ *
+ * @return A proximity event.
+ */
+Event makeAccelerometerEvent();
+
+/**
+ * Make a certain number of proximity type events with the sensorHandle field set to
+ * the proper number for AllSensorsSubHal subhal type.
+ *
+ * @param numEvents The number of events to make.
+ *
+ * @return The created list of events.
+ */
+std::vector<Event> makeMultipleProximityEvents(size_t numEvents);
+
+/**
+ * Make a certain number of accelerometer type events with the sensorHandle field set to
+ * the proper number for AllSensorsSubHal subhal type.
+ *
+ * @param numEvents The number of events to make.
+ *
+ * @return The created list of events.
+ */
+std::vector<Event> makeMultipleAccelerometerEvents(size_t numEvents);
+
+/**
+ * Given a SensorInfo vector and a sensor handles vector populate 'sensors' with SensorInfo
+ * objects that have the sensorHandle property set to int32_ts from start to start + size
+ * (exclusive) and push those sensorHandles also onto 'sensorHandles'.
+ *
+ * @param start The starting sensorHandle value.
+ * @param size The ending (not included) sensorHandle value.
+ * @param sensors The SensorInfo object vector reference to push_back to.
+ * @param sensorHandles The sensor handles int32_t vector reference to push_back to.
+ */
+void makeSensorsAndSensorHandlesStartingAndOfSize(int32_t start, size_t size,
+                                                  std::vector<SensorInfo>& sensors,
+                                                  std::vector<int32_t>& sensorHandles);
+
+// Tests follow
+TEST(HalProxyTest, GetSensorsListOneSubHalTest) {
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> fakeSubHals{&subHal};
+    HalProxy proxy(fakeSubHals);
+
+    proxy.getSensorsList([&](const auto& proxySensorsList) {
+        subHal.getSensorsList([&](const auto& subHalSensorsList) {
+            testSensorsListFromProxyAndSubHal(proxySensorsList, subHalSensorsList);
+        });
+    });
+}
+
+TEST(HalProxyTest, GetSensorsListTwoSubHalTest) {
+    ContinuousSensorsSubHal continuousSubHal;
+    OnChangeSensorsSubHal onChangeSubHal;
+    std::vector<ISensorsSubHal*> fakeSubHals;
+    fakeSubHals.push_back(&continuousSubHal);
+    fakeSubHals.push_back(&onChangeSubHal);
+    HalProxy proxy(fakeSubHals);
+
+    std::vector<SensorInfo> proxySensorsList, combinedSubHalSensorsList;
+
+    proxy.getSensorsList([&](const auto& list) { proxySensorsList = list; });
+    continuousSubHal.getSensorsList([&](const auto& list) {
+        combinedSubHalSensorsList.insert(combinedSubHalSensorsList.end(), list.begin(), list.end());
+    });
+    onChangeSubHal.getSensorsList([&](const auto& list) {
+        combinedSubHalSensorsList.insert(combinedSubHalSensorsList.end(), list.begin(), list.end());
+    });
+
+    testSensorsListFromProxyAndSubHal(proxySensorsList, combinedSubHalSensorsList);
+}
+
+TEST(HalProxyTest, SetOperationModeTwoSubHalSuccessTest) {
+    ContinuousSensorsSubHal subHal1;
+    OnChangeSensorsSubHal subHal2;
+
+    std::vector<ISensorsSubHal*> fakeSubHals{&subHal1, &subHal2};
+    HalProxy proxy(fakeSubHals);
+
+    EXPECT_EQ(subHal1.getOperationMode(), OperationMode::NORMAL);
+    EXPECT_EQ(subHal2.getOperationMode(), OperationMode::NORMAL);
+
+    Result result = proxy.setOperationMode(OperationMode::DATA_INJECTION);
+
+    EXPECT_EQ(result, Result::OK);
+    EXPECT_EQ(subHal1.getOperationMode(), OperationMode::DATA_INJECTION);
+    EXPECT_EQ(subHal2.getOperationMode(), OperationMode::DATA_INJECTION);
+}
+
+TEST(HalProxyTest, SetOperationModeTwoSubHalFailTest) {
+    AllSensorsSubHal subHal1;
+    SetOperationModeFailingSensorsSubHal subHal2;
+
+    std::vector<ISensorsSubHal*> fakeSubHals{&subHal1, &subHal2};
+    HalProxy proxy(fakeSubHals);
+
+    EXPECT_EQ(subHal1.getOperationMode(), OperationMode::NORMAL);
+    EXPECT_EQ(subHal2.getOperationMode(), OperationMode::NORMAL);
+
+    Result result = proxy.setOperationMode(OperationMode::DATA_INJECTION);
+
+    EXPECT_NE(result, Result::OK);
+    EXPECT_EQ(subHal1.getOperationMode(), OperationMode::NORMAL);
+    EXPECT_EQ(subHal2.getOperationMode(), OperationMode::NORMAL);
+}
+
+TEST(HalProxyTest, InitDirectChannelTwoSubHalsUnitTest) {
+    AllSupportDirectChannelSensorsSubHal subHal1;
+    AllSupportDirectChannelSensorsSubHal subHal2;
+
+    std::vector<ISensorsSubHal*> fakeSubHals{&subHal1, &subHal2};
+    HalProxy proxy(fakeSubHals);
+
+    proxy.getSensorsList([&](const auto& sensorsList) {
+        testSensorsListForOneDirectChannelEnabledSubHal(sensorsList, 0);
+    });
+}
+
+TEST(HalProxyTest, InitDirectChannelThreeSubHalsUnitTest) {
+    DoesNotSupportDirectChannelSensorsSubHal subHal1;
+    AllSupportDirectChannelSensorsSubHal subHal2, subHal3;
+    std::vector<ISensorsSubHal*> fakeSubHals{&subHal1, &subHal2, &subHal3};
+    HalProxy proxy(fakeSubHals);
+
+    proxy.getSensorsList([&](const auto& sensorsList) {
+        testSensorsListForOneDirectChannelEnabledSubHal(sensorsList, 1);
+    });
+}
+
+TEST(HalProxyTest, PostSingleNonWakeupEvent) {
+    constexpr size_t kQueueSize = 5;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events{makeAccelerometerEvent()};
+    subHal.postEvents(events, false /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), 1);
+}
+
+TEST(HalProxyTest, PostMultipleNonWakeupEvent) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 3;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events = makeMultipleAccelerometerEvents(kNumEvents);
+    subHal.postEvents(events, false /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), kNumEvents);
+}
+
+TEST(HalProxyTest, PostSingleWakeupEvent) {
+    constexpr size_t kQueueSize = 5;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    EventFlag* eventQueueFlag;
+    EventFlag::createEventFlag(eventQueue->getEventFlagWord(), &eventQueueFlag);
+
+    EventFlag* wakelockQueueFlag;
+    EventFlag::createEventFlag(wakeLockQueue->getEventFlagWord(), &wakelockQueueFlag);
+
+    std::vector<Event> events{makeProximityEvent()};
+    subHal.postEvents(events, true /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), 1);
+
+    readEventsOutOfQueue(1, eventQueue, eventQueueFlag);
+    ackWakeupEventsToHalProxy(1, wakeLockQueue, wakelockQueueFlag);
+}
+
+TEST(HalProxyTest, PostMultipleWakeupEvents) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 3;
+    AllSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    EventFlag* eventQueueFlag;
+    EventFlag::createEventFlag(eventQueue->getEventFlagWord(), &eventQueueFlag);
+
+    EventFlag* wakelockQueueFlag;
+    EventFlag::createEventFlag(wakeLockQueue->getEventFlagWord(), &wakelockQueueFlag);
+
+    std::vector<Event> events = makeMultipleProximityEvents(kNumEvents);
+    subHal.postEvents(events, true /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), kNumEvents);
+
+    readEventsOutOfQueue(kNumEvents, eventQueue, eventQueueFlag);
+    ackWakeupEventsToHalProxy(kNumEvents, wakeLockQueue, wakelockQueueFlag);
+}
+
+TEST(HalProxyTest, PostEventsMultipleSubhals) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 2;
+    AllSensorsSubHal subHal1, subHal2;
+    std::vector<ISensorsSubHal*> subHals{&subHal1, &subHal2};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events = makeMultipleAccelerometerEvents(kNumEvents);
+    subHal1.postEvents(events, false /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), kNumEvents);
+
+    subHal2.postEvents(events, false /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), kNumEvents * 2);
+}
+
+TEST(HalProxyTest, PostEventsDelayedWrite) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 6;
+    AllSensorsSubHal subHal1, subHal2;
+    std::vector<ISensorsSubHal*> subHals{&subHal1, &subHal2};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    EventFlag* eventQueueFlag;
+    EventFlag::createEventFlag(eventQueue->getEventFlagWord(), &eventQueueFlag);
+
+    std::vector<Event> events = makeMultipleAccelerometerEvents(kNumEvents);
+    subHal1.postEvents(events, false /* wakeup */);
+
+    EXPECT_EQ(eventQueue->availableToRead(), kQueueSize);
+
+    // readblock a full queue size worth of events out of queue, timeout for half a second
+    EXPECT_TRUE(readEventsOutOfQueue(kQueueSize, eventQueue, eventQueueFlag));
+
+    // proxy background thread should have wrote remaining events when it saw space
+    EXPECT_TRUE(readEventsOutOfQueue(kNumEvents - kQueueSize, eventQueue, eventQueueFlag));
+
+    EXPECT_EQ(eventQueue->availableToRead(), 0);
+}
+
+TEST(HalProxyTest, PostEventsMultipleSubhalsThreaded) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 2;
+    AllSensorsSubHal subHal1, subHal2;
+    std::vector<ISensorsSubHal*> subHals{&subHal1, &subHal2};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    std::vector<Event> events = makeMultipleAccelerometerEvents(kNumEvents);
+
+    std::thread t1(&AllSensorsSubHal::postEvents, &subHal1, events, false);
+    std::thread t2(&AllSensorsSubHal::postEvents, &subHal2, events, false);
+
+    t1.join();
+    t2.join();
+
+    EXPECT_EQ(eventQueue->availableToRead(), kNumEvents * 2);
+}
+
+TEST(HalProxyTest, DestructingWithEventsPendingOnBackgroundThread) {
+    constexpr size_t kQueueSize = 5;
+    constexpr size_t kNumEvents = 6;
+    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 */);
+
+    // Destructing HalProxy object with events on the background thread
+}
+
+TEST(HalProxyTest, DestructingWithUnackedWakeupEventsPosted) {
+    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
+
+    // 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) {
+    constexpr size_t kNumSensors = 3;
+    AddAndRemoveDynamicSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(0);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(0);
+
+    std::vector<SensorInfo> sensorsToConnect;
+    std::vector<int32_t> sensorHandlesToExpect;
+    makeSensorsAndSensorHandlesStartingAndOfSize(1, kNumSensors, sensorsToConnect,
+                                                 sensorHandlesToExpect);
+
+    TestSensorsCallback* callback = new TestSensorsCallback();
+    ::android::sp<ISensorsCallback> callbackPtr = callback;
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callbackPtr);
+    subHal.addDynamicSensors(sensorsToConnect);
+
+    std::vector<SensorInfo> sensorsSeen = callback->getSensorsConnected();
+    EXPECT_EQ(kNumSensors, sensorsSeen.size());
+    for (size_t i = 0; i < kNumSensors; i++) {
+        auto sensorHandleSeen = sensorsSeen[i].sensorHandle;
+        // Note since only one subhal we do not need to change first byte for expected
+        auto sensorHandleExpected = sensorHandlesToExpect[i];
+        EXPECT_EQ(sensorHandleSeen, sensorHandleExpected);
+    }
+}
+
+TEST(HalProxyTest, DynamicSensorsDisconnectedTest) {
+    constexpr size_t kNumSensors = 3;
+    AddAndRemoveDynamicSensorsSubHal subHal;
+    std::vector<ISensorsSubHal*> subHals{&subHal};
+    HalProxy proxy(subHals);
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(0);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(0);
+
+    std::vector<SensorInfo> sensorsToConnect;
+    std::vector<int32_t> sensorHandlesToExpect;
+    makeSensorsAndSensorHandlesStartingAndOfSize(20, kNumSensors, sensorsToConnect,
+                                                 sensorHandlesToExpect);
+
+    std::vector<int32_t> nonDynamicSensorHandles;
+    for (int32_t sensorHandle = 1; sensorHandle < 10; sensorHandle++) {
+        nonDynamicSensorHandles.push_back(sensorHandle);
+    }
+
+    std::set<int32_t> nonDynamicSensorHandlesSet(nonDynamicSensorHandles.begin(),
+                                                 nonDynamicSensorHandles.end());
+
+    std::vector<int32_t> sensorHandlesToAttemptToRemove;
+    sensorHandlesToAttemptToRemove.insert(sensorHandlesToAttemptToRemove.end(),
+                                          sensorHandlesToExpect.begin(),
+                                          sensorHandlesToExpect.end());
+    sensorHandlesToAttemptToRemove.insert(sensorHandlesToAttemptToRemove.end(),
+                                          nonDynamicSensorHandles.begin(),
+                                          nonDynamicSensorHandles.end());
+
+    TestSensorsCallback* callback = new TestSensorsCallback();
+    ::android::sp<ISensorsCallback> callbackPtr = callback;
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callbackPtr);
+    subHal.addDynamicSensors(sensorsToConnect);
+    subHal.removeDynamicSensors(sensorHandlesToAttemptToRemove);
+
+    std::vector<int32_t> sensorHandlesSeen = callback->getSensorHandlesDisconnected();
+    EXPECT_EQ(kNumSensors, sensorHandlesSeen.size());
+    for (size_t i = 0; i < kNumSensors; i++) {
+        auto sensorHandleSeen = sensorHandlesSeen[i];
+        // Note since only one subhal we do not need to change first byte for expected
+        auto sensorHandleExpected = sensorHandlesToExpect[i];
+        EXPECT_EQ(sensorHandleSeen, sensorHandleExpected);
+        EXPECT_TRUE(nonDynamicSensorHandlesSet.find(sensorHandleSeen) ==
+                    nonDynamicSensorHandlesSet.end());
+    }
+}
+
+TEST(HalProxyTest, InvalidSensorHandleSubHalIndexProxyCalls) {
+    constexpr size_t kNumSubHals = 3;
+    constexpr size_t kQueueSize = 5;
+    int32_t kNumSubHalsInt32 = static_cast<int32_t>(kNumSubHals);
+    std::vector<AllSensorsSubHal> subHalObjs(kNumSubHals);
+    std::vector<ISensorsSubHal*> subHals;
+    for (const auto& subHal : subHalObjs) {
+        subHals.push_back((ISensorsSubHal*)(&subHal));
+    }
+
+    std::unique_ptr<EventMessageQueue> eventQueue = makeEventFMQ(kQueueSize);
+    std::unique_ptr<WakeupMessageQueue> wakeLockQueue = makeWakelockFMQ(kQueueSize);
+    ::android::sp<ISensorsCallback> callback = new SensorsCallback();
+    HalProxy proxy(subHals);
+    // Initialize for the injectSensorData call so callback postEvents is valid
+    proxy.initialize(*eventQueue->getDesc(), *wakeLockQueue->getDesc(), callback);
+
+    // For testing proxy.injectSensorData properly
+    proxy.setOperationMode(OperationMode::DATA_INJECTION);
+
+    // kNumSubHalsInt32 index is one off the end of mSubHalList in proxy object
+    EXPECT_EQ(proxy.activate(0x00000001 | (kNumSubHalsInt32 << 24), true), Result::BAD_VALUE);
+    EXPECT_EQ(proxy.batch(0x00000001 | (kNumSubHalsInt32 << 24), 0, 0), Result::BAD_VALUE);
+    EXPECT_EQ(proxy.flush(0x00000001 | (kNumSubHalsInt32 << 24)), Result::BAD_VALUE);
+    Event event;
+    event.sensorHandle = 0x00000001 | (kNumSubHalsInt32 << 24);
+    EXPECT_EQ(proxy.injectSensorData(event), Result::BAD_VALUE);
+}
+
+TEST(HalProxyTest, PostedEventSensorHandleSubHalIndexValid) {
+    constexpr size_t kQueueSize = 5;
+    constexpr int32_t subhal1Index = 0;
+    constexpr int32_t subhal2Index = 1;
+    AllSensorsSubHal subhal1;
+    AllSensorsSubHal subhal2;
+    std::vector<ISensorsSubHal*> subHals{&subhal1, &subhal2};
+
+    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);
+
+    int32_t sensorHandleToPost = 0x00000001;
+    Event eventIn = makeAccelerometerEvent();
+    eventIn.sensorHandle = sensorHandleToPost;
+    std::vector<Event> eventsToPost{eventIn};
+    subhal1.postEvents(eventsToPost, false);
+
+    Event eventOut;
+    EXPECT_TRUE(eventQueue->read(&eventOut));
+
+    EXPECT_EQ(eventOut.sensorHandle, (subhal1Index << 24) | sensorHandleToPost);
+
+    subhal2.postEvents(eventsToPost, false);
+
+    EXPECT_TRUE(eventQueue->read(&eventOut));
+
+    EXPECT_EQ(eventOut.sensorHandle, (subhal2Index << 24) | sensorHandleToPost);
+}
+
+// Helper implementations follow
+void testSensorsListFromProxyAndSubHal(const std::vector<SensorInfo>& proxySensorsList,
+                                       const std::vector<SensorInfo>& subHalSensorsList) {
+    EXPECT_EQ(proxySensorsList.size(), subHalSensorsList.size());
+
+    for (size_t i = 0; i < proxySensorsList.size(); i++) {
+        const SensorInfo& proxySensor = proxySensorsList[i];
+        const SensorInfo& subHalSensor = subHalSensorsList[i];
+
+        EXPECT_EQ(proxySensor.type, subHalSensor.type);
+        EXPECT_EQ(proxySensor.sensorHandle & 0x00FFFFFF, subHalSensor.sensorHandle);
+    }
+}
+
+void testSensorsListForOneDirectChannelEnabledSubHal(const std::vector<SensorInfo>& sensorsList,
+                                                     size_t enabledSubHalIndex) {
+    for (const SensorInfo& sensor : sensorsList) {
+        size_t subHalIndex = static_cast<size_t>(sensor.sensorHandle >> 24);
+        if (subHalIndex == enabledSubHalIndex) {
+            // First subhal should have been picked as the direct channel subhal
+            // and so have direct channel enabled on all of its sensors
+            EXPECT_NE(sensor.flags & SensorFlagBits::MASK_DIRECT_REPORT, 0);
+            EXPECT_NE(sensor.flags & SensorFlagBits::MASK_DIRECT_CHANNEL, 0);
+        } else {
+            // All other subhals should have direct channel disabled for all sensors
+            EXPECT_EQ(sensor.flags & SensorFlagBits::MASK_DIRECT_REPORT, 0);
+            EXPECT_EQ(sensor.flags & SensorFlagBits::MASK_DIRECT_CHANNEL, 0);
+        }
+    }
+}
+
+void ackWakeupEventsToHalProxy(size_t numEvents, std::unique_ptr<WakeupMessageQueue>& wakelockQueue,
+                               EventFlag* wakelockQueueFlag) {
+    uint32_t numEventsUInt32 = static_cast<uint32_t>(numEvents);
+    wakelockQueue->write(&numEventsUInt32);
+    wakelockQueueFlag->wake(static_cast<uint32_t>(WakeLockQueueFlagBits::DATA_WRITTEN));
+}
+
+bool readEventsOutOfQueue(size_t numEvents, std::unique_ptr<EventMessageQueue>& eventQueue,
+                          EventFlag* eventQueueFlag) {
+    constexpr int64_t kReadBlockingTimeout = INT64_C(500000000);
+    std::vector<Event> events(numEvents);
+    return eventQueue->readBlocking(events.data(), numEvents,
+                                    static_cast<uint32_t>(EventQueueFlagBits::EVENTS_READ),
+                                    static_cast<uint32_t>(EventQueueFlagBits::READ_AND_PROCESS),
+                                    kReadBlockingTimeout, eventQueueFlag);
+}
+
+std::unique_ptr<EventMessageQueue> makeEventFMQ(size_t size) {
+    return std::make_unique<EventMessageQueue>(size, true);
+}
+
+std::unique_ptr<WakeupMessageQueue> makeWakelockFMQ(size_t size) {
+    return std::make_unique<WakeupMessageQueue>(size, true);
+}
+
+Event makeProximityEvent() {
+    Event event;
+    event.timestamp = 0xFF00FF00;
+    // This is the sensorhandle of proximity, which is wakeup type
+    event.sensorHandle = 0x00000008;
+    event.sensorType = SensorType::PROXIMITY;
+    event.u = EventPayload();
+    return event;
+}
+
+Event makeAccelerometerEvent() {
+    Event event;
+    event.timestamp = 0xFF00FF00;
+    // This is the sensorhandle of proximity, which is wakeup type
+    event.sensorHandle = 0x00000001;
+    event.sensorType = SensorType::ACCELEROMETER;
+    event.u = EventPayload();
+    return event;
+}
+
+std::vector<Event> makeMultipleProximityEvents(size_t numEvents) {
+    std::vector<Event> events;
+    for (size_t i = 0; i < numEvents; i++) {
+        events.push_back(makeProximityEvent());
+    }
+    return events;
+}
+
+std::vector<Event> makeMultipleAccelerometerEvents(size_t numEvents) {
+    std::vector<Event> events;
+    for (size_t i = 0; i < numEvents; i++) {
+        events.push_back(makeAccelerometerEvent());
+    }
+    return events;
+}
+
+void makeSensorsAndSensorHandlesStartingAndOfSize(int32_t start, size_t size,
+                                                  std::vector<SensorInfo>& sensors,
+                                                  std::vector<int32_t>& sensorHandles) {
+    for (int32_t sensorHandle = start; sensorHandle < start + static_cast<int32_t>(size);
+         sensorHandle++) {
+        SensorInfo sensor;
+        // Just set the sensorHandle field to the correct value so as to not have
+        // to compare every field
+        sensor.sensorHandle = sensorHandle;
+        sensors.push_back(sensor);
+        sensorHandles.push_back(sensorHandle);
+    }
+}
+
+}  // namespace

sensors/2.0/multihal/tests/fake_subhal/README

@@ -0,0 +1,19 @@
+This directory contains a modified version of the default implementation
+provided for sensors HAL 2.0 to support multi-HAL 2.0. It should be used as a
+means to verify the multi-HAL 2.0 implementation can successfully load and
+interact with sub-HALs.
+
+This sub-HAL implementation has two macros that can be used to configure support
+for different sets of sensors. One "SUPPORT_CONTINUOUS_SENSORS", enables
+support for continuous sensors like accel, and gyro whereas the other
+"SUPPORT_ON_CHANGE_SENSORS" enables support for on change sensors like the
+light and proximity sensor. A build target is defined for each of these macros,
+but more targets could be added to support both in one sub-HAL or none at all,
+if necessary.
+
+When built, the library will be written to
+out/target/product/<device>/vendor/lib64/android.hardware.sensors@2.0-fakesubhal.so
+
+Take this .so and place it where the multi-HAL config will cause the HalProxy to
+look and then restart the system server with adb shell stop / adb shell start
+to cause the multi-HAL to restart and attempt to load in the sub-HAL.

sensors/2.0/multihal/tests/fake_subhal/Sensor.cpp

@@ -0,0 +1,349 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include "Sensor.h"
+
+#include <hardware/sensors.h>
+#include <utils/SystemClock.h>
+
+#include <cmath>
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace subhal {
+namespace implementation {
+
+using ::android::hardware::sensors::V1_0::MetaDataEventType;
+using ::android::hardware::sensors::V1_0::SensorFlagBits;
+using ::android::hardware::sensors::V1_0::SensorStatus;
+
+Sensor::Sensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : mIsEnabled(false),
+      mSamplingPeriodNs(0),
+      mLastSampleTimeNs(0),
+      mCallback(callback),
+      mMode(OperationMode::NORMAL) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    constexpr float kDefaultMaxDelayUs = 1000 * 1000;
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+    mRunThread = std::thread(startThread, this);
+}
+
+Sensor::~Sensor() {
+    // Ensure that lock is unlocked before calling mRunThread.join() or a
+    // deadlock will occur.
+    {
+        std::unique_lock<std::mutex> lock(mRunMutex);
+        mStopThread = true;
+        mIsEnabled = false;
+        mWaitCV.notify_all();
+    }
+    mRunThread.join();
+}
+
+const SensorInfo& Sensor::getSensorInfo() const {
+    return mSensorInfo;
+}
+
+void Sensor::batch(int32_t samplingPeriodNs) {
+    samplingPeriodNs =
+            std::clamp(samplingPeriodNs, mSensorInfo.minDelay * 1000, mSensorInfo.maxDelay * 1000);
+
+    if (mSamplingPeriodNs != samplingPeriodNs) {
+        mSamplingPeriodNs = samplingPeriodNs;
+        // Wake up the 'run' thread to check if a new event should be generated now
+        mWaitCV.notify_all();
+    }
+}
+
+void Sensor::activate(bool enable) {
+    if (mIsEnabled != enable) {
+        std::unique_lock<std::mutex> lock(mRunMutex);
+        mIsEnabled = enable;
+        mWaitCV.notify_all();
+    }
+}
+
+Result Sensor::flush() {
+    // Only generate a flush complete event if the sensor is enabled and if the sensor is not a
+    // one-shot sensor.
+    if (!mIsEnabled || (mSensorInfo.flags & static_cast<uint32_t>(SensorFlagBits::ONE_SHOT_MODE))) {
+        return Result::BAD_VALUE;
+    }
+
+    // Note: If a sensor supports batching, write all of the currently batched events for the sensor
+    // to the Event FMQ prior to writing the flush complete event.
+    Event ev;
+    ev.sensorHandle = mSensorInfo.sensorHandle;
+    ev.sensorType = SensorType::META_DATA;
+    ev.u.meta.what = MetaDataEventType::META_DATA_FLUSH_COMPLETE;
+    std::vector<Event> evs{ev};
+    mCallback->postEvents(evs, isWakeUpSensor());
+
+    return Result::OK;
+}
+
+void Sensor::startThread(Sensor* sensor) {
+    sensor->run();
+}
+
+void Sensor::run() {
+    std::unique_lock<std::mutex> runLock(mRunMutex);
+    constexpr int64_t kNanosecondsInSeconds = 1000 * 1000 * 1000;
+
+    while (!mStopThread) {
+        if (!mIsEnabled || mMode == OperationMode::DATA_INJECTION) {
+            mWaitCV.wait(runLock, [&] {
+                return ((mIsEnabled && mMode == OperationMode::NORMAL) || mStopThread);
+            });
+        } else {
+            timespec curTime;
+            clock_gettime(CLOCK_REALTIME, &curTime);
+            int64_t now = (curTime.tv_sec * kNanosecondsInSeconds) + curTime.tv_nsec;
+            int64_t nextSampleTime = mLastSampleTimeNs + mSamplingPeriodNs;
+
+            if (now >= nextSampleTime) {
+                mLastSampleTimeNs = now;
+                nextSampleTime = mLastSampleTimeNs + mSamplingPeriodNs;
+                mCallback->postEvents(readEvents(), isWakeUpSensor());
+            }
+
+            mWaitCV.wait_for(runLock, std::chrono::nanoseconds(nextSampleTime - now));
+        }
+    }
+}
+
+bool Sensor::isWakeUpSensor() {
+    return mSensorInfo.flags & static_cast<uint32_t>(SensorFlagBits::WAKE_UP);
+}
+
+std::vector<Event> Sensor::readEvents() {
+    std::vector<Event> events;
+    Event event;
+    event.sensorHandle = mSensorInfo.sensorHandle;
+    event.sensorType = mSensorInfo.type;
+    event.timestamp = ::android::elapsedRealtimeNano();
+    event.u.vec3.x = 0;
+    event.u.vec3.y = 0;
+    event.u.vec3.z = 0;
+    event.u.vec3.status = SensorStatus::ACCURACY_HIGH;
+    events.push_back(event);
+    return events;
+}
+
+void Sensor::setOperationMode(OperationMode mode) {
+    if (mMode != mode) {
+        std::unique_lock<std::mutex> lock(mRunMutex);
+        mMode = mode;
+        mWaitCV.notify_all();
+    }
+}
+
+bool Sensor::supportsDataInjection() const {
+    return mSensorInfo.flags & static_cast<uint32_t>(SensorFlagBits::DATA_INJECTION);
+}
+
+Result Sensor::injectEvent(const Event& event) {
+    Result result = Result::OK;
+    if (event.sensorType == SensorType::ADDITIONAL_INFO) {
+        // When in OperationMode::NORMAL, SensorType::ADDITIONAL_INFO is used to push operation
+        // environment data into the device.
+    } else if (!supportsDataInjection()) {
+        result = Result::INVALID_OPERATION;
+    } else if (mMode == OperationMode::DATA_INJECTION) {
+        mCallback->postEvents(std::vector<Event>{event}, isWakeUpSensor());
+    } else {
+        result = Result::BAD_VALUE;
+    }
+    return result;
+}
+
+OnChangeSensor::OnChangeSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : Sensor(sensorHandle, callback), mPreviousEventSet(false) {
+    mSensorInfo.flags |= SensorFlagBits::ON_CHANGE_MODE;
+}
+
+void OnChangeSensor::activate(bool enable) {
+    Sensor::activate(enable);
+    if (!enable) {
+        mPreviousEventSet = false;
+    }
+}
+
+std::vector<Event> OnChangeSensor::readEvents() {
+    std::vector<Event> events = Sensor::readEvents();
+    std::vector<Event> outputEvents;
+
+    for (auto iter = events.begin(); iter != events.end(); ++iter) {
+        Event ev = *iter;
+        if (ev.u.vec3 != mPreviousEvent.u.vec3 || !mPreviousEventSet) {
+            outputEvents.push_back(ev);
+            mPreviousEvent = ev;
+            mPreviousEventSet = true;
+        }
+    }
+    return outputEvents;
+}
+
+ContinuousSensor::ContinuousSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : Sensor(sensorHandle, callback) {
+    mSensorInfo.flags |= SensorFlagBits::CONTINUOUS_MODE;
+}
+
+AccelSensor::AccelSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : ContinuousSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Accel Sensor";
+    mSensorInfo.type = SensorType::ACCELEROMETER;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_ACCELEROMETER;
+    mSensorInfo.maxRange = 78.4f;  // +/- 8g
+    mSensorInfo.resolution = 1.52e-5;
+    mSensorInfo.power = 0.001f;        // mA
+    mSensorInfo.minDelay = 20 * 1000;  // microseconds
+    mSensorInfo.flags |= SensorFlagBits::DATA_INJECTION;
+}
+
+std::vector<Event> AccelSensor::readEvents() {
+    std::vector<Event> events;
+    Event event;
+    event.sensorHandle = mSensorInfo.sensorHandle;
+    event.sensorType = mSensorInfo.type;
+    event.timestamp = ::android::elapsedRealtimeNano();
+    event.u.vec3.x = 0;
+    event.u.vec3.y = 0;
+    event.u.vec3.z = -9.815;
+    event.u.vec3.status = SensorStatus::ACCURACY_HIGH;
+    events.push_back(event);
+    return events;
+}
+
+PressureSensor::PressureSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : ContinuousSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Pressure Sensor";
+    mSensorInfo.type = SensorType::PRESSURE;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_PRESSURE;
+    mSensorInfo.maxRange = 1100.0f;     // hPa
+    mSensorInfo.resolution = 0.005f;    // hPa
+    mSensorInfo.power = 0.001f;         // mA
+    mSensorInfo.minDelay = 100 * 1000;  // microseconds
+}
+
+MagnetometerSensor::MagnetometerSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : ContinuousSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Magnetic Field Sensor";
+    mSensorInfo.type = SensorType::MAGNETIC_FIELD;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_MAGNETIC_FIELD;
+    mSensorInfo.maxRange = 1300.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;        // mA
+    mSensorInfo.minDelay = 20 * 1000;  // microseconds
+}
+
+LightSensor::LightSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Light Sensor";
+    mSensorInfo.type = SensorType::LIGHT;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_LIGHT;
+    mSensorInfo.maxRange = 43000.0f;
+    mSensorInfo.resolution = 10.0f;
+    mSensorInfo.power = 0.001f;         // mA
+    mSensorInfo.minDelay = 200 * 1000;  // microseconds
+}
+
+ProximitySensor::ProximitySensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Proximity Sensor";
+    mSensorInfo.type = SensorType::PROXIMITY;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_PROXIMITY;
+    mSensorInfo.maxRange = 5.0f;
+    mSensorInfo.resolution = 1.0f;
+    mSensorInfo.power = 0.012f;         // mA
+    mSensorInfo.minDelay = 200 * 1000;  // microseconds
+    mSensorInfo.flags |= SensorFlagBits::WAKE_UP;
+}
+
+GyroSensor::GyroSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : ContinuousSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Gyro Sensor";
+    mSensorInfo.type = SensorType::GYROSCOPE;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_GYROSCOPE;
+    mSensorInfo.maxRange = 1000.0f * M_PI / 180.0f;
+    mSensorInfo.resolution = 1000.0f * M_PI / (180.0f * 32768.0f);
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 2.5f * 1000;  // microseconds
+}
+
+std::vector<Event> GyroSensor::readEvents() {
+    std::vector<Event> events;
+    Event event;
+    event.sensorHandle = mSensorInfo.sensorHandle;
+    event.sensorType = mSensorInfo.type;
+    event.timestamp = ::android::elapsedRealtimeNano();
+    event.u.vec3.x = 0;
+    event.u.vec3.y = 0;
+    event.u.vec3.z = 0;
+    event.u.vec3.status = SensorStatus::ACCURACY_HIGH;
+    events.push_back(event);
+    return events;
+}
+
+AmbientTempSensor::AmbientTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Ambient Temp Sensor";
+    mSensorInfo.type = SensorType::AMBIENT_TEMPERATURE;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_AMBIENT_TEMPERATURE;
+    mSensorInfo.maxRange = 80.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 40 * 1000;  // microseconds
+}
+
+DeviceTempSensor::DeviceTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : ContinuousSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Device Temp Sensor";
+    mSensorInfo.type = SensorType::TEMPERATURE;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_TEMPERATURE;
+    mSensorInfo.maxRange = 80.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 40 * 1000;  // microseconds
+}
+
+RelativeHumiditySensor::RelativeHumiditySensor(int32_t sensorHandle,
+                                               ISensorsEventCallback* callback)
+    : OnChangeSensor(sensorHandle, callback) {
+    mSensorInfo.name = "Relative Humidity Sensor";
+    mSensorInfo.type = SensorType::RELATIVE_HUMIDITY;
+    mSensorInfo.typeAsString = SENSOR_STRING_TYPE_RELATIVE_HUMIDITY;
+    mSensorInfo.maxRange = 100.0f;
+    mSensorInfo.resolution = 0.1f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 40 * 1000;  // microseconds
+}
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/tests/fake_subhal/Sensor.h

@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include <android/hardware/sensors/1.0/types.h>
+
+#include <condition_variable>
+#include <memory>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+using ::android::hardware::sensors::V1_0::Event;
+using ::android::hardware::sensors::V1_0::OperationMode;
+using ::android::hardware::sensors::V1_0::Result;
+using ::android::hardware::sensors::V1_0::SensorInfo;
+using ::android::hardware::sensors::V1_0::SensorType;
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace subhal {
+namespace implementation {
+
+class ISensorsEventCallback {
+  public:
+    virtual ~ISensorsEventCallback(){};
+    virtual void postEvents(const std::vector<Event>& events, bool wakeup) = 0;
+};
+
+class Sensor {
+  public:
+    Sensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+    virtual ~Sensor();
+
+    const SensorInfo& getSensorInfo() const;
+    void batch(int32_t samplingPeriodNs);
+    virtual void activate(bool enable);
+    Result flush();
+
+    void setOperationMode(OperationMode mode);
+    bool supportsDataInjection() const;
+    Result injectEvent(const Event& event);
+
+  protected:
+    void run();
+    virtual std::vector<Event> readEvents();
+    static void startThread(Sensor* sensor);
+
+    bool isWakeUpSensor();
+
+    bool mIsEnabled;
+    int64_t mSamplingPeriodNs;
+    int64_t mLastSampleTimeNs;
+    SensorInfo mSensorInfo;
+
+    std::atomic_bool mStopThread;
+    std::condition_variable mWaitCV;
+    std::mutex mRunMutex;
+    std::thread mRunThread;
+
+    ISensorsEventCallback* mCallback;
+
+    OperationMode mMode;
+};
+
+class OnChangeSensor : public Sensor {
+  public:
+    OnChangeSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+    virtual void activate(bool enable) override;
+
+  protected:
+    virtual std::vector<Event> readEvents() override;
+
+  protected:
+    Event mPreviousEvent;
+    bool mPreviousEventSet;
+};
+
+class ContinuousSensor : public Sensor {
+  public:
+    ContinuousSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class AccelSensor : public ContinuousSensor {
+  public:
+    AccelSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    std::vector<Event> readEvents() override;
+};
+
+class GyroSensor : public ContinuousSensor {
+  public:
+    GyroSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    std::vector<Event> readEvents() override;
+};
+
+class DeviceTempSensor : public ContinuousSensor {
+  public:
+    DeviceTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class PressureSensor : public ContinuousSensor {
+  public:
+    PressureSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class MagnetometerSensor : public ContinuousSensor {
+  public:
+    MagnetometerSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class AmbientTempSensor : public OnChangeSensor {
+  public:
+    AmbientTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class LightSensor : public OnChangeSensor {
+  public:
+    LightSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class ProximitySensor : public OnChangeSensor {
+  public:
+    ProximitySensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class RelativeHumiditySensor : public OnChangeSensor {
+  public:
+    RelativeHumiditySensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/tests/fake_subhal/SensorsSubHal.cpp

@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include "SensorsSubHal.h"
+
+#include <android/hardware/sensors/2.0/types.h>
+#include <log/log.h>
+
+ISensorsSubHal* sensorsHalGetSubHal(uint32_t* version) {
+#if defined SUPPORT_CONTINUOUS_SENSORS && defined SUPPORT_ON_CHANGE_SENSORS
+    static ::android::hardware::sensors::V2_0::subhal::implementation::AllSensorsSubHal subHal;
+#elif defined SUPPORT_CONTINUOUS_SENSORS
+    static ::android::hardware::sensors::V2_0::subhal::implementation::ContinuousSensorsSubHal
+            subHal;
+#elif defined SUPPORT_ON_CHANGE_SENSORS
+    static ::android::hardware::sensors::V2_0::subhal::implementation::OnChangeSensorsSubHal subHal;
+#else
+    static ::android::hardware::sensors::V2_0::subhal::implementation::SensorsSubHal subHal;
+#endif  // defined SUPPORT_CONTINUOUS_SENSORS && defined SUPPORT_ON_CHANGE_SENSORS
+    *version = SUB_HAL_2_0_VERSION;
+    return &subHal;
+}
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace subhal {
+namespace implementation {
+
+using ::android::hardware::Void;
+using ::android::hardware::sensors::V1_0::Event;
+using ::android::hardware::sensors::V1_0::OperationMode;
+using ::android::hardware::sensors::V1_0::RateLevel;
+using ::android::hardware::sensors::V1_0::Result;
+using ::android::hardware::sensors::V1_0::SharedMemInfo;
+using ::android::hardware::sensors::V2_0::SensorTimeout;
+using ::android::hardware::sensors::V2_0::WakeLockQueueFlagBits;
+using ::android::hardware::sensors::V2_0::implementation::ScopedWakelock;
+
+SensorsSubHal::SensorsSubHal() : mCallback(nullptr), mNextHandle(1) {}
+
+// Methods from ::android::hardware::sensors::V2_0::ISensors follow.
+Return<void> SensorsSubHal::getSensorsList(getSensorsList_cb _hidl_cb) {
+    std::vector<SensorInfo> sensors;
+    for (const auto& sensor : mSensors) {
+        sensors.push_back(sensor.second->getSensorInfo());
+    }
+
+    _hidl_cb(sensors);
+    return Void();
+}
+
+Return<Result> SensorsSubHal::setOperationMode(OperationMode mode) {
+    for (auto sensor : mSensors) {
+        sensor.second->setOperationMode(mode);
+    }
+    mCurrentOperationMode = mode;
+    return Result::OK;
+}
+
+Return<Result> SensorsSubHal::activate(int32_t sensorHandle, bool enabled) {
+    auto sensor = mSensors.find(sensorHandle);
+    if (sensor != mSensors.end()) {
+        sensor->second->activate(enabled);
+        return Result::OK;
+    }
+    return Result::BAD_VALUE;
+}
+
+Return<Result> SensorsSubHal::batch(int32_t sensorHandle, int64_t samplingPeriodNs,
+                                    int64_t /* maxReportLatencyNs */) {
+    auto sensor = mSensors.find(sensorHandle);
+    if (sensor != mSensors.end()) {
+        sensor->second->batch(samplingPeriodNs);
+        return Result::OK;
+    }
+    return Result::BAD_VALUE;
+}
+
+Return<Result> SensorsSubHal::flush(int32_t sensorHandle) {
+    auto sensor = mSensors.find(sensorHandle);
+    if (sensor != mSensors.end()) {
+        return sensor->second->flush();
+    }
+    return Result::BAD_VALUE;
+}
+
+Return<Result> SensorsSubHal::injectSensorData(const Event& event) {
+    auto sensor = mSensors.find(event.sensorHandle);
+    if (sensor != mSensors.end()) {
+        return sensor->second->injectEvent(event);
+    }
+
+    return Result::BAD_VALUE;
+}
+
+Return<void> SensorsSubHal::registerDirectChannel(const SharedMemInfo& /* mem */,
+                                                  registerDirectChannel_cb _hidl_cb) {
+    _hidl_cb(Result::INVALID_OPERATION, -1 /* channelHandle */);
+    return Return<void>();
+}
+
+Return<Result> SensorsSubHal::unregisterDirectChannel(int32_t /* channelHandle */) {
+    return Result::INVALID_OPERATION;
+}
+
+Return<void> SensorsSubHal::configDirectReport(int32_t /* sensorHandle */,
+                                               int32_t /* channelHandle */, RateLevel /* rate */,
+                                               configDirectReport_cb _hidl_cb) {
+    _hidl_cb(Result::INVALID_OPERATION, 0 /* reportToken */);
+    return Return<void>();
+}
+
+Return<void> SensorsSubHal::debug(const hidl_handle& fd, const hidl_vec<hidl_string>& args) {
+    if (fd.getNativeHandle() == nullptr || fd->numFds < 1) {
+        ALOGE("%s: missing fd for writing", __FUNCTION__);
+        return Void();
+    }
+
+    FILE* out = fdopen(dup(fd->data[0]), "w");
+
+    if (args.size() != 0) {
+        fprintf(out,
+                "Note: sub-HAL %s currently does not support args. Input arguments are "
+                "ignored.\n",
+                getName().c_str());
+    }
+
+    std::ostringstream stream;
+    stream << "Available sensors:" << std::endl;
+    for (auto sensor : mSensors) {
+        SensorInfo info = sensor.second->getSensorInfo();
+        stream << "Name: " << info.name << std::endl;
+        stream << "Min delay: " << info.minDelay << std::endl;
+        stream << "Flags: " << info.flags << std::endl;
+    }
+    stream << std::endl;
+
+    fprintf(out, "%s", stream.str().c_str());
+
+    fclose(out);
+    return Return<void>();
+}
+
+Return<Result> SensorsSubHal::initialize(const sp<IHalProxyCallback>& halProxyCallback) {
+    mCallback = halProxyCallback;
+    setOperationMode(OperationMode::NORMAL);
+    return Result::OK;
+}
+
+void SensorsSubHal::postEvents(const std::vector<Event>& events, bool wakeup) {
+    ScopedWakelock wakelock = mCallback->createScopedWakelock(wakeup);
+    mCallback->postEvents(events, std::move(wakelock));
+}
+
+ContinuousSensorsSubHal::ContinuousSensorsSubHal() {
+    AddSensor<AccelSensor>();
+    AddSensor<GyroSensor>();
+    AddSensor<MagnetometerSensor>();
+    AddSensor<PressureSensor>();
+    AddSensor<DeviceTempSensor>();
+}
+
+OnChangeSensorsSubHal::OnChangeSensorsSubHal() {
+    AddSensor<AmbientTempSensor>();
+    AddSensor<LightSensor>();
+    AddSensor<ProximitySensor>();
+    AddSensor<RelativeHumiditySensor>();
+}
+
+AllSensorsSubHal::AllSensorsSubHal() {
+    AddSensor<AccelSensor>();
+    AddSensor<GyroSensor>();
+    AddSensor<MagnetometerSensor>();
+    AddSensor<PressureSensor>();
+    AddSensor<DeviceTempSensor>();
+    AddSensor<AmbientTempSensor>();
+    AddSensor<LightSensor>();
+    AddSensor<ProximitySensor>();
+    AddSensor<RelativeHumiditySensor>();
+}
+
+Return<Result> SetOperationModeFailingSensorsSubHal::setOperationMode(OperationMode /*mode*/) {
+    return Result::BAD_VALUE;
+}
+
+Return<void> AllSupportDirectChannelSensorsSubHal::getSensorsList(getSensorsList_cb _hidl_cb) {
+    std::vector<SensorInfo> sensors;
+    for (const auto& sensor : mSensors) {
+        SensorInfo sensorInfo = sensor.second->getSensorInfo();
+        sensorInfo.flags |= V1_0::SensorFlagBits::MASK_DIRECT_CHANNEL;
+        sensorInfo.flags |= V1_0::SensorFlagBits::MASK_DIRECT_REPORT;
+        sensors.push_back(sensorInfo);
+    }
+    _hidl_cb(sensors);
+    return Void();
+}
+
+Return<void> DoesNotSupportDirectChannelSensorsSubHal::getSensorsList(getSensorsList_cb _hidl_cb) {
+    std::vector<SensorInfo> sensors;
+    for (const auto& sensor : mSensors) {
+        SensorInfo sensorInfo = sensor.second->getSensorInfo();
+        sensorInfo.flags &= ~static_cast<uint32_t>(V1_0::SensorFlagBits::MASK_DIRECT_CHANNEL);
+        sensorInfo.flags &= ~static_cast<uint32_t>(V1_0::SensorFlagBits::MASK_DIRECT_REPORT);
+        sensors.push_back(sensorInfo);
+    }
+    _hidl_cb(sensors);
+    return Void();
+}
+
+void AddAndRemoveDynamicSensorsSubHal::addDynamicSensors(
+        const std::vector<SensorInfo>& sensorsAdded) {
+    mCallback->onDynamicSensorsConnected(sensorsAdded);
+}
+
+void AddAndRemoveDynamicSensorsSubHal::removeDynamicSensors(
+        const std::vector<int32_t>& sensorHandlesRemoved) {
+    mCallback->onDynamicSensorsDisconnected(sensorHandlesRemoved);
+}
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/tests/fake_subhal/SensorsSubHal.h

@@ -0,0 +1,165 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#pragma once
+
+#include "SubHal.h"
+
+#include "Sensor.h"
+
+#include <vector>
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace subhal {
+namespace implementation {
+
+using ::android::hardware::sensors::V1_0::OperationMode;
+using ::android::hardware::sensors::V1_0::Result;
+using ::android::hardware::sensors::V2_0::implementation::IHalProxyCallback;
+
+/**
+ * Implementation of a ISensorsSubHal that can be used to test the implementation of multihal 2.0.
+ * See the README file for more details on how this class can be used for testing.
+ */
+class SensorsSubHal : public ISensorsSubHal, public ISensorsEventCallback {
+    using Event = ::android::hardware::sensors::V1_0::Event;
+    using RateLevel = ::android::hardware::sensors::V1_0::RateLevel;
+    using SharedMemInfo = ::android::hardware::sensors::V1_0::SharedMemInfo;
+
+  public:
+    SensorsSubHal();
+
+    // Methods from ::android::hardware::sensors::V2_0::ISensors follow.
+    virtual Return<void> getSensorsList(getSensorsList_cb _hidl_cb) override;
+
+    virtual Return<Result> setOperationMode(OperationMode mode) override;
+
+    OperationMode getOperationMode() const { return mCurrentOperationMode; }
+
+    Return<Result> activate(int32_t sensorHandle, bool enabled) override;
+
+    Return<Result> batch(int32_t sensorHandle, int64_t samplingPeriodNs,
+                         int64_t maxReportLatencyNs) override;
+
+    Return<Result> flush(int32_t sensorHandle) override;
+
+    Return<Result> injectSensorData(const Event& event) override;
+
+    Return<void> registerDirectChannel(const SharedMemInfo& mem,
+                                       registerDirectChannel_cb _hidl_cb) override;
+
+    Return<Result> unregisterDirectChannel(int32_t channelHandle) override;
+
+    Return<void> configDirectReport(int32_t sensorHandle, int32_t channelHandle, RateLevel rate,
+                                    configDirectReport_cb _hidl_cb) override;
+
+    Return<void> debug(const hidl_handle& fd, const hidl_vec<hidl_string>& args) override;
+
+    // Methods from ::android::hardware::sensors::V2_0::implementation::ISensorsSubHal follow.
+    const std::string getName() override {
+#ifdef SUB_HAL_NAME
+        return SUB_HAL_NAME;
+#else   // SUB_HAL_NAME
+        return "FakeSubHal";
+#endif  // SUB_HAL_NAME
+    }
+
+    Return<Result> initialize(const sp<IHalProxyCallback>& halProxyCallback) override;
+
+    // Method from ISensorsEventCallback.
+    void postEvents(const std::vector<Event>& events, bool wakeup) override;
+
+  protected:
+    template <class SensorType>
+    void AddSensor() {
+        std::shared_ptr<SensorType> sensor =
+                std::make_shared<SensorType>(mNextHandle++ /* sensorHandle */, this /* callback */);
+        mSensors[sensor->getSensorInfo().sensorHandle] = sensor;
+    }
+
+    /**
+     * A map of the available sensors
+     */
+    std::map<int32_t, std::shared_ptr<Sensor>> mSensors;
+
+    /**
+     * Callback used to communicate to the HalProxy when dynamic sensors are connected /
+     * disconnected, sensor events need to be sent to the framework, and when a wakelock should be
+     * acquired.
+     */
+    sp<IHalProxyCallback> mCallback;
+
+  private:
+    /**
+     * The current operation mode of the multihal framework. Ensures that all subhals are set to
+     * the same operation mode.
+     */
+    OperationMode mCurrentOperationMode = OperationMode::NORMAL;
+
+    /**
+     * The next available sensor handle
+     */
+    int32_t mNextHandle;
+};
+
+// SubHal that has continuous sensors for testing purposes.
+class ContinuousSensorsSubHal : public SensorsSubHal {
+  public:
+    ContinuousSensorsSubHal();
+};
+
+// SubHal that has on-change sensors for testing purposes.
+class OnChangeSensorsSubHal : public SensorsSubHal {
+  public:
+    OnChangeSensorsSubHal();
+};
+
+// SubHal that has both continuous and on-change sensors for testing purposes.
+class AllSensorsSubHal : public SensorsSubHal {
+  public:
+    AllSensorsSubHal();
+};
+
+class SetOperationModeFailingSensorsSubHal : public AllSensorsSubHal {
+  public:
+    Return<Result> setOperationMode(OperationMode mode) override;
+};
+
+class AllSupportDirectChannelSensorsSubHal : public AllSensorsSubHal {
+  public:
+    Return<void> getSensorsList(getSensorsList_cb _hidl_cb) override;
+};
+
+class DoesNotSupportDirectChannelSensorsSubHal : public AllSensorsSubHal {
+  public:
+    Return<void> getSensorsList(getSensorsList_cb _hidl_cb) override;
+};
+
+class AddAndRemoveDynamicSensorsSubHal : public AllSensorsSubHal {
+  public:
+    void addDynamicSensors(const std::vector<SensorInfo>& sensorsAdded);
+    void removeDynamicSensors(const std::vector<int32_t>& sensorHandlesAdded);
+};
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android