Add a sub-HAL implementation for testing multi-HAL

Creates a fake sub-HAL using the default implementation for sensors HAL
2.0 with some small modifications to support the multi-HAL interface.

This sub-HAL can be configured to support two different sets of sensors
making it easier to build and load two different sub-HAL implementations
onto device and verify the multihal implementation works.

Bug: 136511617
Test: compile only. Once multihal can load in sub-HALs, then this can be
accurately tested.

Change-Id: I9b136506bdbc8a3b196fd363748bddfcdd564daf

sensors/2.0/multihal/Android.bp

@@ -23,6 +23,9 @@ cc_binary {
         "HalProxy.cpp",
     ],
     init_rc: ["android.hardware.sensors@2.0-service-multihal.rc"],
+    header_libs: [
+        "android.hardware.sensors@2.0-subhal.header",
+    ],
     shared_libs: [
         "android.hardware.sensors@1.0",
         "android.hardware.sensors@2.0",
@@ -36,3 +39,9 @@ cc_binary {
     ],
     vintf_fragments: ["android.hardware.sensors@2.0-multihal.xml"],
 }
+
+cc_library_headers {
+    name: "android.hardware.sensors@2.0-subhal.header",
+    vendor: true,
+    export_include_dirs: ["include"],
+}

sensors/2.0/multihal/include/SubHal.h

@@ -163,7 +163,7 @@ class ISensorsSubHal : public ISensors {
     /**
      * @return A human-readable name for use in wake locks and logging.
      */
-    virtual const std::string& getName() = 0;
+    virtual const std::string getName() = 0;
 
     /**
      * First method invoked on the sub-HAL after it's allocated through sensorsHalGetSubHal() by the

sensors/2.0/multihal/testing/Android.bp

@@ -0,0 +1,55 @@
+//
+// 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",
+    vendor: true,
+    srcs: [
+        "Sensor.cpp",
+        "SensorsSubHal.cpp",
+    ],
+    header_libs: [
+        "android.hardware.sensors@2.0-subhal.header",
+    ],
+    shared_libs: [
+        "android.hardware.sensors@1.0",
+        "android.hardware.sensors@2.0",
+        "libcutils",
+        "libfmq",
+        "libhidlbase",
+        "libhidltransport",
+        "liblog",
+        "libpower",
+        "libutils",
+    ],
+}
+
+cc_library {
+    name: "android.hardware.sensors@2.0-fakesubhal-config1",
+    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",
+    defaults: ["android.hardware.sensors@2.0-fakesubhal-defaults"],
+    cflags: [
+        "-DSUPPORT_ON_CHANGE_SENSORS",
+        "-DSUB_HAL_NAME=\"FakeSubHal-OnChange\"",
+    ],
+}

sensors/2.0/multihal/testing/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/testing/Sensor.cpp

@@ -0,0 +1,372 @@
+/*
+ * 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 <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;
+
+static constexpr float kDefaultMaxDelayUs = 10 * 1000 * 1000;
+
+Sensor::Sensor(ISensorsEventCallback* callback)
+    : mIsEnabled(false),
+      mSamplingPeriodNs(0),
+      mLastSampleTimeNs(0),
+      mCallback(callback),
+      mMode(OperationMode::NORMAL) {
+    mRunThread = std::thread(startThread, this);
+}
+
+Sensor::~Sensor() {
+    std::unique_lock<std::mutex> lock(mRunMutex);
+    mStopThread = true;
+    mIsEnabled = false;
+    mWaitCV.notify_all();
+    lock.release();
+    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(ISensorsEventCallback* callback)
+    : Sensor(callback), mPreviousEventSet(false) {}
+
+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;
+}
+
+AccelSensor::AccelSensor(int32_t sensorHandle, ISensorsEventCallback* callback) : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Accel Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::ACCELEROMETER;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 78.4f;  // +/- 8g
+    mSensorInfo.resolution = 1.52e-5;
+    mSensorInfo.power = 0.001f;        // mA
+    mSensorInfo.minDelay = 20 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorFlagBits::DATA_INJECTION);
+};
+
+PressureSensor::PressureSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Pressure Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::PRESSURE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 1100.0f;     // hPa
+    mSensorInfo.resolution = 0.005f;    // hPa
+    mSensorInfo.power = 0.001f;         // mA
+    mSensorInfo.minDelay = 100 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+};
+
+MagnetometerSensor::MagnetometerSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Magnetic Field Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::MAGNETIC_FIELD;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 1300.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;        // mA
+    mSensorInfo.minDelay = 20 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+};
+
+LightSensor::LightSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Light Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::LIGHT;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 43000.0f;
+    mSensorInfo.resolution = 10.0f;
+    mSensorInfo.power = 0.001f;         // mA
+    mSensorInfo.minDelay = 200 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorFlagBits::ON_CHANGE_MODE);
+};
+
+ProximitySensor::ProximitySensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Proximity Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::PROXIMITY;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 5.0f;
+    mSensorInfo.resolution = 1.0f;
+    mSensorInfo.power = 0.012f;         // mA
+    mSensorInfo.minDelay = 200 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags =
+            static_cast<uint32_t>(SensorFlagBits::ON_CHANGE_MODE | SensorFlagBits::WAKE_UP);
+};
+
+GyroSensor::GyroSensor(int32_t sensorHandle, ISensorsEventCallback* callback) : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Gyro Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::GYROSCOPE;
+    mSensorInfo.typeAsString = "";
+    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
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+};
+
+AmbientTempSensor::AmbientTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Ambient Temp Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::AMBIENT_TEMPERATURE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 80.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 40 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorFlagBits::ON_CHANGE_MODE);
+};
+
+DeviceTempSensor::DeviceTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Device Temp Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::TEMPERATURE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 80.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 40 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorFlagBits::ON_CHANGE_MODE);
+}
+
+RelativeHumiditySensor::RelativeHumiditySensor(int32_t sensorHandle,
+                                               ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Relative Humidity Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::RELATIVE_HUMIDITY;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 100.0f;
+    mSensorInfo.resolution = 0.1f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelay = 40 * 1000;  // microseconds
+    mSensorInfo.maxDelay = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorFlagBits::ON_CHANGE_MODE);
+}
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/testing/Sensor.h

@@ -0,0 +1,146 @@
+/*
+ * 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(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(ISensorsEventCallback* callback);
+
+    virtual void activate(bool enable) override;
+
+  protected:
+    virtual std::vector<Event> readEvents() override;
+
+  protected:
+    Event mPreviousEvent;
+    bool mPreviousEventSet;
+};
+
+class AccelSensor : public Sensor {
+  public:
+    AccelSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class GyroSensor : public Sensor {
+  public:
+    GyroSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class AmbientTempSensor : public OnChangeSensor {
+  public:
+    AmbientTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class DeviceTempSensor : public OnChangeSensor {
+  public:
+    DeviceTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class PressureSensor : public Sensor {
+  public:
+    PressureSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+};
+
+class MagnetometerSensor : public Sensor {
+  public:
+    MagnetometerSensor(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/testing/SensorsSubHal.cpp

@@ -0,0 +1,179 @@
+/*
+ * 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) {
+    static ::android::hardware::sensors::V2_0::subhal::implementation::SensorsSubHal subHal;
+    *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) {
+#ifdef SUPPORT_CONTINUOUS_SENSORS
+    AddSensor<AccelSensor>();
+    AddSensor<GyroSensor>();
+    AddSensor<MagnetometerSensor>();
+    AddSensor<PressureSensor>();
+#endif  // SUPPORT_CONTINUOUS_SENSORS
+
+#ifdef SUPPORT_ON_CHANGE_SENSORS
+    AddSensor<AmbientTempSensor>();
+    AddSensor<DeviceTempSensor>();
+    AddSensor<LightSensor>();
+    AddSensor<ProximitySensor>();
+    AddSensor<RelativeHumiditySensor>();
+#endif  // SUPPORT_ON_CHANGE_SENSORS
+}
+
+// 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);
+    }
+    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;
+    return Result::OK;
+}
+
+void SensorsSubHal::postEvents(const std::vector<Event>& events, bool wakeup) {
+    ScopedWakelock wakelock = mCallback->createScopedWakelock(wakeup);
+    mCallback->postEvents(events, std::move(wakelock));
+}
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android

sensors/2.0/multihal/testing/SensorsSubHal.h

@@ -0,0 +1,115 @@
+/*
+ * 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"
+
+namespace android {
+namespace hardware {
+namespace sensors {
+namespace V2_0 {
+namespace subhal {
+namespace implementation {
+
+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 OperationMode = ::android::hardware::sensors::V1_0::OperationMode;
+    using RateLevel = ::android::hardware::sensors::V1_0::RateLevel;
+    using Result = ::android::hardware::sensors::V1_0::Result;
+    using SharedMemInfo = ::android::hardware::sensors::V1_0::SharedMemInfo;
+
+  public:
+    SensorsSubHal();
+
+    // 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> 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;
+
+  private:
+    template <class SensorType>
+    void AddSensor() {
+        std::shared_ptr<SensorType> sensor =
+                std::make_shared<SensorType>(mNextHandle++ /* sensorHandle */, this /* callback */);
+        mSensors[sensor->getSensorInfo().sensorHandle] = sensor;
+    }
+
+    /**
+     * 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;
+
+    /**
+     * A map of the available sensors
+     */
+    std::map<int32_t, std::shared_ptr<Sensor>> mSensors;
+
+    /**
+     * The next available sensor handle
+     */
+    int32_t mNextHandle;
+};
+
+}  // namespace implementation
+}  // namespace subhal
+}  // namespace V2_0
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android