sensors/multihal_sensors.h

/*
 * Copyright (C) 2020 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-base/unique_fd.h>
#include <SubHal.h>
#include <cstdint>
#include <thread>

namespace goldfish {
namespace ahs = ::android::hardware::sensors;
namespace ahs20 = ahs::V2_0;
namespace ahs10 = ahs::V1_0;

using ahs20::implementation::IHalProxyCallback;
using ahs10::Event;
using ahs10::OperationMode;
using ahs10::RateLevel;
using ahs10::Result;
using ahs10::SharedMemInfo;

using ::android::base::unique_fd;
using ::android::hardware::hidl_handle;
using ::android::hardware::hidl_string;
using ::android::hardware::hidl_vec;
using ::android::hardware::Return;
using ::android::sp;

struct MultihalSensors : public ahs20::implementation::ISensorsSubHal {
    MultihalSensors();
    ~MultihalSensors();

    Return<void> debug(const hidl_handle& fd, const hidl_vec<hidl_string>& args) override;
    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;

    const std::string getName() override;
    Return<Result> initialize(const sp<IHalProxyCallback>& halProxyCallback) override;

private:
    struct QemuSensorsProtocolState {
        int64_t timeBiasNs = -500000000;

        static constexpr float kSensorNoValue = -1e+30;

        // on change sensors (host does not support them)
        float lastAmbientTemperatureValue = kSensorNoValue;
        float lastProximityValue = kSensorNoValue;
        float lastLightValue = kSensorNoValue;
        float lastRelativeHumidityValue = kSensorNoValue;
    };

    static bool activateQemuSensorImpl(int pipe, int sensorHandle, bool enabled);
    bool disableAllSensors();
    void parseQemuSensorEvent(const int pipe, QemuSensorsProtocolState* state);
    void postSensorEvent(const Event& event);
    void postSensorEventLocked(const Event& event);

    void qemuSensorListenerThread();
    static void qemuSensorListenerThreadStart(MultihalSensors* that);

    static constexpr char kCMD_QUIT = 'q';
    bool qemuSensorThreadSendCommand(char cmd) const;

    // set in ctor, never change
    const unique_fd     m_qemuSensorsFd;
    uint32_t            m_availableSensorsMask = 0;
    // a pair of connected sockets to talk to the worker thread
    unique_fd           m_callersFd;        // a caller writes here
    unique_fd           m_sensorThreadFd;   // the worker thread listens from here
    std::thread         m_sensorThread;

    // changed by API
    uint32_t                m_activeSensorsMask = 0;
    OperationMode           m_opMode = OperationMode::NORMAL;
    sp<IHalProxyCallback>   m_halProxyCallback;
    mutable std::mutex      m_apiMtx;
};

}  // namespace goldfish