Vehicle HAL(2)--Vehicle HAL 的启动

目录

1. VehicleService-main 函数分析

2. 构建EmulatedVehicleHal

2.1 EmulatedVehicleHal::EmulatedVehicleHal(xxx)

2.2 EmulatedVehicleHal::initStaticConfig()

2.3 EmulatedVehicleHal::onPropertyValue()

3. 构建VehicleEmulator

4. 构建VehicleHalManager

(1)初始化成员变量SubscriptionManager mSubscriptionManager

(2)调用VehicleHalManager::init()

a. 调用VehicleHal::init()

b. mHal->listProperties() 获取支持的属性

5. 构建WatchdogClient对象，并初始化

6. vhal主线程开启while(true)循环

1. VehicleService-main 函数分析

vhal在VehicleService-main中启动。具体代码如下：

hardware/interfaces/automotive/vehicle/2.0/default/VehicleService.cpp

17  #define LOG_TAG "automotive.vehicle@2.0-service"
18  #include <android/log.h>
19  #include <hidl/HidlTransportSupport.h>
20  
21  #include <iostream>
22  
23  #include <android/binder_process.h>
24  #include <utils/Looper.h>
25  #include <vhal_v2_0/EmulatedVehicleConnector.h>
26  #include <vhal_v2_0/EmulatedVehicleHal.h>
27  #include <vhal_v2_0/VehicleHalManager.h>
28  #include <vhal_v2_0/WatchdogClient.h>
29  
30  using namespace android;
31  using namespace android::hardware;
32  using namespace android::hardware::automotive::vehicle::V2_0;
33  
34  int main(int /* argc */, char* /* argv */ []) {
35      auto store = std::make_unique<VehiclePropertyStore>();//新建对象，采用默认构造函数VehiclePropertyStore
36      auto connector = std::make_unique<impl::EmulatedVehicleConnector>();//同上，构建EmulatedVehicleConnector
37      auto hal = std::make_unique<impl::EmulatedVehicleHal>(store.get(), connector.get());//第2章，获取对象的指针，来新建EmulatedVehicleHal
38      auto emulator = std::make_unique<impl::VehicleEmulator>(hal.get());//第3章，新建VehicleEmulator
39      auto service = std::make_unique<VehicleHalManager>(hal.get());//第4章，构建VehicleHalManager，传入hal指针，VehicleHalManager是实现hidl服务的主体
40      connector->setValuePool(hal->getValuePool());//属性池的指针设置给connector
41  
42      configureRpcThreadpool(4, false /* callerWillJoin */);
43  
44      ALOGI("Registering as service...");
45      status_t status = service->registerAsService();//hidl服务注册
46  
47      if (status != OK) {
48          ALOGE("Unable to register vehicle service (%d)", status);
49          return 1;
50      }
51  
52      // Setup a binder thread pool to be a car watchdog client.
53      ABinderProcess_setThreadPoolMaxThreadCount(1);
54      ABinderProcess_startThreadPool();
55      sp<Looper> looper(Looper::prepare(0 /* opts */));
56      std::shared_ptr<WatchdogClient> watchdogClient =
57              ndk::SharedRefBase::make<WatchdogClient>(looper, service.get());//第5章，构建WatchdogClient对象，并初始化
58      // The current health check is done in the main thread, so it falls short of capturing the real
59      // situation. Checking through HAL binder thread should be considered.
60      if (!watchdogClient->initialize()) {//初始化
61          ALOGE("Failed to initialize car watchdog client");
62          return 1;
63      }
64      ALOGI("Ready");
65      while (true) {
66          looper->pollAll(-1 /* timeoutMillis */);//第6章，开启while(true)循环
67      }
68  
69      return 1;
70  }
71  

2. 构建EmulatedVehicleHal

EmulatedVehicleHal实现了vhal中的VehicleHal抽象类。

从下图可以看出继承关系。

android11/hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/EmulatedVehicleHal.h

android11/hardware/interfaces/automotive/vehicle/2.0/default/common/include/vhal_v2_0/VehicleHal.h

获取对象的指针，来新建EmulatedVehicleHal

EmulatedVehicleHal(VehiclePropertyStore* propStore, VehicleHalClient* client,EmulatedUserHal* emulatedUserHal = nullptr);

EmulatedVehicleHal本身存放了很多静态配置的属性值，构建的时候会传入mPropStore。

2.1 EmulatedVehicleHal::EmulatedVehicleHal(xxx)

EmulatedVehicleHal::EmulatedVehicleHal(VehiclePropertyStore* propStore, VehicleHalClient* client,EmulatedUserHal* emulatedUserHal): mPropStore(propStore),//缓存，属性storemHvacPowerProps(std::begin(kHvacPowerProperties), std::end(kHvacPowerProperties)),mRecurrentTimer(std::bind(&EmulatedVehicleHal::onContinuousPropertyTimer, this,std::placeholders::_1)),mVehicleClient(client),//VehicleHalClient* mVehicleClient; 缓存，多重继承的EmulatedVehicleConnectormEmulatedUserHal(emulatedUserHal) {//初始化为nullinitStaticConfig();//初始化静态配置，里面会调用mPropStore->registerProperty()，有mPropStore的进一步操作for (size_t i = 0; i < arraysize(kVehicleProperties); i++) {mPropStore->registerProperty(kVehicleProperties[i].config);//继续初始化mPropStore，注册一些属性}mVehicleClient->registerPropertyValueCallback(std::bind(&EmulatedVehicleHal::onPropertyValue,//会从mVehicleClient触发回调回来this, std::placeholders::_1,std::placeholders::_2));//关键调用，属性变化之后的回调
}

2.2 EmulatedVehicleHal::initStaticConfig()

EmulatedVehicleHal() > EmulatedVehicleHal::initStaticConfig() > mPropStore->registerProperty()

kVehicleProperties是静态配置好了的。

195  const ConfigDeclaration kVehicleProperties[]

android11/hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h

360  void EmulatedVehicleHal::initStaticConfig() {
361      for (auto&& it = std::begin(kVehicleProperties); it != std::end(kVehicleProperties); ++it) {
362          const auto& cfg = it->config;
363          VehiclePropertyStore::TokenFunction tokenFunction = nullptr;
364  
365          switch (cfg.prop) {
366              case OBD2_FREEZE_FRAME: {
367                  tokenFunction = [](const VehiclePropValue& propValue) {
368                      return propValue.timestamp;
369                  };
370                  break;
371              }
372              default:
373                  break;
374          }
375  
376          mPropStore->registerProperty(cfg, tokenFunction);//关键代码
377      }
378  }

38  void VehiclePropertyStore::registerProperty(const VehiclePropConfig& config,
39                                              VehiclePropertyStore::TokenFunction tokenFunc) {
40      MuxGuard g(mLock);
41      mConfigs.insert({ config.prop, RecordConfig { config, tokenFunc } });//向std::unordered_map中插入
42  }

hardware/interfaces/automotive/vehicle/2.0/default/common/include/vhal_v2_0/VehiclePropertyStore.h
93      std::unordered_map<int32_t /* VehicleProperty */, RecordConfig> mConfigs;

2.3 EmulatedVehicleHal::onPropertyValue()

此为传递属性改变的关键函数

351  void EmulatedVehicleHal::onPropertyValue(const VehiclePropValue& value, bool updateStatus) {
352      VehiclePropValuePtr updatedPropValue = getValuePool()->obtain(value);
353  
354      if (mPropStore->writeValue(*updatedPropValue, updateStatus)) {//更新属性
355          getEmulatorOrDie()->doSetValueFromClient(*updatedPropValue);//关键调用，Emulator，client，获取时通过socket走到can的另外一端
356          doHalEvent(std::move(updatedPropValue));//关键调用，返回变化到carservice
357      }
358  }

3. 构建VehicleEmulator

模拟车，做一些通信接口相关的初始化。把消息发给可能存在的ecu。在原生上是通过can给ecu发消息。见上一节EmulatedVehicleHal的onPropertyValue消息处理中有getEmulatorOrDie()->doSetValueFromClient(xxx)。

class VehicleEmulator : public MessageProcessor

用刚才构建的EmulatedVehicleHal来构建VehicleEmulator。VehicleEmulator模拟的vehicle，或者说模拟的car。

/**
 * Emulates vehicle by providing controlling interface from host side either through ADB or Pipe.
 */

VehicleEmulator(EmulatedVehicleHalIface* hal);

VehicleEmulator::VehicleEmulator(EmulatedVehicleHalIface* hal) : mHal{hal} {mHal->registerEmulator(this);//把自己注册到EmulatedVehicleHal中，VehicleEmulator和mHal产生关系。mHal可以调用到VehicleEmulator。ALOGI("Starting SocketComm");mSocketComm = std::make_unique<SocketComm>(this);//新建socket通信相关对象mSocketComm->start();if (android::base::GetBoolProperty("ro.kernel.qemu", false)) {ALOGI("Starting PipeComm");mPipeComm = std::make_unique<PipeComm>(this);//pipe相关的mPipeComm->start();}if (android::base::GetBoolProperty("persist.vendor.cansocket", false)) {//enable siengine CanSocketCommALOGI("Starting CanSocketComm");mCanSocketComm = std::make_unique<CanSocketComm>(this);//CanSocketCommmCanSocketComm->start();}
}

4. 构建VehicleHalManager

构建VehicleHalManager的关键过程为有3步。VehicleHalManager实现了IVehiclel接口，hal服务的主体。

    VehicleHalManager(VehicleHal* vehicleHal): mHal(vehicleHal),//初始化mHalmSubscriptionManager(std::bind(&VehicleHalManager::onAllClientsUnsubscribed,this, std::placeholders::_1)) {//初始化mSubscriptionManagerinit();//调用自己的init()函数}

(1)初始化成员变量SubscriptionManager mSubscriptionManager

SubscriptionManager 的构造函数

    /*** Constructs SubscriptionManager** @param onPropertyUnsubscribed - called when no more clients are subscribed to the property.*/SubscriptionManager(const OnPropertyUnsubscribed& onPropertyUnsubscribed): mOnPropertyUnsubscribed(onPropertyUnsubscribed),//初始化给mOnPropertyUnsubscribedmCallbackDeathRecipient(new DeathRecipient(std::bind(&SubscriptionManager::onCallbackDead, this, std::placeholders::_1))){}

(2)调用VehicleHalManager::init()

hardware/interfaces/automotive/vehicle/2.0/default/common/src/VehicleHalManager.cpp

431  void VehicleHalManager::init() {
432      ALOGI("VehicleHalManager::init");
433  
434      mHidlVecOfVehiclePropValuePool.resize(kMaxHidlVecOfVehiclPropValuePoolSize);
435  
436  
437      mBatchingConsumer.run(&mEventQueue,
438                            kHalEventBatchingTimeWindow,
439                            std::bind(&VehicleHalManager::onBatchHalEvent,
440                                      this, _1));//启动mBatchingConsumer
441  
442      mHal->init(&mValueObjectPool,
443                 std::bind(&VehicleHalManager::onHalEvent, this, _1),
444                 std::bind(&VehicleHalManager::onHalPropertySetError, this,
445                           _1, _2, _3));//a.调用hal的init函数
446  
447      // Initialize index with vehicle configurations received from VehicleHal.
448      auto supportedPropConfigs = mHal->listProperties();//b.获取支持的属性
449      mConfigIndex.reset(new VehiclePropConfigIndex(supportedPropConfigs));//放入mConfigIndex
450  
451      std::vector<int32_t> supportedProperties(
452          supportedPropConfigs.size());
453      for (const auto& config : supportedPropConfigs) {
454          supportedProperties.push_back(config.prop);
455      }
456  }

a. 调用VehicleHal::init()

调用hal的init函数：VehicleHal的init函数

93      void init(
94          VehiclePropValuePool* valueObjectPool,
95          const HalEventFunction& onHalEvent,
96          const HalErrorFunction& onHalError) {
97          mValuePool = valueObjectPool;
98          mOnHalEvent = onHalEvent;
99          mOnHalPropertySetError = onHalError;
100  
101          onCreate();
102      }

b. mHal->listProperties() 获取支持的属性

hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/EmulatedVehicleHal.cpp

290  std::vector<VehiclePropConfig> EmulatedVehicleHal::listProperties()  {
291      return mPropStore->getAllConfigs();
292  }

mHal中mPropStore的来源

hardware/interfaces/automotive/vehicle/2.0/default/impl/vhal_v2_0/EmulatedVehicleHal.cpp

90  EmulatedVehicleHal::EmulatedVehicleHal(VehiclePropertyStore* propStore, VehicleHalClient* client,
91                                         EmulatedUserHal* emulatedUserHal)
92      : mPropStore(propStore),//mPropStore的来源
93        mHvacPowerProps(std::begin(kHvacPowerProperties), std::end(kHvacPowerProperties)),
94        mRecurrentTimer(std::bind(&EmulatedVehicleHal::onContinuousPropertyTimer, this,
95                                  std::placeholders::_1)),
96        mVehicleClient(client),
97        mEmulatedUserHal(emulatedUserHal) {
98      initStaticConfig();
99      for (size_t i = 0; i < arraysize(kVehicleProperties); i++) {
100          mPropStore->registerProperty(kVehicleProperties[i].config);
101      }
102      mVehicleClient->registerPropertyValueCallback(std::bind(&EmulatedVehicleHal::onPropertyValue,
103                                                              this, std::placeholders::_1,
104                                                              std::placeholders::_2));
105  }
106  

mPropStore->getAllConfigs()的实现:

hardware/interfaces/automotive/vehicle/2.0/default/common/src/VehiclePropertyStore.cpp

124  std::vector<VehiclePropConfig> VehiclePropertyStore::getAllConfigs() const {
125      MuxGuard g(mLock);
126      std::vector<VehiclePropConfig> configs;
127      configs.reserve(mConfigs.size());//从mConfigs来
128      for (auto&& recordConfigIt: mConfigs) {//遍历mConfigs
129          configs.push_back(recordConfigIt.second.propConfig);
130      }
131      return configs;
132  }

5. 构建WatchdogClient对象，并初始化

    explicit WatchdogClient(const ::android::sp<::android::Looper>& handlerLooper,
                            VehicleHalManager* vhalManager);

将自己加入car watchdog的监控。

WatchdogClient::WatchdogClient(const sp<Looper>& handlerLooper, VehicleHalManager* vhalManager): mHandlerLooper(handlerLooper), mVhalManager(vhalManager), mCurrentSessionId(-1) {mMessageHandler = new MessageHandlerImpl(this);//新建内部的handler
}

bool WatchdogClient::initialize() {ndk::SpAIBinder binder(AServiceManager_getService("android.automotive.watchdog.ICarWatchdog/default"));//获取服务if (binder.get() == nullptr) {ALOGE("Failed to get carwatchdog daemon");return false;}std::shared_ptr<ICarWatchdog> server = ICarWatchdog::fromBinder(binder);if (server == nullptr) {ALOGE("Failed to connect to carwatchdog daemon");return false;}mWatchdogServer = server;//保存serverbinder = this->asBinder();if (binder.get() == nullptr) {ALOGE("Failed to get car watchdog client binder object");return false;}std::shared_ptr<ICarWatchdogClient> client = ICarWatchdogClient::fromBinder(binder);if (client == nullptr) {ALOGE("Failed to get ICarWatchdogClient from binder");return false;}mTestClient = client;mWatchdogServer->registerClient(client, TimeoutLength::TIMEOUT_NORMAL);//把自己注册到sever端，类型为TIMEOUT_NORMAL型的checkALOGI("Successfully registered the client to car watchdog server");return true;
}

接收来自sever(carwatchdogd)的回调

ndk::ScopedAStatus WatchdogClient::prepareProcessTermination() {return ndk::ScopedAStatus::ok();
}

6. vhal主线程开启while(true)循环

64      ALOGI("Ready");
65      while (true) {
66          looper->pollAll(-1 /* timeoutMillis */);//开启while(true)循环，主线程一直睡在这里
67      }