跟着源码学习OpenHarmony应用启动流程-Application&Ability初始化

一、引言

本文基于OpenAtom OpenHarmony（以下简称“OpenHarmony”） v4.0 Release版本的源码，对应用进程初始化后MainThread初始化及调用AttachApplication、LaunchApplication、LaunchAbility的过程做了分析和总结，该流程贯穿了应用程序的用户进程和系统服务进程。

二、启动框架与核心类简介

2.1 启动框架须知

如下图所示，OpenHarmony应用冷启动过程大致分为四个阶段：应用进程创建&初始化、Application&Ability初始化、Ability/AbilityStage生命周期、加载绘制首页。

2.2 应用启动流程的核心类须知

• AppMgrService是应用管理服务主线程类，实现了IPC调用IAppMgr的接口，并通过AMSEventHandler将进程内各类事件及任务发送到主线程。
• AppRunningManager记录了应用的信息、应用的运行状态、进程信息等，内部持有了模块运行信息列表，应用第一次启动时，会先创建。
• AppSpawn是app孵化器，通过监听本地socket，接收客户端的请求消息。创建Ability应用所在进程，为Ability应用设置相应的权限，并预加载一些通用的模块。
• AbilityLoader负责注册和加载开发者Ability模块。开发者开发的Ability先调用AbilityLoader的注册接口注册到框架中，接着Ability启动时会被实例化。
• AbilityManager负责AbilityKit和Ability管理服务进行IPC的通信。
• MainThread是应用进程的核心类。应用进程内各类事件及任务通过MainThread中mainHandler投递到主线程并调用MainThread中的方法执行。
• AbilityThread是应用线程的核心类，是操作各种Ability生命周期及方法的入口。

三、源码分析

3.1.主线程初始化

通过IPC机制，AMS调用AttachApplication，再回调AMS端 foundation\ability\ability_runtime\frameworks\native\appkit\app\main_thread.cpp

1. void MainThread::Start()
2. {

3.  sptr<MainThread> thread = sptr<MainThread>(new (std::nothrow) MainThread());

4.  ......

5.  thread->Init(runner);

6.  thread->Attach();  }

8. void MainThread::Init()
9. {

10.  auto task = [weak]() {

11.      auto appThread = weak.promote();

12.      appThread->SetRunnerStarted(true);

13.  };

14.  if (!mainHandler\_->PostTask(task)) {

15.      HILOG\_ERROR("MainThread::Init PostTask task failed");

16.  }

17.  watchdog\_->Init(mainHandler\_);

18.  extensionConfigMgr\_->Init();

19. }
21. void MainThread::Attach()
22. {

23.  if (!ConnectToAppMgr()) {

24.      return;

25.  }

26.  mainThreadState\_ = MainThreadState::ATTACH;

27. }
29. bool MainThread::ConnectToAppMgr()
30. {

31.  auto object = OHOS::DelayedSingleton<SysMrgClient>::GetInstance()->GetSystemAbility(APP\_MGR\_SERVICE\_ID);

32.  appMgr\_ = iface\_cast<IAppMgr>(object);

33.  appMgr\_->AttachApplication(this);

34. }

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客户端发送 attach application 请求

foundation\ability\ability_runtime\interfaces\inner_api\app_manager\src\appmgr\app_mgr_proxy.cpp

1. AppMgrProxy::AttachApplication(const sptr<IRemoteObject> &obj)
2. {

3. sptr<IRemoteObject> remote = Remote();

4. remote->SendRequest(static\_cast<uint32\_t>(IAppMgr::Message::APP\_ATTACH\_APPLICATION), ...);

5. }

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服务端收到 attach application 请求

foundation\ability\ability_runtime\interfaces\inner_api\app_manager\src\appmgr\app_mgr_stub.cpp

1. int32_t AppMgrStub::HandleAttachApplication(MessageParcel &data, MessageParcel &reply)
2. {

3. sptr<IRemoteObject> client = data.ReadRemoteObject();

4. AttachApplication(client);

5. }

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foundation\ability\ability_runtime\services\appmgr\src\app_mgr_service.cpp

1. void AppMgrService::AttachApplication(const sptr<IRemoteObject> &app)
2. {
3. pid_t pid = IPCSkeleton::GetCallingPid();

4. AddAppDeathRecipient(pid);

5. std::function<void()> attachApplicationFunc =

6.     std::bind(&AppMgrServiceInner::AttachApplication, appMgrServiceInner\_, pid, iface\_cast<IAppScheduler>(app));

7. taskHandler\_->SubmitTask(attachApplicationFunc, TASK\_ATTACH\_APPLICATION);

8. }

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函数处理逻辑回到服务层

foundation\ability\ability_runtime\services\appmgr\src/app_mgr_service_inner.cpp

1. void AppMgrServiceInner::AttachApplication(const pid_t pid, const sptr<IAppScheduler> &appScheduler)
2. {

3. ......

4. appRecord->SetApplicationClient(appScheduler);

5. appRecord->RegisterAppDeathRecipient();

6. if (appRecord->GetState() == ApplicationState::APP\_STATE\_CREATE) {

7.     LaunchApplication(appRecord);

8. }

9. eventInfo.pid = appRecord->GetPriorityObject()->GetPid();

10.  eventInfo.processName = appRecord->GetProcessName();

11.  AAFwk::EventReport::SendAppEvent(AAFwk::EventName::APP\_ATTACH, HiSysEventType::BEHAVIOR, eventInfo);

12. }<div class="document"><div class="section"><p class="paragraph text-align-type-left" style="margin: 3pt 0pt; font-family: 等线; font-size: 12pt;"><span data-font-family="default" style="font-size: 11pt; letter-spacing: 0pt; vertical-align: baseline;">
13. </span></p></div></div>void AppMgrServiceInner::LaunchApplication(const std::shared_ptr<AppRunningRecord> &appRecord)
14. {

15.  appRecord->LaunchApplication(\*configuration\_);

16.  appRecord->SetState(ApplicationState::APP\_STATE\_READY);

17.  appRecord->SetRestartResidentProcCount(restartResidentProcCount);

18.  ......

19.  appRecord->LaunchPendingAbilities();

20.  AAFwk::EventReport::SendAppEvent(AAFwk::EventName::APP\_LAUNCH, HiSysEventType::BEHAVIOR, eventInfo);

21. }

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2.应用初始化，通过AppRunningRecord调用LaunchApplication应用第一次启动时，会先创建AppRunningRecord

foundation\ability\ability_runtime\services\appmgr\src\app_running_record.cpp

1. void AppRunningRecord::LaunchApplication(const Configuration &config)
2. {

3. appLifeCycleDeal\_->GetApplicationClient()

4. ......

5. launchData.SetProcessInfo(processInfo);

6. launchData.SetRecordId(appRecordId\_);

7. launchData.SetUId(mainUid\_);

8. launchData.SetUserTestInfo(userTestRecord\_);

9. launchData.SetAppIndex(appIndex\_);

10.  appLifeCycleDeal\_->LaunchApplication(launchData, config);

11. }

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foundation\ability\ability_runtime\services\appmgr\src\app_lifecycle_deal.cpp

1. void AppLifeCycleDeal::LaunchAbility(const std::shared_ptr<AbilityRunningRecord> &ability)
2. {

3. appThread\_->ScheduleLaunchApplication(launchData, config);

4. }

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处理启动应用（加载依赖库、初始化资源管理器等）等逻辑

foundation\ability\ability_runtime\frameworks\native\appkit\app\main_thread.cpp

1. void MainThread::ScheduleLaunchApplication(const AppLaunchData &data, const Configuration &config)
2. {

3. appThread->HandleLaunchApplication(data, config);

4. }
6. void MainThread::HandleLaunchApplication(const AppLaunchData &data, const Configuration &config)
7. {

8. if (!InitCreate(contextDeal, appInfo, processInfo)) {

9.     return;

10.  }

11.  if (IsNeedLoadLibrary(bundleName)) {

12.      ChangeToLocalPath(bundleName, appInfo.moduleSourceDirs, localPaths);

13.      LoadAbilityLibrary(localPaths);

14.      LoadNativeLiabrary(bundleInfo, appInfo.nativeLibraryPath);

15.  }

16.  if (appInfo.needAppDetail) {

17.      LoadAppDetailAbilityLibrary(appInfo.appDetailAbilityLibraryPath);

18.  }

19.  LoadAppLibrary();

20.  if (isStageBased) {

21.      AppRecovery::GetInstance().InitApplicationInfo(GetMainHandler(), GetApplicationInfo());

22.  }

23.  // create contextImpl

24.  ......

25.  if (isStageBased) {

26.      // Create runtime

27.      ......

28.      application\_->SetRuntime(std::move(runtime));

29.      AbilityLoader::GetInstance().RegisterAbility("Ability", [application = application\_]() {

30.          return Ability::Create(application->GetRuntime());

31.      });

32.  LoadAllExtensions(jsEngine);

33.  contextDeal->initResourceManager(resourceManager);

34.  contextDeal->SetApplicationContext(application\_);

35.  application\_->AttachBaseContext(contextDeal);

36.  application\_->SetAbilityRecordMgr(abilityRecordMgr\_);

37.  application\_->SetConfiguration(config);

38.  contextImpl->SetConfiguration(application\_->GetConfiguration());

40.  applicationImpl\_->SetRecordId(appLaunchData.GetRecordId());

41.  applicationImpl\_->SetApplication(application\_);

42.  mainThreadState\_ = MainThreadState::READY;

43.  ......

44.  applicationImpl\_->PerformAppReady()

45.  nwebMgr->PreStartNWebSpawnProcess();

46.  ......

47.  // init resourceManager.

48.  ......

49. }

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3. 通过RunningRecord调用LaunchPendingAbilities,最终创建Abilityfoundation\ability\ability_runtime\services\appmgr\src/module_running_record.cpp

1. void ModuleRunningRecord::LaunchPendingAbilities()
2. {

3. for (const auto &item : abilities\_) {

4.     const auto &ability = item.second;

5.     if (ability->GetState() == AbilityState::ABILITY\_STATE\_CREATE && ability->GetToken() &&

6.         appLifeCycleDeal\_->GetApplicationClient()) {

7.         appLifeCycleDeal\_->LaunchAbility(ability);

8.         ability->SetState(AbilityState::ABILITY\_STATE\_READY);

9.     }

10.  }

11. }
12. void ModuleRunningRecord::LaunchAbility(const std::shared_ptr<AbilityRunningRecord> &ability)
13. {

14.  appLifeCycleDeal\_->LaunchAbility(ability);

15.  ability->SetState(AbilityState::ABILITY\_STATE\_READY);

16. }

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通过IPC调用ScheduleLaunchAbility函数

foundation\ability\ability_runtime\services\appmgr\src/app_lifecycle_deal.cpp

1. AppLifeCycleDeal::LaunchAbility(const std::shared_ptr<AbilityRunningRecord> &ability)
2. {

3. if (appThread\_ && ability) {

4.     appThread\_->ScheduleLaunchAbility(\*(ability->GetAbilityInfo()), ability->GetToken(),

5.         ability->GetWant());

6. }

7. }

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foundation\ability\ability_runtime\frameworks\native\appkit\app\main_thread.cpp

1. MainThread::ScheduleLaunchAbility(const AbilityInfo &info, const sptr<IRemoteObject> &token, const std::shared_ptrAAFwk::Want &want)
2. {

3. auto task = [weak, abilityRecord]() {

4.     ...

5.     auto appThread = weak.promote();

6.     appThread->HandleLaunchAbility(abilityRecord);

7. };

8. mainHandler\_->PostTask(task);

9. }
10. MainThread::HandleLaunchAbility(const std::shared_ptr<AbilityLocalRecord> &abilityRecord)
11. {

12.  abilityRecordMgr\_->SetToken(abilityToken);

13.  abilityRecordMgr\_->AddAbilityRecord(abilityToken, abilityRecord);

14.  //创建AbilityStage

15.  std::shared\_ptr<AbilityRuntime::Context> stageContext = application\_->AddAbilityStage(abilityRecord);

16.  //启动Ability线程

17.  AbilityThread::AbilityThreadMain(application\_, abilityRecord, stageContext);

18. }

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foundation\ability\ability_runtime\frameworks\native\appkit\app\ohos_application.cpp

1. bool OHOSApplication::AddAbilityStage(const AppExecFwk::HapModuleInfo &hapModuleInfo)
2. {

3.  ......

4. auto stageContext = std::make\_shared<AbilityRuntime::ContextImpl>();

5. stageContext->SetParentContext(abilityRuntimeContext\_);

6. stageContext->InitHapModuleInfo(hapModuleInfo);

7. stageContext->SetConfiguration(GetConfiguration());

8. auto abilityStage = AbilityRuntime::AbilityStage::Create(runtime\_, \*moduleInfo);

9. abilityStage->Init(stageContext);

10.  Want want;

11.  abilityStage->OnCreate(want);

12.  abilityStages\_[hapModuleInfo.moduleName] = abilityStage;

13.  return true;

14. }

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foundation\ability\ability_runtime\frameworks\native\appkit\ability_runtime\app\ability_stage.cpp

1. std::shared_ptr<AbilityStage> AbilityStage::Create(

2. const std::unique\_ptr<Runtime>& runtime, const AppExecFwk::HapModuleInfo& hapModuleInfo)

3. {

4. ......

5. switch (runtime->GetLanguage()) {

6.     case Runtime::Language::JS:

7.         return JsAbilityStage::Create(runtime, hapModuleInfo);

8.     default:

9.         return std::make\_shared<AbilityStage>();

10.  }

11. }
13. void AbilityStage::AddAbility(const sptr<IRemoteObject> &token,

14.  const std::shared\_ptr<AppExecFwk::AbilityLocalRecord> &abilityRecord)

15. {

16.  ......

17.  abilityRecords\_[token] = abilityRecord;

18. }

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foundation\ability\ability_runtime\frameworks\native\appkit\ability_runtime\app\ability_stage.cpp

1. td::shared_ptr<AbilityStage> JsAbilityStage::Create(){

2. auto& jsRuntime = static\_cast<JsRuntime&>(\*runtime);

3. std::string srcPath(hapModuleInfo.name);

4. std::string moduleName(hapModuleInfo.moduleName);

5. moduleName.append("::").append("AbilityStage");

6. ......

7. //srcPath.append("/assets/js/");

8. //srcPath.append("AbilityStage.abc");

9. srcPath.append(hapModuleInfo.srcPath);

10.  srcPath.append("/AbilityStage.abc");

11.  auto moduleObj = jsRuntime.LoadModule(moduleName, srcPath, hapModuleInfo.hapPath,

12.      hapModuleInfo.compileMode == AppExecFwk::CompileMode::ES\_MODULE, commonChunkFlag);

13.  return std::make\_shared<JsAbilityStage>(jsRuntime, std::move(moduleObj));

14. }
16. void JsAbilityStage::Init(const std::shared_ptr<Context> &context)
17. {

18.  AbilityStage::Init(context);

19. }
21. void JsAbilityStage::OnCreate(const AAFwk::Want &want) const
22. {

23.  AbilityStage::OnCreate(want);

24.  ......

25.  auto& nativeEngine = jsRuntime\_.GetNativeEngine();

26.  NativeValue\* value = jsAbilityStageObj\_->Get();

27.  nativeEngine.CallFunction(value, methodOnCreate, nullptr, 0);

28. }
29. //AbilityStage
30. void AbilityStage::Init(const std::shared_ptr<Context>& context){

31.  context\_ = context;

32. }
33. void AbilityStage::OnCreate(const AAFwk::Want &want) cons{

34.  HILOG\_DEBUG("AbilityStage OnCreate come.");

35. }

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foundation\ability\ability_runtime\frameworks\native\ability\native\ability_thread.cpp

至此，关于应用启动过程中application和ability初始化梳理清楚，OpenHarmony的源码关键Api和源码路径也都列举了出来，有疑问可自行获取源码加深理解。

四、总结-时序图 本文基于以上源码分析进行了总结，绘制了时序图，如下图所示。