13. Gradle编译其他应用代码流程（二 )

2024-11-05 技术教程

接着上一篇博客开始讲：

5. Gradle编译其他应用程序流程(一)

一. BuildActionsFactory.runBuildInProcess

这个方法就是很绕的地方了！看了半天才大概明白。

首先runBuildInProcess这个方法分成两个部分

1. 初始化

2. 执行

首先来看初始化，也就是：

ServiceRegistryglobalServices=ServiceRegistryBuilder.builder().displayName("Globalservices").parent(loggingServices).parent(NativeServices.getInstance()).provider(newGlobalScopeServices(startParameter.isContinuous())).build();

直接看build():

publicServiceRegistrybuild(){DefaultServiceRegistryregistry=newDefaultServiceRegistry(displayName,parents);for(Objectprovider:providers){registry.addProvider(provider);}returnregistry;}

实例化的是DefaultServiceRegistry对象，那来看看DefaultServiceRegistry的Javadoc，看看怎么描述的。

org.gradle.internal.service.DefaultServiceRegistryAhierarchicalServiceRegistryimplementation.Subclassescanregisterservicesby:Callingadd(Class,Object)toregisteraserviceinstance.CallingaddProvider(Object)toregisteraserviceproviderbean.Aproviderbeanmayhavefactory,decoratorandconfigurationmethodsasdescribedbelow.Addingafactorymethod.Afactorymethodshouldhaveanamethatstartswith'create',andhaveanon-voidreturntype.Forexample,protectedSomeServicecreateSomeService(){....}.Parametersareinjectedusingservicesfromthisregistryoritsparents.Notethatfactorymethodswithasingleparameterandanreturntypeequaltothatparametertypeareinterpretedasdecoratormethods.Addingadecoratormethod.Adecoratormethodshouldhaveanamethatstartswith'decorate',takeasingleparameter,andahavereturntypeequaltotheparametertype.Beforeinvokingthemethod,theparameterislocatedintheparentserviceregistryandthenpassedtothemethod.Addingaconfiguremethod.Aconfiguremethodshouldbecalled'configure',takeaServiceRegistrationparameter,andahaveavoidreturntype.Additionalparametersareinjectedusingservicesfromthisregistryoritsparents.Serviceinstancesarecreatedondemand.getFactory(Class)looksforaserviceinstancewhichimplementsFactory<T>whereTistheexpectedtype.Serviceinstancesandfactoriesareclosedwhentheregistrythatcreatedthemisclosedusingclose().Ifaserviceinstanceorfactoryimplementsjava.io.Closeableororg.gradle.internal.concurrent.Stoppablethentheappropriateclose()orstop()methodiscalled.Instancesareclosedinreversedependencyorder.Serviceregistriesarearrangedinahierarchy.Ifaserviceofagiventypecannotbelocated,theregistryusesitsparentregistry,ifany,tolocatetheservice.主要意思就是DefaultServiceRegistry可以通过add(xxx)方法接受服务对象，通过addProvider(xxx)方法接受serviceproviderbean对象。而serviceproviderbean可以有3种类型的方法factory方法'create'开头，不是void的返回值，等等decorator方法'decorator'开头，等等configure方法'configure'方法，有个ServiceRegistration参数，void返回类型，等等。

那我们回过头来看初始化方法，里面传入了GlobalScopeServices作为provider，所以看下GlobalScopeServices。

二. GlobalScopeServices

publicclassGlobalScopeServices{...voidconfigure(ServiceRegistrationregistration,ClassLoaderRegistryclassLoaderRegistry){System.out.println("GlobalScopeServicesconfigureregistration:"+registration+"classLoaderRegistry:"+classLoaderRegistry);finalList<PluginServiceRegistry>pluginServiceFactories=newDefaultServiceLocator(classLoaderRegistry.getRuntimeClassLoader(),classLoaderRegistry.getPluginsClassLoader()).getAll(PluginServiceRegistry.class);for(PluginServiceRegistrypluginServiceRegistry:pluginServiceFactories){registration.add(PluginServiceRegistry.class,pluginServiceRegistry);pluginServiceRegistry.registerGlobalServices(registration);}}...ClassLoaderRegistrycreateClassLoaderRegistry(ClassPathRegistryclassPathRegistry,HashingClassLoaderFactoryclassLoaderFactory){if(GradleRuntimeShadedJarDetector.isLoadedFrom(getClass())){returnnewFlatClassLoaderRegistry(getClass().getClassLoader());}System.out.println("createClassLoaderRegistry");returnnewDefaultClassLoaderRegistry(classPathRegistry,classLoaderFactory);}...}

首先看configure方法

pluginServiceRegistry.registerGlobalServices(registration);

这行代码registerGlobalServices其实调用的是LauncherServices.registerGlobalServices

也就是：

publicclassLauncherServicesimplementsPluginServiceRegistry{publicvoidregisterGlobalServices(ServiceRegistrationregistration){registration.addProvider(newToolingGlobalScopeServices());}staticclassToolingGlobalScopeServices{BuildExecutercreateBuildExecuter(GradleLauncherFactorygradleLauncherFactory,ServiceRegistryglobalServices,ListenerManagerlistenerManager,FileWatcherFactoryfileWatcherFactory,ExecutorFactoryexecutorFactory,StyledTextOutputFactorystyledTextOutputFactory){List<BuildActionRunner>buildActionRunners=globalServices.getAll(BuildActionRunner.class);BuildActionExecuter<BuildActionParameters>delegate=newInProcessBuildActionExecuter(gradleLauncherFactory,newChainingBuildActionRunner(buildActionRunners));returnnewContinuousBuildActionExecuter(delegate,fileWatcherFactory,listenerManager,styledTextOutputFactory,executorFactory);}ExecuteBuildActionRunnercreateExecuteBuildActionRunner(){returnnewExecuteBuildActionRunner();}ClassLoaderCachecreateClassLoaderCache(){returnnewClassLoaderCache();}}}

registerGlobalServices的时候，实例化并添加了ToolingGlobalScopeServices对象。

最主要的是实例化了一个InProcessBuildActionExecuter对象，当然这里又不能免俗的使用了装饰者模式(ContinuousBuildActionExecuter包含了InProcessBuildActionExecuter，其实还是调用InProcessBuildActionExecuter.execute)

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这个中间的逻辑非常绕，就是怎么回调到provider的factory和config方法？

有兴趣的同学可以自己去看。我贴一段中间回调createXXX的代码调用堆栈(也就是factory方法的调用)

java.lang.Exception:SandyDefaultModuleinitatorg.gradle.api.internal.classpath.DefaultModuleRegistry$DefaultModule.<init>(DefaultModuleRegistry.java:256)atorg.gradle.api.internal.classpath.DefaultModuleRegistry.module(DefaultModuleRegistry.java:121)atorg.gradle.api.internal.classpath.DefaultModuleRegistry.loadModule(DefaultModuleRegistry.java:89)atorg.gradle.api.internal.classpath.DefaultModuleRegistry.getModule(DefaultModuleRegistry.java:77)atorg.gradle.api.internal.DynamicModulesClassPathProvider.findClassPath(DynamicModulesClassPathProvider.java:38)atorg.gradle.api.internal.DefaultClassPathRegistry.getClassPath(DefaultClassPathRegistry.java:34)atorg.gradle.initialization.DefaultClassLoaderRegistry.<init>(DefaultClassLoaderRegistry.java:32)atorg.gradle.internal.service.scopes.GlobalScopeServices.createClassLoaderRegistry(GlobalScopeServices.java:212)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)atjava.lang.reflect.Method.invoke(Method.java:483)atorg.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)atorg.gradle.internal.service.DefaultServiceRegistry.invoke(DefaultServiceRegistry.java:468)atorg.gradle.internal.service.DefaultServiceRegistry.access$1200(DefaultServiceRegistry.java:84)atorg.gradle.internal.service.DefaultServiceRegistry$FactoryMethodService.invokeMethod(DefaultServiceRegistry.java:803)atorg.gradle.internal.service.DefaultServiceRegistry$FactoryService.create(DefaultServiceRegistry.java:758)atorg.gradle.internal.service.DefaultServiceRegistry$ManagedObjectProvider.getInstance(DefaultServiceRegistry.java:595)atorg.gradle.internal.service.DefaultServiceRegistry$SingletonService.get(DefaultServiceRegistry.java:640)atorg.gradle.internal.service.DefaultServiceRegistry.applyConfigureMethod(DefaultServiceRegistry.java:257)atorg.gradle.internal.service.DefaultServiceRegistry.findProviderMethods(DefaultServiceRegistry.java:216)atorg.gradle.internal.service.DefaultServiceRegistry.addProvider(DefaultServiceRegistry.java:358)atorg.gradle.internal.service.ServiceRegistryBuilder.build(ServiceRegistryBuilder.java:52)atorg.gradle.launcher.cli.BuildActionsFactory.runBuildInProcess(BuildActionsFactory.java:135)atorg.gradle.launcher.cli.BuildActionsFactory.createAction(BuildActionsFactory.java:91)atorg.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.createAction(CommandLineActionFactory.java:255)atorg.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:240)atorg.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.execute(CommandLineActionFactory.java:217)atorg.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:33)atorg.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRuntimeValidationAction.java:24)atorg.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:33)atorg.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionReportingAction.java:22)atorg.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:210)atorg.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(CommandLineActionFactory.java:174)atorg.gradle.launcher.Main.doAction(Main.java:33)atorg.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)atsun.reflect.NativeMethodAccessorImpl.invoke0(NativeMethod)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)atjava.lang.reflect.Method.invoke(Method.java:483)atorg.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBootstrap.java:60)atorg.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.java:37)atorg.gradle.launcher.GradleMain.main(GradleMain.java:24)

三. 执行

privateRunnablerunBuildInProcess(StartParameterstartParameter,DaemonParametersdaemonParameters,ServiceRegistryloggingServices){ServiceRegistryglobalServices=ServiceRegistryBuilder.builder().displayName("Globalservices").parent(loggingServices).parent(NativeServices.getInstance()).provider(newGlobalScopeServices(startParameter.isContinuous())).build();returnrunBuildAndCloseServices(startParameter,daemonParameters,globalServices.get(BuildExecuter.class),globalServices);}privateRunnablerunBuildAndCloseServices(StartParameterstartParameter,DaemonParametersdaemonParameters,BuildActionExecuter<BuildActionParameters>executer,ServiceRegistrysharedServices,Object...stopBeforeSharedServices){BuildActionParametersparameters=createBuildActionParamters(startParameter,daemonParameters);Stoppablestoppable=newCompositeStoppable().add(stopBeforeSharedServices).add(sharedServices);returnnewRunBuildAction(executer,startParameter,clientMetaData(),getBuildStartTime(),parameters,sharedServices,stoppable);}publicclassRunBuildActionimplementsRunnable{ServiceRegistryglobalServices=ServiceRegistryBuilder.builder().displayName("Globalservices").parent(loggingServices).parent(NativeServices.getInstance()).provider(newGlobalScopeServices(startParameter.isContinuous())).build();publicvoidrun(){try{System.out.println("RunBuildActionexecuter:"+executer+"startParameter:"+startParameter+"buildActionParameters:"+buildActionParameters);executer.execute(newExecuteBuildAction(startParameter),newDefaultBuildRequestContext(newDefaultBuildRequestMetaData(clientMetaData,startTime),newDefaultBuildCancellationToken(),newNoOpBuildEventConsumer()),buildActionParameters,sharedServices);}finally{if(stoppable!=null){stoppable.stop();}}}}

在RunBuildAction里面执行的还是executer.execute，也就是第三个参数globalServices.get(BuildExecuter.class)

globalServices是build出来的DefaultServiceRegistry对象

其实就是GlobalScopeServices.configure方法里面的ServiceRegistration对象。

voidconfigure(ServiceRegistrationregistration,ClassLoaderRegistryclassLoaderRegistry){System.out.println("GlobalScopeServicesconfigureregistration:"+registration+"classLoaderRegistry:"+classLoaderRegistry);finalList<PluginServiceRegistry>pluginServiceFactories=newDefaultServiceLocator(classLoaderRegistry.getRuntimeClassLoader(),classLoaderRegistry.getPluginsClassLoader()).getAll(PluginServiceRegistry.class);for(PluginServiceRegistrypluginServiceRegistry:pluginServiceFactories){registration.add(PluginServiceRegistry.class,pluginServiceRegistry);pluginServiceRegistry.registerGlobalServices(registration);}}

打印日志：

GlobalScopeServicesconfigureregistration:org.gradle.internal.service.DefaultServiceRegistry$1@56620197classLoaderRegistry:org.gradle.initialization.DefaultClassLoaderRegistry@393671df

接下来又继续在configure然后调用

pluginServiceRegistry.registerGlobalServices(registration);

根据前面说明的分析，这个registerGlobalServices方法就是调用LauncherServices.registerGlobalServices(registration)，参数是DefaultServiceRegistry registration

所以也就是给DefaultServiceRegistry registration add了一个ToolingGlobalScopeServices对象。

这样就关联起来了，也就是说RunBuildAction.run方法里面执行的executer.execute走的就是ContinuousBuildActionExecuter.execute，然后通过装饰者模式，最后走的是InProcessBuildActionExecuter.execute方法。

很绕！！！

下面来看InProcessBuildActionExecuter.execute方法。

四. InProcessBuildActionExecuter

@OverridepublicGradleLaunchernewInstance(StartParameterstartParameter,BuildRequestContextrequestContext,ServiceRegistryparentRegistry){//Thisshouldonlybeusedfortop-levelbuildsif(tracker.getCurrentBuild()!=null){thrownewIllegalStateException("Cannothaveacurrentbuild");}BuildScopeServicesbuildScopeServices=createBuildScopeServices(parentRegistry);DefaultGradleLauncherlauncher=doNewInstance(startParameter,false,requestContext.getCancellationToken(),requestContext,requestContext.getEventConsumer(),buildScopeServices);DeploymentRegistrydeploymentRegistry=parentRegistry.get(DeploymentRegistry.class);deploymentRegistry.onNewBuild(launcher.getGradle());returnlauncher;}publicclassInProcessBuildActionExecuterimplementsBuildActionExecuter<BuildActionParameters>{privatefinalGradleLauncherFactorygradleLauncherFactory;privatefinalBuildActionRunnerbuildActionRunner;publicInProcessBuildActionExecuter(GradleLauncherFactorygradleLauncherFactory,BuildActionRunnerbuildActionRunner){this.gradleLauncherFactory=gradleLauncherFactory;this.buildActionRunner=buildActionRunner;}publicObjectexecute(BuildActionaction,BuildRequestContextbuildRequestContext,BuildActionParametersactionParameters,ServiceRegistrycontextServices){GradleLaunchergradleLauncher=gradleLauncherFactory.newInstance(action.getStartParameter(),buildRequestContext,contextServices);try{gradleLauncher.addStandardOutputListener(buildRequestContext.getOutputListener());gradleLauncher.addStandardErrorListener(buildRequestContext.getErrorListener());GradleBuildControllerbuildController=newGradleBuildController(gradleLauncher);buildActionRunner.run(action,buildController);System.out.println("SandybuildController.getResult():"+buildController.getResult());returnbuildController.getResult();}finally{gradleLauncher.stop();}}}

从代码来看newInstance返回的对象是DefaultGradleLauncher，那么接下来就真正走到开始编译的过程了，这个下篇再继续分析。

最后，附上一点DefaultGradleLauncher源代码：

publicclassDefaultGradleLauncherextendsGradleLauncher{privateenumStage{Load,Configure,Build}...@OverridepublicBuildResultrun(){returndoBuild(Stage.Build);}@OverridepublicBuildResultgetBuildAnalysis(){returndoBuild(Stage.Configure);}@OverridepublicBuildResultload()throwsReportedException{returndoBuild(Stage.Load);}privateBuildResultdoBuild(finalStageupTo){returnbuildOperationExecutor.run("Runbuild",newFactory<BuildResult>(){@OverridepublicBuildResultcreate(){...doBuildStages(upTo);...}});}privatevoiddoBuildStages(StageupTo){if(stage==Stage.Build){thrownewIllegalStateException("CannotbuildwithGradleLaunchermultipletimes");}if(stage==null){//EvaluateinitscriptsinitScriptHandler.executeScripts(gradle);//Build`buildSrc`,loadsettings.gradle,andconstructcomposite(ifappropriate)settings=settingsLoader.findAndLoadSettings(gradle);stage=Stage.Load;}if(upTo==Stage.Load){return;}if(stage==Stage.Load){//ConfigurebuildbuildOperationExecutor.run("Configurebuild",newRunnable(){@Overridepublicvoidrun(){buildConfigurer.configure(gradle);if(!gradle.getStartParameter().isConfigureOnDemand()){buildListener.projectsEvaluated(gradle);}modelConfigurationListener.onConfigure(gradle);}});stage=Stage.Configure;}if(upTo==Stage.Configure){return;}//Afterthispoint,theGradleLaunchercannotbereusedstage=Stage.Build;//PopulatetaskgraphbuildOperationExecutor.run("Calculatetaskgraph",newRunnable(){@Overridepublicvoidrun(){buildConfigurationActionExecuter.select(gradle);if(gradle.getStartParameter().isConfigureOnDemand()){buildListener.projectsEvaluated(gradle);}}});//ExecutebuildbuildOperationExecutor.run("Runtasks",newRunnable(){@Overridepublicvoidrun(){buildExecuter.execute(gradle);}});}...}