Android应用程序安装过程源代码分析.docx

Android系统在启动的过程中，会启动一个应用程序管理服务PackageManagerService，这个服务负责扫描系统中特定的目录，找到里面的应用程序文件，即以Apk为后缀的文件，然后对这些文件进解析，得到应用程序的相关信息，完成应用源代码位于frameworks/base/cmds/system_server/library/：
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1・extern"C"status_tsystem_init()
{
LOGI("Enteredsystem_init()")；
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5・sp<ProcessState>proc(ProcessState::self());
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7・sp<IServiceManager>sm=defaultServiceManager();
LOGI("ServiceManager:%p\n",());
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sp<GrimReaper>grim=newGrimReaper();
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sm->asBinder()->linkToDeath(grim,grim・get(),0);
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charpropBuf[PROPERTY_VALUE_MAX];
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property_get("",propBuf,"1");
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if(strcmp(propBuf,"1")==0){
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//StarttheSurfaceFlinger
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SurfaceFlinger::instantiate();
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}
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//Startthesensorservice
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SensorService::instantiate();
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//Onthesimulator,audioflingeretaldon'tgetstartedthe
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//samewayasonthedevice,andweneedtostartthemhere
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if(!proc->supportsProcesses()){
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//StarttheAudioFlinger
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AudioFlinger::instantiate();
//Startthemediaplaybackservice
MediaPlayerService::instantiate();
//Startthecameraservice
CameraService::instantiate();
//Starttheaudiopolicyservice
AudioPolicyService::instantiate();
}
//
//ofnastinessbecausetheAndroidruntimeinitializationrequires
//someofthecoresystemservicestoalreadybestarted.
//AllotherserversshouldjuststarttheAndroidruntimeat
//thebeginningoftheirprocesses'smain(),beforecalling
//theinitfunction.
LOGI("Systemserver:startingAndroidruntime・\n");
AndroidRuntime*runtime=AndroidRuntime::getRuntime();
LOGI("Systemserver:startingAndroidservices.\n");
runtime->callStatic("com/android/server/SystemServer","init2");
//Ifrunninginourownprocess,justgointothethread
//,calltheinitializationfinis