PackageManagerService创建过程简略

本文深入解析Android系统的启动过程,从SystemServer.init1方法入手,详细介绍了AudioFlinger、MediaPlayerService和CameraService等服务的启动机制,以及如何通过AndroidRuntime调用System.init2。进一步讲解了ServerThread的运行机制,它如何创建PackageManagerService,并将其注册到ServiceManager中。最后,分析了PackageManagerService如何扫描AndroidManifest.xml文件,解析其中的activity和服务信息。

1.SystemServer.init1,这是一个jni方法,里面启动了AudioFlinger,MediaPlayerService,CameraService等服务,最后调用到了AndroidRuntime

2.AndroidRuntime.callStatic,,c++调用到了System.init2

3.启动了ServerThread,ServerThread的run方法创建了PackageMangerService,

4.PackageManagerService的构造方法中,将自己添加到了ServiceManager中。

5.PackageManagerService.scanPackageLi 解析 AndroidMainfest.xml中的 activity,service等信息。

### Package Manager Service (PMS) in Android System The Package Manager Service (PMS), an essential component of the Android operating system, manages application packages on devices. PMS handles installation, updates, and removals while ensuring security through mechanisms like SELinux policies[^1]. The service operates within defined domains and types specified by the core Android SELinux policy configuration which is common across all devices but can have device-specific extensions[^2]. #### Issues with PackageManagerService Common issues associated with PMS include: - **Installation Failures**: Problems during app installations may arise due to insufficient storage space or conflicts between existing applications. - **Security Violations**: Security violations might occur when there are misconfigurations in SELinux policies that govern how different parts of the system interact with each other. - **Performance Bottlenecks**: Performance bottlenecks could happen because of inefficient handling of large numbers of installed apps leading to slow response times from the package manager itself. ```java // Example code snippet showing part of PackageManagerService initialization process public class PackageManagerService extends IPackageManager.Stub { private final Context mContext; public void init() throws RemoteException { // Initialization logic here... enforceCallingOrSelfPermission(Manifest.permission.INTERACT_ACROSS_USERS_FULL); mInstaller = Installer.getInstance(); readLPw(null); // Load current state // More initialization steps... } } ``` #### Solutions for Common Issues To address these challenges effectively: - For _installation failures_, developers must ensure adequate checks before initiating any operation involving file systems operations such as installing new APK files. This includes verifying available disk space and checking compatibility among components involved in the transaction. - Regarding _security concerns_, maintaining up-to-date versions of both platform-level configurations and individual app permissions settings helps mitigate risks posed by outdated software stacks. Additionally, customizing SELinux rules according to specific use cases ensures tighter control over what actions various processes can perform without compromising overall stability. - To tackle _performance-related problems_, optimizing internal algorithms used inside PMS along with leveraging multi-threading techniques where appropriate will contribute positively towards enhancing responsiveness even under heavy loads. --related questions-- 1. How does one customize SELinux policies specifically tailored for managing third-party applications? 2. What measures exist within Android's architecture to prevent unauthorized access attempts targeting sensitive areas managed by PMS? 3. Can you provide examples illustrating best practices when implementing performance optimizations within critical sections of PMS? 4. In scenarios requiring frequent interaction between multiple users sharing a single device instance, how would modifications look like concerning user isolation features provided by PMS?
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值