Android PMS APP安装流程

仓库网址：http://androidxref.com/9.0.0_r3/xref/frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

一、PMS安装APP流程图

二、文件复制

PMS处理安装HandlerParams安装参数流程图

PackageManagerService.java#installStage方法介绍

1、创建了一个InstallParams对象
2、创建并发送了一个INIT_COPY的Message消息。
3、InstallParams继承自HandlerParams，用来记录安装应用的参数。
InstallParams中有一个成员变量mArgs，是一个抽象类型InstallArgs，主要是用来执行APK的复制，真正的实现类包括：
FileInstallArgs：用来完成非ASEC应用的安装，ASEC全称是Android Secure External Cache
MoveInstallArgs：用来完成已安装应用的移动安装

void installStage(String packageName, File stagedDir, String stagedCid,
           IPackageInstallObserver2 observer, PackageInstaller.SessionParams sessionParams,
           String installerPackageName, int installerUid, UserHandle user,
           Certificate[][] certificates) {
   
       ...
       final Message msg = mHandler.obtainMessage(INIT_COPY);
       final int installReason = fixUpInstallReason(installerPackageName, installerUid,
               sessionParams.installReason);
       final InstallParams params = new InstallParams(origin, null, observer,
               sessionParams.installFlags, installerPackageName, sessionParams.volumeUuid,
               verificationInfo, user, sessionParams.abiOverride,
               sessionParams.grantedRuntimePermissions, certificates, installReason);
       params.setTraceMethod("installStage").setTraceCookie(System.identityHashCode(params));
       msg.obj = params;
       ...
       //发送信息拷贝INIT_COPY 信息
       mHandler.sendMessage(msg);
   }

PackageManagerService.java#PackageHandler

connectToService(): 用于检查和复制可移动文件的服务
发送MCS_BOUND信息，触发处理第一个安装请求

       void doHandleMessage(Message msg) {
   
           switch (msg.what) {
   
               case INIT_COPY: {
   
                   HandlerParams params = (HandlerParams) msg.obj;
                   int idx = mPendingInstalls.size();
                   if (DEBUG_INSTALL) Slog.i(TAG, "init_copy idx=" + idx + ": " + params);
                   //mBound用于标识是否绑定了服务，默认值为false
                   if (!mBound) {
    
                       Trace.asyncTraceBegin(TRACE_TAG_PACKAGE_MANAGER, "bindingMCS",
                               System.identityHashCode(mHandler));
                      //connectToService里面的DefaultContainerService是用于检查和复制可移动文件的服务
                       if (!connectToService()) {
     
                           Slog.e(TAG, "Failed to bind to media container service");
                           params.serviceError();
                           Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, "bindingMCS",
                                   System.identityHashCode(mHandler));
                           if (params.traceMethod != null) {
   
                               Trace