当前位置：首页 > article >正文

Android 安装应用-提交阶段之后剩下的操作

article 2024/10/1 23:09:18

它的实现代码在executePostCommitSteps(commitRequest)中，看一下它的代码：

    /**
     * On successful install, executes remaining steps after commit completes and the package lock
     * is released. These are typically more expensive or require calls to installd, which often
     * locks on {@link #mLock}.
     */
    private void executePostCommitSteps(CommitRequest commitRequest) {
        final ArraySet<IncrementalStorage> incrementalStorages = new ArraySet<>();
        for (ReconciledPackage reconciledPkg : commitRequest.reconciledPackages.values()) {
            final boolean instantApp = ((reconciledPkg.scanResult.request.scanFlags
                            & PackageManagerService.SCAN_AS_INSTANT_APP) != 0);
            final AndroidPackage pkg = reconciledPkg.pkgSetting.pkg;
            final String packageName = pkg.getPackageName();
            final String codePath = pkg.getPath();
            final boolean onIncremental = mIncrementalManager != null
                    && isIncrementalPath(codePath);
            if (onIncremental) {
                IncrementalStorage storage = mIncrementalManager.openStorage(codePath);
                if (storage == null) {
                    throw new IllegalArgumentException(
                            "Install: null storage for incremental package " + packageName);
                }
                incrementalStorages.add(storage);
            }
            prepareAppDataAfterInstallLIF(pkg);
            if (reconciledPkg.prepareResult.clearCodeCache) {
                clearAppDataLIF(pkg, UserHandle.USER_ALL, FLAG_STORAGE_DE | FLAG_STORAGE_CE
                        | FLAG_STORAGE_EXTERNAL | Installer.FLAG_CLEAR_CODE_CACHE_ONLY);
            }
            if (reconciledPkg.prepareResult.replace) {
                mDexManager.notifyPackageUpdated(pkg.getPackageName(),
                        pkg.getBaseApkPath(), pkg.getSplitCodePaths());
            }

            // Prepare the application profiles for the new code paths.
            // This needs to be done before invoking dexopt so that any install-time profile
            // can be used for optimizations.
            mArtManagerService.prepareAppProfiles(
                    pkg,
                    resolveUserIds(reconciledPkg.installArgs.user.getIdentifier()),
                    /* updateReferenceProfileContent= */ true);

            // Compute the compilation reason from the installation scenario.
            final int compilationReason = mDexManager.getCompilationReasonForInstallScenario(
                    reconciledPkg.installArgs.mInstallScenario);

            // Construct the DexoptOptions early to see if we should skip running dexopt.
            //
            // Do not run PackageDexOptimizer through the local performDexOpt
            // method because `pkg` may not be in `mPackages` yet.
            //
            // Also, don't fail application installs if the dexopt step fails.
            final boolean isBackupOrRestore =
                    reconciledPkg.installArgs.installReason == INSTALL_REASON_DEVICE_RESTORE
                    || reconciledPkg.installArgs.installReason == INSTALL_REASON_DEVICE_SETUP;

            final int dexoptFlags = DexoptOptions.DEXOPT_BOOT_COMPLETE
                    | DexoptOptions.DEXOPT_INSTALL_WITH_DEX_METADATA_FILE
                    | (isBackupOrRestore ? DexoptOptions.DEXOPT_FOR_RESTORE : 0);
            DexoptOptions dexoptOptions =
                    new DexoptOptions(packageName, compilationReason, dexoptFlags);

            // Check whether we need to dexopt the app.
            //
            // NOTE: it is IMPORTANT to call dexopt:
            //   - after doRename which will sync the package data from AndroidPackage and
            //     its corresponding ApplicationInfo.
            //   - after installNewPackageLIF or replacePackageLIF which will update result with the
            //     uid of the application (pkg.applicationInfo.uid).
            //     This update happens in place!
            //
            // We only need to dexopt if the package meets ALL of the following conditions:
            //   1) it is not an instant app or if it is then dexopt is enabled via gservices.
            //   2) it is not debuggable.
            //   3) it is not on Incremental File System.
            //
            // Note that we do not dexopt instant apps by default. dexopt can take some time to
            // complete, so we skip this step during installation. Instead, we'll take extra time
            // the first time the instant app starts. It's preferred to do it this way to provide
            // continuous progress to the useur instead of mysteriously blocking somewhere in the
            // middle of running an instant app. The default behaviour can be overridden
            // via gservices.
            //
            // Furthermore, dexopt may be skipped, depending on the install scenario and current
            // state of the device.
            //
            // TODO(b/174695087): instantApp and onIncremental should be removed and their install
            //       path moved to SCENARIO_FAST.
            final boolean performDexopt =
                    (!instantApp || Global.getInt(mContext.getContentResolver(),
                    Global.INSTANT_APP_DEXOPT_ENABLED, 0) != 0)
                    && !pkg.isDebuggable()
                    && (!onIncremental)
                    && dexoptOptions.isCompilationEnabled();

            if (performDexopt) {
                // Compile the layout resources.
                if (SystemProperties.getBoolean(PRECOMPILE_LAYOUTS, false)) {
                    Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "compileLayouts");
                    mViewCompiler.compileLayouts(pkg);
                    Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
                }

                Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "dexopt");
                ScanResult result = reconciledPkg.scanResult;

                // This mirrors logic from commitReconciledScanResultLocked, where the library files
                // needed for dexopt are assigned.
                // TODO: Fix this to have 1 mutable PackageSetting for scan/install. If the previous
                //  setting needs to be passed to have a comparison, hide it behind an immutable
                //  interface. There's no good reason to have 3 different ways to access the real
                //  PackageSetting object, only one of which is actually correct.
                PackageSetting realPkgSetting = result.existingSettingCopied
                        ? result.request.pkgSetting : result.pkgSetting;
                if (realPkgSetting == null) {
                    realPkgSetting = reconciledPkg.pkgSetting;
                }

                // Unfortunately, the updated system app flag is only tracked on this PackageSetting
                boolean isUpdatedSystemApp = reconciledPkg.pkgSetting.getPkgState()
                        .isUpdatedSystemApp();

                realPkgSetting.getPkgState().setUpdatedSystemApp(isUpdatedSystemApp);

                mPackageDexOptimizer.performDexOpt(pkg, realPkgSetting,
                        null /* instructionSets */,
                        getOrCreateCompilerPackageStats(pkg),
                        mDexManager.getPackageUseInfoOrDefault(packageName),
                        dexoptOptions);
                Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
            }

            // Notify BackgroundDexOptService that the package has been changed.
            // If this is an update of a package which used to fail to compile,
            // BackgroundDexOptService will remove it from its denylist.
            // TODO: Layering violation
            BackgroundDexOptService.notifyPackageChanged(packageName);

            notifyPackageChangeObserversOnUpdate(reconciledPkg);
        }
        waitForNativeBinariesExtraction(incrementalStorages);
    }

首先对ReconciledPackage对象循环，得到AndroidPackage对象pkg，包名、文件路径。
接着调用prepareAppDataAfterInstallLIF(pkg)，它主要用来创建应用需要使用的文件或文件夹。应用需要使用的文件或文件夹和参数uuid（存储位置相关）、userId和包名相关。如果uuid为null，userId为0，则文件夹为"/data/data/“（版本遗留） + 包名或 “/data/user/0/” + 包名，及其目录下面的"cache"和"code_cache"目录；”/data/user_de/0/" + 包名，及其目录下面的"cache"和"code_cache"目录，如果"dalvik.vm.usejitprofiles"属性值为true的情况下（和JIT编译有关），还会创建 “/data/misc/profiles/cur/0” + 包名目录和 “/data/misc/profiles/ref/” + 包名目录。
如果reconciledPkg.prepareResult.clearCodeCache为true，代表需要清除代码缓存，所以调用带有Installer.FLAG_CLEAR_CODE_CACHE_ONLY标识的clearAppDataLIF()方法。带这个标识的方法，就是清除这个应用数据文件夹下面的"code_cache"目录及其中文件。
reconciledPkg.prepareResult.replace为true，代表是替换升级。mDexManager.notifyPackageUpdated()通知mDexManager应用包发生了更新，它会更新其中应用的安装位置，去除使用该应用的其他APP。
mArtManagerService.prepareAppProfiles()是和使用profile优化应用有关，它的参数updateReferenceProfileContent为true，代表它需要将dex元数据文件（“.dm"结尾文件）更新到它自己引用的profile内容中，这块需要使用Profman程序。主APK文件相关的profile文件名为"primary.prof”。
接着往下就是和执行Dex优化相关的，就是将相关的Dex指令转化成对应的机器指令。
在属性变量PRECOMPILE_LAYOUTS值为true，调用mViewCompiler.compileLayouts(pkg)。它是用来将布局资源文件转化成dex文件。生成的dex文件为包的数据目录 + “/code_cache/compiled_view.dex”。包的数据目录和uuid、userId、ce标识相关，如果uuid为null，userId为0，ce标识存在，则生成的文件位置为"/data/user/0/" + packageName + “/code_cache/compiled_view.dex”。它是对应用的一种优化。
可以看到执行dexopt需要满足几个条件：不是instantApp，除非设置了Global.INSTANT_APP_DEXOPT_ENABLED对应的值不为0；包不是debuggable；不是在增量文件系统上。
接着，BackgroundDexOptService.notifyPackageChanged(packageName) 是从BackgroundDexOptService中将应用包从之前编译失败的名单中去除。
notifyPackageChangeObserversOnUpdate(reconciledPkg) 是通知注册在PackageManagerService对象成员mPackageChangeObservers集合中的每一个元素，调用它的onPackageChanged(event)方法。
最后waitForNativeBinariesExtraction(incrementalStorages) 是处理增量更新的。