略久没有写自己写博客了，现在要重新抓起来。最近对Android Framework的内容感兴趣，所以接下来可能会阅读下Framework部分的代码，Android系统部分的代码有机会也会分析分析。今天就先来看看PackageManager和PackageManagerService好了。
一. 简述
PackageManagerService（PKMS）和PackageManger(PKM)的关系如下图，PKMS是Android系统中核心服务之一，负责package的相关工作，例如安装，卸载以及查询等。
根据博主之前关于Binder部分的博客和上面的图片可以看出，PackageManger继承于IPackageManager.Stub.Porxy，而PackageManagerService则继承于IPackageManager.Stub。相关的父类则是有IPackageManager.aidl编译生成。下面来看PackageManagerService的启动过程。
二. Android启动过程中PKMS所完成的动作
在之前讲述Android启动流程时有提到，在启动Android过程中会先启动一些重要的service，这里面就包括PKMS，下面我们来看看PKMS启动的代码。
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private void startBootstrapServices() { ............... // 启动Installer traceBeginAndSlog("StartInstaller"); Installer installer = mSystemServiceManager.startService(Installer.class); traceEnd(); ............ // 下面的代码判断是否只启动系统的核心进程，只在加密data的时候才会将mOnlyCore设置为true String cryptState = SystemProperties.get("vold.decrypt"); if (ENCRYPTING_STATE.equals(cryptState)) { Slog.w(TAG, "Detected encryption in progress - only parsing core apps"); mOnlyCore = true; } else if (ENCRYPTED_STATE.equals(cryptState)) { Slog.w(TAG, "Device encrypted - only parsing core apps"); mOnlyCore = true; } .................... traceBeginAndSlog("StartPackageManagerService"); // 初始化PKMS mPackageManagerService = PackageManagerService.main(mSystemContext, installer, mFactoryTestMode != FactoryTest.FACTORY_TEST_OFF, mOnlyCore); // 判断PKMS是否是第一次启动 mFirstBoot = mPackageManagerService.isFirstBoot(); // 获取PackageManager mPackageManager = mSystemContext.getPackageManager(); traceEnd(); .............. } private void startOtherServices() { ............... // 如果是首次开机或者升级的话，判断是否需要对Packages的信息进行更新 if (!mOnlyCore) { traceBeginAndSlog("UpdatePackagesIfNeeded"); try { mPackageManagerService.updatePackagesIfNeeded(); } catch (Throwable e) { reportWtf("update packages", e); } traceEnd(); } // 执行类似磁盘STRIM的技术 traceBeginAndSlog("PerformFstrimIfNeeded"); try { mPackageManagerService.performFstrimIfNeeded(); } catch (Throwable e) { reportWtf("performing fstrim", e); } traceEnd(); ............. // 执行PKMS的systemReady，通知系统进入就绪状态 traceBeginAndSlog("MakePackageManagerServiceReady"); try { mPackageManagerService.systemReady(); } catch (Throwable e) { reportWtf("making Package Manager Service ready", e); } traceEnd(); .............. // Wait for all packages to be prepared // 等待所有的Packages准备就绪 mPackageManagerService.waitForAppDataPrepared(); } |
从上面的代码总结Android启动过程，PKMS所执行的主要操作如下：
- PackageManagerService.main
- mPackageManagerService.updatePackagesIfNeeded
- mPackageManagerService.performFstrimIfNeeded
- mPackageManagerService.systemReady
- mPackageManagerService.waitForAppDataPrepared
所以按照上面的执行过程一步一步看代码分析。
2.1 PackageManagerService.main
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public static PackageManagerService main(Context context, Installer installer, boolean factoryTest, boolean onlyCore) { // 检查一些系统属性，貌似和编译相关，这里暂时不分析 PackageManagerServiceCompilerMapping.checkProperties(); // 重点分析的对象，调用PackageManagerService的构造函数 PackageManagerService m = new PackageManagerService(context, installer, factoryTest, onlyCore); // enable系统用户的APP m.enableSystemUserPackages(); // 将PackageManagerService添加到ServiceManager中，service名为package ServiceManager.addService("package", m); final PackageManagerNative pmn = m.new PackageManagerNative(); // 添加package_native service到ServiceManager ServiceManager.addService("package_native", pmn); return m; } |
main方法的主要动作就是调用PackageManagerService的构造函数，进行初始化并将其添加到ServiceManager中
PackageManagerService构造函数
PackageManagerService的构造函数可以分成5个阶段进行分析，分阶段的过程主要是按照写EventLog的时间进行区分。PKMS的构造函数
- EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_START,SystemClock.uptimeMillis());
- EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SYSTEM_SCAN_START,startTime);
- EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_DATA_SCAN_START,SystemClock.uptimeMillis());
- EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SCAN_END,SystemClock.uptimeMillis());
- EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_READY,SystemClock.uptimeMillis());
2.1.1. BOOT_PROGRESS_PMS_START
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public PackageManagerService(Context context, Installer installer, boolean factoryTest, boolean onlyCore) { .............. EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_START, SystemClock.uptimeMillis()); if (mSdkVersion <= 0) { Slog.w(TAG, "**** ro.build.version.sdk not set!"); } mContext = context; mPermissionReviewRequired = context.getResources().getBoolean( R.bool.config_permissionReviewRequired); mFactoryTest = factoryTest; mOnlyCore = onlyCore; // 创建DisplayMetrics获取显示屏相关信息 mMetrics = new DisplayMetrics(); // 创建settings对象，下面解析该对象 mSettings = new Settings(mPackages); // 将一些shared uid添加到settings对象中 mSettings.addSharedUserLPw("android.uid.system", Process.SYSTEM_UID, ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED); mSettings.addSharedUserLPw("android.uid.phone", RADIO_UID, ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED); mSettings.addSharedUserLPw("android.uid.log", LOG_UID, ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED); mSettings.addSharedUserLPw("android.uid.nfc", NFC_UID, ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED); mSettings.addSharedUserLPw("android.uid.bluetooth", BLUETOOTH_UID, ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED); mSettings.addSharedUserLPw("android.uid.shell", SHELL_UID, ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED); ............... mInstaller = installer; // 初始化一些对象 mPackageDexOptimizer = new PackageDexOptimizer(installer, mInstallLock, context, "*dexopt*"); mDexManager = new DexManager(this, mPackageDexOptimizer, installer, mInstallLock); mMoveCallbacks = new MoveCallbacks(FgThread.get().getLooper()); mOnPermissionChangeListeners = new OnPermissionChangeListeners( FgThread.get().getLooper()); getDefaultDisplayMetrics(context, mMetrics); Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "get system config"); // 获取系统的配置信息，后面会解析 SystemConfig systemConfig = SystemConfig.getInstance(); mGlobalGids = systemConfig.getGlobalGids(); mSystemPermissions = systemConfig.getSystemPermissions(); mAvailableFeatures = systemConfig.getAvailableFeatures(); Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER); mProtectedPackages = new ProtectedPackages(mContext); synchronized (mInstallLock) { // writer synchronized (mPackages) { // 创建名为“PackageManager”的handler线程 mHandlerThread = new ServiceThread(TAG, Process.THREAD_PRIORITY_BACKGROUND, true /*allowIo*/); mHandlerThread.start(); mHandler = new PackageHandler(mHandlerThread.getLooper()); mProcessLoggingHandler = new ProcessLoggingHandler(); Watchdog.getInstance().addThread(mHandler, WATCHDOG_TIMEOUT); mDefaultPermissionPolicy = new DefaultPermissionGrantPolicy(this); mInstantAppRegistry = new InstantAppRegistry(this); // 创建/data下的各个目录 File dataDir = Environment.getDataDirectory(); mAppInstallDir = new File(dataDir, "app"); mAppLib32InstallDir = new File(dataDir, "app-lib"); mAsecInternalPath = new File(dataDir, "app-asec").getPath(); mDrmAppPrivateInstallDir = new File(dataDir, "app-private"); mRegionalizationAppInstallDir = new File(dataDir, "app-regional"); sUserManager = new UserManagerService(context, this, new UserDataPreparer(mInstaller, mInstallLock, mContext, mOnlyCore), mPackages); // 将系统配置的permission添加到settings中 ArrayMap<String, SystemConfig.PermissionEntry> permConfig = systemConfig.getPermissions(); for (int i=0; i < permConfig.size(); i++) { SystemConfig.PermissionEntry perm = permConfig.valueAt(i); BasePermission bp = mSettings.mPermissions.get(perm.name); if (bp == null) { bp = new BasePermission(perm.name, "android", BasePermission.TYPE_BUILTIN); mSettings.mPermissions.put(perm.name, bp); } if (perm.gids != null) { bp.setGids(perm.gids, perm.perUser); } } // 配置共享库 ArrayMap<String, String> libConfig = systemConfig.getSharedLibraries(); final int builtInLibCount = libConfig.size(); for (int i = 0; i < builtInLibCount; i++) { String name = libConfig.keyAt(i); String path = libConfig.valueAt(i); addSharedLibraryLPw(path, null, name, SharedLibraryInfo.VERSION_UNDEFINED, SharedLibraryInfo.TYPE_BUILTIN, PLATFORM_PACKAGE_NAME, 0); } // 读取SELinux所需的platform permission xml文件 mFoundPolicyFile = SELinuxMMAC.readInstallPolicy(); Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "read user settings"); mFirstBoot = !mSettings.readLPw(sUserManager.getUsers(false)); Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER); // 清理因系统升级而导致的孤立程序包 final int packageSettingCount = mSettings.mPackages.size(); for (int i = packageSettingCount - 1; i >= 0; i--) { PackageSetting ps = mSettings.mPackages.valueAt(i); if (!isExternal(ps) && (ps.codePath == null || !ps.codePath.exists()) && mSettings.getDisabledSystemPkgLPr(ps.name) != null) { mSettings.mPackages.removeAt(i); mSettings.enableSystemPackageLPw(ps.name); } } if (mFirstBoot) { requestCopyPreoptedFiles(); } String customResolverActivity = Resources.getSystem().getString( R.string.config_customResolverActivity); if (TextUtils.isEmpty(customResolverActivity)) { customResolverActivity = null; } else { mCustomResolverComponentName = ComponentName.unflattenFromString( customResolverActivity); } long startTime = SystemClock.uptimeMillis(); } |
上面的内容我们主要分析其中的两部分，一是创建配置settings的对象，二是创建配置systemConfig对象。
创建settings对象
接下来直接看settings对象创建的相关内容。
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Settings(Object lock) { this(Environment.getDataDirectory(), lock); } // dataDir为/data Settings(File dataDir, Object lock) { mLock = lock; mRuntimePermissionsPersistence = new RuntimePermissionPersistence(mLock); // 创建data/system目录 mSystemDir = new File(dataDir, "system"); mSystemDir.mkdirs(); FileUtils.setPermissions(mSystemDir.toString(), FileUtils.S_IRWXU|FileUtils.S_IRWXG |FileUtils.S_IROTH|FileUtils.S_IXOTH, -1, -1); // 读取data/system下的xml文件 mSettingsFilename = new File(mSystemDir, "packages.xml"); mBackupSettingsFilename = new File(mSystemDir, "packages-backup.xml"); mPackageListFilename = new File(mSystemDir, "packages.list"); FileUtils.setPermissions(mPackageListFilename, 0640, SYSTEM_UID, PACKAGE_INFO_GID); final File kernelDir = new File("/config/sdcardfs"); mKernelMappingFilename = kernelDir.exists() ? kernelDir : null; // Deprecated: Needed for migration mStoppedPackagesFilename = new File(mSystemDir, "packages-stopped.xml"); mBackupStoppedPackagesFilename = new File(mSystemDir, "packages-stopped-backup.xml"); } |
上面读取的5个文件所包含的内容如下表
SystemConfig对象
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// SystemConfig的单例模式 public static SystemConfig getInstance() { synchronized (SystemConfig.class) { if (sInstance == null) { sInstance = new SystemConfig(); } return sInstance; } } SystemConfig() { // 读取系统信息配置文件 readPermissions(Environment.buildPath( Environment.getRootDirectory(), "etc", "sysconfig"), ALLOW_ALL); readPermissions(Environment.buildPath( Environment.getRootDirectory(), "etc", "permissions"), ALLOW_ALL); // 允许Vendor供应商配置libs、features、permissions和apps int vendorPermissionFlag = ALLOW_LIBS | ALLOW_FEATURES | ALLOW_PERMISSIONS | ALLOW_APP_CONFIGS; readPermissions(Environment.buildPath( Environment.getVendorDirectory(), "etc", "sysconfig"), vendorPermissionFlag); readPermissions(Environment.buildPath( Environment.getVendorDirectory(), "etc", "permissions"), vendorPermissionFlag); // 允许ODM供应商配置libs、features、permissions和apps int odmPermissionFlag = ALLOW_LIBS | ALLOW_FEATURES | ALLOW_APP_CONFIGS; readPermissions(Environment.buildPath( Environment.getOdmDirectory(), "etc", "sysconfig"), odmPermissionFlag); readPermissions(Environment.buildPath( Environment.getOdmDirectory(), "etc", "permissions"), odmPermissionFlag); // 仅允许OEM对features进行配置 readPermissions(Environment.buildPath( Environment.getOemDirectory(), "etc", "sysconfig"), ALLOW_FEATURES); readPermissions(Environment.buildPath( Environment.getOemDirectory(), "etc", "permissions"), ALLOW_FEATURES); //Remove vulkan specific features if (SystemProperties.getBoolean("persist.graphics.vulkan.disable", false)) { removeFeature(PackageManager.FEATURE_VULKAN_HARDWARE_LEVEL); removeFeature(PackageManager.FEATURE_VULKAN_HARDWARE_VERSION); } // Remove android extension pack for opengles version 3.0 int value = SystemProperties.getInt("ro.opengles.version", 0); if (value > 0 && (value == 196608)) { if (mAvailableFeatures.remove("android.hardware.opengles.aep") != null) { Slog.d(TAG, "Removed android.hardware.opengles.aep feature for opengles 3.0"); } } } |
readPermissions会读取对应目录下所有的xml文件，根据xml文件对应的节点对libs、features和apps等内容进行配置。查找读取的xml文件路径如下：
- /system/etc/sysconfig
- /system/etc/permissions
- /vendor/etc/sysconfig
- /vendor/etc/permissions
- /odm/etc/sysconfig
- /odm/etc/permissions
- /oem/etc/sysconfig
- /oem/etc/permissions
readPermissions代码如下所示：
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void readPermissions(File libraryDir, int permissionFlag) { // 判断目录存在 if (!libraryDir.exists() || !libraryDir.isDirectory()) { if (permissionFlag == ALLOW_ALL) { Slog.w(TAG, "No directory " + libraryDir + ", skipping"); } return; } // 判断目录可读 if (!libraryDir.canRead()) { Slog.w(TAG, "Directory " + libraryDir + " cannot be read"); return; } // Iterate over the files in the directory and scan .xml files File platformFile = null; for (File f : libraryDir.listFiles()) { // 如果存在platform.xml先记录下来，最后再解析 if (f.getPath().endsWith("etc/permissions/platform.xml")) { platformFile = f; continue; } // 只解析xml文件 if (!f.getPath().endsWith(".xml")) { Slog.i(TAG, "Non-xml file " + f + " in " + libraryDir + " directory, ignoring"); continue; } // 判断文件是否可读 if (!f.canRead()) { Slog.w(TAG, "Permissions library file " + f + " cannot be read"); continue; } // 解析该目录下所有可读取的xml文件 readPermissionsFromXml(f, permissionFlag); } // 最后读取解析platform.xml文件 if (platformFile != null) { readPermissionsFromXml(platformFile, permissionFlag); } } |
上面的代码比较好理解，这里不做过多解释了。
2.1.2 BOOT_PROGRESS_PMS_SYSTEM_SCAN_START
接下来看第二个Eventlog前的内容
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EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SYSTEM_SCAN_START, startTime); // 获取环境变量中BOOTCLASSPATH和SYSTEMSERVERCLASSPATH的值，这两个值可以通过adb shell env进行查看 final String bootClassPath = System.getenv("BOOTCLASSPATH"); final String systemServerClassPath = System.getenv("SYSTEMSERVERCLASSPATH"); if (bootClassPath == null) { Slog.w(TAG, "No BOOTCLASSPATH found!"); } if (systemServerClassPath == null) { Slog.w(TAG, "No SYSTEMSERVERCLASSPATH found!"); } // frameworkDir的路径为/system/framework File frameworkDir = new File(Environment.getRootDirectory(), "framework"); final VersionInfo ver = mSettings.getInternalVersion(); mIsUpgrade = !Build.FINGERPRINT.equals(ver.fingerprint); if (mIsUpgrade) { logCriticalInfo(Log.INFO, "Upgrading from " + ver.fingerprint + " to " + Build.FINGERPRINT); } // 下面是从不同版本上级上来时需要做的处理 // when upgrading from pre-M, promote system app permissions from install to runtime mPromoteSystemApps = mIsUpgrade && ver.sdkVersion <= Build.VERSION_CODES.LOLLIPOP_MR1; // When upgrading from pre-N, we need to handle package extraction like first boot, // as there is no profiling data available. mIsPreNUpgrade = mIsUpgrade && ver.sdkVersion < Build.VERSION_CODES.N; mIsPreNMR1Upgrade = mIsUpgrade && ver.sdkVersion < Build.VERSION_CODES.N_MR1; // save off the names of pre-existing system packages prior to scanning; we don't // want to automatically grant runtime permissions for new system apps if (mPromoteSystemApps) { Iterator<PackageSetting> pkgSettingIter = mSettings.mPackages.values().iterator(); while (pkgSettingIter.hasNext()) { PackageSetting ps = pkgSettingIter.next(); if (isSystemApp(ps)) { mExistingSystemPackages.add(ps.name); } } } // 准备packages parser的cache空间 mCacheDir = preparePackageParserCache(mIsUpgrade); // Set flag to monitor and not change apk file paths when // scanning install directories. int scanFlags = SCAN_BOOTING | SCAN_INITIAL; if (mIsUpgrade || mFirstBoot) { scanFlags = scanFlags | SCAN_FIRST_BOOT_OR_UPGRADE; } // 扫描/vendor/overlay目录下的package scanDirTracedLI(new File(VENDOR_OVERLAY_DIR), mDefParseFlags | PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR | PackageParser.PARSE_TRUSTED_OVERLAY, scanFlags | SCAN_TRUSTED_OVERLAY, 0); // 扫描静态overlay的packages mParallelPackageParserCallback.findStaticOverlayPackages(); // 扫描/system/framework目录下的package scanDirTracedLI(frameworkDir, mDefParseFlags | PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR | PackageParser.PARSE_IS_PRIVILEGED, scanFlags | SCAN_NO_DEX, 0); // 扫描/system/priv-app目录下的系统package final File privilegedAppDir = new File(Environment.getRootDirectory(), "priv-app"); scanDirTracedLI(privilegedAppDir, mDefParseFlags | PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR | PackageParser.PARSE_IS_PRIVILEGED, scanFlags, 0); // 扫描/system/app目录下的普通package final File systemAppDir = new File(Environment.getRootDirectory(), "app"); scanDirTracedLI(systemAppDir, mDefParseFlags | PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanFlags, 0); // 扫描/vendor/app目录下的vendor供应商package File vendorAppDir = new File("/vendor/app"); try { vendorAppDir = vendorAppDir.getCanonicalFile(); } catch (IOException e) { // failed to look up canonical path, continue with original one } scanDirTracedLI(vendorAppDir, mDefParseFlags | PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanFlags, 0); // 扫描/oem/app目录下的oem制造商的package final File oemAppDir = new File(Environment.getOemDirectory(), "app"); scanDirTracedLI(oemAppDir, mDefParseFlags | PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanFlags, 0); // 如果支持运营商/区域化，则扫描加载运营商的package if (RegionalizationEnvironment.isSupported()) { Log.d(TAG, "Load Regionalization vendor apks"); final List<File> RegionalizationDirs = RegionalizationEnvironment.getAllPackageDirectories(); for (File f : RegionalizationDirs) { File RegionalizationSystemDir = new File(f, "system"); // Collect packages in <Package>/system/priv-app scanDirLI(new File(RegionalizationSystemDir, "priv-app"), PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR | PackageParser.PARSE_IS_PRIVILEGED, scanFlags, 0); // Collect packages in <Package>/system/app scanDirLI(new File(RegionalizationSystemDir, "app"), PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR, scanFlags, 0); // Collect overlay in <Package>/system/vendor scanDirLI(new File(RegionalizationSystemDir, "vendor/overlay"), PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR | PackageParser.PARSE_TRUSTED_OVERLAY, scanFlags | SCAN_TRUSTED_OVERLAY, 0); } } // 删除不再存在的系统package final List<String> possiblyDeletedUpdatedSystemApps = new ArrayList<>(); // stub package估计只是一个小的apk，用来下载正式版的package并安装 final List<String> stubSystemApps = new ArrayList<>(); if (!mOnlyCore) { // do this first before mucking with mPackages for the "expecting better" case final Iterator<PackageParser.Package> pkgIterator = mPackages.values().iterator(); while (pkgIterator.hasNext()) { final PackageParser.Package pkg = pkgIterator.next(); if (pkg.isStub) { stubSystemApps.add(pkg.packageName); } } final Iterator<PackageSetting> psit = mSettings.mPackages.values().iterator(); while (psit.hasNext()) { PackageSetting ps = psit.next(); // 如果不是系统package，则可设置为disabled的，这里先跳过 if ((ps.pkgFlags & ApplicationInfo.FLAG_SYSTEM) == 0) { continue; } /* * If the package is scanned, it's not erased. */ final PackageParser.Package scannedPkg = mPackages.get(ps.name); if (scannedPkg != null) { /* * If the system app is both scanned and in the * disabled packages list, then it must have been * added via OTA. Remove it from the currently * scanned package so the previously user-installed * application can be scanned. */ if (mSettings.isDisabledSystemPackageLPr(ps.name)) { logCriticalInfo(Log.WARN, "Expecting better updated system app for " + ps.name + "; removing system app. Last known codePath=" + ps.codePathString + ", installStatus=" + ps.installStatus + ", versionCode=" + ps.versionCode + "; scanned versionCode=" + scannedPkg.mVersionCode); removePackageLI(scannedPkg, true); mExpectingBetter.put(ps.name, ps.codePath); } continue; } if (!mSettings.isDisabledSystemPackageLPr(ps.name)) { psit.remove(); logCriticalInfo(Log.WARN, "System package " + ps.name + " no longer exists; it's data will be wiped"); // Actual deletion of code and data will be handled by later // reconciliation step } else { // we still have a disabled system package, but, it still might have // been removed. check the code path still exists and check there's // still a package. the latter can happen if an OTA keeps the same // code path, but, changes the package name. final PackageSetting disabledPs = mSettings.getDisabledSystemPkgLPr(ps.name); if (disabledPs.codePath == null || !disabledPs.codePath.exists() || disabledPs.pkg == null) { possiblyDeletedUpdatedSystemApps.add(ps.name); } } } } // 查找那些安装不完整的package，并将其删除 ArrayList<PackageSetting> deletePkgsList = mSettings.getListOfIncompleteInstallPackagesLPr(); for (int i = 0; i < deletePkgsList.size(); i++) { // Actual deletion of code and data will be handled by later // reconciliation step final String packageName = deletePkgsList.get(i).name; logCriticalInfo(Log.WARN, "Cleaning up incompletely installed app: " + packageName); synchronized (mPackages) { mSettings.removePackageLPw(packageName); } } //删除临时package deleteTempPackageFiles(); final int cachedSystemApps = PackageParser.sCachedPackageReadCount.get(); // 删除那些没有对应package的shared uid mSettings.pruneSharedUsersLPw(); final long systemScanTime = SystemClock.uptimeMillis() - startTime; final int systemPackagesCount = mPackages.size(); Slog.i(TAG, "Finished scanning system apps. Time: " + systemScanTime + " ms, packageCount: " + systemPackagesCount + " , timePerPackage: " + (systemPackagesCount == 0 ? 0 : systemScanTime / systemPackagesCount) + " , cached: " + cachedSystemApps); if (mIsUpgrade && systemPackagesCount > 0) { MetricsLogger.histogram(null, "ota_package_manager_system_app_avg_scan_time", ((int) systemScanTime) / systemPackagesCount); } |
BOOTCLASSPATH和SYSTEMSERVERCLASSPATH的值可以通过adb shell env进行查看，查看的结果如下图所示：
scanDirTracedLI会扫描指定目录下的package，最终调用PackageParser.parseBaseApk来完成AndroidManifest.xml文件的解析，生成Application, activity,service,broadcast, provider等信息。
2.1.3 BOOT_PROGRESS_PMS_SCAN_END
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// 处理非系统package if (!mOnlyCore) { EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_DATA_SCAN_START, SystemClock.uptimeMillis()); // 扫描/data/app目录下的package scanDirTracedLI(mAppInstallDir, 0, scanFlags | SCAN_REQUIRE_KNOWN, 0); // 扫描/data/app-private目录下的package scanDirTracedLI(mDrmAppPrivateInstallDir, mDefParseFlags | PackageParser.PARSE_FORWARD_LOCK, scanFlags | SCAN_REQUIRE_KNOWN, 0); // 扫描运营商第三方package if (RegionalizationEnvironment.isSupported()) { Log.d(TAG, "Load Regionalization 3rd apks from res packages."); final List<String> packages = RegionalizationEnvironment.getAllPackageNames(); for (String pack : packages) { File appFolder = new File(mRegionalizationAppInstallDir, pack); Log.d(TAG, "Load Regionalization 3rd apks of path " + appFolder.getPath()); scanDirLI(appFolder, 0, scanFlags | SCAN_REQUIRE_KNOWN, 0); } } // 删除通过OTA升级禁用的Package for (String deletedAppName : possiblyDeletedUpdatedSystemApps) { PackageParser.Package deletedPkg = mPackages.get(deletedAppName); mSettings.removeDisabledSystemPackageLPw(deletedAppName); final String msg; if (deletedPkg == null) { // should have found an update, but, we didn't; remove everything msg = "Updated system package " + deletedAppName + " no longer exists; removing its data"; // Actual deletion of code and data will be handled by later // reconciliation step } else { // found an update; revoke system privileges msg = "Updated system package + " + deletedAppName + " no longer exists; revoking system privileges"; // Don't do anything if a stub is removed from the system image. If // we were to remove the uncompressed version from the /data partition, // this is where it'd be done. final PackageSetting deletedPs = mSettings.mPackages.get(deletedAppName); deletedPkg.applicationInfo.flags &= ~ApplicationInfo.FLAG_SYSTEM; deletedPs.pkgFlags &= ~ApplicationInfo.FLAG_SYSTEM; } logCriticalInfo(Log.WARN, msg); } // 确保所有系统package正确显示 for (int i = 0; i < mExpectingBetter.size(); i++) { final String packageName = mExpectingBetter.keyAt(i); if (!mPackages.containsKey(packageName)) { final File scanFile = mExpectingBetter.valueAt(i); logCriticalInfo(Log.WARN, "Expected better " + packageName + " but never showed up; reverting to system"); int reparseFlags = mDefParseFlags; if (FileUtils.contains(privilegedAppDir, scanFile)) { reparseFlags = PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR | PackageParser.PARSE_IS_PRIVILEGED; } else if (FileUtils.contains(systemAppDir, scanFile)) { reparseFlags = PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR; } else if (FileUtils.contains(vendorAppDir, scanFile)) { reparseFlags = PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR; } else if (FileUtils.contains(oemAppDir, scanFile)) { reparseFlags = PackageParser.PARSE_IS_SYSTEM | PackageParser.PARSE_IS_SYSTEM_DIR; } else { Slog.e(TAG, "Ignoring unexpected fallback path " + scanFile); continue; } mSettings.enableSystemPackageLPw(packageName); try { scanPackageTracedLI(scanFile, reparseFlags, scanFlags, 0, null); } catch (PackageManagerException e) { Slog.e(TAG, "Failed to parse original system package: " + e.getMessage()); } } } // Uncompress and install any stubbed system applications. // This must be done last to ensure all stubs are replaced or disabled. decompressSystemApplications(stubSystemApps, scanFlags); final int cachedNonSystemApps = PackageParser.sCachedPackageReadCount.get() - cachedSystemApps; final long dataScanTime = SystemClock.uptimeMillis() - systemScanTime - startTime; final int dataPackagesCount = mPackages.size() - systemPackagesCount; Slog.i(TAG, "Finished scanning non-system apps. Time: " + dataScanTime + " ms, packageCount: " + dataPackagesCount + " , timePerPackage: " + (dataPackagesCount == 0 ? 0 : dataScanTime / dataPackagesCount) + " , cached: " + cachedNonSystemApps); if (mIsUpgrade && dataPackagesCount > 0) { MetricsLogger.histogram(null, "ota_package_manager_data_app_avg_scan_time", ((int) dataScanTime) / dataPackagesCount); } } mExpectingBetter.clear(); // 解析存储管理器 mStorageManagerPackage = getStorageManagerPackageName(); // 解析受保护action过滤，仅setupwizard拥有最高优先级处理这个过滤 mSetupWizardPackage = getSetupWizardPackageName(); if (mProtectedFilters.size() > 0) { if (DEBUG_FILTERS && mSetupWizardPackage == null) { Slog.i(TAG, "No setup wizard;" + " All protected intents capped to priority 0"); } for (ActivityIntentInfo filter : mProtectedFilters) { if (filter.activity.info.packageName.equals(mSetupWizardPackage)) { if (DEBUG_FILTERS) { Slog.i(TAG, "Found setup wizard;" + " allow priority " + filter.getPriority() + ";" + " package: " + filter.activity.info.packageName + " activity: " + filter.activity.className + " priority: " + filter.getPriority()); } // skip setup wizard; allow it to keep the high priority filter continue; } if (DEBUG_FILTERS) { Slog.i(TAG, "Protected action; cap priority to 0;" + " package: " + filter.activity.info.packageName + " activity: " + filter.activity.className + " origPrio: " + filter.getPriority()); } filter.setPriority(0); } } mDeferProtectedFilters = false; mProtectedFilters.clear(); // 已经获取到所有共享库的路径，这里需要为各个package更新路径 updateAllSharedLibrariesLPw(null); for (SharedUserSetting setting : mSettings.getAllSharedUsersLPw()) { // NOTE: We ignore potential failures here during a system scan (like // the rest of the commands above) because there's precious little we // can do about it. A settings error is reported, though. adjustCpuAbisForSharedUserLPw(setting.packages, null /*scannedPackage*/); } // 更新上一次使用时间 mPackageUsage.read(mPackages); mCompilerStats.read(); |
这里主要是更新非系统package的信息，主要处在/data/app和/data/priv-app路径下面，下面继续往下看
2.1.4 BOOT_PROGRESS_PMS_READY
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// 如果系统SDK版本有升级，这里需要让所有的apk重新获取运行时权限 int updateFlags = UPDATE_PERMISSIONS_ALL; if (ver.sdkVersion != mSdkVersion) { Slog.i(TAG, "Platform changed from " + ver.sdkVersion + " to " + mSdkVersion + "; regranting permissions for internal storage"); updateFlags |= UPDATE_PERMISSIONS_REPLACE_PKG | UPDATE_PERMISSIONS_REPLACE_ALL; } updatePermissionsLPw(null, null, StorageManager.UUID_PRIVATE_INTERNAL, updateFlags); ver.sdkVersion = mSdkVersion; // 如果是第一次开机或者是从pre-M版本升级上来的，我们需要为用户定义某些默认使用的package if (!onlyCore && (mPromoteSystemApps || mFirstBoot)) { for (UserInfo user : sUserManager.getUsers(true)) { mSettings.applyDefaultPreferredAppsLPw(this, user.id); applyFactoryDefaultBrowserLPw(user.id); primeDomainVerificationsLPw(user.id); } } // 为系统用户准备内存空间 final int storageFlags; if (StorageManager.isFileEncryptedNativeOrEmulated()) { storageFlags = StorageManager.FLAG_STORAGE_DE; } else { storageFlags = StorageManager.FLAG_STORAGE_DE | StorageManager.FLAG_STORAGE_CE; } List<String> deferPackages = reconcileAppsDataLI(StorageManager.UUID_PRIVATE_INTERNAL, UserHandle.USER_SYSTEM, storageFlags, true /* migrateAppData */, true /* onlyCoreApps */); mPrepareAppDataFuture = SystemServerInitThreadPool.get().submit(() -> { TimingsTraceLog traceLog = new TimingsTraceLog("SystemServerTimingAsync", Trace.TRACE_TAG_PACKAGE_MANAGER); traceLog.traceBegin("AppDataFixup"); try { mInstaller.fixupAppData(StorageManager.UUID_PRIVATE_INTERNAL, StorageManager.FLAG_STORAGE_DE | StorageManager.FLAG_STORAGE_CE); } catch (InstallerException e) { Slog.w(TAG, "Trouble fixing GIDs", e); } traceLog.traceEnd(); traceLog.traceBegin("AppDataPrepare"); if (deferPackages == null || deferPackages.isEmpty()) { return; } int count = 0; for (String pkgName : deferPackages) { PackageParser.Package pkg = null; synchronized (mPackages) { PackageSetting ps = mSettings.getPackageLPr(pkgName); if (ps != null && ps.getInstalled(UserHandle.USER_SYSTEM)) { pkg = ps.pkg; } } if (pkg != null) { synchronized (mInstallLock) { prepareAppDataAndMigrateLIF(pkg, UserHandle.USER_SYSTEM, storageFlags, true /* maybeMigrateAppData */); } count++; } } traceLog.traceEnd(); Slog.i(TAG, "Deferred reconcileAppsData finished " + count + " packages"); }, "prepareAppData"); // 如果是OTA后第一次正常开机，我们需要清楚code cache if (mIsUpgrade && !onlyCore) { Slog.i(TAG, "Build fingerprint changed; clearing code caches"); for (int i = 0; i < mSettings.mPackages.size(); i++) { final PackageSetting ps = mSettings.mPackages.valueAt(i); if (Objects.equals(StorageManager.UUID_PRIVATE_INTERNAL, ps.volumeUuid)) { // No apps are running this early, so no need to freeze clearAppDataLIF(ps.pkg, UserHandle.USER_ALL, StorageManager.FLAG_STORAGE_DE | StorageManager.FLAG_STORAGE_CE | Installer.FLAG_CLEAR_CODE_CACHE_ONLY); } } ver.fingerprint = Build.FINGERPRINT; } checkDefaultBrowser(); // //当权限和其他默认项都完成更新，则清理相关信息 mExistingSystemPackages.clear(); mPromoteSystemApps = false; // All the changes are done during package scanning. ver.databaseVersion = Settings.CURRENT_DATABASE_VERSION; // can downgrade to reader Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "write settings"); // 信息写回packages.xml文件 mSettings.writeLPr(); Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER); |
2.1.5 BOOT_PROGRESS_PMS_READY
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EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_READY, SystemClock.uptimeMillis()); if (!mOnlyCore) { // 估计是对扫描的Package做一些校验吧，水平有限，具体情况暂时没看出来 mRequiredVerifierPackage = getRequiredButNotReallyRequiredVerifierLPr(); mOptionalVerifierPackage = getOptionalVerifierLPr(); mRequiredInstallerPackage = getRequiredInstallerLPr(); mRequiredUninstallerPackage = getRequiredUninstallerLPr(); mIntentFilterVerifierComponent = getIntentFilterVerifierComponentNameLPr(); if (mIntentFilterVerifierComponent != null) { mIntentFilterVerifier = new IntentVerifierProxy(mContext, mIntentFilterVerifierComponent); } else { mIntentFilterVerifier = null; } mServicesSystemSharedLibraryPackageName = getRequiredSharedLibraryLPr( PackageManager.SYSTEM_SHARED_LIBRARY_SERVICES, SharedLibraryInfo.VERSION_UNDEFINED); mSharedSystemSharedLibraryPackageName = getRequiredSharedLibraryLPr( PackageManager.SYSTEM_SHARED_LIBRARY_SHARED, SharedLibraryInfo.VERSION_UNDEFINED); } else { mRequiredVerifierPackage = null; mOptionalVerifierPackage = null; mRequiredInstallerPackage = null; mRequiredUninstallerPackage = null; mIntentFilterVerifierComponent = null; mIntentFilterVerifier = null; mServicesSystemSharedLibraryPackageName = null; mSharedSystemSharedLibraryPackageName = null; } // 创建PackageInstallerService mInstallerService = new PackageInstallerService(context, this); final Pair<ComponentName, String> instantAppResolverComponent = getInstantAppResolverLPr(); if (instantAppResolverComponent != null) { if (DEBUG_EPHEMERAL) { Slog.d(TAG, "Set ephemeral resolver: " + instantAppResolverComponent); } mInstantAppResolverConnection = new EphemeralResolverConnection( mContext, instantAppResolverComponent.first, instantAppResolverComponent.second); mInstantAppResolverSettingsComponent = getInstantAppResolverSettingsLPr(instantAppResolverComponent.first); } else { mInstantAppResolverConnection = null; mInstantAppResolverSettingsComponent = null; } updateInstantAppInstallerLocked(null); // Read and update the usage of dex files. // Do this at the end of PM init so that all the packages have their // data directory reconciled. // At this point we know the code paths of the packages, so we can validate // the disk file and build the internal cache. // The usage file is expected to be small so loading and verifying it // should take a fairly small time compare to the other activities (e.g. package // scanning). final Map<Integer, List<PackageInfo>> userPackages = new HashMap<>(); final int[] currentUserIds = UserManagerService.getInstance().getUserIds(); for (int userId : currentUserIds) { userPackages.put(userId, getInstalledPackages(/*flags*/ 0, userId).getList()); } mDexManager.load(userPackages); if (mIsUpgrade) { MetricsLogger.histogram(null, "ota_package_manager_init_time", (int) (SystemClock.uptimeMillis() - startTime)); } } // synchronized (mPackages) } // synchronized (mInstallLock) // Now after opening every single application zip, make sure they // are all flushed. Not really needed, but keeps things nice and // tidy. Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "GC"); Runtime.getRuntime().gc(); Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER); Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "loadFallbacks"); FallbackCategoryProvider.loadFallbacks(); Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER); // The initial scanning above does many calls into installd while // holding the mPackages lock, but we're mostly interested in yelling // once we have a booted system. mInstaller.setWarnIfHeld(mPackages); // 创建并添加PackageManagerInternalImpl服务到ServiceManager LocalServices.addService(PackageManagerInternal.class, new PackageManagerInternalImpl()); Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER); |
上面这最后的部分有点难啊，看不出来做了什么操作，先留着，以后再分析吧。现在主要看的是上面会创建一个PackageInstallerService服务，我们接下来分析这个服务
2.1.6 创建PackageInstallerService
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public PackageInstallerService(Context context, PackageManagerService pm) { mContext = context; mPm = pm; // 创建名为“PackageInstaller”的Handler线程 mInstallThread = new HandlerThread(TAG); mInstallThread.start(); mInstallHandler = new Handler(mInstallThread.getLooper()); mCallbacks = new Callbacks(mInstallThread.getLooper()); // 打开/data/system/install_sessions.xml文件 mSessionsFile = new AtomicFile( new File(Environment.getDataSystemDirectory(), "install_sessions.xml")); // 创建/data/system/install_sessions文件夹 mSessionsDir = new File(Environment.getDataSystemDirectory(), "install_sessions"); mSessionsDir.mkdirs(); } |
真不容易，这PackageManagerService的第一部分就先分析到这里，到现在我们才主要分析了PKMS启动的第一个部分：PackageManagerService.main，下面列出的部分我们再下一篇再做分析。
- mPackageManagerService.updatePackagesIfNeeded
- mPackageManagerService.performFstrimIfNeeded
- mPackageManagerService.systemReady
- mPackageManagerService.waitForAppDataPrepared
