PackageManagerService也是系统里面一个很重要的服务，管理着所有的跟包(package)相关的工作，譬如应用的安装，卸载，升级等，PackageManagerService的启动和其他服务一样也是在SystemServer里面启动，Systemserver启动过程中涉及到PMS的主要在启动引导服务startBootstrapServices和启动其他服务的时候这两个方法中有涉及到，下面就来看看具体的涉及到的点，本文是基于Android9.0来分析的
PMS的启动
private void startBootstrapServices() {
// Wait for installd to finish starting up so that it has a chance to
// create critical directories such as /data/user with the appropriate
// permissions. We need this to complete before we initialize other services.
traceBeginAndSlog("StartInstaller");
Installer installer = mSystemServiceManager.startService(Installer.class);
traceEnd();
// Only run "core" apps if we're encrypting the device.
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;
}
// Start the package manager.
if (!mRuntimeRestart) {
MetricsLogger.histogram(null, "boot_package_manager_init_start",
(int) SystemClock.elapsedRealtime());
}
traceBeginAndSlog("StartPackageManagerService");
mPackageManagerService = PackageManagerService.main(mSystemContext, installer,
mFactoryTestMode != FactoryTest.FACTORY_TEST_OFF, mOnlyCore);
mFirstBoot = mPackageManagerService.isFirstBoot();
mPackageManager = mSystemContext.getPackageManager();
traceEnd();
if (!mRuntimeRestart && !isFirstBootOrUpgrade()) {
MetricsLogger.histogram(null, "boot_package_manager_init_ready",
(int) SystemClock.elapsedRealtime());
}
// Manages A/B OTA dexopting. This is a bootstrap service as we need it to rename
// A/B artifacts after boot, before anything else might touch/need them.
// Note: this isn't needed during decryption (we don't have /data anyways).
if (!mOnlyCore) {
boolean disableOtaDexopt = SystemProperties.getBoolean("config.disable_otadexopt",
false);
if (!disableOtaDexopt) {
traceBeginAndSlog("StartOtaDexOptService");
try {
OtaDexoptService.main(mSystemContext, mPackageManagerService);
} catch (Throwable e) {
reportWtf("starting OtaDexOptService", e);
} finally {
traceEnd();
}
}
}
该过程中首先有个关键的动作就是启动Installer服务，也就是安装器，随后判断当前的设备是否处于加密状态，如果是则只是解析核心应用，接着调用PackageManagerService的静态方法main来创建pms对象
public static PackageManagerService main(Context context, Installer installer,
boolean factoryTest, boolean onlyCore) {
// Self-check for initial settings.
PackageManagerServiceCompilerMapping.checkProperties();
PackageManagerService m = new PackageManagerService(context, installer,
factoryTest, onlyCore);
m.enableSystemUserPackages();
ServiceManager.addService("package", m);
final PackageManagerNative pmn = m.new PackageManagerNative();
ServiceManager.addService("package_native", pmn);
return m;
}
创建完成之后将其注册到ServiceManager中，serviceManager是所有服务的管家
接着，根据上面判断设备是否加密来判断是否启动OtaDexoptService服务
if (!mOnlyCore) {
boolean disableOtaDexopt = SystemProperties.getBoolean("config.disable_otadexopt",
false);
if (!disableOtaDexopt) {
traceBeginAndSlog("StartOtaDexOptService");
try {
OtaDexoptService.main(mSystemContext, mPackageManagerService);
} catch (Throwable e) {
reportWtf("starting OtaDexOptService", e);
} finally {
traceEnd();
}
}
}
再来看看startOtherService
traceBeginAndSlog("MakePackageManagerServiceReady");
mPackageManagerService.systemReady();
traceEnd();
接下来就分析几个关键的点
PMS::main方法和systemReady方法
PMS之构造方法
主要是分为两部分，需要持有两个同步锁和不需要持锁的部分
LockGuard.installLock(mPackages, LockGuard.INDEX_PACKAGES);
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "create package
manager");
EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_START,
SystemClock.uptimeMillis());
if (mSdkVersion <= 0) { //检查sdk版本
Slog.w(TAG, "**** ro.build.version.sdk not set!");
}
mContext = context;//上下文对象
mFactoryTest = factoryTest;//工程测试
mOnlyCore = onlyCore;
mMetrics = new DisplayMetrics();//构造和显示屏幕相关的信息，分辨率，屏幕尺寸等
mInstaller = installer;//安装器，和本地守护进程installed交换的，通信方式socket
需要同时持有两个同步锁的部分
// Create sub-components that provide services / data. Order here is important.
synchronized (mInstallLock) {
synchronized (mPackages) {
// Expose private service for system components to use.
LocalServices.addService(
PackageManagerInternal.class, new PackageManagerInternalImpl());
sUserManager = new UserManagerService(context, this,//用户管理相关的
new UserDataPreparer(mInstaller, mInstallLock, mContext, mOnlyCore), mPackages);
mPermissionManager = PermissionManagerService.create(context,
new DefaultPermissionGrantedCallback() {
@Override
public void onDefaultRuntimePermissionsGranted(int userId) {
synchronized(mPackages) {
mSettings.onDefaultRuntimePermissionsGrantedLPr(userId);
}
}
}, mPackages /*externalLock*/);
mDefaultPermissionPolicy = mPermissionManager.getDefaultPermissionGrantPolicy();
mSettings = new Settings(mPermissionManager.getPermissionSettings(), mPackages);
//settings对象主要是存储系统运行过程中的用户的一些设置信息
}
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);
mSettings.addSharedUserLPw("android.uid.se", SE_UID,
ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED);
添加七种shardeduserid到settings中
Settings对象
构造方法
Settings(PermissionSettings permissions, Object lock) {
this(Environment.getDataDirectory(), permissions, lock);
}
Settings(File dataDir, PermissionSettings permission, Object lock) {
mLock = lock;
mPermissions = permission;
mRuntimePermissionsPersistence = new RuntimePermissionPersistence(mLock);
mSystemDir = new File(dataDir, "system");//创建指向/data/system/目录的文件
mSystemDir.mkdirs();//创建目录
FileUtils.setPermissions(mSystemDir.toString(),
FileUtils.S_IRWXU|FileUtils.S_IRWXG
|FileUtils.S_IROTH|FileUtils.S_IXOTH,
-1, -1);
mSettingsFilename = new File(mSystemDir, "packages.xml");//用于描述系统所安装的package信息
mBackupSettingsFilename = new File(mSystemDir, "packages-backup.xml");//备份文件，防止由于突然断电等异常情况
mPackageListFilename = new File(mSystemDir, "packages.list");//记录应用的数据信息
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
//记录系统中处于stopped状态的应用信息，例如被强制停止运行的，第一次安装（install）的应用
mStoppedPackagesFilename = new File(mSystemDir, "packages-stopped.xml");
//上面文件的备份文件
mBackupStoppedPackagesFilename = new File(mSystemDir, "packages-stopped-backup.xml");
}
settings构造方法主要的任务是建立与某些系统配置文件、目录之间的关联
上面有两个备份文件back-up，其实android在修改packages.xml、packages-stopped.xml 之前会对其备份，如果对他们的修改正常完成，则完成之后删除备份文件，如果在修改过程中出现了断电，设备重启等异常情况，下一次操作时发现上面两个文件还存在，系统此时会读取之前的非备份文件，并且认为上一次对这两个文件的修改出现了异常
Settings之addSharedUserLPw
mSettings.addSharedUserLPw("android.uid.system", Process.SYSTEM_UID,
ApplicationInfo.FLAG_SYSTEM, ApplicationInfo.PRIVATE_FLAG_PRIVILEGED);
找到addSharedUserLPw的实现
SharedUserSetting addSharedUserLPw(String name, int uid, int pkgFlags, int pkgPrivateFlags) {
SharedUserSetting s = mSharedUsers.get(name);
if (s != null) {
if (s.userId == uid) {
return s;
}
PackageManagerService.reportSettingsProblem(Log.ERROR,
"Adding duplicate shared user, keeping first: " + name);
return null;
}
s = new SharedUserSetting(name, pkgFlags, pkgPrivateFlags);
s.userId = uid;
if (addUserIdLPw(uid, s, name)) {// 在系统中保存值为uid 的用户id，成功返回 true
mSharedUsers.put(name, s); //将 name 与 s 键值对添加到 mSharedUsers 中保存
return s;
}
return null;
}
我们可以看到Settings 中有一个 mSharedUsers 成员，该成员存储的是 【“字符串” 与 “SharedUserSetting” 键值对】，也就是说可以通过 字符串 为 key 得到对应的 SharedUserSetting 对象。
SharedUserSetting
如果我们做系统应用的话可以会接触到android:sharedUserId="android.uid.system"
这句话的意思是让其运行在system进程中，
1：如果两个应用或是更多都声明了同一个sharedUserId 是可以共享数据的，并且可以运行在同一个进程中
2：通过声明特定的 sharedUserId，该 APK 所在 进程 将被赋予指定的 UID，其进程就可以享受该用户所对应的权限，譬如system,shell用户的权限
有 3 个关键点需要注意：
XML 中 sharedUserId 属性指定了一个字符串，它是 UID 的字符串描述，故对应数据结构中也应该有这样一个字符串，这样就把代码和 XML 中的属性联系起来了。
在 LINUX 系统中，真正的 uid 是一个整数，所以该数据结构中必然有一个整型变量。
多个 Package 可声明同一个 sharedUserId，因此该数据结构必然会保存那些声明了相同 sharedUserId 的 Package 的某些信息。
我们回到上面的方法可以看到
final ArrayMap<String, SharedUserSetting> mSharedUsers =
new ArrayMap<String, SharedUserSetting>();
settings中定义了一个成员变量mSharedUsers，他是ArrayMap类型，它的key类型是String,像android.uid.system，value值是SharedUserSetting对象，SharedUserSetting中定义了 一个packages对象
final ArraySet<PackageSetting> packages = new ArraySet<PackageSetting>();
它的类型是packages，类型是ArraySet，保存的是packagesetting信息，我们可以看下PackageSetting描述的有哪些信息
PackageSetting
它有四个成员变量
int appId;//应用的id
PackageParser.Package pkg; //package对象
/**
* WARNING. The object reference is important. We perform integer equality and NOT
* object equality to check whether shared user settings are the same.
*/
SharedUserSetting sharedUser;
/**
* Temporary holding space for the shared user ID. While parsing package settings, the
* shared users tag may come after the packages. In this case, we must delay linking the
* shared user setting with the package setting. The shared user ID lets us link the
* two objects.
*/
private int sharedUserId;
PackageSetting本身是继承PackageSettingBase的，PackageSettingBase又继承SettingBase
public final class PackageSetting extends PackageSettingBase {}
public abstract class PackageSettingBase extends SettingBase {}
settingBase有三个成员变量
int pkgFlags;//flag
int pkgPrivateFlags;//私有的flag
protected final PermissionsState mPermissionsState;//权限信息，权限分为运行时权限和安装时就赋予的权限，mPermissionsState里面存储的就是这些可用的权限信息
public boolean hasPermission(String name, int userId) {//判断对应的user是否具有该权限name
enforceValidUserId(userId);
if (mPermissions == null) {
return false;
}
PermissionData permissionData = mPermissions.get(name);
return permissionData != null && permissionData.isGranted(userId);
}
Dex优化相关
mPackageDexOptimizer = new PackageDexOptimizer(installer, mInstallLock, context,
"*dexopt*");//dex优化的辅助类
DexManager.Listener dexManagerListener = DexLogger.getListener(this,
installer, mInstallLock);
mDexManager = new DexManager(mContext, this, mPackageDexOptimizer, installer, mInstallLock,
dexManagerListener);//dex管理器
mArtManagerService = new ArtManagerService(mContext, this, installer, mInstallLock);
mMoveCallbacks = new MoveCallbacks(FgThread.get().getLooper());
//handler工作类，对应于android.fg线程
mOnPermissionChangeListeners = new OnPermissionChangeListeners(
FgThread.get().getLooper());//权限变更监听器
getDefaultDisplayMetrics(context, mMetrics);
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "get system config");
SystemConfig systemConfig = SystemConfig.getInstance();//系统配置
mAvailableFeatures = systemConfig.getAvailableFeatures();
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
mProtectedPackages = new ProtectedPackages(mContext);
SystemConfig
我们看到SystemConfig的构造方法，主要是从文件中读取权限
// Read configuration from system
readPermissions(Environment.buildPath(
Environment.getRootDirectory(), "etc", "sysconfig"), ALLOW_ALL);
// Read configuration from the old permissions dir
readPermissions(Environment.buildPath(
Environment.getRootDirectory(), "etc", "permissions"), ALLOW_ALL);
// Vendors are only allowed to customze libs, features and privapp permissions
int vendorPermissionFlag = ALLOW_LIBS | ALLOW_FEATURES | ALLOW_PRIVAPP_PERMISSIONS;
if (Build.VERSION.FIRST_SDK_INT <= Build.VERSION_CODES.O_MR1) {
// For backward compatibility
vendorPermissionFlag |= (ALLOW_PERMISSIONS | ALLOW_APP_CONFIGS);
}
readPermissions(Environment.buildPath(
Environment.getVendorDirectory(), "etc", "sysconfig"), vendorPermissionFlag);
readPermissions(Environment.buildPath(
Environment.getVendorDirectory(), "etc", "permissions"), vendorPermissionFlag);
// Allow ODM to customize system configs as much as Vendor, because /odm is another
// vendor partition other than /vendor.
int odmPermissionFlag = vendorPermissionFlag;
readPermissions(Environment.buildPath(
Environment.getOdmDirectory(), "etc", "sysconfig"), odmPermissionFlag);
readPermissions(Environment.buildPath(
Environment.getOdmDirectory(), "etc", "permissions"), odmPermissionFlag);
// Allow OEM to customize features and OEM permissions
int oemPermissionFlag = ALLOW_FEATURES | ALLOW_OEM_PERMISSIONS;
readPermissions(Environment.buildPath(
Environment.getOemDirectory(), "etc", "sysconfig"), oemPermissionFlag);
readPermissions(Environment.buildPath(
Environment.getOemDirectory(), "etc", "permissions"), oemPermissionFlag);
// Allow Product to customize system configs around libs, features, permissions and apps
int productPermissionFlag = ALLOW_LIBS | ALLOW_FEATURES | ALLOW_PERMISSIONS |
ALLOW_APP_CONFIGS | ALLOW_PRIVAPP_PERMISSIONS;
readPermissions(Environment.buildPath(
Environment.getProductDirectory(), "etc", "sysconfig"), productPermissionFlag);
readPermissions(Environment.buildPath(
Environment.getProductDirectory(), "etc", "permissions"), productPermissionFlag);
我们可以看下readPermissions的方法实现
void readPermissions(File libraryDir, int permissionFlag) {
// Read permissions from given directory.
if (!libraryDir.exists() || !libraryDir.isDirectory()) {//判断目录或是文件是否存在
if (permissionFlag == ALLOW_ALL) {
Slog.w(TAG, "No directory " + libraryDir + ", skipping");
}
return;
}
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()) {
// We'll read platform.xml last
if (f.getPath().endsWith("etc/permissions/platform.xml")) {//platform.xml最后处理
platformFile = f;
continue;
}
if (!f.getPath().endsWith(".xml")) {
Slog.i(TAG, "Non-xml file " + f + " in " + libraryDir + " directory, ignoring");
continue;
}
if (!f.canRead()) {
Slog.w(TAG, "Permissions library file " + f + " cannot be read");
continue;
}
readPermissionsFromXml(f, permissionFlag);//从xml中读取权限，也是解析xml的过程
}
// Read platform permissions last so it will take precedence
if (platformFile != null) {
readPermissionsFromXml(platformFile, permissionFlag);
}
}
readPermissionFromXML
private void readPermissionsFromXml(File permFile, int permissionFlag) {
FileReader permReader = null;
try {
permReader = new FileReader(permFile);
} catch (FileNotFoundException e) {
Slog.w(TAG, "Couldn't find or open permissions file " + permFile);
return;
}
final boolean lowRam = ActivityManager.isLowRamDeviceStatic();
try {
XmlPullParser parser = Xml.newPullParser();
parser.setInput(permReader);
int type;
while ((type=parser.next()) != parser.START_TAG
&& type != parser.END_DOCUMENT) {
;
}
if (type != parser.START_TAG) {
throw new XmlPullParserException("No start tag found");
}
if (!parser.getName().equals("permissions") && !parser.getName().equals("config")) {
throw new XmlPullParserException("Unexpected start tag in " + permFile
+ ": found " + parser.getName() + ", expected 'permissions' or 'config'");
}
boolean allowAll = permissionFlag == ALLOW_ALL;
boolean allowLibs = (permissionFlag & ALLOW_LIBS) != 0;
boolean allowFeatures = (permissionFlag & ALLOW_FEATURES) != 0;
boolean allowPermissions = (permissionFlag & ALLOW_PERMISSIONS) != 0;
boolean allowAppConfigs = (permissionFlag & ALLOW_APP_CONFIGS) != 0;
boolean allowPrivappPermissions = (permissionFlag & ALLOW_PRIVAPP_PERMISSIONS) != 0;
boolean allowOemPermissions = (permissionFlag & ALLOW_OEM_PERMISSIONS) != 0;
boolean allowApiWhitelisting = (permissionFlag & ALLOW_HIDDENAPI_WHITELISTING) != 0;
while (true) {
XmlUtils.nextElement(parser);
if (parser.getEventType() == XmlPullParser.END_DOCUMENT) {
break;
}
String name = parser.getName();
if ("group".equals(name) && allowAll) {
String gidStr = parser.getAttributeValue(null, "gid");
if (gidStr != null) {
int gid = android.os.Process.getGidForName(gidStr);
mGlobalGids = appendInt(mGlobalGids, gid);
} else {
Slog.w(TAG, "<group> without gid in " + permFile + " at "
+ parser.getPositionDescription());
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("permission".equals(name) && allowPermissions) {
String perm = parser.getAttributeValue(null, "name");
if (perm == null) {
Slog.w(TAG, "<permission> without name in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
perm = perm.intern();
readPermission(parser, perm);
} else if ("assign-permission".equals(name) && allowPermissions) {
String perm = parser.getAttributeValue(null, "name");
if (perm == null) {
Slog.w(TAG, "<assign-permission> without name in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
String uidStr = parser.getAttributeValue(null, "uid");
if (uidStr == null) {
Slog.w(TAG, "<assign-permission> without uid in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
int uid = Process.getUidForName(uidStr);
if (uid < 0) {
Slog.w(TAG, "<assign-permission> with unknown uid \""
+ uidStr + " in " + permFile + " at "
+ parser.getPositionDescription());
XmlUtils.skipCurrentTag(parser);
continue;
}
perm = perm.intern();
ArraySet<String> perms = mSystemPermissions.get(uid);
if (perms == null) {
perms = new ArraySet<String>();
mSystemPermissions.put(uid, perms);
}
perms.add(perm);
XmlUtils.skipCurrentTag(parser);
} else if ("library".equals(name) && allowLibs) {
String lname = parser.getAttributeValue(null, "name");
String lfile = parser.getAttributeValue(null, "file");
if (lname == null) {
Slog.w(TAG, "<library> without name in " + permFile + " at "
+ parser.getPositionDescription());
} else if (lfile == null) {
Slog.w(TAG, "<library> without file in " + permFile + " at "
+ parser.getPositionDescription());
} else {
//Log.i(TAG, "Got library " + lname + " in " + lfile);
mSharedLibraries.put(lname, lfile);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("feature".equals(name) && allowFeatures) {
String fname = parser.getAttributeValue(null, "name");
int fversion = XmlUtils.readIntAttribute(parser, "version", 0);
boolean allowed;
if (!lowRam) {
allowed = true;
} else {
String notLowRam = parser.getAttributeValue(null, "notLowRam");
allowed = !"true".equals(notLowRam);
}
if (fname == null) {
Slog.w(TAG, "<feature> without name in " + permFile + " at "
+ parser.getPositionDescription());
} else if (allowed) {
addFeature(fname, fversion);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("unavailable-feature".equals(name) && allowFeatures) {
String fname = parser.getAttributeValue(null, "name");
if (fname == null) {
Slog.w(TAG, "<unavailable-feature> without name in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mUnavailableFeatures.add(fname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-in-power-save-except-idle".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-in-power-save-except-idle> without package in "
+ permFile + " at " + parser.getPositionDescription());
} else {
mAllowInPowerSaveExceptIdle.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-in-power-save".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-in-power-save> without package in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mAllowInPowerSave.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-in-data-usage-save".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-in-data-usage-save> without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mAllowInDataUsageSave.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-unthrottled-location".equals(name) && allowAll) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<allow-unthrottled-location> without package in "
+ permFile + " at " + parser.getPositionDescription());
} else {
mAllowUnthrottledLocation.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("allow-implicit-broadcast".equals(name) && allowAll) {
String action = parser.getAttributeValue(null, "action");
if (action == null) {
Slog.w(TAG, "<allow-implicit-broadcast> without action in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mAllowImplicitBroadcasts.add(action);
}
XmlUtils.skipCurrentTag(parser);
continue;
} else if ("app-link".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<app-link> without package in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mLinkedApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("system-user-whitelisted-app".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<system-user-whitelisted-app> without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mSystemUserWhitelistedApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("system-user-blacklisted-app".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<system-user-blacklisted-app without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mSystemUserBlacklistedApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("default-enabled-vr-app".equals(name) && allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
String clsname = parser.getAttributeValue(null, "class");
if (pkgname == null) {
Slog.w(TAG, "<default-enabled-vr-app without package in " + permFile
+ " at " + parser.getPositionDescription());
} else if (clsname == null) {
Slog.w(TAG, "<default-enabled-vr-app without class in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mDefaultVrComponents.add(new ComponentName(pkgname, clsname));
}
XmlUtils.skipCurrentTag(parser);
} else if ("backup-transport-whitelisted-service".equals(name) && allowFeatures) {
String serviceName = parser.getAttributeValue(null, "service");
if (serviceName == null) {
Slog.w(TAG, "<backup-transport-whitelisted-service> without service in "
+ permFile + " at " + parser.getPositionDescription());
} else {
ComponentName cn = ComponentName.unflattenFromString(serviceName);
if (cn == null) {
Slog.w(TAG,
"<backup-transport-whitelisted-service> with invalid service name "
+ serviceName + " in "+ permFile
+ " at " + parser.getPositionDescription());
} else {
mBackupTransportWhitelist.add(cn);
}
}
XmlUtils.skipCurrentTag(parser);
} else if ("disabled-until-used-preinstalled-carrier-associated-app".equals(name)
&& allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
String carrierPkgname = parser.getAttributeValue(null, "carrierAppPackage");
if (pkgname == null || carrierPkgname == null) {
Slog.w(TAG, "<disabled-until-used-preinstalled-carrier-associated-app"
+ " without package or carrierAppPackage in " + permFile + " at "
+ parser.getPositionDescription());
} else {
List<String> associatedPkgs =
mDisabledUntilUsedPreinstalledCarrierAssociatedApps.get(
carrierPkgname);
if (associatedPkgs == null) {
associatedPkgs = new ArrayList<>();
mDisabledUntilUsedPreinstalledCarrierAssociatedApps.put(
carrierPkgname, associatedPkgs);
}
associatedPkgs.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("disabled-until-used-preinstalled-carrier-app".equals(name)
&& allowAppConfigs) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG,
"<disabled-until-used-preinstalled-carrier-app> without "
+ "package in " + permFile + " at "
+ parser.getPositionDescription());
} else {
mDisabledUntilUsedPreinstalledCarrierApps.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else if ("privapp-permissions".equals(name) && allowPrivappPermissions) {
// privapp permissions from system, vendor and product partitions are stored
// separately. This is to prevent xml files in the vendor partition from
// granting permissions to priv apps in the system partition and vice
// versa.
boolean vendor = permFile.toPath().startsWith(
Environment.getVendorDirectory().toPath())
|| permFile.toPath().startsWith(
Environment.getOdmDirectory().toPath());
boolean product = permFile.toPath().startsWith(
Environment.getProductDirectory().toPath());
if (vendor) {
readPrivAppPermissions(parser, mVendorPrivAppPermissions,
mVendorPrivAppDenyPermissions);
} else if (product) {
readPrivAppPermissions(parser, mProductPrivAppPermissions,
mProductPrivAppDenyPermissions);
} else {
readPrivAppPermissions(parser, mPrivAppPermissions,
mPrivAppDenyPermissions);
}
} else if ("oem-permissions".equals(name) && allowOemPermissions) {
readOemPermissions(parser);
} else if ("hidden-api-whitelisted-app".equals(name) && allowApiWhitelisting) {
String pkgname = parser.getAttributeValue(null, "package");
if (pkgname == null) {
Slog.w(TAG, "<hidden-api-whitelisted-app> without package in " + permFile
+ " at " + parser.getPositionDescription());
} else {
mHiddenApiPackageWhitelist.add(pkgname);
}
XmlUtils.skipCurrentTag(parser);
} else {
Slog.w(TAG, "Tag " + name + " is unknown or not allowed in "
+ permFile.getParent());
XmlUtils.skipCurrentTag(parser);
continue;
}
}
} catch (XmlPullParserException e) {
Slog.w(TAG, "Got exception parsing permissions.", e);
} catch (IOException e) {
Slog.w(TAG, "Got exception parsing permissions.", e);
} finally {
IoUtils.closeQuietly(permReader);
}
// Some devices can be field-converted to FBE, so offer to splice in
// those features if not already defined by the static config
if (StorageManager.isFileEncryptedNativeOnly()) {
addFeature(PackageManager.FEATURE_FILE_BASED_ENCRYPTION, 0);
addFeature(PackageManager.FEATURE_SECURELY_REMOVES_USERS, 0);
}
// Help legacy devices that may not have updated their static config
if (StorageManager.hasAdoptable()) {
addFeature(PackageManager.FEATURE_ADOPTABLE_STORAGE, 0);
}
if (ActivityManager.isLowRamDeviceStatic()) {
addFeature(PackageManager.FEATURE_RAM_LOW, 0);
} else {
addFeature(PackageManager.FEATURE_RAM_NORMAL, 0);
}
for (String featureName : mUnavailableFeatures) {
removeFeature(featureName);
}
}
我们可以看到上面主要的作用就是将xml转化为对应的数据结构
HandleThread之创建
mHandlerThread = new ServiceThread(TAG,
Process.THREAD_PRIORITY_BACKGROUND, true /*allowIo*/);//创建packagemanager线程
mHandlerThread.start();//启动线程
mHandler = new PackageHandler(mHandlerThread.getLooper());
mProcessLoggingHandler = new ProcessLoggingHandler();
Watchdog.getInstance().addThread(mHandler, WATCHDOG_TIMEOUT);
mInstantAppRegistry = new InstantAppRegistry(this);
ArrayMap<String, String> libConfig = systemConfig.getSharedLibraries();//libs库
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);
}
SELinuxMMAC.readInstallPolicy();
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "loadFallbacks");
FallbackCategoryProvider.loadFallbacks();
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "read user settings");
mFirstBoot = !mSettings.readLPw(sUserManager.getUsers(false));//是否是首次启动
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
// Clean up orphaned packages for which the code path doesn't exist
// and they are an update to a system app - caused by bug/32321269
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);//移除不存在的package
mSettings.enableSystemPackageLPw(ps.name);
}
}
if (!mOnlyCore && mFirstBoot) {
requestCopyPreoptedFiles();
}
String customResolverActivity = Resources.getSystem().getString(
R.string.config_customResolverActivity);//读取自定义的ResolverActivity
if (TextUtils.isEmpty(customResolverActivity)) {
customResolverActivity = null;
} else {
mCustomResolverComponentName = ComponentName.unflattenFromString(
customResolverActivity);//获取自定义的组件名称
}
long startTime = SystemClock.uptimeMillis();//启动时间
EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SYSTEM_SCAN_START,
startTime);
final String bootClassPath = System.getenv("BOOTCLASSPATH");
final String systemServerClassPath = System.getenv("SYSTEMSERVERCLASSPATH");环境变量SYSTEMSERVERCLASSPATH所执行的文件
if (bootClassPath == null) {
Slog.w(TAG, "No BOOTCLASSPATH found!");
}
if (systemServerClassPath == null) {
Slog.w(TAG, "No SYSTEMSERVERCLASSPATH found!");
}
File frameworkDir = new File(Environment.getRootDirectory(), "framework");//system/framework/目录所对应的文件
final VersionInfo ver = mSettings.getInternalVersion();
mIsUpgrade = !Build.FINGERPRINT.equals(ver.fingerprint);
if (mIsUpgrade) {
logCriticalInfo(Log.INFO,
"Upgrading from " + ver.fingerprint + " to " + Build.FINGERPRINT);
}
// 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);//遍历系统应用
}
}
}
mCacheDir = preparePackageParserCache(mIsUpgrade);
扫描几个系统应用目录
// Collect vendor/product overlay packages. (Do this before scanning any apps.)
// For security and version matching reason, only consider
// overlay packages if they reside in the right directory.
scanDirTracedLI(new File(VENDOR_OVERLAY_DIR),
mDefParseFlags
| PackageParser.PARSE_IS_SYSTEM_DIR,
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_VENDOR,
0);
// Collect privileged vendor packages.
File privilegedVendorAppDir = new File(Environment.getVendorDirectory(), "priv-app");
try {
privilegedVendorAppDir = privilegedVendorAppDir.getCanonicalFile();
} catch (IOException e) {
// failed to look up canonical path, continue with original one
}
scanDirTracedLI(privilegedVendorAppDir,
mDefParseFlags
| PackageParser.PARSE_IS_SYSTEM_DIR,
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_VENDOR
| SCAN_AS_PRIVILEGED,
0);
// Collect ordinary vendor packages.
File vendorAppDir = new File(Environment.getVendorDirectory(), "app");
try {
vendorAppDir = vendorAppDir.getCanonicalFile();
} catch (IOException e) {
// failed to look up canonical path, continue with original one
}
// Collect privileged odm packages. /odm is another vendor partition
// other than /vendor.
File privilegedOdmAppDir = new File(Environment.getOdmDirectory(),
"priv-app");
try {
privilegedOdmAppDir = privilegedOdmAppDir.getCanonicalFile();
} catch (IOException e) {
// failed to look up canonical path, continue with original one
}
// Collect ordinary odm packages. /odm is another vendor partition
// other than /vendor.
File odmAppDir = new File(Environment.getOdmDirectory(), "app");
try {
odmAppDir = odmAppDir.getCanonicalFile();
} catch (IOException e) {
// failed to look up canonical path, continue with original one
}
...省去部分代码
scanDirTracedLI(productAppDir,
mDefParseFlags
| PackageParser.PARSE_IS_SYSTEM_DIR,
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_PRODUCT,
0);
扫描完之后的工作
if (!mOnlyCore) {//处理非系统应用的 EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_DATA_SCAN_START,
SystemClock.uptimeMillis());//data/app目录
scanDirTracedLI(sAppInstallDir, 0, scanFlags | SCAN_REQUIRE_KNOWN, 0);
scanDirTracedLI(sDrmAppPrivateInstallDir, mDefParseFlags//收集data/app-private
| PackageParser.PARSE_FORWARD_LOCK,
scanFlags | SCAN_REQUIRE_KNOWN, 0);
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";
final PackageSetting deletedPs = mSettings.mPackages.get(deletedAppName);
deletedPkg.applicationInfo.flags &= ~ApplicationInfo.FLAG_SYSTEM;
deletedPs.pkgFlags &= ~ApplicationInfo.FLAG_SYSTEM;
}
logCriticalInfo(Log.WARN, msg);
}
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");
final @ParseFlags int reparseFlags;
final @ScanFlags int rescanFlags;
if (FileUtils.contains(privilegedAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_PRIVILEGED;
} else if (FileUtils.contains(systemAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM;
} else if (FileUtils.contains(privilegedVendorAppDir, scanFile)
|| FileUtils.contains(privilegedOdmAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_VENDOR
| SCAN_AS_PRIVILEGED;
} else if (FileUtils.contains(vendorAppDir, scanFile)
|| FileUtils.contains(odmAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_VENDOR;
} else if (FileUtils.contains(oemAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_OEM;
} else if (FileUtils.contains(privilegedProductAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_PRODUCT
| SCAN_AS_PRIVILEGED;
} else if (FileUtils.contains(productAppDir, scanFile)) {
reparseFlags =
mDefParseFlags |
PackageParser.PARSE_IS_SYSTEM_DIR;
rescanFlags =
scanFlags
| SCAN_AS_SYSTEM
| SCAN_AS_PRODUCT;
} else {
Slog.e(TAG, "Ignoring unexpected fallback path " + scanFile);
continue;
}
mSettings.enableSystemPackageLPw(packageName);
try {
scanPackageTracedLI(scanFile, reparseFlags, rescanFlags, 0, null);
} catch (PackageManagerException e) {
Slog.e(TAG, "Failed to parse original system package: "
+ e.getMessage());
}
}
}
当monlyCore=false的时候会扫描/data/app/, data/private/目录
扫描结束
EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_SCAN_END,
SystemClock.uptimeMillis());
final boolean sdkUpdated = (ver.sdkVersion != mSdkVersion);
if (sdkUpdated) {
Slog.i(TAG, "Platform changed from " + ver.sdkVersion + " to "
+ mSdkVersion + "; regranting permissions for internal storage");
}
mPermissionManager.updateAllPermissions(
StorageManager.UUID_PRIVATE_INTERNAL, sdkUpdated, mPackages.values(),
mPermissionCallback);//当sdk版本不一致时则需要更新权限
ver.sdkVersion = mSdkVersion;
if (!onlyCore && (mPromoteSystemApps || mFirstBoot)) {
for (UserInfo user : sUserManager.getUsers(true)) {
mSettings.applyDefaultPreferredAppsLPw(this, user.id);
applyFactoryDefaultBrowserLPw(user.id);
primeDomainVerificationsLPw(user.id);
}
}
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");
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();
// clear only after permissions and other defaults have been updated
mExistingSystemPackages.clear();//清理动作
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");
mSettings.writeLPr();//写package.xml文件
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
PMS的准备ready
EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_READY,
SystemClock.uptimeMillis());
if (!mOnlyCore) {//非系统应用
mRequiredVerifierPackage = getRequiredButNotReallyRequiredVerifierLPr();
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;
mRequiredInstallerPackage = null;
mRequiredUninstallerPackage = null;
mIntentFilterVerifierComponent = null;
mIntentFilterVerifier = null;
mServicesSystemSharedLibraryPackageName = null;
mSharedSystemSharedLibraryPackageName = null;
}
mInstallerService = new PackageInstallerService(context, this);//创建一个包安装服务
final Pair<ComponentName, String> instantAppResolverComponent =
getInstantAppResolverLPr();
if (instantAppResolverComponent != null) {
if (DEBUG_INSTANT) {
Slog.d(TAG, "Set ephemeral resolver: " + instantAppResolverComponent);
}
mInstantAppResolverConnection = new InstantAppResolverConnection(
mContext, instantAppResolverComponent.first,
instantAppResolverComponent.second);
mInstantAppResolverSettingsComponent =
getInstantAppResolverSettingsLPr(instantAppResolverComponent.first);
} else {
mInstantAppResolverConnection = null;
mInstantAppResolverSettingsComponent = null;
}
updateInstantAppInstallerLocked(null);
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)
PackageInstallerService服务的创建
public PackageInstallerService(Context context, PackageManagerService pm) {
mContext = context;
mPm = pm;
mPermissionManager = LocalServices.getService(PermissionManagerInternal.class);
mInstallThread = new HandlerThread(TAG);//PackageInstaller线程创建
mInstallThread.start();//启动线程
mInstallHandler = new Handler(mInstallThread.getLooper());//创建一个handler对象，用于处理各种事物
mCallbacks = new Callbacks(mInstallThread.getLooper());
mSessionsFile = new AtomicFile(
new File(Environment.getDataSystemDirectory(), "install_sessions.xml"),
"package-session");
mSessionsDir = new File(Environment.getDataSystemDirectory(), "install_sessions");
mSessionsDir.mkdirs();//创建data/system/目录
}
这样pms的初始化阶段基本完成，接下来就是pms在startOtherService部分的工作
总结
PMS的初始化分为5个阶段
1：PMS_START阶段：
创建Settings对象；
将6类shareUserId到mSettings；
初始化SystemConfig；
创建名为“PackageManager”的handler线程mHandlerThread;
创建UserManagerService多用户管理服务；
通过解析4大目录中的xmL文件构造共享mSharedLibraries；
2:PMS_SYSTEM_SCAN_START阶段：系统应用阶段
mSharedLibraries共享库中的文件执行dexopt操作；
system/framework目录中满足条件的apk或jar文件执行dexopt操作；
扫描系统apk;
3:PMS_DATA_SCAN_START阶段：非系统应用阶段
扫描/data/app目录下的apk;
扫描/data/app-private目录下的apk;
4:PMS_SCAN_END阶段：//扫描结束事件，写xml文件
将上述信息写回/data/system/packages.xml;
5:PMS_READY阶段：
创建服务PackageInstallerService；
