Android 8.1 源碼_核心篇 -- 深入研究 PackageManagerService 系列(3)

開篇

核心源碼

關鍵類 路徑
SystemServer.java frameworks/base/services/java/com/android/server/SystemServer.java
PackageManagerService.java frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java
Process.java frameworks/base/core/java/android/os/Process.java
SystemConfig.java frameworks/base/core/java/com/android/server/SystemConfig.java
Settings.java frameworks/base/services/core/java/com/android/server/pm/Settings.java

簡介

PackageManagerService(PMS)是 SystemServer 啓動後的第一個核心服務,也是 Android 系統中最常用的服務之一。它負責系統中 Package 的管理,應用程序的安裝、卸載、信息查詢等。如果你是面向 Android 系統開發的工程師,基礎概念我也不需要再多贅述,我們直接跟源碼。

PackageParser

parseMonolithicPackageLite

    private static PackageLite parseMonolithicPackageLite(File packageFile, int flags)
            throws PackageParserException {
        final ApkLite baseApk = parseApkLite(packageFile, flags);
        final String packagePath = packageFile.getAbsolutePath();
        return new PackageLite(packagePath, baseApk, null, null, null, null, null, null);
    }

這個方法就是調用parseApkLite()方法來獲取一個ApkLite對象,然後用這個ApkLite對象構造一個PackageLite對象。

parseApkLite-01

    /**
     * Utility method that retrieves lightweight details about a single APK
     * file, including package name, split name, and install location.
     *
     * @param apkFile path to a single APK
     * @param flags optional parse flags, such as
     *            {@link #PARSE_COLLECT_CERTIFICATES}
     */
    public static ApkLite parseApkLite(File apkFile, int flags)
            throws PackageParserException {
        final String apkPath = apkFile.getAbsolutePath();

        // 創建 AssetManager 對象
        AssetManager assets = null;
        XmlResourceParser parser = null;
        try {
            assets = newConfiguredAssetManager();
            int cookie = assets.addAssetPath(apkPath);
            if (cookie == 0) {
                throw new PackageParserException(INSTALL_PARSE_FAILED_NOT_APK,
                        "Failed to parse " + apkPath);
            }

            final DisplayMetrics metrics = new DisplayMetrics();
            metrics.setToDefaults();

            parser = assets.openXmlResourceParser(cookie, ANDROID_MANIFEST_FILENAME);

            final Signature[] signatures;
            final Certificate[][] certificates;
            // 設置簽名
            if ((flags & PARSE_COLLECT_CERTIFICATES) != 0) {
                // TODO: factor signature related items out of Package object
                final Package tempPkg = new Package((String) null);
                Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "collectCertificates");
                try {
                    collectCertificates(tempPkg, apkFile, flags);
                } finally {
                    Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
                }
                signatures = tempPkg.mSignatures;
                certificates = tempPkg.mCertificates;
            } else {
                signatures = null;
                certificates = null;
            }

            final AttributeSet attrs = parser;
            return parseApkLite(apkPath, parser, attrs, signatures, certificates);

        } catch (XmlPullParserException | IOException | RuntimeException e) {
            Slog.w(TAG, "Failed to parse " + apkPath, e);
            throw new PackageParserException(INSTALL_PARSE_FAILED_UNEXPECTED_EXCEPTION,
                    "Failed to parse " + apkPath, e);
        } finally {
            // 關閉資源管理器與解析器
            IoUtils.closeQuietly(parser);
            IoUtils.closeQuietly(assets);
        }
    }

parseApkLite-02

    private static ApkLite parseApkLite(String codePath, XmlPullParser parser, AttributeSet attrs,
            Signature[] signatures, Certificate[][] certificates)
            throws IOException, XmlPullParserException, PackageParserException {
        // 調用了parsePackageSplitNames()方法來獲取packageSplit
        final Pair<String, String> packageSplit = parsePackageSplitNames(parser, attrs);

        int installLocation = PARSE_DEFAULT_INSTALL_LOCATION;
        int versionCode = 0;
        int revisionCode = 0;
        boolean coreApp = false;
        boolean debuggable = false;
        boolean multiArch = false;
        boolean use32bitAbi = false;
        boolean extractNativeLibs = true;
        boolean isolatedSplits = false;
        boolean isFeatureSplit = false;
        String configForSplit = null;
        String usesSplitName = null;

        // 遍歷屬性,並獲取相應的值
        for (int i = 0; i < attrs.getAttributeCount(); i++) {
            final String attr = attrs.getAttributeName(i);
            if (attr.equals("installLocation")) {
                installLocation = attrs.getAttributeIntValue(i,
                        PARSE_DEFAULT_INSTALL_LOCATION);
            } else if (attr.equals("versionCode")) {
                versionCode = attrs.getAttributeIntValue(i, 0);
            } else if (attr.equals("revisionCode")) {
                revisionCode = attrs.getAttributeIntValue(i, 0);
            } else if (attr.equals("coreApp")) {
                coreApp = attrs.getAttributeBooleanValue(i, false);
            } else if (attr.equals("isolatedSplits")) {
                isolatedSplits = attrs.getAttributeBooleanValue(i, false);
            } else if (attr.equals("configForSplit")) {
                configForSplit = attrs.getAttributeValue(i);
            } else if (attr.equals("isFeatureSplit")) {
                isFeatureSplit = attrs.getAttributeBooleanValue(i, false);
            }
        }

        // Only search the tree when the tag is directly below <manifest>
        int type;
        final int searchDepth = parser.getDepth() + 1;

        final List<VerifierInfo> verifiers = new ArrayList<VerifierInfo>();
        // private static final String TAG_PACKAGE_VERIFIER = "package-verifier"
        // 繼續解析package-verifier節點
        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
                && (type != XmlPullParser.END_TAG || parser.getDepth() >= searchDepth)) {
            if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                continue;
            }

            if (parser.getDepth() != searchDepth) {
                continue;
            }

            if (TAG_PACKAGE_VERIFIER.equals(parser.getName())) {
                final VerifierInfo verifier = parseVerifier(attrs);
                if (verifier != null) {
                    verifiers.add(verifier);
                }
            } else if (TAG_APPLICATION.equals(parser.getName())) {
                for (int i = 0; i < attrs.getAttributeCount(); ++i) {
                    final String attr = attrs.getAttributeName(i);
                    if ("debuggable".equals(attr)) {
                        debuggable = attrs.getAttributeBooleanValue(i, false);
                    }
                    if ("multiArch".equals(attr)) {
                        multiArch = attrs.getAttributeBooleanValue(i, false);
                    }
                    if ("use32bitAbi".equals(attr)) {
                        use32bitAbi = attrs.getAttributeBooleanValue(i, false);
                    }
                    if ("extractNativeLibs".equals(attr)) {
                        extractNativeLibs = attrs.getAttributeBooleanValue(i, true);
                    }
                }
            } else if (TAG_USES_SPLIT.equals(parser.getName())) {
                if (usesSplitName != null) {
                    Slog.w(TAG, "Only one <uses-split> permitted. Ignoring others.");
                    continue;
                }

                usesSplitName = attrs.getAttributeValue(ANDROID_RESOURCES, "name");
                if (usesSplitName == null) {
                    throw new PackageParserException(
                            PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED,
                            "<uses-split> tag requires 'android:name' attribute");
                }
            }
        }
        
        //利用解析出來的數據去構造一個ApkLite對象
        return new ApkLite(codePath, packageSplit.first, packageSplit.second, isFeatureSplit,
                configForSplit, usesSplitName, versionCode, revisionCode, installLocation,
                verifiers, signatures, certificates, coreApp, debuggable, multiArch, use32bitAbi,
                extractNativeLibs, isolatedSplits);
    }

parsePackageSplitNames

// 這個方法主要是解析manifest
    private static Pair<String, String> parsePackageSplitNames(XmlPullParser parser,
            AttributeSet attrs) throws IOException, XmlPullParserException,
            PackageParserException {

        int type;
        while ((type = parser.next()) != XmlPullParser.START_TAG
                && type != XmlPullParser.END_DOCUMENT) {
        }

        if (type != XmlPullParser.START_TAG) {
            throw new PackageParserException(INSTALL_PARSE_FAILED_MANIFEST_MALFORMED,
                    "No start tag found");
        }
        if (!parser.getName().equals(TAG_MANIFEST)) {
            throw new PackageParserException(INSTALL_PARSE_FAILED_MANIFEST_MALFORMED,
                    "No <manifest> tag");
        }

        final String packageName = attrs.getAttributeValue(null, "package");
        if (!"android".equals(packageName)) {
            // 這個方法主要就是檢測是否是數字、字母、下劃線和點分隔符,這也是取包名的規則,
            // 比如是字母數字下劃線加點分隔符,否則都不是合法的應用包名。並且合法的包名至少包含一個點分隔符。
            final String error = validateName(packageName, true, true);
            if (error != null) {
                throw new PackageParserException(INSTALL_PARSE_FAILED_BAD_PACKAGE_NAME,
                        "Invalid manifest package: " + error);
            }
        }

        String splitName = attrs.getAttributeValue(null, "split");
        if (splitName != null) {
            if (splitName.length() == 0) {
                splitName = null;
            } else {
                final String error = validateName(splitName, false, false);
                if (error != null) {
                    throw new PackageParserException(INSTALL_PARSE_FAILED_BAD_PACKAGE_NAME,
                            "Invalid manifest split: " + error);
                }
            }
        }

        return Pair.create(packageName.intern(),
                (splitName != null) ? splitName.intern() : splitName);
    }

parseBaseApk

    private Package parseBaseApk(File apkFile, AssetManager assets, int flags)
            throws PackageParserException {
        final String apkPath = apkFile.getAbsolutePath();

        String volumeUuid = null;
        if (apkPath.startsWith(MNT_EXPAND)) {
            final int end = apkPath.indexOf('/', MNT_EXPAND.length());
            volumeUuid = apkPath.substring(MNT_EXPAND.length(), end);
        }

        mParseError = PackageManager.INSTALL_SUCCEEDED;
        mArchiveSourcePath = apkFile.getAbsolutePath();

        if (DEBUG_JAR) Slog.d(TAG, "Scanning base APK: " + apkPath);

        final int cookie = loadApkIntoAssetManager(assets, apkPath, flags);

        Resources res = null;
        XmlResourceParser parser = null;
        try {
            res = new Resources(assets, mMetrics, null);
            parser = assets.openXmlResourceParser(cookie, ANDROID_MANIFEST_FILENAME);

            final String[] outError = new String[1];
            final Package pkg = parseBaseApk(apkPath, res, parser, flags, outError);
            if (pkg == null) {
                throw new PackageParserException(mParseError,
                        apkPath + " (at " + parser.getPositionDescription() + "): " + outError[0]);
            }

            pkg.setVolumeUuid(volumeUuid);
            pkg.setApplicationVolumeUuid(volumeUuid);
            pkg.setBaseCodePath(apkPath);
            pkg.setSignatures(null);

            return pkg;

        } catch (PackageParserException e) {
            throw e;
        } catch (Exception e) {
            throw new PackageParserException(INSTALL_PARSE_FAILED_UNEXPECTED_EXCEPTION,
                    "Failed to read manifest from " + apkPath, e);
        } finally {
            IoUtils.closeQuietly(parser);
        }
    }

parseBaseApk

    private Package parseBaseApk(String apkPath, Resources res, XmlResourceParser parser, int flags,
            String[] outError) throws XmlPullParserException, IOException {
        final String splitName;
        final String pkgName;

        try {
            Pair<String, String> packageSplit = parsePackageSplitNames(parser, parser);
            pkgName = packageSplit.first;
            splitName = packageSplit.second;

            if (!TextUtils.isEmpty(splitName)) {
                outError[0] = "Expected base APK, but found split " + splitName;
                mParseError = PackageManager.INSTALL_PARSE_FAILED_BAD_PACKAGE_NAME;
                return null;
            }
        } catch (PackageParserException e) {
            mParseError = PackageManager.INSTALL_PARSE_FAILED_BAD_PACKAGE_NAME;
            return null;
        }

        if (mCallback != null) {
            String[] overlayPaths = mCallback.getOverlayPaths(pkgName, apkPath);
            if (overlayPaths != null && overlayPaths.length > 0) {
                for (String overlayPath : overlayPaths) {
                    res.getAssets().addOverlayPath(overlayPath);
                }
            }
        }

        // 用包名構造一個Package
        final Package pkg = new Package(pkgName);

        // 獲取資源數組
        TypedArray sa = res.obtainAttributes(parser,
                com.android.internal.R.styleable.AndroidManifest);

        // 初始化pkg的屬性mVersionCode、baseRevisionCode和mVersionName
        pkg.mVersionCode = pkg.applicationInfo.versionCode = sa.getInteger(
                com.android.internal.R.styleable.AndroidManifest_versionCode, 0);
        pkg.baseRevisionCode = sa.getInteger(
                com.android.internal.R.styleable.AndroidManifest_revisionCode, 0);
        pkg.mVersionName = sa.getNonConfigurationString(
                com.android.internal.R.styleable.AndroidManifest_versionName, 0);
        if (pkg.mVersionName != null) {
            pkg.mVersionName = pkg.mVersionName.intern();
        }

        // 判斷是不是核心app
        pkg.coreApp = parser.getAttributeBooleanValue(null, "coreApp", false);

        sa.recycle();

        // 解析AndroidManifest下面的每一個節點
        return parseBaseApkCommon(pkg, null, res, parser, flags, outError);
    }

parseBaseApkCommon

    private Package parseBaseApkCommon(Package pkg, Set<String> acceptedTags, Resources res,
            XmlResourceParser parser, int flags, String[] outError) throws XmlPullParserException,
            IOException {

        ... ...

        /* Set the global "forward lock" flag */
        if ((flags & PARSE_FORWARD_LOCK) != 0) {
            pkg.applicationInfo.privateFlags |= ApplicationInfo.PRIVATE_FLAG_FORWARD_LOCK;
        }

        /* Set the global "on SD card" flag */
        // 是否要安裝在SD卡上
        if ((flags & PARSE_EXTERNAL_STORAGE) != 0) {
            pkg.applicationInfo.flags |= ApplicationInfo.FLAG_EXTERNAL_STORAGE;
        }

        // Resource boolean are -1, so 1 means we don't know the value.
        int supportsSmallScreens = 1;
        int supportsNormalScreens = 1;
        int supportsLargeScreens = 1;
        int supportsXLargeScreens = 1;
        int resizeable = 1;
        int anyDensity = 1;

        int outerDepth = parser.getDepth();

        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
                && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
            if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                continue;
            }

            ... ...
            
            // 解析<application> 標籤
            if (tagName.equals(TAG_APPLICATION)) {
                if (foundApp) {
                    if (RIGID_PARSER) {
                        outError[0] = "<manifest> has more than one <application>";
                        mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                        return null;
                    } else {
                        Slog.w(TAG, "<manifest> has more than one <application>");
                        XmlUtils.skipCurrentTag(parser);
                        continue;
                    }
                }

                foundApp = true;
                if (!parseBaseApplication(pkg, res, parser, flags, outError)) {
                    return null;
                }
            // 解析<overlay> 標籤
            } else if (tagName.equals(TAG_OVERLAY)) {
                sa = res.obtainAttributes(parser,
                        com.android.internal.R.styleable.AndroidManifestResourceOverlay);
                pkg.mOverlayTarget = sa.getString(
                        com.android.internal.R.styleable.AndroidManifestResourceOverlay_targetPackage);
                pkg.mOverlayPriority = sa.getInt(
                        com.android.internal.R.styleable.AndroidManifestResourceOverlay_priority,
                        0);
                pkg.mIsStaticOverlay = sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestResourceOverlay_isStatic,
                        false);
                final String propName = sa.getString(
                        com.android.internal.R.styleable
                        .AndroidManifestResourceOverlay_requiredSystemPropertyName);
                final String propValue = sa.getString(
                        com.android.internal.R.styleable
                        .AndroidManifestResourceOverlay_requiredSystemPropertyValue);
                sa.recycle();

                if (pkg.mOverlayTarget == null) {
                    outError[0] = "<overlay> does not specify a target package";
                    mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return null;
                }

                if (pkg.mOverlayPriority < 0 || pkg.mOverlayPriority > 9999) {
                    outError[0] = "<overlay> priority must be between 0 and 9999";
                    mParseError =
                        PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return null;
                }

                // check to see if overlay should be excluded based on system property condition
                if (!checkOverlayRequiredSystemProperty(propName, propValue)) {
                    Slog.i(TAG, "Skipping target and overlay pair " + pkg.mOverlayTarget + " and "
                        + pkg.baseCodePath+ ": overlay ignored due to required system property: "
                        + propName + " with value: " + propValue);
                    return null;
                }

                XmlUtils.skipCurrentTag(parser);
            // 解析<key-sets> 標籤
            } else if (tagName.equals(TAG_KEY_SETS)) {
                if (!parseKeySets(pkg, res, parser, outError)) {
                    return null;
                }
            // 解析<permission-group> 標籤
            } else if (tagName.equals(TAG_PERMISSION_GROUP)) {
                if (!parsePermissionGroup(pkg, flags, res, parser, outError)) {
                    return null;
                }
            // 解析<permission> 標籤
            } else if (tagName.equals(TAG_PERMISSION)) {
                if (!parsePermission(pkg, res, parser, outError)) {
                    return null;
                }
            // 解析<permission-tree> 標籤
            } else if (tagName.equals(TAG_PERMISSION_TREE)) {
                if (!parsePermissionTree(pkg, res, parser, outError)) {
                    return null;
                }
            // 解析<uses-permission> 標籤
            } else if (tagName.equals(TAG_USES_PERMISSION)) {
                if (!parseUsesPermission(pkg, res, parser)) {
                    return null;
                }
            // 解析<uses-permission-sdk-m> 標籤或者 <uses-permission-sdk-23> 標籤
            } else if (tagName.equals(TAG_USES_PERMISSION_SDK_M)
                    || tagName.equals(TAG_USES_PERMISSION_SDK_23)) {
                if (!parseUsesPermission(pkg, res, parser)) {
                    return null;
                }
            // 解析<uses-configuration>標籤
            } else if (tagName.equals(TAG_USES_CONFIGURATION)) {
                ConfigurationInfo cPref = new ConfigurationInfo();
                sa = res.obtainAttributes(parser,
                        com.android.internal.R.styleable.AndroidManifestUsesConfiguration);
                cPref.reqTouchScreen = sa.getInt(
                        com.android.internal.R.styleable.AndroidManifestUsesConfiguration_reqTouchScreen,
                        Configuration.TOUCHSCREEN_UNDEFINED);
                cPref.reqKeyboardType = sa.getInt(
                        com.android.internal.R.styleable.AndroidManifestUsesConfiguration_reqKeyboardType,
                        Configuration.KEYBOARD_UNDEFINED);
                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestUsesConfiguration_reqHardKeyboard,
                        false)) {
                    cPref.reqInputFeatures |= ConfigurationInfo.INPUT_FEATURE_HARD_KEYBOARD;
                }
                cPref.reqNavigation = sa.getInt(
                        com.android.internal.R.styleable.AndroidManifestUsesConfiguration_reqNavigation,
                        Configuration.NAVIGATION_UNDEFINED);
                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestUsesConfiguration_reqFiveWayNav,
                        false)) {
                    cPref.reqInputFeatures |= ConfigurationInfo.INPUT_FEATURE_FIVE_WAY_NAV;
                }
                sa.recycle();
                pkg.configPreferences = ArrayUtils.add(pkg.configPreferences, cPref);

                XmlUtils.skipCurrentTag(parser);
            // 解析<uses-feature>標籤
            } else if (tagName.equals(TAG_USES_FEATURE)) {
                FeatureInfo fi = parseUsesFeature(res, parser);
                pkg.reqFeatures = ArrayUtils.add(pkg.reqFeatures, fi);

                if (fi.name == null) {
                    ConfigurationInfo cPref = new ConfigurationInfo();
                    cPref.reqGlEsVersion = fi.reqGlEsVersion;
                    pkg.configPreferences = ArrayUtils.add(pkg.configPreferences, cPref);
                }

                XmlUtils.skipCurrentTag(parser);
            // 解析<feature-group>標籤
            } else if (tagName.equals(TAG_FEATURE_GROUP)) {
                FeatureGroupInfo group = new FeatureGroupInfo();
                ArrayList<FeatureInfo> features = null;
                final int innerDepth = parser.getDepth();
                while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
                        && (type != XmlPullParser.END_TAG || parser.getDepth() > innerDepth)) {
                    if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                        continue;
                    }

                    final String innerTagName = parser.getName();
                    if (innerTagName.equals("uses-feature")) {
                        FeatureInfo featureInfo = parseUsesFeature(res, parser);
                        // FeatureGroups are stricter and mandate that
                        // any <uses-feature> declared are mandatory.
                        featureInfo.flags |= FeatureInfo.FLAG_REQUIRED;
                        features = ArrayUtils.add(features, featureInfo);
                    } else {
                        Slog.w(TAG, "Unknown element under <feature-group>: " + innerTagName +
                                " at " + mArchiveSourcePath + " " +
                                parser.getPositionDescription());
                    }
                    XmlUtils.skipCurrentTag(parser);
                }

                if (features != null) {
                    group.features = new FeatureInfo[features.size()];
                    group.features = features.toArray(group.features);
                }
                pkg.featureGroups = ArrayUtils.add(pkg.featureGroups, group);
            // 解析<uses-sdk>標籤
            } else if (tagName.equals(TAG_USES_SDK)) {
                if (SDK_VERSION > 0) {
                    sa = res.obtainAttributes(parser,
                            com.android.internal.R.styleable.AndroidManifestUsesSdk);

                    int minVers = 1;
                    String minCode = null;
                    int targetVers = 0;
                    String targetCode = null;

                    TypedValue val = sa.peekValue(
                            com.android.internal.R.styleable.AndroidManifestUsesSdk_minSdkVersion);
                    if (val != null) {
                        if (val.type == TypedValue.TYPE_STRING && val.string != null) {
                            targetCode = minCode = val.string.toString();
                        } else {
                            // If it's not a string, it's an integer.
                            targetVers = minVers = val.data;
                        }
                    }

                    val = sa.peekValue(
                            com.android.internal.R.styleable.AndroidManifestUsesSdk_targetSdkVersion);
                    if (val != null) {
                        if (val.type == TypedValue.TYPE_STRING && val.string != null) {
                            targetCode = val.string.toString();
                            if (minCode == null) {
                                minCode = targetCode;
                            }
                        } else {
                            // If it's not a string, it's an integer.
                            targetVers = val.data;
                        }
                    }

                    sa.recycle();

                    final int minSdkVersion = PackageParser.computeMinSdkVersion(minVers, minCode,
                            SDK_VERSION, SDK_CODENAMES, outError);
                    if (minSdkVersion < 0) {
                        mParseError = PackageManager.INSTALL_FAILED_OLDER_SDK;
                        return null;
                    }

                    final int targetSdkVersion = PackageParser.computeTargetSdkVersion(targetVers,
                            targetCode, SDK_VERSION, SDK_CODENAMES, outError);
                    if (targetSdkVersion < 0) {
                        mParseError = PackageManager.INSTALL_FAILED_OLDER_SDK;
                        return null;
                    }

                    pkg.applicationInfo.minSdkVersion = minSdkVersion;
                    pkg.applicationInfo.targetSdkVersion = targetSdkVersion;
                }

                XmlUtils.skipCurrentTag(parser);
            // 解析<supports-screens>標籤
            } else if (tagName.equals(TAG_SUPPORT_SCREENS)) {
                sa = res.obtainAttributes(parser,
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens);

                pkg.applicationInfo.requiresSmallestWidthDp = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_requiresSmallestWidthDp,
                        0);
                pkg.applicationInfo.compatibleWidthLimitDp = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_compatibleWidthLimitDp,
                        0);
                pkg.applicationInfo.largestWidthLimitDp = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_largestWidthLimitDp,
                        0);

                // This is a trick to get a boolean and still able to detect
                // if a value was actually set.
                supportsSmallScreens = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_smallScreens,
                        supportsSmallScreens);
                supportsNormalScreens = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_normalScreens,
                        supportsNormalScreens);
                supportsLargeScreens = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_largeScreens,
                        supportsLargeScreens);
                supportsXLargeScreens = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_xlargeScreens,
                        supportsXLargeScreens);
                resizeable = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_resizeable,
                        resizeable);
                anyDensity = sa.getInteger(
                        com.android.internal.R.styleable.AndroidManifestSupportsScreens_anyDensity,
                        anyDensity);

                sa.recycle();

                XmlUtils.skipCurrentTag(parser);
            // 解析<protected-broadcast>標籤
            } else if (tagName.equals(TAG_PROTECTED_BROADCAST)) {
                sa = res.obtainAttributes(parser,
                        com.android.internal.R.styleable.AndroidManifestProtectedBroadcast);

                // Note: don't allow this value to be a reference to a resource
                // that may change.
                String name = sa.getNonResourceString(
                        com.android.internal.R.styleable.AndroidManifestProtectedBroadcast_name);

                sa.recycle();

                if (name != null && (flags&PARSE_IS_SYSTEM) != 0) {
                    if (pkg.protectedBroadcasts == null) {
                        pkg.protectedBroadcasts = new ArrayList<String>();
                    }
                    if (!pkg.protectedBroadcasts.contains(name)) {
                        pkg.protectedBroadcasts.add(name.intern());
                    }
                }

                XmlUtils.skipCurrentTag(parser);
            // 解析<instrumentation>標籤
            } else if (tagName.equals(TAG_INSTRUMENTATION)) {
                if (parseInstrumentation(pkg, res, parser, outError) == null) {
                    return null;
                }
            // 解析<original-package>標籤
            } else if (tagName.equals(TAG_ORIGINAL_PACKAGE)) {
                sa = res.obtainAttributes(parser,
                        com.android.internal.R.styleable.AndroidManifestOriginalPackage);

                String orig =sa.getNonConfigurationString(
                        com.android.internal.R.styleable.AndroidManifestOriginalPackage_name, 0);
                if (!pkg.packageName.equals(orig)) {
                    if (pkg.mOriginalPackages == null) {
                        pkg.mOriginalPackages = new ArrayList<String>();
                        pkg.mRealPackage = pkg.packageName;
                    }
                    pkg.mOriginalPackages.add(orig);
                }

                sa.recycle();

                XmlUtils.skipCurrentTag(parser);
            // 解析<adopt-permissions>標籤
            } else if (tagName.equals(TAG_ADOPT_PERMISSIONS)) {
                sa = res.obtainAttributes(parser,
                        com.android.internal.R.styleable.AndroidManifestOriginalPackage);

                String name = sa.getNonConfigurationString(
                        com.android.internal.R.styleable.AndroidManifestOriginalPackage_name, 0);

                sa.recycle();

                if (name != null) {
                    if (pkg.mAdoptPermissions == null) {
                        pkg.mAdoptPermissions = new ArrayList<String>();
                    }
                    pkg.mAdoptPermissions.add(name);
                }

                XmlUtils.skipCurrentTag(parser);
            // 解析<uses-gl-texture>標籤
            } else if (tagName.equals(TAG_USES_GL_TEXTURE)) {
                // Just skip this tag
                XmlUtils.skipCurrentTag(parser);
                continue;
            // 解析<compatible-screens>標籤
            } else if (tagName.equals(TAG_COMPATIBLE_SCREENS)) {
                // Just skip this tag
                XmlUtils.skipCurrentTag(parser);
                continue;
            // 解析<supports-input>標籤
            } else if (tagName.equals(TAG_SUPPORTS_INPUT)) {//
                XmlUtils.skipCurrentTag(parser);
                continue;
            // 解析<eat-comment>標籤
            } else if (tagName.equals(TAG_EAT_COMMENT)) {
                // Just skip this tag
                XmlUtils.skipCurrentTag(parser);
                continue;

            } else if (tagName.equals(TAG_PACKAGE)) {
                if (!MULTI_PACKAGE_APK_ENABLED) {
                    XmlUtils.skipCurrentTag(parser);
                    continue;
                }
                if (!parseBaseApkChild(pkg, res, parser, flags, outError)) {
                    // If parsing a child failed the error is already set
                    return null;
                }

            } else if (tagName.equals(TAG_RESTRICT_UPDATE)) {
                if ((flags & PARSE_IS_SYSTEM_DIR) != 0) {
                    sa = res.obtainAttributes(parser,
                            com.android.internal.R.styleable.AndroidManifestRestrictUpdate);
                    final String hash = sa.getNonConfigurationString(
                            com.android.internal.R.styleable.AndroidManifestRestrictUpdate_hash, 0);
                    sa.recycle();

                    pkg.restrictUpdateHash = null;
                    if (hash != null) {
                        final int hashLength = hash.length();
                        final byte[] hashBytes = new byte[hashLength / 2];
                        for (int i = 0; i < hashLength; i += 2){
                            hashBytes[i/2] = (byte) ((Character.digit(hash.charAt(i), 16) << 4)
                                    + Character.digit(hash.charAt(i + 1), 16));
                        }
                        pkg.restrictUpdateHash = hashBytes;
                    }
                }

                XmlUtils.skipCurrentTag(parser);

            } else if (RIGID_PARSER) {
                outError[0] = "Bad element under <manifest>: "
                    + parser.getName();
                mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                return null;

            } else {
                Slog.w(TAG, "Unknown element under <manifest>: " + parser.getName()
                        + " at " + mArchiveSourcePath + " "
                        + parser.getPositionDescription());
                XmlUtils.skipCurrentTag(parser);
                continue;
            }
        }

parseBaseApplication

    private boolean parseBaseApplication(Package owner, Resources res,
            XmlResourceParser parser, int flags, String[] outError)
        throws XmlPullParserException, IOException {
        // 獲取ApplicationInfo對象ai
        final ApplicationInfo ai = owner.applicationInfo;
        // 獲取包名
        final String pkgName = owner.applicationInfo.packageName;

        // 從資源裏面獲取AndroidManifest的數組
        TypedArray sa = res.obtainAttributes(parser,
                com.android.internal.R.styleable.AndroidManifestApplication);

        if (!parsePackageItemInfo(owner, ai, outError,
                "<application>", sa, false /*nameRequired*/,
                com.android.internal.R.styleable.AndroidManifestApplication_name,
                com.android.internal.R.styleable.AndroidManifestApplication_label,
                com.android.internal.R.styleable.AndroidManifestApplication_icon,
                com.android.internal.R.styleable.AndroidManifestApplication_roundIcon,
                com.android.internal.R.styleable.AndroidManifestApplication_logo,
                com.android.internal.R.styleable.AndroidManifestApplication_banner)) {
            sa.recycle();
            mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
            return false;
        }

        if (ai.name != null) {
            ai.className = ai.name;
        }

        // 在AndroidManifest裏面是否設置了android:manageSpaceActivity屬性,
        // 如果設置了則manageSpaceActivity不爲空,沒有設置manageSpaceActivity爲空
        String manageSpaceActivity = sa.getNonConfigurationString(
                com.android.internal.R.styleable.AndroidManifestApplication_manageSpaceActivity,
                Configuration.NATIVE_CONFIG_VERSION);
        if (manageSpaceActivity != null) {
            // 如果設置了,則添加類名
            ai.manageSpaceActivityName = buildClassName(pkgName, manageSpaceActivity,
                    outError);
        }

        // 是否設置了androidMannifest.xml文件中android:allowBackup屬性;
        boolean allowBackup = sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_allowBackup, true);
        // 如果設置了允許備份
        if (allowBackup) {
            ai.flags |= ApplicationInfo.FLAG_ALLOW_BACKUP;

            // backupAgent, killAfterRestore, fullBackupContent, backupInForeground,
            // and restoreAnyVersion are only relevant if backup is possible for the
            // given application.
            // 獲取backupAgent,如果在AndroidManifest裏面設置了android:backupAgent屬性,
            // 則backupAgent不爲空,否則backupAgent爲空
            String backupAgent = sa.getNonConfigurationString(
                    com.android.internal.R.styleable.AndroidManifestApplication_backupAgent,
                    Configuration.NATIVE_CONFIG_VERSION);
            // 設置了backupAgent,這構建類名
            if (backupAgent != null) {
                ai.backupAgentName = buildClassName(pkgName, backupAgent, outError);
                if (DEBUG_BACKUP) {
                    Slog.v(TAG, "android:backupAgent = " + ai.backupAgentName
                            + " from " + pkgName + "+" + backupAgent);
                }

                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestApplication_killAfterRestore,
                        true)) {
                    ai.flags |= ApplicationInfo.FLAG_KILL_AFTER_RESTORE;
                }
                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestApplication_restoreAnyVersion,
                        false)) {
                    ai.flags |= ApplicationInfo.FLAG_RESTORE_ANY_VERSION;
                }
                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestApplication_fullBackupOnly,
                        false)) {
                    ai.flags |= ApplicationInfo.FLAG_FULL_BACKUP_ONLY;
                }
                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestApplication_backupInForeground,
                        false)) {
                    ai.privateFlags |= ApplicationInfo.PRIVATE_FLAG_BACKUP_IN_FOREGROUND;
                }
            }

            TypedValue v = sa.peekValue(
                    com.android.internal.R.styleable.AndroidManifestApplication_fullBackupContent);
            if (v != null && (ai.fullBackupContent = v.resourceId) == 0) {
                if (DEBUG_BACKUP) {
                    Slog.v(TAG, "fullBackupContent specified as boolean=" +
                            (v.data == 0 ? "false" : "true"));
                }
                // "false" => -1, "true" => 0
                ai.fullBackupContent = (v.data == 0 ? -1 : 0);
            }
            if (DEBUG_BACKUP) {
                Slog.v(TAG, "fullBackupContent=" + ai.fullBackupContent + " for " + pkgName);
            }
        }

        ai.theme = sa.getResourceId(
                com.android.internal.R.styleable.AndroidManifestApplication_theme, 0);
        ai.descriptionRes = sa.getResourceId(
                com.android.internal.R.styleable.AndroidManifestApplication_description, 0);

        if ((flags&PARSE_IS_SYSTEM) != 0) {
            if (sa.getBoolean(
                    com.android.internal.R.styleable.AndroidManifestApplication_persistent,
                    false)) {
                // Check if persistence is based on a feature being present
                final String requiredFeature = sa.getNonResourceString(
                    com.android.internal.R.styleable.
                    AndroidManifestApplication_persistentWhenFeatureAvailable);
                if (requiredFeature == null || mCallback.hasFeature(requiredFeature)) {
                    ai.flags |= ApplicationInfo.FLAG_PERSISTENT;
                }
            }
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_requiredForAllUsers,
                false)) {
            owner.mRequiredForAllUsers = true;
        }

        String restrictedAccountType = sa.getString(com.android.internal.R.styleable
                .AndroidManifestApplication_restrictedAccountType);
        if (restrictedAccountType != null && restrictedAccountType.length() > 0) {
            owner.mRestrictedAccountType = restrictedAccountType;
        }

        String requiredAccountType = sa.getString(com.android.internal.R.styleable
                .AndroidManifestApplication_requiredAccountType);
        if (requiredAccountType != null && requiredAccountType.length() > 0) {
            owner.mRequiredAccountType = requiredAccountType;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_debuggable,
                false)) {
            ai.flags |= ApplicationInfo.FLAG_DEBUGGABLE;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_vmSafeMode,
                false)) {
            ai.flags |= ApplicationInfo.FLAG_VM_SAFE_MODE;
        }

        owner.baseHardwareAccelerated = sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_hardwareAccelerated,
                owner.applicationInfo.targetSdkVersion >= Build.VERSION_CODES.ICE_CREAM_SANDWICH);
        if (owner.baseHardwareAccelerated) {
            ai.flags |= ApplicationInfo.FLAG_HARDWARE_ACCELERATED;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_hasCode,
                true)) {
            ai.flags |= ApplicationInfo.FLAG_HAS_CODE;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_allowTaskReparenting,
                false)) {
            ai.flags |= ApplicationInfo.FLAG_ALLOW_TASK_REPARENTING;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_allowClearUserData,
                true)) {
            ai.flags |= ApplicationInfo.FLAG_ALLOW_CLEAR_USER_DATA;
        }

        // The parent package controls installation, hence specify test only installs.
        if (owner.parentPackage == null) {
            if (sa.getBoolean(
                    com.android.internal.R.styleable.AndroidManifestApplication_testOnly,
                    false)) {
                ai.flags |= ApplicationInfo.FLAG_TEST_ONLY;
            }
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_largeHeap,
                false)) {
            ai.flags |= ApplicationInfo.FLAG_LARGE_HEAP;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_usesCleartextTraffic,
                true)) {
            ai.flags |= ApplicationInfo.FLAG_USES_CLEARTEXT_TRAFFIC;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_supportsRtl,
                false /* default is no RTL support*/)) {
            ai.flags |= ApplicationInfo.FLAG_SUPPORTS_RTL;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_multiArch,
                false)) {
            ai.flags |= ApplicationInfo.FLAG_MULTIARCH;
        }

        if (sa.getBoolean(
                com.android.internal.R.styleable.AndroidManifestApplication_extractNativeLibs,
                true)) {
            ai.flags |= ApplicationInfo.FLAG_EXTRACT_NATIVE_LIBS;
        }

        if (sa.getBoolean(
                R.styleable.AndroidManifestApplication_defaultToDeviceProtectedStorage,
                false)) {
            ai.privateFlags |= ApplicationInfo.PRIVATE_FLAG_DEFAULT_TO_DEVICE_PROTECTED_STORAGE;
        }
        if (sa.getBoolean(
                R.styleable.AndroidManifestApplication_directBootAware,
                false)) {
            ai.privateFlags |= ApplicationInfo.PRIVATE_FLAG_DIRECT_BOOT_AWARE;
        }

        if (sa.hasValueOrEmpty(R.styleable.AndroidManifestApplication_resizeableActivity)) {
            if (sa.getBoolean(R.styleable.AndroidManifestApplication_resizeableActivity, true)) {
                ai.privateFlags |= PRIVATE_FLAG_ACTIVITIES_RESIZE_MODE_RESIZEABLE;
            } else {
                ai.privateFlags |= PRIVATE_FLAG_ACTIVITIES_RESIZE_MODE_UNRESIZEABLE;
            }
        } else if (owner.applicationInfo.targetSdkVersion >= Build.VERSION_CODES.N) {
            ai.privateFlags |= PRIVATE_FLAG_ACTIVITIES_RESIZE_MODE_RESIZEABLE_VIA_SDK_VERSION;
        }

        ai.maxAspectRatio = sa.getFloat(R.styleable.AndroidManifestApplication_maxAspectRatio, 0);

        ai.networkSecurityConfigRes = sa.getResourceId(
                com.android.internal.R.styleable.AndroidManifestApplication_networkSecurityConfig,
                0);
        ai.category = sa.getInt(
                com.android.internal.R.styleable.AndroidManifestApplication_appCategory,
                ApplicationInfo.CATEGORY_UNDEFINED);

        String str;
        str = sa.getNonConfigurationString(
                com.android.internal.R.styleable.AndroidManifestApplication_permission, 0);
        ai.permission = (str != null && str.length() > 0) ? str.intern() : null;

        if (owner.applicationInfo.targetSdkVersion >= Build.VERSION_CODES.FROYO) {
            str = sa.getNonConfigurationString(
                    com.android.internal.R.styleable.AndroidManifestApplication_taskAffinity,
                    Configuration.NATIVE_CONFIG_VERSION);
        } else {
            // Some older apps have been seen to use a resource reference
            // here that on older builds was ignored (with a warning).  We
            // need to continue to do this for them so they don't break.
            str = sa.getNonResourceString(
                    com.android.internal.R.styleable.AndroidManifestApplication_taskAffinity);
        }
        ai.taskAffinity = buildTaskAffinityName(ai.packageName, ai.packageName,
                str, outError);

        if (outError[0] == null) {
            CharSequence pname;
            if (owner.applicationInfo.targetSdkVersion >= Build.VERSION_CODES.FROYO) {
                pname = sa.getNonConfigurationString(
                        com.android.internal.R.styleable.AndroidManifestApplication_process,
                        Configuration.NATIVE_CONFIG_VERSION);
            } else {
                // Some older apps have been seen to use a resource reference
                // here that on older builds was ignored (with a warning).  We
                // need to continue to do this for them so they don't break.
                pname = sa.getNonResourceString(
                        com.android.internal.R.styleable.AndroidManifestApplication_process);
            }
            ai.processName = buildProcessName(ai.packageName, null, pname,
                    flags, mSeparateProcesses, outError);

            ai.enabled = sa.getBoolean(
                    com.android.internal.R.styleable.AndroidManifestApplication_enabled, true);

            if (sa.getBoolean(
                    com.android.internal.R.styleable.AndroidManifestApplication_isGame, false)) {
                ai.flags |= ApplicationInfo.FLAG_IS_GAME;
            }

            if (false) {
                if (sa.getBoolean(
                        com.android.internal.R.styleable.AndroidManifestApplication_cantSaveState,
                        false)) {
                    ai.privateFlags |= ApplicationInfo.PRIVATE_FLAG_CANT_SAVE_STATE;

                    // A heavy-weight application can not be in a custom process.
                    // We can do direct compare because we intern all strings.
                    if (ai.processName != null && ai.processName != ai.packageName) {
                        outError[0] = "cantSaveState applications can not use custom processes";
                    }
                }
            }
        }

        ai.uiOptions = sa.getInt(
                com.android.internal.R.styleable.AndroidManifestApplication_uiOptions, 0);

        ai.classLoaderName = sa.getString(
            com.android.internal.R.styleable.AndroidManifestApplication_classLoader);
        if (ai.classLoaderName != null
                && !ClassLoaderFactory.isValidClassLoaderName(ai.classLoaderName)) {
            outError[0] = "Invalid class loader name: " + ai.classLoaderName;
        }

        sa.recycle();

        if (outError[0] != null) {
            mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
            return false;
        }

        final int innerDepth = parser.getDepth();
        // IMPORTANT: These must only be cached for a single <application> to avoid components
        // getting added to the wrong package.
        final CachedComponentArgs cachedArgs = new CachedComponentArgs();
        int type;

        // 開始解析
        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
                && (type != XmlPullParser.END_TAG || parser.getDepth() > innerDepth)) {
            if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
                continue;
            }

            String tagName = parser.getName();
            // 解析activity
            if (tagName.equals("activity")) {
                Activity a = parseActivity(owner, res, parser, flags, outError, cachedArgs, false,
                        owner.baseHardwareAccelerated);
                if (a == null) {
                    mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return false;
                }

                owner.activities.add(a);

            // 解析receiver
            } else if (tagName.equals("receiver")) {
                Activity a = parseActivity(owner, res, parser, flags, outError, cachedArgs,
                        true, false);
                if (a == null) {
                    mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return false;
                }

                owner.receivers.add(a);
            // 解析service
            } else if (tagName.equals("service")) {
                Service s = parseService(owner, res, parser, flags, outError, cachedArgs);
                if (s == null) {
                    mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return false;
                }

                owner.services.add(s);
            // 解析provider
            } else if (tagName.equals("provider")) {
                Provider p = parseProvider(owner, res, parser, flags, outError, cachedArgs);
                if (p == null) {
                    mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return false;
                }

                owner.providers.add(p);
            
            ... ...
            
            } else {
                if (!RIGID_PARSER) {
                    Slog.w(TAG, "Unknown element under <application>: " + tagName
                            + " at " + mArchiveSourcePath + " "
                            + parser.getPositionDescription());
                    XmlUtils.skipCurrentTag(parser);
                    continue;
                } else {
                    outError[0] = "Bad element under <application>: " + tagName;
                    mParseError = PackageManager.INSTALL_PARSE_FAILED_MANIFEST_MALFORMED;
                    return false;
                }
            }
        }

        // Must be ran after the entire {@link ApplicationInfo} has been fully processed and after
        // every activity info has had a chance to set it from its attributes.
        setMaxAspectRatio(owner);

        PackageBackwardCompatibility.modifySharedLibraries(owner);

        // 檢查IntentFilter之一是否包含DEFAULT / VIEW和HTTP / HTTPS數據URI
        if (hasDomainURLs(owner)) {
            owner.applicationInfo.privateFlags |= ApplicationInfo.PRIVATE_FLAG_HAS_DOMAIN_URLS;
        } else {
            owner.applicationInfo.privateFlags &= ~ApplicationInfo.PRIVATE_FLAG_HAS_DOMAIN_URLS;
        }

        return true;
    }

其實這個方法就是解析了application節點下的所有信息,比如activity、service、receiver、provider、library、users-librayry等信息,同時將解析後的每一個屬性生成相應的對象,添加到傳入的package裏面,這些信息最後都會在PackageManagerService中用到。

掃描非系統 Package

            if (!mOnlyCore) {   // mOnlyCore 用於控制是否掃描非系統 Package
                // 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();

                    /*
                     * If this is not a system app, it can't be a
                     * disable system app.
                     */
                    if ((ps.pkgFlags & ApplicationInfo.FLAG_SYSTEM) == 0) {
                        /// M: Operator apps are belong to system domain, therefore, need prune.
                        /// We should also consider OTA from old version without mtkFlag
                        if (sPmsExt.isNotOperatorApp(ps))
                            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);
                        }
                    }
                }
            }
            
            if (!mOnlyCore) {
                scanDirTracedLI(mAppInstallDir, 0, scanFlags | SCAN_REQUIRE_KNOWN, 0);

                scanDirTracedLI(mDrmAppPrivateInstallDir, mDefParseFlags
                        | PackageParser.PARSE_FORWARD_LOCK,
                        scanFlags | SCAN_REQUIRE_KNOWN, 0);

                // Remove disable package settings for updated system apps that were
                // removed via an OTA. If the update is no longer present, remove the
                // app completely. Otherwise, revoke their system privileges.
                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;
                        /// M: [Operator] Revoke operator permissions for the original operator
                        sPmsExt.clearExtFlags(deletedPkg, deletedPs);
                    }
                    logCriticalInfo(Log.WARN, msg);
                }

                /*
                 * Make sure all system apps that we expected to appear on
                 * the userdata partition actually showed up. If they never
                 * appeared, crawl back and revive the system version.
                 */
                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);
                }
            }

構造函數分析 - 掃尾工作

這部分任務比較簡單,就是將第二階段手機的信息再集中整理一次,可自行研究。

總結

第二階段分析就此結束!

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