卸载apk时的另外一个AssetManager对象分析

在之前的分析中，重点一直是分析打开应用的时候创建的AssetManager，在查看log的时候，可以看到另外一个AssetManager对象，这个对象创建后有对其进行回收操作

05-02 04:21:22.852: D/AssetManager(18460): =====CCAM decRefsLocked,

05-02 04:21:22.852: D/AssetManager(18460): =====CCAM  if (mNumRefs == 0), destroy(),mstrPath=/mnt/asec/com.UCMobile-2/base.apk, iNum=302325,this=android.content.res.AssetManager@6280cad

05-02 04:21:22.853: D/AssetManager(18460): ===== begin =====

05-02 04:21:22.853: D/AssetManager(18460): android.content.res.AssetManager.decRefsLocked(AssetManager.java:1120)

05-02 04:21:22.853: D/AssetManager(18460): android.content.res.AssetManager.close(AssetManager.java:165)

05-02 04:21:22.853: D/AssetManager(18460): libcore.io.IoUtils.closeQuietly(IoUtils.java:56)

05-02 04:21:22.853: D/AssetManager(18460): android.content.pm.PackageParser.parseApkLite(PackageParser.java:1338)

05-02 04:21:22.853: D/AssetManager(18460): android.content.pm.PackageParser.parseClusterPackageLite(PackageParser.java:744)

05-02 04:21:22.853: D/AssetManager(18460): android.content.pm.PackageParser.parsePackageLite(PackageParser.java:717)

05-02 04:21:22.853: D/AssetManager(18460): com.android.server.pm.PackageManagerService$AsecInstallArgs.getAllCodePaths(PackageManagerService.java:13169)

05-02 04:21:22.853: D/AssetManager(18460): com.android.server.pm.PackageManagerService$AsecInstallArgs.doPostDeleteLI(PackageManagerService.java:13194)

05-02 04:21:22.853: D/AssetManager(18460): com.android.server.pm.PackageManagerService.deletePackageX(PackageManagerService.java:14618)

05-02 04:21:22.853: D/AssetManager(18460): com.android.server.pm.PackageManagerService.-wrap11(PackageManagerService.java)

05-02 04:21:22.853: D/AssetManager(18460): com.android.server.pm.PackageManagerService$12.run(PackageManagerService.java:14485)

05-02 04:21:22.853: D/AssetManager(18460): android.os.Handler.handleCallback(Handler.java:815)

05-02 04:21:22.853: D/AssetManager(18460): android.os.Handler.dispatchMessage(Handler.java:104)

05-02 04:21:22.853: D/AssetManager(18460): android.os.Looper.loop(Looper.java:207)

05-02 04:21:22.853: D/AssetManager(18460): android.os.HandlerThread.run(HandlerThread.java:61)

05-02 04:21:22.853: D/AssetManager(18460): com.android.server.ServiceThread.run(ServiceThread.java:46)

05-02 04:21:22.853: W/assetJNI(18460): =====jni Destroying AssetManager 0x7f5d660d40 for Java object 0x7f66af38c4

05-02 04:21:22.853: W/assetJNI(18460): =====jni L2178   delete am; am=0x7f5d660d40

查看调用流程

以卸载sd卡里的应用为例，在卸载的时候，调用到

AsecInstallArgs里的

        private List<String> getAllCodePaths() {
            final File codeFile = new File(getCodePath());
            if (codeFile != null && codeFile.exists()) {
                try {
                    final PackageLite pkg = PackageParser.parsePackageLite(codeFile, 0);
                    return pkg.getAllCodePaths();
                } catch (PackageParserException e) {
                    // Ignored; we tried our best
                }
            }
            return Collections.EMPTY_LIST;
        }

查看PackageParser.parsePackageLite(codeFile, 0);

    public static PackageLite parsePackageLite(File packageFile, int flags)
            throws PackageParserException {
        if (packageFile.isDirectory()) {
            return parseClusterPackageLite(packageFile, flags);
        } else {
            return parseMonolithicPackageLite(packageFile, flags);
        }
    }

    private static PackageLite parseClusterPackageLite(File packageDir, int flags)
            throws PackageParserException {
        final File[] files = packageDir.listFiles();
        if (ArrayUtils.isEmpty(files)) {
            throw new PackageParserException(INSTALL_PARSE_FAILED_NOT_APK,
                    "No packages found in split");
        }


        String packageName = null;
        int versionCode = 0;


        final ArrayMap<String, ApkLite> apks = new ArrayMap<>();
        for (File file : files) {
            if (isApkFile(file)) {
                final ApkLite lite = parseApkLite(file, flags);

查看parseApkLite

   public static ApkLite parseApkLite(File apkFile, int flags)
            throws PackageParserException {
        final String apkPath = apkFile.getAbsolutePath();


        AssetManager assets = null;
        XmlResourceParser parser = null;
        try {
            assets = new AssetManager();
            assets.setConfiguration(0, 0, null, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                    Build.VERSION.RESOURCES_SDK_INT);


            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();


            final Resources res = new Resources(assets, metrics, null);
            parser = assets.openXmlResourceParser(cookie, ANDROID_MANIFEST_FILENAME);


            final Signature[] signatures;
            if ((flags & PARSE_COLLECT_CERTIFICATES) != 0) {
                // TODO: factor signature related items out of Package object
                final Package tempPkg = new Package(null);
                collectCertificates(tempPkg, apkFile, 0);
                signatures = tempPkg.mSignatures;
            } else {
                signatures = null;
            }


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


        } catch (XmlPullParserException | IOException | RuntimeException e) {
            throw new PackageParserException(INSTALL_PARSE_FAILED_UNEXPECTED_EXCEPTION,
                    "Failed to parse " + apkPath, e);
        } finally {
            IoUtils.closeQuietly(parser);
            IoUtils.closeQuietly(assets);
        }
    }

在这里     IoUtils.closeQuietly(assets);进行了释放