本文转载于：http://www.iloveandroid.net/2016/06/20/Android_PackageManagerService-2/
安装一个apk分为：检查权限，复制文件，装在应用。前面分析了前两步，现在开始分析app的装载。
这一步中主要完成将dex转换为ART虚拟机的oat格式的执行文件，并为应用创建数据沙箱目录，最后把应用的信息装载进PMS的数据结构中去。
在前面的处理MCS_BOUND时调用的HandlerParams的startCopy方法中
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | final boolean startCopy() { boolean res; try { ........................... if (++mRetries > MAX_RETRIES) { .................................................... return false; } else { handleStartCopy(); res = true; } } catch (RemoteException e) { .............................. } handleReturnCode(); return res; } |
可以知道当复制完文件之后，会调用InstallParams的handleReturnCode方法：
1 2 3 4 5 6 7 8 | void handleReturnCode() { // If mArgs is null, then MCS couldn't be reached. When it // reconnects, it will try again to install. At that point, this // will succeed. if (mArgs != null) { processPendingInstall(mArgs, mRet); } } |
代码如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | private void processPendingInstall(final InstallArgs args, final int currentStatus) { // Queue up an async operation since the package installation may take a little while. mHandler.post(new Runnable() { public void run() { mHandler.removeCallbacks(this); // Result object to be returned PackageInstalledInfo res = new PackageInstalledInfo(); res.returnCode = currentStatus; res.uid = -1; res.pkg = null; res.removedInfo = new PackageRemovedInfo(); if (res.returnCode == PackageManager.INSTALL_SUCCEEDED) { //一般情况下，什么都不会做的 args.doPreInstall(res.returnCode); synchronized (mInstallLock) { installPackageLI(args, res); } args.doPostInstall(res.returnCode, res.uid); } ..................................... /* 省略关于云备份的代码*/ ..................................... if (!doRestore) { // No restore possible, or the Backup Manager was mysteriously not // available -- just fire the post-install work request directly. if (DEBUG_INSTALL) Log.v(TAG, "No restore - queue post-install for " + token); Message msg = mHandler.obtainMessage(POST_INSTALL, token, 0); mHandler.sendMessage(msg); } } }); } |
processPendingInstall()方法中post了一个消息，这样安装过程将以异步的方式继续执行。在post消息中，首先是调用installPackageLI()来装载应用，接下来的一大段代码是在执行设备备份操作，备份是通过BackupManagerService来完成的，这里就不分析了。备份完成之后，通过发送POST_INSTALL消息继续处理。
doPreInstall()一般情况下是什么都不会做的，接着看installPackageLI()方法，代码很长，所以依旧是以分段解析。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | private void installPackageLI(InstallArgs args, PackageInstalledInfo res) { //得到installFlags，里面记录了app需要安装到哪里 final int installFlags = args.installFlags; // 安装程序的包名 final String installerPackageName = args.installerPackageName; // 与sd卡安装有关，一般为null final String volumeUuid = args.volumeUuid; // 前面已经把apk拷贝到了临时阶段性文件夹/data/app/vmdl<安装回话id>.tmp/这个目录了 final File tmpPackageFile = new File(args.getCodePath()); // 没有设定INSTALL_FORWARD_LOCK final boolean forwardLocked = ((installFlags & PackageManager.INSTALL_FORWARD_LOCK) != 0); // 是否安装到外部存储 final boolean onExternal = (((installFlags & PackageManager.INSTALL_EXTERNAL) != 0) || (args.volumeUuid != null)); // 初始化替换flag为假 boolean replace = false; // 设置浏览参数 int scanFlags = SCAN_NEW_INSTALL | SCAN_UPDATE_SIGNATURE; // 我们不是移动app，所以为null，不走这块代码 if (args.move != null) { // moving a complete application; perfom an initial scan on the new install location scanFlags |= SCAN_INITIAL; } // 初始化返回码 // Result object to be returned res.returnCode = PackageManager.INSTALL_SUCCEEDED; |
这里就是做了一些初始化值的工作。详情看上述注释。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | if (DEBUG_INSTALL) Slog.d(TAG, "installPackageLI: path=" + tmpPackageFile); // Retrieve PackageSettings and parse package // 设置解析apk的flags final int parseFlags = mDefParseFlags | PackageParser.PARSE_CHATTY | (forwardLocked ? PackageParser.PARSE_FORWARD_LOCK : 0) | (onExternal ? PackageParser.PARSE_EXTERNAL_STORAGE : 0); // 创建一个解析器 PackageParser pp = new PackageParser(); pp.setSeparateProcesses(mSeparateProcesses); // 获得屏幕参数 pp.setDisplayMetrics(mMetrics); final PackageParser.Package pkg; try { // 开始解析apk,要注意此时传入tmpPackageFile为一个文件夹 pkg = pp.parsePackage(tmpPackageFile, parseFlags); } catch (PackageParserException e) { res.setError("Failed parse during installPackageLI", e); return; } // Mark that we have an install time CPU ABI override. pkg.cpuAbiOverride = args.abiOverride; String pkgName = res.name = pkg.packageName; if ((pkg.applicationInfo.flags&ApplicationInfo.FLAG_TEST_ONLY) != 0) { if ((installFlags & PackageManager.INSTALL_ALLOW_TEST) == 0) { res.setError(INSTALL_FAILED_TEST_ONLY, "installPackageLI"); return; } } |
这里主要是解析APK，也就是解析AndroidMainifest.xml文件，将结果记录在PackageParser.Package中。前面已经详细介绍如何解析一个APK了，所以这里不在赘述了。
接下来是搜集apk的签名信息，代码如下：
1 2 3 4 5 6 7 | try { pp.collectCertificates(pkg, parseFlags); pp.collectManifestDigest(pkg); } catch (PackageParserException e) { res.setError("Failed collect during installPackageLI", e); return; } |
如果安装程序此前传入了一个清单文件，那么将解析到的清单文件与传入的进行对比。安装器的确传入了一个清单，PackageInstallerActivity中也解析了apk,那时记录了这个清单，并一并传入到这里了。这里又做了一步判断，判断两者是同一个apk.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | /* If the installer passed in a manifest digest, compare it now. */ if (args.manifestDigest != null) { if (DEBUG_INSTALL) { final String parsedManifest = pkg.manifestDigest == null ? "null" : pkg.manifestDigest.toString(); Slog.d(TAG, "Comparing manifests: " + args.manifestDigest.toString() + " vs. " + parsedManifest); } if (!args.manifestDigest.equals(pkg.manifestDigest)) { res.setError(INSTALL_FAILED_PACKAGE_CHANGED, "Manifest digest changed"); return; } } else if (DEBUG_INSTALL) { final String parsedManifest = pkg.manifestDigest == null ? "null" : pkg.manifestDigest.toString(); Slog.d(TAG, "manifestDigest was not present, but parser got: " + parsedManifest); } |
继续分析installPackageLI：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 | // Check if installing already existing package // 如果安装已经存在的应用的时候，PackageInstaller应用安装器会在会在installFlags中设置INSTALL_REPLACE_EXISTING if ((installFlags & PackageManager.INSTALL_REPLACE_EXISTING) != 0) { // 看看要替换的apk的包名是否存在原始包名 // 当app升级导致前后包名不一致的时候，需要记录仍然是原始包名， // 所以这里要先检查要覆盖的app是否是这样的情况，是的话设置包名为旧的包名 String oldName = mSettings.mRenamedPackages.get(pkgName); if (pkg.mOriginalPackages != null && pkg.mOriginalPackages.contains(oldName) && mPackages.containsKey(oldName)) { // This package is derived from an original package, // and this device has been updating from that original // name. We must continue using the original name, so // rename the new package here. pkg.setPackageName(oldName); pkgName = pkg.packageName; replace = true; if (DEBUG_INSTALL) Slog.d(TAG, "Replacing existing renamed package: oldName=" + oldName + " pkgName=" + pkgName); } else if (mPackages.containsKey(pkgName)) { // This package, under its official name, already exists // on the device; we should replace it. replace = true; if (DEBUG_INSTALL) Slog.d(TAG, "Replace existing pacakge: " + pkgName); } // Prevent apps opting out from runtime permissions // 检查新的app编译的时候选择的target目标版本低于6.0，而原来的app编译的时候target选择的是6.0， // 当一个app按照6.0来编译的话，需要按照6.0的规则来解析app的权限。 if (replace) { PackageParser.Package oldPackage = mPackages.get(pkgName); final int oldTargetSdk = oldPackage.applicationInfo.targetSdkVersion; final int newTargetSdk = pkg.applicationInfo.targetSdkVersion; if (oldTargetSdk > Build.VERSION_CODES.LOLLIPOP_MR1 && newTargetSdk <= Build.VERSION_CODES.LOLLIPOP_MR1) { res.setError(PackageManager.INSTALL_FAILED_PERMISSION_MODEL_DOWNGRADE, "Package " + pkg.packageName + " new target SDK " + newTargetSdk + " doesn't support runtime permissions but the old" + " target SDK " + oldTargetSdk + " does."); return; } } } // 如果ps不为null,同样说明，已经存在一个同包名的程序被安装， // 也就是还是处理覆盖安装的情况 // 这里主要是验证包名的签名，不一致的话，是不能覆盖安装的，另外版本号也不能比安装的低，否则也不能安装 PackageSetting ps = mSettings.mPackages.get(pkgName); if (ps != null) { if (DEBUG_INSTALL) Slog.d(TAG, "Existing package: " + ps); // Quick sanity check that we're signed correctly if updating; // we'll check this again later when scanning, but we want to // bail early here before tripping over redefined permissions. if (shouldCheckUpgradeKeySetLP(ps, scanFlags)) { if (!checkUpgradeKeySetLP(ps, pkg)) { res.setError(INSTALL_FAILED_UPDATE_INCOMPATIBLE, "Package " + pkg.packageName + " upgrade keys do not match the " + "previously installed version"); return; } } else { try { verifySignaturesLP(ps, pkg); } catch (PackageManagerException e) { res.setError(e.error, e.getMessage()); return; } } oldCodePath = mSettings.mPackages.get(pkgName).codePathString; if (ps.pkg != null && ps.pkg.applicationInfo != null) { systemApp = (ps.pkg.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0; } res.origUsers = ps.queryInstalledUsers(sUserManager.getUserIds(), true); } |
这里主要是对覆盖安装的时候，设置一些变量。
继续分析，接下来是对apk定义的权限进行初步检查：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | // Check whether the newly-scanned package wants to define an already-defined perm int N = pkg.permissions.size(); for (int i = N-1; i >= 0; i--) { PackageParser.Permission perm = pkg.permissions.get(i); BasePermission bp = mSettings.mPermissions.get(perm.info.name); if (bp != null) { // If the defining package is signed with our cert, it's okay. This // also includes the "updating the same package" case, of course. // "updating same package" could also involve key-rotation. final boolean sigsOk; if (bp.sourcePackage.equals(pkg.packageName) && (bp.packageSetting instanceof PackageSetting) && (shouldCheckUpgradeKeySetLP((PackageSetting) bp.packageSetting, scanFlags))) { sigsOk = checkUpgradeKeySetLP((PackageSetting) bp.packageSetting, pkg); } else { sigsOk = compareSignatures(bp.packageSetting.signatures.mSignatures, pkg.mSignatures) == PackageManager.SIGNATURE_MATCH; } if (!sigsOk) { // If the owning package is the system itself, we log but allow // install to proceed; we fail the install on all other permission // redefinitions. if (!bp.sourcePackage.equals("android")) { res.setError(INSTALL_FAILED_DUPLICATE_PERMISSION, "Package " + pkg.packageName + " attempting to redeclare permission " + perm.info.name + " already owned by " + bp.sourcePackage); res.origPermission = perm.info.name; res.origPackage = bp.sourcePackage; return; } else { Slog.w(TAG, "Package " + pkg.packageName + " attempting to redeclare system permission " + perm.info.name + "; ignoring new declaration"); pkg.permissions.remove(i); } } } } |
这段代码作用是检查apk中定义的所有的权限是否已经被其他应用定义了，如果重定义的是系统应用定义的权限，那么忽略本app定义的这个权限。如果重定义的是非系统应用的权限，那么本次安装就以失败返回。
继续分析，当一个app是系统应用，但又希望安装在外部存储，那么就报错。
1 2 3 4 5 6 | if (systemApp && onExternal) { // Disable updates to system apps on sdcard res.setError(INSTALL_FAILED_INVALID_INSTALL_LOCATION, "Cannot install updates to system apps on sdcard"); return; } |
意味着，系统app是不能安装到外部存储的。
继续分析：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 | // 我们不是在移动app，所以不走这个分支 if (args.move != null) { // We did an in-place move, so dex is ready to roll scanFlags |= SCAN_NO_DEX; scanFlags |= SCAN_MOVE; synchronized (mPackages) { final PackageSetting ps = mSettings.mPackages.get(pkgName); if (ps == null) { res.setError(INSTALL_FAILED_INTERNAL_ERROR, "Missing settings for moved package " + pkgName); } // We moved the entire application as-is, so bring over the // previously derived ABI information. pkg.applicationInfo.primaryCpuAbi = ps.primaryCpuAbiString; pkg.applicationInfo.secondaryCpuAbi = ps.secondaryCpuAbiString; } } else if (!forwardLocked && !pkg.applicationInfo.isExternalAsec()) { //走这个分支 // Enable SCAN_NO_DEX flag to skip dexopt at a later stage // 设置SCAN_NO_DEX，这样在这个阶段就不会执行dexopt scanFlags |= SCAN_NO_DEX; try { derivePackageAbi(pkg, new File(pkg.codePath), args.abiOverride, true /* extract libs */); } catch (PackageManagerException pme) { Slog.e(TAG, "Error deriving application ABI", pme); res.setError(INSTALL_FAILED_INTERNAL_ERROR, "Error deriving application ABI"); return; } // Run dexopt before old package gets removed, to minimize time when app is unavailable int result = mPackageDexOptimizer .performDexOpt(pkg, null /* instruction sets */, false /* forceDex */, false /* defer */, false /* inclDependencies */); if (result == PackageDexOptimizer.DEX_OPT_FAILED) { res.setError(INSTALL_FAILED_DEXOPT, "Dexopt failed for " + pkg.codePath); return; } } |
derivePackageAbi()方法也很重要，主要完成了apk的so库路径设置，以及主次abi的值。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 | /** * Derive the ABI of a non-system package located at {@code scanFile}. This information * is derived purely on the basis of the contents of {@code scanFile} and * {@code cpuAbiOverride}. * * If {@code extractLibs} is true, native libraries are extracted from the app if required. */ public void derivePackageAbi(PackageParser.Package pkg, File scanFile, String cpuAbiOverride, boolean extractLibs) throws PackageManagerException { //这里是第一次调用，主要确定pkg中的applicationInfo中的下面三个字段 // nativeLibraryRootDir /data/app/vmdl<回话id>.tmp/lib // nativeLibraryRootRequiresIsa 为true,用户安装的第三方app，该字段就为true,说明需要在lib/加前缀，如arm,arm64等 // nativeLibraryDir :/data/app/vmdl<回话id>.tmp/lib/<前缀> setNativeLibraryPaths(pkg); // We would never need to extract libs for forward-locked and external packages, // since the container service will do it for us. We shouldn't attempt to // extract libs from system app when it was not updated. if (pkg.isForwardLocked() || isExternal(pkg) || (isSystemApp(pkg) && !pkg.isUpdatedSystemApp()) ) { extractLibs = false; } final String nativeLibraryRootStr = pkg.applicationInfo.nativeLibraryRootDir; // 对于用户安装的第三方app，该标志为true，预示着要在nativeLibraryRootStr路径后面加上“arm”或者”arm64"或者“x86” // 这类的前缀，具体原因请参考setNativeLibraryPaths() final boolean useIsaSpecificSubdirs = pkg.applicationInfo.nativeLibraryRootRequiresIsa; NativeLibraryHelper.Handle handle = null; try { handle = NativeLibraryHelper.Handle.create(scanFile); // TODO(multiArch): This can be null for apps that didn't go through the // usual installation process. We can calculate it again, like we // do during install time. // // TODO(multiArch): Why do we need to rescan ASEC apps again ? It seems totally // unnecessary. final File nativeLibraryRoot = new File(nativeLibraryRootStr); // Null out the abis so that they can be recalculated. pkg.applicationInfo.primaryCpuAbi = null; pkg.applicationInfo.secondaryCpuAbi = null; if (isMultiArch(pkg.applicationInfo)) { // Warn if we've set an abiOverride for multi-lib packages.. // By definition, we need to copy both 32 and 64 bit libraries for // such packages. // cpuAbiOverride对于有多个so库文件夹的apk是无效的 if (pkg.cpuAbiOverride != null && !NativeLibraryHelper.CLEAR_ABI_OVERRIDE.equals(pkg.cpuAbiOverride)) { Slog.w(TAG, "Ignoring abiOverride for multi arch application."); } int abi32 = PackageManager.NO_NATIVE_LIBRARIES; int abi64 = PackageManager.NO_NATIVE_LIBRARIES; if (Build.SUPPORTED_32_BIT_ABIS.length > 0) { if (extractLibs) { // 这里再次拷贝，如果apk中的lib中的so库时间戳没有发生变化的时候，是不会在拷贝的，因为前面已经拷贝过了 // 只有当so库发生变化的时候，才会再次拷贝 abi32 = NativeLibraryHelper.copyNativeBinariesForSupportedAbi(handle, nativeLibraryRoot, Build.SUPPORTED_32_BIT_ABIS, useIsaSpecificSubdirs); } else { abi32 = NativeLibraryHelper.findSupportedAbi(handle, Build.SUPPORTED_32_BIT_ABIS); } } maybeThrowExceptionForMultiArchCopy( "Error unpackaging 32 bit native libs for multiarch app.", abi32); if (Build.SUPPORTED_64_BIT_ABIS.length > 0) { if (extractLibs) { // 这里再次拷贝，如果apk中的lib中的so库时间戳没有发生变化的时候，是不会在拷贝的，因为前面已经拷贝过了 // 只有当so库发生变化的时候，才会再次拷贝 abi64 = NativeLibraryHelper.copyNativeBinariesForSupportedAbi(handle, nativeLibraryRoot, Build.SUPPORTED_64_BIT_ABIS, useIsaSpecificSubdirs); } else { abi64 = NativeLibraryHelper.findSupportedAbi(handle, Build.SUPPORTED_64_BIT_ABIS); } } maybeThrowExceptionForMultiArchCopy( "Error unpackaging 64 bit native libs for multiarch app.", abi64); if (abi64 >= 0) { // 如果so库支持64位的abi,而且系统也是64位的话Message1 // 就把主abi设置为ro.product.cpu.abilist64列表中abi64索引的值 pkg.applicationInfo.primaryCpuAbi = Build.SUPPORTED_64_BIT_ABIS[abi64]; } if (abi32 >= 0) { final String abi = Build.SUPPORTED_32_BIT_ABIS[abi32]; if (abi64 >= 0) { // 当系统是64位。且apk中即包含了64位的库，又包含了32位的库， // 那么就把次abi设置为ro.product.cpu.abilist32列表中abi32索引的值 pkg.applicationInfo.secondaryCpuAbi = abi; } else { // 如果app只有32位的库，那么就把 // 主abi设置为ro.product.cpu.abilist32列表中abi32索引的值 pkg.applicationInfo.primaryCpuAbi = abi; } } } else { //对于apk中的lib中只有一个so库文件夹，走这个分支 // cpuAbiOverride传入的为null // 所以abiList为ro.product.cpu.abilist列表中的值 String[] abiList = (cpuAbiOverride != null) ? new String[] { cpuAbiOverride } : Build.SUPPORTED_ABIS; // Enable gross and lame hacks for apps that are built with old // SDK tools. We must scan their APKs for renderscript bitcode and // not launch them if it's present. Don't bother checking on devices // that don't have 64 bit support. boolean needsRenderScriptOverride = false; if (Build.SUPPORTED_64_BIT_ABIS.length > 0 && cpuAbiOverride == null && NativeLibraryHelper.hasRenderscriptBitcode(handle)) { abiList = Build.SUPPORTED_32_BIT_ABIS; needsRenderScriptOverride = true; } final int copyRet; if (extractLibs) { // 同样只有当so库发生变化时，才会再次拷贝 copyRet = NativeLibraryHelper.copyNativeBinariesForSupportedAbi(handle, nativeLibraryRoot, abiList, useIsaSpecificSubdirs); } else { copyRet = NativeLibraryHelper.findSupportedAbi(handle, abiList); } if (copyRet < 0 && copyRet != PackageManager.NO_NATIVE_LIBRARIES) { throw new PackageManagerException(INSTALL_FAILED_INTERNAL_ERROR, "Error unpackaging native libs for app, errorCode=" + copyRet); } // 因为只有一个so库文件夹，所以只需要设置主abi即可 if (copyRet >= 0) { pkg.applicationInfo.primaryCpuAbi = abiList[copyRet]; } else if (copyRet == PackageManager.NO_Message1NATIVE_LIBRARIES && cpuAbiOverride != null) { pkg.applicationInfo.primaryCpuAbi = cpuAbiOverride; } else if (needsRenderScriptOverride) { pkg.Message1applicationInfo.primaryCpuAbi = abiList[0]; } } } catch (IOException ioe) { Slog.e(TAG, "Unable to get canonical file " + ioe.toString()); } finally { IoUtils.closeQuietly(handle); } // Now that we've calculated the ABIs and determined if it's an internal app, // we will go ahead and populate the nativeLibraryPath. // 再次执行该方法，设置pkg中的applicationInfo的字段 // secondaryNativeLibraryDir setNativeLibraryPaths(pkg); } |
接下来调用下面的代码进行了dexopt操作：
1 2 3 4 5 6 7 8 | // Run dexopt before old package gets removed, to minimize time when app is unavailable int result = mPackageDexOptimizer .performDexOpt(pkg, null /* instruction sets */, false /* forceDex */, false /* defer */, false /* inclDependencies */); if (result == PackageDexOptimizer.DEX_OPT_FAILED) { res.setError(INSTALL_FAILED_DEXOPT, "Dexopt failed for " + pkg.codePath); return; } |
代码如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | int performDexOpt(PackageParser.Package pkg, String[] instructionSets, boolean forceDex, boolean defer, boolean inclDependencies) { ArraySet<String> done; if (inclDependencies && (pkg.usesLibraries != null || pkg.usesOptionalLibraries != null)) { done = new ArraySet<String>(); done.add(pkg.packageName); } else { // 走这个分支 done = null; } synchronized (mPackageManagerService.mInstallLock) { final boolean useLock = mSystemReady; if (useLock) { mDexoptWakeLock.setWorkSource(new WorkSource(pkg.applicationInfo.uid)); mDexoptWakeLock.acquire(); } try { // -----------------调用下面的方法 return performDexOptLI(pkg, instructionSets, forceDex, defer, done); } finally { if (useLock) { mDexoptWakeLock.release(); } } } } |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 | private int performDexOptLI(PackageParser.Package pkg, String[] targetInstructionSets, boolean forceDex, boolean defer, ArraySet<String> done) { // 传入的targetInstructionSets为null // 所以instructionSets为前面设置pkg.applicationInfo的主次abi值 // 如果没有so库，也就没有设置主次abi,这时以ro.product.cpu.abilist列表第一个值，获取isa final String[] instructionSets = targetInstructionSets != null ? targetInstructionSets : getAppDexInstructionSets(pkg.applicationInfo); // done 为null。所以跳过 if (done != null) { done.add(pkg.packageName); if (pkg.usesLibraries != null) { performDexOptLibsLI(pkg.usesLibraries, instructionSets, forceDex, defer, done); } if (pkg.usesOptionalLibraries != null) { performDexOptLibsLI(pkg.usesOptionalLibraries, instructionSets, forceDex, defer, done); } } if ((pkg.applicationInfo.flags & ApplicationInfo.FLAG_HAS_CODE) == 0) { return DEX_OPT_SKIPPED; } final boolean vmSafeMode = (pkg.applicationInfo.flags & ApplicationInfo.FLAG_VM_SAFE_MODE) != 0; final boolean debuggable = (pkg.applicationInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0; final List<String> paths = pkg.getAllCodePathsExcludingResourceOnly(); boolean performedDexOpt = false; // There are three basic cases here: // 1.) we need to dexopt, either because we are forced or it is needed // 2.) we are deferring a needed dexopt // 3.) we are skipping an unneeded dexopt final String[] dexCodeInstructionSets = getDexCodeInstructionSets(instructionSets); for (String dexCodeInstructionSet : dexCodeInstructionSets) { if (!forceDex && pkg.mDexOptPerformed.contains(dexCodeInstructionSet)) { continue; } for (String path : paths) { final int dexoptNeeded; if (forceDex) { // 为false,所以不走这里 dexoptNeeded = DexFile.DEX2OAT_NEEDED; } else { try { // 因为是在安装apk，所以getDexOptNeeded返回的是DEX2OAT_NEEDED dexoptNeeded = DexFile.getDexOptNeeded(path, pkg.packageName, dexCodeInstructionSet, defer); } catch (IOException ioe) { Slog.w(TAG, "IOException reading apk: " + path, ioe); return DEX_OPT_FAILED; } } if (!forceDex && defer && dexoptNeeded != DexFile.NO_DEXOPT_NEEDED) { // We're deciding to defer a needed dexopt. Don't bother dexopting for other // paths and instruction sets. We'll deal with them all together when we process // our list of deferred dexopts. addPackageForDeferredDexopt(pkg); return DEX_OPT_DEFERRED; } if (dexoptNeeded != DexFile.NO_DEXOPT_NEEDED) { final String dexoptType; String oatDir = null; if (dexoptNeeded == DexFile.DEX2OAT_NEEDED) { dexoptType = "dex2oat"; try { // 获取oat目录：/data/app/vmdl<安装回话id>.tmp/oat oatDir = createOatDirIfSupported(pkg, dexCodeInstructionSet); } catch (IOException ioe) { Slog.w(TAG, "Unable to create oatDir for package: " + pkg.packageName); return DEX_OPT_FAILED; } } else if (dexoptNeeded == DexFile.PATCHOAT_NEEDED) { dexoptType = "patchoat"; } else if (dexoptNeeded == DexFile.SELF_PATCHOAT_NEEDED) { dexoptType = "self patchoat"; } else { throw new IllegalStateException("Invalid dexopt needed: " + dexoptNeeded); } // 开始执行dex2oat Log.i(TAG, "Running dexopt (" + dexoptType + ") on: " + path + " pkg=" + pkg.applicationInfo.packageName + " isa=" + dexCodeInstructionSet + " vmSafeMode=" + vmSafeMode + " debuggable=" + debuggable + " oatDir = " + oatDir); final int sharedGid = UserHandle.getSharedAppGid(pkg.applicationInfo.uid); final int ret = mPackageManagerService.mInstaller.dexopt(path, sharedGid, !pkg.isForwardLocked(), pkg.packageName, dexCodeInstructionSet, dexoptNeeded, vmSafeMode, debuggable, oatDir); // Dex2oat might fail due to compiler / verifier errors. We soldier on // regardless, and attempt to interpret the app as a safety net. if (ret == 0) { performedDexOpt = true; } } } pkg.mDexOptPerformed.add(dexCodeInstructionSet); } return performedDexOpt ? DEX_OPT_PERFORMED : DEX_OPT_SKIPPED; } |
这里执行dexopt实际上是在执行dex2oat，用来将apk中的dex文件转换为oat文件。值得注意的是，Android 6.0之前生成的oat文件都在
1
| /data/dalvik_cache/
|
文件夹中，从Android 6.0 开始这个文件夹中只存放系统内置应用的oat文件，用户安装的app的oat文件在，最终会在
1
| /data/app/包名/oat/<isa>/
|
继续分析installPackageLI：
1 2 3 4 | if (!args.doRename(res.returnCode, pkg, oldCodePath)) { res.setError(INSTALL_FAILED_INSUFFICIENT_STORAGE, "Failed rename"); return; } |
这段代码作用从名字上就很清楚了:重命名。就是将
1
| /data/app/vmdl<安装会话id>.tmp
|
重名为
1
| /data/app/包名-suffix
|
suffix为1,2…….
同时更新pkg中的受影响的字段。
继续分析installPackageLI：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | startIntentFilterVerifications(args.user.getIdentifier(), replace, pkg); if (replace) { // 如果是覆盖安装，则走这里 replacePackageLI(pkg, parseFlags, scanFlags | SCAN_REPLACING, args.user, installerPackageName, volumeUuid, res); } else { // 初次安装，走这里 installNewPackageLI(pkg, parseFlags, scanFlags | SCAN_DELETE_DATA_ON_FAILURES, args.user, installerPackageName, volumeUuid, res); } synchronized (mPackages) { final PackageSetting ps = mSettings.mPackages.get(pkgName); if (ps != null) { res.newUsers = ps.queryInstalledUsers(sUserManager.getUserIds(), true); } } |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 | private void installNewPackageLI(PackageParser.Package pkg, int parseFlags, int scanFlags, UserHandle user, String installerPackageName, String volumeUuid, PackageInstalledInfo res) { // Remember this for later, in case we need to rollback this install String pkgName = pkg.packageName; if (DEBUG_INSTALL) Slog.d(TAG, "installNewPackageLI: " + pkg); final boolean dataDirExists = Environment .getDataUserPackageDirectory(volumeUuid, UserHandle.USER_OWNER, pkgName).exists(); synchronized(mPackages) { // 判断是否构成升级关系 if (mSettings.mRenamedPackages.containsKey(pkgName)) { res.setError(INSTALL_FAILED_ALREADY_EXISTS, "Attempt to re-install " + pkgName + " without first uninstalling package running as " + mSettings.mRenamedPackages.get(pkgName)); return; } // 看是否已经安装了 if (mPackages.containsKey(pkgName)) { // Don't allow installation over an existing package with the same name. res.setError(INSTALL_FAILED_ALREADY_EXISTS, "Attempt to re-install " + pkgName + " without first uninstalling."); return; } } try { // 很熟悉了吧，这里又调用了scanPackageLI PackageParser.Package newPackage = scanPackageLI(pkg, parseFlags, scanFlags, System.currentTimeMillis(), user); updateSettingsLI(newPackage, installerPackageName, volumeUuid, null, null, res, user); if (res.returnCode != PackageManager.INSTALL_SUCCEEDED) { deletePackageLI(pkgName, UserHandle.ALL, false, null, null, dataDirExists ? PackageManager.DELETE_KEEP_DATA : 0, res.removedInfo, true); } } catch (PackageManagerException e) { res.setError("Package couldn't be installed in " + pkg.codePath, e); } } |
重点又回到了scanPackageLI参数为Package的方法了。该方法内部又调用scanPackageDirtyLI方法,前面文章详细讲解过了，这里值贴出与用户安装app相关的代码
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 | private PackageParser.Package scanPackageDirtyLI(PackageParser.Package pkg, int parseFlags, int scanFlags, long currentTime, UserHandle user) throws PackageManagerException { final File scanFile = new File(pkg.codePath); ........................ if ((parseFlags&PackageParser.PARSE_IS_SYSTEM) != 0) { pkg.applicationInfo.flags |= ApplicationInfo.FLAG_SYSTEM; } else { // Only allow system apps to be flagged as core apps. pkg.coreApp = false; } ......................................... // Initialize package source and resource directories File destCodeFile = new File(pkg.applicationInfo.getCodePath()); File destResourceFile = new File(pkg.applicationInfo.getResourcePath()); SharedUserSetting suid = null; PackageSetting pkgSetting = null; ............................................. // writer synchronized (mPackages) { if (pkg.mSharedUserId != null) { ................................. } // Check if we are renaming from an original package name. PackageSetting origPackage = null; String realName = null; if (pkg.mOriginalPackages != null) { ............................... } .................................. // 很重要，在这个方法里面，给该apk分配了UID // 并且将一些信息记录当前用户的包状态文件： // /data/system/users/userid/package-restrictions.xml // 不如当前app是否被隐藏，或者禁用，以及当前app哪些组件被禁用等。 pkgSetting = mSettings.getPackageLPw(pkg, origPackage, realName, suid, destCodeFile, destResourceFile, pkg.applicationInfo.nativeLibraryRootDir, pkg.applicationInfo.primaryCpuAbi, pkg.applicationInfo.secondaryCpuAbi, pkg.applicationInfo.flags, pkg.applicationInfo.privateFlags, user, false); if (pkgSetting == null) { throw new PackageManagerException(INSTALL_FAILED_INSUFFICIENT_STORAGE, "Creating application package " + pkg.packageName + " failed"); } ................................. pkg.applicationInfo.uid = pkgSetting.appId; pkg.mExtras = pkgSetting; ..................................... //检查安装的app与已经安装的app定义的组件是否冲突 if ((scanFlags & SCAN_NEW_INSTALL) != 0) { final int N = pkg.providers.size(); int i; for (i=0; i<N; i++) { PackageParser.Provider p = pkg.providers.get(i); ................................... } } } .................................... final String pkgName = pkg.packageName; final long scanFileTime = scanFile.lastModified(); final boolean forceDex = (scanFlags & SCAN_FORCE_DEX) != 0; //修改进程信息，如名字等 pkg.applicationInfo.processName = fixProcessName( pkg.applicationInfo.packageName, pkg.applicationInfo.processName, pkg.applicationInfo.uid); File dataPath; if (mPlatformPackage == pkg) { .................................... } else { // 开始创建数据沙箱目录 dataPath = Environment.getDataUserPackageDirectory(pkg.volumeUuid, UserHandle.USER_OWNER, pkg.packageName); boolean uidError = false; if (dataPath.exists()) { .......................................... } else { ............... // 调用守护进程installd来完成实际的创建工作 // installd的install会创建"/data/data/包名",权限751，默认是给userid为0的用户使用 // 其内部会调用installd的createUserData为每一个非0的系统用户都创建沙箱目录 // /data/user/userid/包名 ，并设置权限751，chown设置为该用户的属主 int ret = createDataDirsLI(pkg.volumeUuid, pkgName, pkg.applicationInfo.uid, pkg.applicationInfo.seinfo); if (ret < 0) { // Error from installer throw new PackageManagerException(INSTALL_FAILED_INSUFFICIENT_STORAGE, "Unable to create data dirs [errorCode=" + ret + "]"); } ............................................ } final String path = scanFile.getPath(); final String cpuAbiOverride = deriveAbiOverride(pkg.cpuAbiOverride, pkgSetting); if ((scanFlags & SCAN_NEW_INSTALL) == 0) { .......................................... } else { if ((scanFlags & SCAN_MOVE) != 0) { ..................................... } ......................... } // 开始创建so库文件的连接 if (DEBUG_INSTALL) Slog.i(TAG, "Linking native library dir for " + path);//======================================== final int[] userIds = sUserManager.getUserIds(); synchronized (mInstallLock) { ................................ //只有设置了主abi,且主abi的so库是32位的才进行软连接 if (pkg.applicationInfo.primaryCpuAbi != null && !VMRuntime.is64BitAbi(pkg.applicationInfo.primaryCpuAbi)) { final String nativeLibPath = pkg.applicationInfo.nativeLibraryDir; for (int userId : userIds) { // 对该app在所有用户中的沙箱目录中创建lib指向/data/app/包名-suffix/lib/<isa>/的软连接 if (mInstaller.linkNativeLibraryDirectory(pkg.volumeUuid, pkg.packageName, nativeLibPath, userId) < 0) { throw new PackageManagerException(INSTALL_FAILED_INTERNAL_ERROR, "Failed linking native library dir (user=" + userId + ")"); } } } } pkgSetting.primaryCpuAbiString = pkg.applicationInfo.primaryCpuAbi; pkgSetting.secondaryCpuAbiString = pkg.applicationInfo.secondaryCpuAbi; pkgSetting.cpuAbiOverrideString = cpuAbiOverride; ........................... pkgSetting.legacyNativeLibraryPathString = pkg.applicationInfo.nativeLibraryRootDir; .......................................... // 将安装该apk是产生的PackageSetting对象pkgSetting，加入mSettings中的mPackages，以及也加入到PMS中的mPackages // writer synchronized (mPackages) { // Add the new setting to mSettings mSettings.insertPackageSettingLPw(pkgSetting, pkg); // Add the new setting to mPackages mPackages.put(pkg.applicationInfo.packageName, pkg); // Add the package's KeySets to the global KeySetManagerService ksms.addScannedPackageLPw(pkg); int N = pkg.providers.size(); StringBuilder r = null; int i; // 将安装的apk中的内容提供者加入到PMS中的mProviders for (i=0; i<N; i++) { ................... mProviders.addProvider(p); .......................... } if (r != null) { if (DEBUG_PACKAGE_SCANNING) Log.d(TAG, " Providers: " + r); } N = pkg.services.size(); r = null; // 将安装的apk中的service加入到PMS中的mServices for (i=0; i<N; i++) { ....................... mServices.addService(s); ...................... } if (r != null) { if (DEBUG_PACKAGE_SCANNING) Log.d(TAG, " Services: " + r); } // 将安装的apk中的receivers加入到PMS中的mReceivers N = pkg.receivers.size(); r = null; for (i=0; i<N; i++) { ..................... mReceivers.addActivity(a, "receiver"); ............ } if (r != null) { if (DEBUG_PACKAGE_SCANNING) Log.d(TAG, " Receivers: " + r); } N = pkg.activities.size(); r = null; // 将安装的apk中的activity加入到PMS中的mActivities for (i=0; i<N; i++) { .................................... mActivities.addActivity(a, "activity"); ............................. } if (r != null) { if (DEBUG_PACKAGE_SCANNING) Log.d(TAG, " Activities: " + r); } N = pkg.permissionGroups.size(); r = null; for (i=0; i<N; i++) { PackageParser.PermissionGroup pg = pkg.permissionGroups.get(i); PackageParser.PermissionGroup cur = mPermissionGroups.get(pg.info.name); if (cur == null) { mPermissionGroups.put(pg.info.name, pg); ......................... } else { ............................. } } if (r != null) { if (DEBUG_PACKAGE_SCANNING) Log.d(TAG, " Permission Groups: " + r); } N = pkg.permissions.size(); r = null; for (i=0; i<N; i++) { .................................... if (pkg.applicationInfo.targetSdkVersion > Build.VERSION_CODES.LOLLIPOP_MR1) { p.group = mPermissionGroups.get(p.info.group); ..................................... } .................... if (bp == null) { bp = new BasePermission(p.info.name, p.info.packageName, BasePermission.TYPE_NORMAL); permissionMap.put(p.info.name, bp); } ................................ //设置instrumentation N = pkg.instrumentation.size(); r = null; for (i=0; i<N; i++) { PackageParser.Instrumentation a = pkg.instrumentation.get(i); a.info.packageName = pkg.applicationInfo.packageName; ................................. } if (r != null) { if (DEBUG_PACKAGE_SCANNING) Log.d(TAG, " Instrumentation: " + r); } if (pkg.protectedBroadcasts != null) { N = pkg.protectedBroadcasts.size(); for (i=0; i<N; i++) { mProtectedBroadcasts.add(pkg.protectedBroadcasts.get(i)); } } pkgSetting.setTimeStamp(scanFileTime); .............................. return pkg; } |
从installPackageLI的重要执行过程如下图所示：
执行完installPackageLI之后，返回processPendingInstall方法中，如下所示：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | private void processPendingInstall(final InstallArgs args, final int currentStatus) { // Queue up an async operation since the package installation may take a little while. mHandler.post(new Runnable() { public void run() { ........................... if (res.returnCode == PackageManager.INSTALL_SUCCEEDED) { //一般情况下，什么都不会做的 args.doPreInstall(res.returnCode); synchronized (mInstallLock) { installPackageLI(args, res); } // 安装失败时，删除/data/app/包名中的内容 args.doPostInstall(res.returnCode, res.uid); } ..................................... /* 省略关于云备份的代码*/ ..................................... if (!doRestore) { // No restore possible, or the Backup Manager was mysteriously not // available -- just fire the post-install work request directly. if (DEBUG_INSTALL) Log.v(TAG, "No restore - queue post-install for " + token); Message msg = mHandler.obtainMessage(POST_INSTALL, token, 0); mHandler.sendMessage(msg); } } }); } |
接下来就是发送POST_INSTALL消息，该消息的处理主要就是在发送广播，应用安装完成之后要通知系统中的其他应用开始处理，比如在launcher需要增加app的图标等。等发完广播，安装也就结束了，最后通过最初安装是传入的安装观察者observer返回最初的调用者。
发送的广播有
android.intent.action.PACKAGE_ADDED
覆盖安装时，还要发送:android.intent.extra.REPLACING
代码如下：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | sendPackageBroadcast(Intent.ACTION_PACKAGE_ADDED, packageName, extras, null, null, firstUsers); final boolean update = res.removedInfo.removedPackage != null; if (update) { extras.putBoolean(Intent.EXTRA_REPLACING, true); } sendPackageBroadcast(Intent.ACTION_PACKAGE_ADDED, packageName, extras, null, null, updateUsers); if (update) { sendPackageBroadcast(Intent.ACTION_PACKAGE_REPLACED, packageName, extras, null, null, updateUsers); sendPackageBroadcast(Intent.ACTION_MY_PACKAGE_REPLACED, null, null, packageName, null, updateUsers); ................ |
