Android PackageManagerService总结(四) APK安装流程

￡神魔★判官ぃ 2024-03-26 21:05 87阅读 0赞

## 一. 概述 ##

PackageManagerService(简称PKMS)，是Android系统中核心服务之一，管理着所有与package相关的工作，常见的比如安装、卸载应用, 信息查询等工作, 主要完成以下核心功能

1. 解析AndroidManifest.xml清单文件，解析清单文件中的所有节点信息

2. 扫描本地文件，主要针对apk，主要是系统应用、本地安装应用等。

3. 管理本地apk，主要包括安装、删除等等

4. 管理设备上安装的所有应用程序，并在系统启动时加载应用程序

5. 根据请求的Intent匹配到对应的Activity、Provider、Service，提供包含包名和Component的信息对象

6. 调用需要权限的系统函数时，检查程序是否具备相应权限从而保证系统安全

7. 提供应用程序的安装、卸载的接口

本篇文章重点介绍一下apk安装流程

## 二. 安装apk的方式 ##

> Android应用安装有如下四种方式：
> 
> 1. 系统应用和预制应用安装――开机时完成，没有安装界面，在PKMS的构造函数中完成安装;
> 
> 2. 网络下载应用安装――通过应用商店应用完成，调用PackageManager.installPackages()，有安装界面;
> 
> 3. ADB工具安装――没有安装界面，它通过启动pm脚本的形式，然后调用com.android.commands.pm.Pm类，之后调用到PKMS.installStage()完成安装;
> 
> 4. 第三方应用安装――通过SD卡里的APK文件安装，有安装界面，由packageinstaller.apk应用处理安装及卸载过程的界面。
> 
> 上述几种方式均通过PackageInstallObserver来监听安装是否成功

## 三. apk文件结构 ##

生成的APK文件本质还是一个zip文件，只不过被Google强行修改了一下后缀名称而已。所以我们将APK的后缀修改成.zip就可以查看其包含的内容了.

1）主要有7部分组成 (下图来源于其他作者博客: [Android apk结构分析][Android apk] )

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70][]

2）META-INF目录下3个重要文件

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70 1]

3）res目录下的文件说明

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70 2]

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70 3]

细节说明:

> **META-INF**：关于签名的信息存放，应用安装验证签名的时候会验证该文件里面的信息, 里面的资源文件，是被编译过的。raw和图片是保持原样的，但是其他的文件会被编译成二进制文件。
> 
> **res**: 这里面的资源是不经过编译原样打包进来的
> 
> **AndroidManifest.xml**：程序全局配置文件。该文件是每个应用程序都必须定义和包含的文件，它描述了应用程序的名字、版本、权限、引用的库文件等等信息。
> 
> **classes.dex**：Dalvik字节码文件，Android会将所有的class文件全部放到这一个文件里。
> 
> **resources.arsc**：编译后的二进制资源文件，保存资源文件的索引，由aapt生成
> 
> **lib:** 如果存在的话，存放的是ndk编出来的so库

## 四. apk安装过程 ##

这里我们主要来讲解下载APK后，点击进行安装的过程, 整体上来说,大致分为4个步骤:

> 1. 将APK的信息通过IO流的形式写入到PackageInstaller.Session中;
> 
> 2. 调用PackageInstaller.Session的commit方法，将APK的信息交由PKMS处理;
> 
> 3. 拷贝APK;
> 
> 4. 安装apk.

整个过程涉及到3个跨进程通信的Binder

<table style="width:678px;"> 
 <tbody> 
 <tr> 
 <td style="width:236px;">客户端</td> 
 <td style="width:258px;">跨进程通信AIDL文件&nbsp;&nbsp;</td> 
 <td style="width:184px;">服务端</td> 
 </tr> 
 <tr> 
 <td style="width:236px;"> PackageManager(抽象类) 它的实现类：ApplicationPackageManager </td> 
 <td style="width:258px;">IPackageManager.aidl</td> 
 <td style="width:184px;">PKMS</td> 
 </tr> 
 <tr> 
 <td style="width:236px;">PackageInstaller</td> 
 <td style="width:258px;">IPackageInstaller.aidl</td> 
 <td style="width:184px;">PackageInstallerService</td> 
 </tr> 
 <tr> 
 <td style="width:236px;">PackageInstaller.Session</td> 
 <td style="width:258px;">IPackageInstallerSession.aidl</td> 
 <td style="width:184px;">PackageInstallerSession</td> 
 </tr> 
 </tbody> 
</table>

APK从应用市场下载后点击安装, 则会跳转到(com.android.packageinstaller) PackageInstaller.apk 的安装界面上,供用户选择安装或取消, 笔者之前也分析过前半段的流程,是怎么跳转到PackageInstaller.apk 的安装界面中, 请查阅:

[Android PackageManagerService 总结(一)应用市场下载安装apk流程][Android PackageManagerService _apk]

#### 4.1 点击安装后到完成APK的拷贝流程 ####

先画下本小结的时序图:

![204bcd81870542bb99942e787f0b4716.png][]

![f85d1014799447958997c424145bbd3e.png][]

点击一个未安装的apk后，会弹出安装界面，点击确定按钮后，会进入PackageInstallerActivity.java的bindUI()中的mAlert点击事件，点击apk后，弹出的安装界面底部显示的是一个Dialog，主要由bindUI构成，上面有取消和安装两个按钮，点击安装之后调用startInstall()进行安装。bindUI方法的代码如下：

/frameworks/base/packages/apps/PackageInstaller/src/com/android/packageinstaller/PackageInstallerActivity.java

private void bindUi() {
            mAlert.setIcon(mAppSnippet.icon);
            mAlert.setTitle(mAppSnippet.label);
            mAlert.setView(R.layout.install_content_view);
            mAlert.setButton(DialogInterface.BUTTON_POSITIVE, getString(R.string.install),
                    (ignored, ignored2) -> {
                        if (mOk.isEnabled()) {
                            if (mSessionId != -1) {
                                mInstaller.setPermissionsResult(mSessionId, true);
                                finish();
                            } else {
                                // 进行APK的安装, 重要关键代码
                                startInstall();
                            }
                        }
                    }, null);
            mAlert.setButton(DialogInterface.BUTTON_NEGATIVE, getString(R.string.cancel),
                    (ignored, ignored2) -> {
                        // Cancel and finish
                        setResult(RESULT_CANCELED);
                        if (mSessionId != -1) {
                            // 如果mSessionId存在，执行setPermissionResult()完成取消安装
                            mInstaller.setPermissionsResult(mSessionId, false);
                        }
                        finish();
                    }, null);
            setupAlert();
     
            mOk = mAlert.getButton(DialogInterface.BUTTON_POSITIVE);
            mOk.setEnabled(false);
     
            if (!mOk.isInTouchMode()) {
                mAlert.getButton(DialogInterface.BUTTON_NEGATIVE).requestFocus();
            }
    }

接下来看看 startInstall()方法, 封装了一个Intent 跳转到 InstallInstalling.java文件中

/frameworks/base/packages/PackageInstaller/src/com/android/packageinstaller/InstallInstalling.java

private void startInstall() {
        Intent newIntent = new Intent();
        ...
        newIntent.setClass(this, InstallInstalling.class);
        ...
        startActivity(newIntent);
    }

InstallInstalling 的Activity启动后，进入onCreate方法

protected void onCreate(@Nullable Bundle savedInstanceState) {
    
    ....
     if ("package".equals(mPackageURI.getScheme())) {
                try {
                    getPackageManager().installExistingPackage(appInfo.packageName);
                    launchSuccess();
                } catch (PackageManager.NameNotFoundException e) {
                    launchFailure(PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
                }
            } else {
                //根据mPackageURI创建一个对应的File
                final File sourceFile = new File(mPackageURI.getPath());
    
        // 1. 如果savedInstanceState不为null，获取此前保存的mSessionId和mInstallId，
        // 其中mSessionId是安装包的会话Id，mInstallId是等待安装的事件Id
        if (savedInstanceState != null) {
                    mSessionId = savedInstanceState.getInt(SESSION_ID);
                    mInstallId = savedInstanceState.getInt(INSTALL_ID);
    
                    // Reregister for result; might instantly call back if result was delivered while
                    // activity was destroyed
                    try {
                        // 2. 根据mInstallId向InstallEventReceiver注册一个观察者，           
                        // launchFinishBasedOnResult会接收到安装事件的回调，无论安装成功还是失败
                        // 都会关闭当前的Activity(InstallInstalling)。如果savedInstanceState为null，代码的逻辑也是类似的
                        InstallEventReceiver.addObserver(this, mInstallId,
                                this::launchFinishBasedOnResult);
                    } catch (EventResultPersister.OutOfIdsException e) {
                        // Does not happen
                    }
    ....
    } else {
                    //3. 创建SessionParams，它用来代表安装会话的参数，组装params
                    PackageInstaller.SessionParams params = new PackageInstaller.SessionParams(
                            PackageInstaller.SessionParams.MODE_FULL_INSTALL);
                    params.setInstallAsInstantApp(false);
                    params.setReferrerUri(getIntent().getParcelableExtra(Intent.EXTRA_REFERRER));
                    params.setOriginatingUri(getIntent()
                            .getParcelableExtra(Intent.EXTRA_ORIGINATING_URI));
                    params.setOriginatingUid(getIntent().getIntExtra(Intent.EXTRA_ORIGINATING_UID,
                            UID_UNKNOWN));
                    params.setInstallerPackageName(getIntent().getStringExtra(
                            Intent.EXTRA_INSTALLER_PACKAGE_NAME));
                    params.setInstallReason(PackageManager.INSTALL_REASON_USER);
                    // 4. 根据mPackageUri对包进行轻量级的解析，并将解析的参数赋值给SessionParams
                    File file = new File(mPackageURI.getPath());
                    try {
                        PackageParser.PackageLite pkg = PackageParser.parsePackageLite(file, 0);
                        params.setAppPackageName(pkg.packageName);
                        //设置apk的安装路径
                        params.setInstallLocation(pkg.installLocation);
                        //设置apk的大小
                        params.setSize(
                                PackageHelper.calculateInstalledSize(pkg, false, params.abiOverride));
    
    
    ....
                         //5. 向InstallEventReceiver注册一个观察者返回一个新的mInstallId，
                        // 其中InstallEventReceiver继承自BroadcastReceiver，用于接收安装事件
                        // 并回调给EventResultPersister
             try {
                        mInstallId = InstallEventReceiver
                                .addObserver(this, EventResultPersister.GENERATE_NEW_ID,
                                        this::launchFinishBasedOnResult);
                    } catch (EventResultPersister.OutOfIdsException e) {
                        launchFailure(PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
                    }
    
    ....
             try {
                        // 6. PackageInstaller的createSession方法内部会通过IPackageInstaller与
                        // PackageInstallerService进行进程间通信，最终调用的是
                        // PackageInstallerService的createSession方法阿里创建并返回mSessionId
                        mSessionId = getPackageManager().getPackageInstaller().createSession(params);
                    } catch (IOException e) {
                        launchFailure(PackageManager.INSTALL_FAILED_INTERNAL_ERROR, null);
                    }
    .....
    }

再来总结一下上面onCreate方法中所做的工作:

> 主要分为6步：
> 
> 1. 如果savedInstanceState不为null，获取此前保存的mSessionId和mInstallId，其中mSessionId是安装包的会话Id，mInstallId是等待的安装事件Id
> 
> 2. 根据mInstallId向InstallEventReceiver注册一个观察者，launchFinishBasedOnResult会接收到安装事件的回调，无论安装成功或者是安装失败都会关闭当前的Activity(InstallInstalling)。如果saveInstanceState为null，代码的逻辑也是类似的。
> 
> 3. 创建SessionParams，它用来代表安装会话的参数，组装Params
> 
> 4. 根据mPackageUri对包（APK）进行轻量级的解析，并将解析的参数赋值SessionParams
> 
> 5. 向InstallEventReceiver注册一个观察者返回一个新的mInstallId
> 
> 6. PackageInstaller的createSession方法内部会通过IPackageInstallerService进行进程间通信，最终调用的是PackageInstallerService的createSession方法来创建并返回mSessionId

接下来继续分析 InstallInstalling.java 的onResume()方法

@Override
    protected void onResume() {
        super.onResume();
    ...
        if (sessionInfo != null && !sessionInfo.isActive()) {
                    // 创建内部类InstallingAsyncTask的对象，调用execute()，最终进入onPostExecute()方法
                    mInstallingTask = new InstallingAsyncTask();
                    mInstallingTask.execute();
                } else {
                    // we will receive a broadcast when the install is finished
                    mCancelButton.setEnabled(false);
                    setFinishOnTouchOutside(false);
                }
    ...
    }

InstallingAsyncTask 的DoInBackground()会根据包(APK)的Uri，将APK的信息通过IO流的形式写入到PackageInstaller.Session中, 最后在onPostExecute()中调用PackageInstaller.Session的commit方法，进行安装。只贴出关键代码

private final class InstallingAsyncTask extends AsyncTask<Void, Void,
 PackageInstaller.Session> {
 
 PackageInstaller.Session session;
 try {
 session = getPackageManager().getPackageInstaller().openSession(mSessionId);
 } catch (IOException e) {
 return null;
 }
 
 session.setStagingProgress(0);
 
 try (InputStream in = new FileInputStream(file)) {
 long sizeBytes = file.length();
 try (OutputStream out = session
 .openWrite("PackageInstaller", 0, sizeBytes)) {
 byte[] buffer = new byte[1024 * 1024];
 while (true) {
 int numRead = in.read(buffer);
 
 if (numRead == -1) {
 session.fsync(out);
 break;
 }
 
 if (isCancelled()) {
 session.close();
 break;
 }
 // 将APK的信息通过IO流的形式写入到PackageInstaller.Session中
 out.write(buffer, 0, numRead);
 if (sizeBytes > 0) {
 float fraction = ((float) numRead / (float) sizeBytes);
 session.addProgress(fraction);
 }
 }
 }
 }
 
 
 @Override
 protected void onPostExecute(PackageInstaller.Session session) {
 ..... // 调用PackageInstaller.Session的commit方法，进行安装
 session.commit(pendingIntent.getIntentSender());
 }
 ....
 }

接着看一下PackageInstaller.Session的commit方法, 通过**IPackageInstallerSession.aidl** 跨进程通信,调用 PackageInstallerSession.java 中的commit方法

/frameworks/base/services/core/java/com/android/server/pm/PackageInstallerSession.java

public void commit(@NonNull IntentSender statusReceiver, boolean forTransfer) {
    ...
        //调用markAsCommitted()
        if (!markAsCommitted(statusReceiver, forTransfer)) {
                return;
            }
    
    
         mHandler.obtainMessage(MSG_COMMIT).sendToTarget();
    ...
    }

markAsCommitted方法中会将包的信息封装为PackageInstallObserverAdapter ，它在PKMS中被定义,然后返回到commit()中，向Handler发送一个类型为MSG\_COMMIT的消息

我们接着看消息处理的方法

private final Handler.Callback mHandlerCallback = new Handler.Callback() {
            @Override
            public boolean handleMessage(Message msg) {
                switch (msg.what) {
                    case MSG_COMMIT:
                        handleCommit();
                        break;
    ....
    }

接下来看handleCommit 方法

private void handleCommit() {
    .....
          synchronized (mLock) {
              commitNonStagedLocked(childSessions);
          }
    ....
    }

commitNonStagedLocked()中首先 调用了PackageInstallObserver的 onPackageInstalled方法，将Complete 方法出现的PackageManagerException的异常信息回调给PackageInstallObserverAdapter.

@GuardedBy("mLock")
 private void commitNonStagedLocked(List<PackageInstallerSession> childSessions)
 throws PackageManagerException {
 ....
 if (!success) {
 try {
 mRemoteObserver.onPackageInstalled(
 null, failure.error, failure.getLocalizedMessage(), null);
 } catch (RemoteException ignored) {
 }
 return;
 }
 //最终调用这个方法
 mPm.installStage(activeChildSessions);
 ....
 }

最终调用installStage()，进入PKMS中

frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java

void installStage(List<ActiveInstallSession> children)
 throws PackageManagerException {
 final Message msg = mHandler.obtainMessage(INIT_COPY);
 .....
 mHandler.sendMessage(msg);
 .....
 }

看消息处理的地方

void doHandleMessage(Message msg) {
                switch (msg.what) {
                    case INIT_COPY: {
                        HandlerParams params = (HandlerParams) msg.obj;
                        if (params != null) {
                            if (DEBUG_INSTALL) Slog.i(TAG, "init_copy: " + params);
                            Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, "queueInstall",
                                    System.identityHashCode(params));
                            Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "startCopy");
                            //执行APK拷贝动作
                            params.startCopy();
                            Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
                        }
                        break;
                    }
    ......
    }

在Handler中对INIT\_COPY消息的处理中，调用了HandlerParams.startCopy方法。

final void startCopy() {
        if (DEBUG_INSTALL) Slog.i(TAG, "startCopy " + mUser + ": " + this);
            handleStartCopy();
            handleReturnCode();
    }

handleStartCopy()需要执行下面几步：

1. 首先检查文件和cid是否已经生成，如果生成则设置installFlags

2. 检查空间大小，如果空间不够就会释放无用的控件

3. 覆盖原有安装位置的文件，并根据返回结果来确定函数的返回值，并设置installFlags

4. 确定是否有任何已安装的包安装器，如果有，则延迟检测。主要分三步：

1）首先新建一个验证Intent，然后设置相关的信息，

2）之后获取验证器列表

3）最后向每个验证器发送验证Intent。

public void handleStartCopy() {
                int ret = PackageManager.INSTALL_SUCCEEDED;
     
                // 1. 首先检查文件和cid是否已经生成，如生成则设置installFlags
                if (origin.staged) {
                    if (origin.file != null) {
                        installFlags |= PackageManager.INSTALL_INTERNAL;
                    } else {
                        throw new IllegalStateException("Invalid stage location");
                    }
                }
                .....
     
                // 2. 检查空间大小，如果空间不够则释放无用空间
                if (!origin.staged && pkgLite.recommendedInstallLocation
                        == PackageHelper.RECOMMEND_FAILED_INSUFFICIENT_STORAGE) {
                    // TODO: focus freeing disk space on the target device
                    final StorageManager storage = StorageManager.from(mContext);
                    final long lowThreshold = storage.getStorageLowBytes(
                            Environment.getDataDirectory());
     
                    final long sizeBytes = PackageManagerServiceUtils.calculateInstalledSize(
                            origin.resolvedPath, packageAbiOverride);
                    if (sizeBytes >= 0) {
                        try {
                            mInstaller.freeCache(null, sizeBytes + lowThreshold, 0, 0);
                            pkgLite = PackageManagerServiceUtils.getMinimalPackageInfo(mContext,
                                    origin.resolvedPath, installFlags, packageAbiOverride);
                        } catch (InstallerException e) {
                            Slog.w(TAG, "Failed to free cache", e);
                        }
                    }
     
                    if (pkgLite.recommendedInstallLocation
                            == PackageHelper.RECOMMEND_FAILED_INVALID_URI) {
                        pkgLite.recommendedInstallLocation
                                = PackageHelper.RECOMMEND_FAILED_INSUFFICIENT_STORAGE;
                    }
                }
     
     
                if (ret == PackageManager.INSTALL_SUCCEEDED) {
                    .....
                    
                        {
                        // 3. 覆盖原有安装位置的文件，并根据范湖结果来确定函数的返回值，
                        // 并设置installFlags
                        loc = installLocationPolicy(pkgLite);
                        if (loc == PackageHelper.RECOMMEND_FAILED_VERSION_DOWNGRADE) {
                            ret = PackageManager.INSTALL_FAILED_VERSION_DOWNGRADE;
                        } else if (loc == PackageHelper.RECOMMEND_FAILED_WRONG_INSTALLED_VERSION) {
                            ret = PackageManager.INSTALL_FAILED_WRONG_INSTALLED_VERSION;
                        } else if (!onInt) {
                            // Override install location with flags
                            if (loc == PackageHelper.RECOMMEND_INSTALL_EXTERNAL) {
                                // Set the flag to install on external media.
                                installFlags &= ~PackageManager.INSTALL_INTERNAL;
                            } else if (loc == PackageHelper.RECOMMEND_INSTALL_EPHEMERAL) {
                                if (DEBUG_INSTANT) {
                                    Slog.v(TAG, "...setting INSTALL_EPHEMERAL install flag");
                                }
                                installFlags |= PackageManager.INSTALL_INSTANT_APP;
                                installFlags &= ~PackageManager.INSTALL_INTERNAL;
                            } else {
                                // Make sure the flag for installing on external
                                // media is unset
                                installFlags |= PackageManager.INSTALL_INTERNAL;
                            }
                        }
                    }
                }
     
                final InstallArgs args = createInstallArgs(this);
                mVerificationCompleted = true;
                mIntegrityVerificationCompleted = true;
                mEnableRollbackCompleted = true;
                mArgs = args;
     
                if (ret == PackageManager.INSTALL_SUCCEEDED) {
                    final int verificationId = mPendingVerificationToken++;
     
                    // Perform package verification (unless we are simply moving the package).
                    if (!origin.existing) {
                        PackageVerificationState verificationState =
                                new PackageVerificationState(this);
                        mPendingVerification.append(verificationId, verificationState);
                        // 发送一个请求来检查包的完整性
                        sendIntegrityVerificationRequest(verificationId, pkgLite, verificationState);
                        // 向验证者发送验证包的请求
                        ret = sendPackageVerificationRequest(
                                verificationId, pkgLite, verificationState); 
                    }
    ...
     
                mRet = ret;
            }

在Android 11.0 中是通过sendPackageVerificationRequest来验证包的:

int sendPackageVerificationRequest(
 int verificationId,
 PackageInfoLite pkgLite,
 PackageVerificationState verificationState) {
 int ret = INSTALL_SUCCEEDED;
 
 ..... 
 
 if (!origin.existing
 && isVerificationEnabled
 && (!isIncrementalInstall || !isV4Signed)) {
 // 4. 确定是否有任何已安装的包验证器，如有，则延迟检测。主要分三步：
 // 首先新建一个验证Intent，然后设置相关的信息，之后获取验证器列表
 // 最后向每个验证器发送验证Intent
 // 4.1 构造验证Intent
 final Intent verification = new Intent(
 Intent.ACTION_PACKAGE_NEEDS_VERIFICATION);
 verification.addFlags(Intent.FLAG_RECEIVER_FOREGROUND);
 verification.setDataAndType(Uri.fromFile(new File(origin.resolvedPath)),
 PACKAGE_MIME_TYPE);
 verification.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
 
 ....
 
 populateInstallerExtras(verification);
 
 // 4.2 获取验证器列表
 final List<ComponentName> sufficientVerifiers = matchVerifiers(pkgLite,
 receivers, verificationState);
 
 DeviceIdleInternal idleController =
 mInjector.getLocalDeviceIdleController();
 final long idleDuration = getVerificationTimeout();
 final BroadcastOptions options = BroadcastOptions.makeBasic();
 options.setTemporaryAppWhitelistDuration(idleDuration);
 
 /*
 * If any sufficient verifiers were listed in the package
 * manifest, attempt to ask them.
 */
 if (sufficientVerifiers != null) {
 final int n = sufficientVerifiers.size();
 if (n == 0) {
 Slog.i(TAG, "Additional verifiers required, but none installed.");
 ret = PackageManager.INSTALL_FAILED_VERIFICATION_FAILURE;
 } else {
 for (int i = 0; i < n; i++) {
 final ComponentName verifierComponent = sufficientVerifiers.get(i);
 idleController.addPowerSaveTempWhitelistApp(Process.myUid(),
 verifierComponent.getPackageName(), idleDuration,
 verifierUser.getIdentifier(), false, "package verifier");
 
 // 4.3 向每个验证器发送验证Intent
 // 向验证器客户端发送Intent，只有当验证成功之后才开启copy工作
 // 如果没有任何验证器则直接拷贝
 final Intent sufficientIntent = new Intent(verification);
 sufficientIntent.setComponent(verifierComponent);
 mContext.sendBroadcastAsUser(sufficientIntent, verifierUser,
 /* receiverPermission= */ null,
 options.toBundle());
 }
 }
 }
 
 ..... 
 
 return ret;
 }

向验证器客户端发送Intent，只有当验证成功之后才会开启copy工作。如果没有任何验证器则直接拷贝。在handleReturnCode中调用copyApk()进行APK的拷贝工作。

void handleReturnCode() {
 if (mVerificationCompleted
 && mIntegrityVerificationCompleted && mEnableRollbackCompleted) {
 if ((installFlags & PackageManager.INSTALL_DRY_RUN) != 0) {
 String packageName = "";
 ParseResult<PackageLite> result = ApkLiteParseUtils.parsePackageLite(
 new ParseTypeImpl(
 (changeId, packageName1, targetSdkVersion) -> {
 ApplicationInfo appInfo = new ApplicationInfo();
 appInfo.packageName = packageName1;
 appInfo.targetSdkVersion = targetSdkVersion;
 return mPackageParserCallback.isChangeEnabled(changeId,
 appInfo);
 }).reset(),
 origin.file, 0);
 if (result.isError()) {
 Slog.e(TAG, "Can't parse package at " + origin.file.getAbsolutePath(),
 result.getException());
 } else {
 packageName = result.getResult().packageName;
 }
 try {
 observer.onPackageInstalled(packageName, mRet, "Dry run", new Bundle());
 } catch (RemoteException e) {
 Slog.i(TAG, "Observer no longer exists.");
 }
 return;
 }
 if (mRet == PackageManager.INSTALL_SUCCEEDED) {
 // 调用copyApk方法
 mRet = mArgs.copyApk();
 }
 processPendingInstall(mArgs, mRet);
 }
 }

调用了InstallArgs.copyApk方法，最终会调用到FileInstallArgs.copyApk方法。

int copyApk() {
                Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "copyApk");
                try {
                    // 调用doCopyApk方法
                    return doCopyApk();
                } finally {
                    Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
                }
            }
     
            private int doCopyApk() {
                
                .....
     
                // 调用PackageManagerServiceUtils.copyPackage方法
                int ret = PackageManagerServiceUtils.copyPackage(
                        origin.file.getAbsolutePath(), codeFile);
                if (ret != PackageManager.INSTALL_SUCCEEDED) {
                    Slog.e(TAG, "Failed to copy package");
                    return ret;
                }
     
                .....
     
                return ret;
            }

在doCopyApk方法中调用了PackageManagerServiceUtils.copyPackage方法，其代码如下：

frameworks/base/services/core/java/com/android/server/pm/PackageManagerServiceUtils.java

public static int copyPackage(String packagePath, File targetDir) {
 if (packagePath == null) {
 return PackageManager.INSTALL_FAILED_INVALID_URI;
 }
 
 try {
 final File packageFile = new File(packagePath);
 final PackageParser.PackageLite pkg = PackageParser.parsePackageLite(packageFile, 0);
 copyFile(pkg.baseCodePath, targetDir, "base.apk");
 if (!ArrayUtils.isEmpty(pkg.splitNames)) {
 for (int i = 0; i < pkg.splitNames.length; i++) {
 // 调用了copyFile方法
 copyFile(pkg.splitCodePaths[i], targetDir,
 "split_" + pkg.splitNames[i] + ".apk");
 }
 }
 return PackageManager.INSTALL_SUCCEEDED;
 } catch (PackageParserException | IOException | ErrnoException e) {
 Slog.w(TAG, "Failed to copy package at " + packagePath + ": " + e);
 return PackageManager.INSTALL_FAILED_INSUFFICIENT_STORAGE;
 }
 }

在copyFile方法中，通过文件流的操作，把APK拷贝到/data/app等目录

private static void copyFile(String sourcePath, File targetDir, String targetName)
                throws ErrnoException, IOException {
            if (!FileUtils.isValidExtFilename(targetName)) {
                throw new IllegalArgumentException("Invalid filename: " + targetName);
            }
            Slog.d(TAG, "Copying " + sourcePath + " to " + targetName);
     
            final File targetFile = new File(targetDir, targetName);
            final FileDescriptor targetFd = Os.open(targetFile.getAbsolutePath(),
                    O_RDWR | O_CREAT, 0644);
            Os.chmod(targetFile.getAbsolutePath(), 0644);
            FileInputStream source = null;
            try {
                source = new FileInputStream(sourcePath);
                FileUtils.copy(source.getFD(), targetFd);
            } finally {
                IoUtils.closeQuietly(source);
            }
        }

#### 4.2 安装apk流程 ####

APK拷贝完成后，进入真正的安装，时序图如下：

![8ef0ee939ba44991b42c9cc50372944a.png][]

在上述handleReturnCode方法中，执行了copyApk方法后，最后又执行了processPendingInstall方法。

private void processPendingInstall(final InstallArgs args, final int currentStatus) {
 if (args.mMultiPackageInstallParams != null) {
 args.mMultiPackageInstallParams.tryProcessInstallRequest(args, currentStatus);
 } else {
 // 1. 设置安装参数
 PackageInstalledInfo res = createPackageInstalledInfo(currentStatus);
 // 2. 创建一个新线程，处理安装参数，进行安装
 processInstallRequestsAsync(
 res.returnCode == PackageManager.INSTALL_SUCCEEDED,
 Collections.singletonList(new InstallRequest(args, res)));
 }
 }
 
 private void processInstallRequestsAsync(boolean success,
 List<InstallRequest> installRequests) {
 mHandler.post(() -> {
 if (success) {
 for (InstallRequest request : installRequests) {
 // 1. 如果之前安装失败，清除无用信息
 request.args.doPreInstall(request.installResult.returnCode);
 }
 synchronized (mInstallLock) {
 // 2. installPackagesTracedLI是安装过程的核心方法
 // 然后调用installPackagesLI进行安装
 installPackagesTracedLI(installRequests);
 }
 for (InstallRequest request : installRequests) {
 // 3. 如果之前安装失败，清除无用信息
 request.args.doPostInstall(
 request.installResult.returnCode, request.installResult.uid);
 }
 }
 for (InstallRequest request : installRequests) {
 restoreAndPostInstall(request.args.user.getIdentifier(), request.installResult,
 new PostInstallData(request.args, request.installResult, null));
 }
 });
 }
 
 int doPreInstall(int status) {
 if (status != PackageManager.INSTALL_SUCCEEDED) {
 // 清除无用信息
 cleanUp();
 }
 return status;
 }
 
 int doPostInstall(int status, int uid) {
 if (status != PackageManager.INSTALL_SUCCEEDED) {
 // 调用cleanUp清除无用信息
 cleanUp();
 }
 return status;
 }

在installPackagesLI方法中，以原子的方式安装一个或多个包。此操作分为四个阶段：

1）Prepare准备：分析任何当前安装状态，分析包并对其进行初始验证。

2）Scan 扫描：扫描分析准备阶段拿到的包

3） Reconcile 协调：包的扫描结果，用于协调可能向系统中添加的一个或多个包

4） Commit 提交：提交所有扫描的包并更新系统状态，这是安装流程中唯一可以修改系统状态的地方放，必须在此阶段之前确定所有的可预测的错误

5）完成APK的安装

private void installPackagesLI(List<InstallRequest> requests) {
 
 .....
 
 // 1. Prepare 准备：分析任何当前安装状态，分析包并对其进行初始验证
 prepareResult = preparePackageLI(request.args, request.installResult);
 
 ..... 
 
 // 2. Scan 扫描：扫描分析准备阶段拿到的包
 final ScanResult result = scanPackageTracedLI(
 prepareResult.packageToScan, prepareResult.parseFlags,
 prepareResult.scanFlags, System.currentTimeMillis(),
 request.args.user, request.args.abiOverride);
 .... 
 
 // 3. Reconcile 协调：包的扫描结果，用于协调可能向系统中添加的一个或多个包
 ReconcileRequest reconcileRequest = new ReconcileRequest(preparedScans, installArgs,
 installResults,
 prepareResults,
 mSharedLibraries,
 Collections.unmodifiableMap(mPackages), versionInfos,
 lastStaticSharedLibSettings);
 
 ......
 
 // 4. Commit 提交：提交所有扫描的包并更新系统状态。这是安装流程中唯一可以修改系统状态的地方，
 // 必须在此阶段之前确定所有的可预测的错误
 commitPackagesLocked(commitRequest);
 
 .....
 
 // 5. 完成APK的安装
 executePostCommitSteps(commitRequest);
 
 }

executePostCommitSteps 安装APK，并为新的代码路径准备应用程序配置文件，并在此检查是否需要dex优化。

如果是直接安装新包，会为新的代码路径准备应用程序配置文件；如果是替换安装，其主要过程为更新设置，清除原有的某些APP数据，重新生成相关的app数据目录等步骤，同时要区分系统应用替换和非系统应用替换。而安装新包，则直接更新设置，生成APP数据即可。

[PackageManagerService.java] executePostCommitSteps()
     
    private void executePostCommitSteps(CommitRequest commitRequest) {
           
        for (ReconciledPackage reconciledPkg : commitRequest.reconciledPackages.values()) {
                
            ......
     
            1) 进行安装
            prepareAppDataAfterInstallLIF(pkg);
            2) 如果需要替换安装，则需要清除原有的App数据
            if (reconciledPkg.prepareResult.clearCodeCache) {
                clearAppDataLIF(pkg, UserHandle.USER_ALL, FLAG_STORAGE_DE | FLAG_STORAGE_CE
                    | FLAG_STORAGE_EXTERNAL | Installer.FLAG_CLEAR_CODE_CACHE_ONLY);
            }
            
            ...
                
            3) 为新的代码路径准备应用程序配置文件。这需要在调用dexopt之前完成，
               以便任何安装时配置文件都可以用于优化
            mArtManagerService.prepareAppProfiles(
                        pkg,
                        resolveUserIds(reconciledPkg.installArgs.user.getIdentifier()),
                        /* updateReferenceProfileContent= */ true);
     
            4) 检查是否需要优化dex文件
            final boolean performDexopt =
                        (!instantApp || Global.getInt(mContext.getContentResolver(),
                        Global.INSTANT_APP_DEXOPT_ENABLED, 0) != 0)
                        && !pkg.isDebuggable()
                        && (!onIncremental);
     
            if (performDexopt) {               
     
     
                5) 执行dex优化
                mPackageDexOptimizer.performDexOpt(pkg, realPkgSetting,
                            null /* instructionSets */,
                            getOrCreateCompilerPackageStats(pkg),
                            mDexManager.getPackageUseInfoOrDefault(packageName),
                            dexoptOptions);
                    
            }
     
                
            BackgroundDexOptService.notifyPackageChanged(packageName);
     
            notifyPackageChangeObserversOnUpdate(reconciledPkg);
        }
    }

PackageManagerService.prepareAppDataAfterInstallLIF()

通过一系列的调用，最终会调用到Installer.java的createAppData()方法进行安装，交给installed进程进行APK的安装。

调用过程如下：

prepareAppDataAfterInstallLIF()  
|  
prepareAppDataLIF()  
|  
prepareAppDataLeafLIF()  
|  
\[Installer.java\]  
createAppData()

private void prepareAppDataAfterInstallLIF(AndroidPackage pkg) {
            
        ..... 
     
        for (UserInfo user : mUserManager.getUsers(false /*excludeDying*/)) {
               
            ......
     
            if (ps.getInstalled(user.id)) {
                // TODO: when user data is locked, mark that we're still dirty
                prepareAppDataLIF(pkg, user.id, flags);
                    
            }
        }
    }
     
     
    private void prepareAppDataLIF(AndroidPackage pkg, int userId, int flags) {
        if (pkg == null) {
            Slog.wtf(TAG, "Package was null!", new Throwable());
            return;
        }
        // 调用prepareAppDataLeafLIF方法
        prepareAppDataLeafLIF(pkg, userId, flags);
    }
     
     
    private void prepareAppDataLeafLIF(AndroidPackage pkg, int userId, int flags) {
            
        ......
     
        try {
            // 调用Install守护进程的入口
            ceDataInode = mInstaller.createAppData(volumeUuid, packageName, userId, flags,
                        appId, seInfo, pkg.getTargetSdkVersion());
        } catch (InstallerException e) {
            if (pkg.isSystem()) {
                 destroyAppDataLeafLIF(pkg, userId, flags);
                 try {
                     ceDataInode = mInstaller.createAppData(volumeUuid, packageName, userId,                 
                         flags,appId, seInfo, pkg.getTargetSdkVersion());
                        
                 } catch (InstallerException e2) {
                     ......
                 }
             }
        }
    }

跳转到frameworks/base/services/core/java/com/android/server/pm/Installer.java中

public long createAppData(String uuid, String packageName, int userId, int flags, int     
            appId,String seInfo, int targetSdkVersion) throws InstallerException {
        if (!checkBeforeRemote()) return -1;
        try {
            // mInstalld为IInstall的对象，即通过Binder调用到进程installd,
            // 最终调用installd的createAppData()
            return mInstalld.createAppData(uuid, packageName, userId, flags, appId, seInfo,
                        targetSdkVersion);
        } catch (Exception e) {
            throw InstallerException.from(e);
        }
    }

总结：

APK的安装主要分为以下四步：

1）将APK的信息通过IO流的形式写入到 PackageInstaller.Session中

2）调用PackageInstaller.Session的commit方法，将APK的信息交由PKMS处理。

3）拷贝APK

4）最后进行安装

最终是交给IInstalld守护进程进行真正的安装操作。

## 五. 参考文章 ##

[Android 10.0 PackageManagerService（四）APK安装流程-\[Android取经之路\]\_writepackage.apk\_IngresGe的博客-CSDN博客][Android 10.0 PackageManagerService_APK_-_Android_writepackage.apk_IngresGe_-CSDN]

[Android 11.0 PackageManagerService（三）APK的安装过程\_小小幸运儿的博客-CSDN博客][Android 11.0 PackageManagerService_APK_-CSDN]

## 六. 待更新 ##

Android10和Android11的apk安装流程大致是相同的, 可以根据时序图找到关键的代码,然后在定位分析解决bug的时候, 着重去看某个方法的细节. 供大家参考,谢谢

[Android apk]: https://blog.csdn.net/zhao_csdn_8/article/details/107303888
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/e2dd521701ab43ccb425d7aa165698ec.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70 2]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/638e84edabc64ffbaa184564271fd30f.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poYW9fY3Nkbl84_size_16_color_FFFFFF_t_70 3]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/76707e27d36f49a88d3b5e21ad71a74b.png
[Android PackageManagerService _apk]: https://blog.csdn.net/u012514113/article/details/124516062
[204bcd81870542bb99942e787f0b4716.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/1adfef53464d4ebf8f7b66c971e4ddaa.png
[f85d1014799447958997c424145bbd3e.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/46058c0168514fa19338d2f7cf5b802c.png
[8ef0ee939ba44991b42c9cc50372944a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/25/c1663f1138244a8980390d3edb176f3d.png
[Android 10.0 PackageManagerService_APK_-_Android_writepackage.apk_IngresGe_-CSDN]: https://blog.csdn.net/yiranfeng/article/details/104073200
[Android 11.0 PackageManagerService_APK_-CSDN]: https://blog.csdn.net/zhourui_1021/article/details/118465753#t2