adb install 深刻分析

adb install 也是用的pm命令去安裝的，因此開始是在pm.java中。

frameworks\base\services\java\com\android\server\pm 

一、調用pm程序開始安裝

得用Pm安裝時，通常是shell運行一個pm命令，並傳送相應的參數，咱們經過adb鏈接到機器，輸入pm,會打出pm的一些參數

# pm
pm

frameworks\base\cmds\pm\src\com\android\commands\pm    

public static void main(String[] args) {
        new Pm().run(args);
    }

public void run(String[] args) {
......進行一系列的判斷......
       if ("install".equals(op)) {
            runInstall();
            return;
        }
}

private void runInstall() {

................此處省略一萬字......................
 mPm.installPackageWithVerification(apkURI, obs, installFlags, installerPackageName,
                    verificationURI, null);
}

   frameworks\base\services\java\com\android\server\pm

public void installPackageWithVerification(Uri packageURI, IPackageInstallObserver observer,
            int flags, String installerPackageName, Uri verificationURI,
            ManifestDigest manifestDigest) {

.................此處省略一萬字.............................
   final Message msg = mHandler.obtainMessage(INIT_COPY);
   msg.obj = new InstallParams(packageURI, observer,filteredFlags,installerPackageName,
                verificationURI, manifestDigest);
        mHandler.sendMessage(msg);
}

void doHandleMessage(Message msg) {
            switch (msg.what) {
                case INIT_COPY: {
                    if (DEBUG_INSTALL) Slog.i(TAG, "init_copy");
                    HandlerParams params = (HandlerParams) msg.obj;
                    int idx = mPendingInstalls.size();
                    if (DEBUG_INSTALL) Slog.i(TAG, "idx=" + idx);
                    // If a bind was already initiated we dont really
                    // need to do anything. The pending install
                    // will be processed later on.
                    if (!mBound) {
                        // If this is the only one pending we might
                        // have to bind to the service again.
						//鏈接服務 連接上返回真走else
                        if (!connectToService()) {
                            Slog.e(TAG, "Failed to bind to media container service");
                            params.serviceError();
                            return;
                        } else {
                            // Once we bind to the service, the first
                            // pending request will be processed.
                            mPendingInstalls.add(idx, params);
                        }
                    } else {
                        mPendingInstalls.add(idx, params);
                        // Already bound to the service. Just make
                        // sure we trigger off processing the first request.
                        if (idx == 0) {
                            mHandler.sendEmptyMessage(MCS_BOUND);
                        }
                    }
                    break;
                }

調用connectToService方法

private boolean connectToService() {
            if (DEBUG_SD_INSTALL) Log.i(TAG, "Trying to bind to" +
                    " DefaultContainerService");
			//鏈接服務DefaultContainerService
            Intent service = new Intent().setComponent(DEFAULT_CONTAINER_COMPONENT);
			//設置線程默認應用的優先級
            Process.setThreadPriority(Process.THREAD_PRIORITY_DEFAULT);
			//在鏈接成功的時候觸發DefaultContainerConnection的onServiceConnected
            if (mContext.bindService(service, mDefContainerConn,
                    Context.BIND_AUTO_CREATE)) {
                Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
                mBound = true;
                return true;
            }
			//設置線程優先級爲後臺，這樣當多個線程併發後不少可有可無的線程分配的CPU時間將會減小，有利於主線程的處理
            Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
            return false;
        }

鏈接服務DefaultContainerConnection 綁定成功發送一條消息MCS_BOUND

final private DefaultContainerConnection mDefContainerConn =
            new DefaultContainerConnection();
    class DefaultContainerConnection implements ServiceConnection {
        public void onServiceConnected(ComponentName name, IBinder service) {
            if (DEBUG_SD_INSTALL) Log.i(TAG, "onServiceConnected");
            IMediaContainerService imcs =
                IMediaContainerService.Stub.asInterface(service);
				//PackageHandler發了一條MCS_BOUND
            mHandler.sendMessage(mHandler.obtainMessage(MCS_BOUND, imcs));
        }

        public void onServiceDisconnected(ComponentName name) {
            if (DEBUG_SD_INSTALL) Log.i(TAG, "onServiceDisconnected");
        }
    };

 發送了一條消息MCS_BOUND和 IMediaContainerService imcs 對象
IMediaContainerService imcs = IMediaContainerService.Stub.asInterface(service);

 調用方法params.startCopy()

 

final boolean startCopy() {
            boolean res;
            try {
                if (DEBUG_INSTALL) Slog.i(TAG, "startCopy");

                if (++mRetries > MAX_RETRIES) {
                    Slog.w(TAG, "Failed to invoke remote methods on default container service. Giving up");
                    mHandler.sendEmptyMessage(MCS_GIVE_UP);
                    handleServiceError();
                    return false;
                } else {
		 //安裝前的準備工做
                    handleStartCopy();
                    res = true;
                }
            } catch (RemoteException e) {
                if (DEBUG_INSTALL) Slog.i(TAG, "Posting install MCS_RECONNECT");
                mHandler.sendEmptyMessage(MCS_RECONNECT);
                res = false;
            }
            handleReturnCode();
            return res;
        }

 handleStartCopy進行一些安裝前準備工做，最後調用handleReturnCode

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);
            }
        }

mArgs 在handleStartCopy進行了初始化

 

/*
         * 調用遠程方法來獲取和安裝包信息
          * Invoke remote method to get package information and install
         * location values. Override install location based on default
         * policy if needed and then create install arguments based
         * on the install location.
         */
        public void handleStartCopy() throws RemoteException {
  
             ..............................
            int ret = PackageManager.INSTALL_SUCCEEDED;
            final InstallArgs args = createInstallArgs(this);
            mArgs = args;

       }

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) {
                    args.doPreInstall(res.returnCode);
                    synchronized (mInstallLock) {
                        installPackageLI(args, true, res);
                    }
                    args.doPostInstall(res.returnCode);
                }

installPackageLI調用這個方法

在installPackageLI中，會new 一個PackageParser對package進行解析，調用parsePackage函數 parsePackage(File sourceFile, String destCodePath,
            DisplayMetrics metrics, int flags)函數根據參數進行一些處理後最終調用parsePackage(
        Resources res, XmlResourceParser parser, int flags, String[] outError)對包進行解析，咱們看到這個函數裏面主要對配置文件AndroidManifest.xml文件進行了解析。

//這個函數裏面主要對配置文件AndroidManifest.xml文件進行了解析
		//返回解析到的全部數據pkg
        final PackageParser.Package pkg = pp.parsePackage(tmpPackageFile,
                null, mMetrics, parseFlags);

private void installPackageLI(InstallArgs args,
            boolean newInstall, PackageInstalledInfo res) {

          ..............................
        //replace判斷設備上面是否有安裝的app
        if (replace) {
            replacePackageLI(pkg, parseFlags, scanMode,
                    installerPackageName, res);
        } else {
            installNewPackageLI(pkg, parseFlags, scanMode,
                    installerPackageName,res);
        }

}
private void installNewPackageLI(PackageParser.Package pkg,  
            int parseFlags,int scanMode,  
            String installerPackageName, PackageInstalledInfo res) {  
     ***********************省略若干*************************************************  
        PackageParser.Package newPackage = scanPackageLI(pkg, parseFlags, scanMode,  
               System.currentTimeMillis());  
     ***********************省略若干**************************************************    
} 

跟蹤scanPackageLI（）方法後發現，程序通過不少次的if else 的篩選，最後斷定能夠安裝後調用了 mInstaller.install

if (mInstaller != null) {  
    int ret = mInstaller.install(pkgName, useEncryptedFSDir,  pkg.applicationInfo.uid,pkg.applicationInfo.uid);  
    if(ret < 0) {  
         // Error from installer  
       mLastScanError =    PackageManager.INSTALL_FAILED_INSUFFICIENT_STORAGE;  
                        return null;  
                    }  
                }

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