一. APK的安装步骤
安装步骤一：把APK的信息通过IO流的形式写入到PackageInstaller.Session中
安装步骤二：调用PackageInstaller.Session的commit方法，把APK的信息交给PackageManagerService处理
安装步骤三：进行Apk的Copy操作，进行安装
二. 点击安装后到完成APK的拷贝流程如下：
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PacakageInstallerActivity.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。bingUi方法的代码如下：
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
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();
}
}startInstall方法组装了一个Intent，并跳转到 InstallInstalling 这个Activity，并关闭掉当前的PackageInstallerActivity。InstallInstalling主要用于向包管理器发送包的信息并处理包管理的回调。
private void startInstall() {
// Start subactivity to actually install the application
Intent newIntent = new Intent();
newIntent.putExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO,
mPkgInfo.applicationInfo);
newIntent.setData(mPackageURI);
// 设置Intent中的class为InstallInstalling，用来进行Activity跳转
newIntent.setClass(this, InstallInstalling.class);
String installerPackageName = getIntent().getStringExtra(
Intent.EXTRA_INSTALLER_PACKAGE_NAME);
if (mOriginatingURI != null) {
newIntent.putExtra(Intent.EXTRA_ORIGINATING_URI, mOriginatingURI);
}
if (mReferrerURI != null) {
newIntent.putExtra(Intent.EXTRA_REFERRER, mReferrerURI);
}
if (mOriginatingUid != PackageInstaller.SessionParams.UID_UNKNOWN) {
newIntent.putExtra(Intent.EXTRA_ORIGINATING_UID, mOriginatingUid);
}
if (installerPackageName != null) {
newIntent.putExtra(Intent.EXTRA_INSTALLER_PACKAGE_NAME,
installerPackageName);
}
if (getIntent().getBooleanExtra(Intent.EXTRA_RETURN_RESULT, false)) {
newIntent.putExtra(Intent.EXTRA_RETURN_RESULT, true);
}
newIntent.addFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT);
if(localLOGV) Log.i(TAG, "downloaded app uri="+mPackageURI);
startActivity(newIntent);
finish();
}InstallInstalling 的Activity启动后，进入onCreate方法
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给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
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ApplicationInfo appInfo = getIntent()
.getParcelableExtra(PackageUtil.INTENT_ATTR_APPLICATION_INFO);
mPackageURI = getIntent().getData();
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());
PackageUtil.AppSnippet as = PackageUtil.getAppSnippet(this, appInfo, sourceFile);
mAlert.setIcon(as.icon);
mAlert.setTitle(as.label);
mAlert.setView(R.layout.install_content_view);
mAlert.setButton(DialogInterface.BUTTON_NEGATIVE, getString(R.string.cancel),
(ignored, ignored2) -> {
if (mInstallingTask != null) {
mInstallingTask.cancel(true);
}
if (mSessionId > 0) {
getPackageManager().getPackageInstaller().abandonSession(mSessionId);
mSessionId = 0;
}
setResult(RESULT_CANCELED);
finish();
}, null);
setupAlert();
requireViewById(R.id.installing).setVisibility(View.VISIBLE);
// 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);
params.setInstallLocation(pkg.installLocation);
params.setSize(
PackageHelper.calculateInstalledSize(pkg, false, params.abiOverride));
} catch (PackageParser.PackageParserException e) {
Log.e(LOG_TAG, "Cannot parse package " + file + ". Assuming defaults.");
Log.e(LOG_TAG,
"Cannot calculate installed size " + file + ". Try only apk size.");
params.setSize(file.length());
} catch (IOException e) {
Log.e(LOG_TAG,
"Cannot calculate installed size " + file + ". Try only apk size.");
params.setSize(file.length());
}
try {
// 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
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);
}
}
mCancelButton = mAlert.getButton(DialogInterface.BUTTON_NEGATIVE);
mSessionCallback = new InstallSessionCallback();
}
}这里 PackageInstaller 的createSession()内部会通过 IPackageInstaller与 PackageInstallerService进行进程间通信，最终调用的是PackageInstallerService的createSession方法来创建并返回mSessionId。
接着在InstallInstalling的onResume方法中，调用onPostExecute()方法，将APK的信息通过IO流的形式写入到PackageInstaller.session中。onResume方法代码如下：
@Override
protected void onResume() {
super.onResume();
// This is the first onResume in a single life of the activity
if (mInstallingTask == null) {
PackageInstaller installer = getPackageManager().getPackageInstaller();
// 获取sessionInfo
PackageInstaller.SessionInfo sessionInfo = installer.getSessionInfo(mSessionId);
if (sessionInfo != null && !sessionInfo.isActive()) {
// 创建内部类InstallingAsyncTask的对象，调用execute()，最终进入onPostExecute()
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。InstallingAsyncTask代码如下：
private final class InstallingAsyncTask extends AsyncTask<Void, Void,
PackageInstaller.Session> {
volatile boolean isDone;
@Override
protected PackageInstaller.Session doInBackground(Void... params) {
.........
try {
File file = new File(mPackageURI.getPath());
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);
}
}
}
}
return session;
} catch (IOException | SecurityException e) {
Log.e(LOG_TAG, "Could not write package", e);
session.close();
return null;
} finally {
synchronized (this) {
isDone = true;
notifyAll();
}
}
}
@Override
protected void onPostExecute(PackageInstaller.Session session) {
if (session != null) {
Intent broadcastIntent = new Intent(BROADCAST_ACTION);
broadcastIntent.setFlags(Intent.FLAG_RECEIVER_FOREGROUND);
broadcastIntent.setPackage(getPackageName());
broadcastIntent.putExtra(EventResultPersister.EXTRA_ID, mInstallId);
PendingIntent pendingIntent = PendingIntent.getBroadcast(
InstallInstalling.this,
mInstallId,
broadcastIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
// 调用PackageInstaller.Session的commit方法，进行安装
session.commit(pendingIntent.getIntentSender());
mCancelButton.setEnabled(false);
setFinishOnTouchOutside(false);
} else {
........
}
}
}接着看一下PackageInstaller.Session的commit方法
@Override
public void commit(@NonNull IntentSender statusReceiver, boolean forTransfer) {
......
if (!markAsSealed(statusReceiver, forTransfer)) {
return;
}
if (isMultiPackage()) {
.....
}
dispatchStreamValidateAndCommit();
}
private void dispatchStreamValidateAndCommit() {
// 向Handler中发送了一个类型为MSG_STREAM_VALIDATE_AND_COMMIT的消息
mHandler.obtainMessage(MSG_STREAM_VALIDATE_AND_COMMIT).sendToTarget();
}MSG_STREAM_VALIDATE_AND_COMMIT在Handler(mHandlerCallback)中进行处理，进入到handleStreamValidateAndCommit()方法
private final Handler.Callback mHandlerCallback = new Handler.Callback() {
@Override
public boolean handleMessage(Message msg) {
switch (msg.what) {
case MSG_STREAM_VALIDATE_AND_COMMIT:
// 处理MSG_STREAM_VALIDATE_AND_COMMIT消息
handleStreamValidateAndCommit();
break;
case MSG_INSTALL:
handleInstall();
break;
.....
}
return true;
}
};handleStreamValidateAndCommit方法的代码如下：
private void handleStreamValidateAndCommit() {
// 最终发送了一条MSG_INSTALL的消息给Handler
mHandler.obtainMessage(MSG_INSTALL).sendToTarget();
}MSG_INSTALL在Handler(mHandlerCallback)中进行处理，进入到handleInstall方法。
private void handleInstall() {
//.......
// For a multiPackage session, read the child sessions
// outside of the lock, because reading the child
// sessions with the lock held could lead to deadlock
// (b/123391593).
List<PackageInstallerSession> childSessions = getChildSessionsNotLocked();
try {
synchronized (mLock) {
// 调用了installNonStagedLocked方法
installNonStagedLocked(childSessions);
}
} catch (PackageManagerException e) {
final String completeMsg = ExceptionUtils.getCompleteMessage(e);
Slog.e(TAG, "Commit of session " + sessionId + " failed: " + completeMsg);
destroyInternal();
dispatchSessionFinished(e.error, completeMsg, null);
}
}在handlerInstall方法中调用了installNonStageLocked方法。
private void installNonStagedLocked(List<PackageInstallerSession> childSessions)
throws PackageManagerException {
//。。。。。
if (isMultiPackage()) {
List<PackageManagerService.ActiveInstallSession> installingChildSessions =
new ArrayList<>(childSessions.size());
boolean success = true;
PackageManagerException failure = null;
for (int i = 0; i < childSessions.size(); ++i) {
final PackageInstallerSession session = childSessions.get(i);
try {
final PackageManagerService.ActiveInstallSession installingChildSession =
session.makeSessionActiveLocked();
if (installingChildSession != null) {
installingChildSessions.add(installingChildSession);
}
} catch (PackageManagerException e) {
failure = e;
success = false;
}
}
if (!success) {
sendOnPackageInstalled(mContext, mRemoteStatusReceiver, sessionId,
isInstallerDeviceOwnerOrAffiliatedProfileOwnerLocked(), userId, null,
failure.error, failure.getLocalizedMessage(), null);
return;
}
// 调用了PackageManagerService的installStage方法
mPm.installStage(installingChildSessions);
} else {
// 调用了PackageManagerService的installStage方法
mPm.installStage(installingSession);
}
}在最后调用了PackageManagerService的installStage方法，在此代码逻辑就回到了PackageManagerService。
void installStage(ActiveInstallSession activeInstallSession) {
if (DEBUG_INSTANT) {
if ((activeInstallSession.getSessionParams().installFlags
& PackageManager.INSTALL_INSTANT_APP) != 0) {
Slog.d(TAG, "Ephemeral install of " + activeInstallSession.getPackageName());
}
}
// 1. 创建了类型为INIT_COPY的消息
final Message msg = mHandler.obtainMessage(INIT_COPY);
// 2. 创建InstallParams，它对应于包的安装数据
final InstallParams params = new InstallParams(activeInstallSession);
params.setTraceMethod("installStage").setTraceCookie(System.identityHashCode(params));
msg.obj = params;
Trace.asyncTraceBegin(TRACE_TAG_PACKAGE_MANAGER, "installStage",
System.identityHashCode(msg.obj));
Trace.asyncTraceBegin(TRACE_TAG_PACKAGE_MANAGER, "queueInstall",
System.identityHashCode(msg.obj));
// 3. 将InstallParams通过消息发送出去
mHandler.sendMessage(msg);
}
// 对INIT_COPY的消息的处理
PackageManagerService.java
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的拷贝工作
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：
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);
}
}三、APK的安装过程
APK拷贝完成后，进入真正的安装，流程如下：
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) {
......
}
}
}
}
Installer.java
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。