在常见的应用市场和安装管理器中，通常有两种常见的方式来调用系统接口来安装APP，那这个安装流程是怎么样的，本文进行部分关键代码和流程的解析。
1、 通过反射方式调用PackageManager的installPackage方法
private boolean intallApp(Context mContext, String apkPath) {
sContext = mContext;
PackageManager packageManager = mContext.getPackageManager(); //获取packageManager
Class<?> pmClz = packageManager.getClass();
try {
if (Build.VERSION.SDK_INT >= 21) {
Class<?> aClass = Class.forName("android.app.PackageInstallObserver");
Constructor<?> constructor = aClass.getDeclaredConstructor();
constructor.setAccessible(true);
Object installObserver = constructor.newInstance();
Method method = pmClz.getDeclaredMethod("installPackage", Uri.class, aClass, int.class, String.class);//通过反射方式获取 packageManager 的方法
method.setAccessible(true);
Object LocalPackageInstallObserver = new LocalPackageInstallObserver();// 自己可以写一个observer 用户后面来监控安装的状态，做对应的回调操作
method.invoke(packageManager, Uri.fromFile(new File(apkPath)), LocalPackageInstallObserver, 2, null);
Log.d("imdm", "intallInSilent apkPath:" + apkPath);
} else {
Method method = pmClz.getDeclaredMethod("installPackage", Uri.class, Class.forName("android.content.pm.IPackageInstallObserver"), int.class, String.class);
method.setAccessible(true);
method.invoke(packageManager, Uri.fromFile(new File(apkPath)), null, 2, null);
Log.d("imdm", "intallInSilent apkPath:" + apkPath);
}
return true;
} catch (Exception e) {
Log.d("imdm", "intallInSilent " + e);
}
return false;
}
这种方法实现简便，同时可以有一个observer 回调方法反馈安装的状态，非常好用。
2、 另一种方法就是使用PackageInstaller，直接调用它的session方法
private void doPackageStage(PackageManager pm, PackageInstaller.SessionParams params) {
final PackageInstaller packageInstaller = pm.getPackageInstaller();
PackageInstaller.Session session = null;
try {
final String packageLocation = mPackageURI.getPath();
final File file = new File(packageLocation);
final int sessionId = packageInstaller.createSession(params);
final byte[] buffer = new byte[65536];
session = packageInstaller.openSession(sessionId);
final InputStream in = new FileInputStream(file);
final long sizeBytes = file.length();
final OutputStream out = session.openWrite("PackageInstaller", 0, sizeBytes);
try {
int c;
while ((c = in.read(buffer)) != -1) {
out.write(buffer, 0, c);
if (sizeBytes > 0) {
final float fraction = ((float) c / (float) sizeBytes);
session.addProgress(fraction);
}
}
session.fsync(out);
} finally {
IoUtils.closeQuietly(in);
IoUtils.closeQuietly(out);
}
// Create a PendingIntent and use it to generate the IntentSender
Intent broadcastIntent = new Intent("com.hra.install");
PendingIntent pendingIntent = PendingIntent.getBroadcast(
InstallService.this /*context*/,
sessionId,
broadcastIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
session.commit(pendingIntent.getIntentSender()); // 通过session 提交整个安装事务给PackageInstaller
} catch (IOException e) {
onPackageInstalled(PackageInstaller.STATUS_FAILURE);
} finally {
IoUtils.closeQuietly(session);
}
这个方法实现稍微复杂一些，是通过session 操作来进行安装操作，同时需要一个broadcast来接收安装状态，这个安装结果时效性较差一些，但是在多APP同时安装时效率会高很多。
下面我们分别来细说这两种方法：
3、在PackageManager中，installPackage只是一个abstract方法，真正的实现放在了
frameworks/base/core/java/android/app/ApplicationPackageManager.java
@Override
public void installPackage(Uri packageURI, IPackageInstallObserver observer, int flags,
String installerPackageName) {
installCommon(packageURI, new LegacyPackageInstallObserver(observer), flags,
installerPackageName, mContext.getUserId());
}
private void installCommon(Uri packageURI,
PackageInstallObserver observer, int flags, String installerPackageName,
int userId) {
if (!"file".equals(packageURI.getScheme())) {
throw new UnsupportedOperationException("Only file:// URIs are supported");
}
final String originPath = packageURI.getPath();
try {
mPM.installPackageAsUser(originPath, observer.getBinder(), flags, installerPackageName,
userId);
} catch (RemoteException e) {
throw e.rethrowFromSystemServer();
}
}
在上面的代码里可以看到主要是调用了（PMS) PackageManagerService的installPackageAsUser方法：
frameworks/base/services/core/java/com/android/server/pm/PackageManagerService.java
public void installPackageAsUser(String originPath, IPackageInstallObserver2 observer,
int installFlags, String installerPackageName, VerificationParams verificationParams,
String packageAbiOverride, int userId) {
mContext.enforceCallingOrSelfPermission(android.Manifest.permission.INSTALL_PACKAGES, null);
......
final Message msg = mHandler.obtainMessage(INIT_COPY);
msg.obj = new InstallParams(origin, null, observer, params.installFlags,
installerPackageName, params.volumeUuid, verifParams, user, params.abiOverride,
params.grantedRuntimePermissions);
mHandler.sendMessage(msg);
}
这里主要是获取用户安装位置，将InstallParams对象封装在Message里，然后发一个Handler消息，发的是INIT_COPY 这个指令
看看对应handler里面的这个case做了什么：
void doHandleMessage(Message msg) {
switch (msg.what) {
case INIT_COPY: {
HandlerParams params = (HandlerParams) msg.obj;
int idx = mPendingInstalls.size();
if (DEBUG_INSTALL) Slog.i(TAG, "init_copy idx=" + idx + ": " + params);
// If a bind was already initiated we dont really
// need to do anything. The pending install
// will be processed later on.
if (!mBound) {
Trace.asyncTraceBegin(TRACE_TAG_PACKAGE_MANAGER, "bindingMCS",
System.identityHashCode(mHandler));
// If this is the only one pending we might
// have to bind to the service again.
if (!connectToService()) {
Slog.e(TAG, "Failed to bind to media container service");
params.serviceError();
Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, "bindingMCS",
System.identityHashCode(mHandler));
if (params.traceMethod != null) {
Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, params.traceMethod,
params.traceCookie);
}
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;
}
case MCS_BOUND: {
if (DEBUG_INSTALL) Slog.i(TAG, "mcs_bound");
if (msg.obj != null) {
mContainerService = (IMediaContainerService) msg.obj;
Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, "bindingMCS",
System.identityHashCode(mHandler));
}
if (mContainerService == null) {
if (!mBound) {
// Something seriously wrong since we are not bound and we are not
// waiting for connection. Bail out.
Slog.e(TAG, "Cannot bind to media container service");
for (HandlerParams params : mPendingInstalls) {
// Indicate service bind error
params.serviceError();
Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, "queueInstall",
System.identityHashCode(params));
if (params.traceMethod != null) {
Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER,
params.traceMethod, params.traceCookie);
}
return;
}
mPendingInstalls.clear();
} else {
Slog.w(TAG, "Waiting to connect to media container service");
}
} else if (mPendingInstalls.size() > 0) {
HandlerParams params = mPendingInstalls.get(0);
if (params != null) {
Trace.asyncTraceEnd(TRACE_TAG_PACKAGE_MANAGER, "queueInstall",
System.identityHashCode(params));
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "startCopy");
if (params.startCopy()) {
// We are done... look for more work or to
// go idle.
if (DEBUG_SD_INSTALL) Log.i(TAG,
"Checking for more work or unbind...");
// Delete pending install
if (mPendingInstalls.size() > 0) {
mPendingInstalls.remove(0);
}
if (mPendingInstalls.size() == 0) {
if (mBound) {
if (DEBUG_SD_INSTALL) Log.i(TAG,
"Posting delayed MCS_UNBIND");
removeMessages(MCS_UNBIND);
Message ubmsg = obtainMessage(MCS_UNBIND);
// Unbind after a little delay, to avoid
// continual thrashing.
sendMessageDelayed(ubmsg, 10000);
}
} else {
// There are more pending requests in queue.
// Just post MCS_BOUND message to trigger processing
// of next pending install.
if (DEBUG_SD_INSTALL) Log.i(TAG,
"Posting MCS_BOUND for next work");
mHandler.sendEmptyMessage(MCS_BOUND);
}
}
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
}
} else {
// Should never happen ideally.
Slog.w(TAG, "Empty queue");
}
break;
}
.......
}
上面代码的意思是：如果msg.what是INIT_COPY：则连接DefaultContainerService服务，将我们要安装的信息方法HandlerParams的mPendingInstalls中，然后再发送MCS_BOUND消息。
如果msg.what是MCS_BOUND:则通过HandlerParams params = mPendingInstalls.get(0)获取要安装包的信息，然后清除包信息，如果还有其他包，则继续发MCS_BOUND消息，一直循环，直到安装包都安装完。
最后再调用PackageManagerService.HandlerParams的startCopy方法：
final boolean startCopy() {
boolean res;
try {
if (DEBUG_INSTALL) Slog.i(TAG, "startCopy " + mUser + ": " + this);
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 {
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;
}
startCopy中主要调用两个重要的方法handleStartCopy和handleReturnCode。
handleStartCopy中会检查应用是否能安装成功，如果不能安装成功，则会返回failed的CODE；返回res标识，判断是否安装成功。
下面这个函数代码中，会判断是否还有安装空间，以及对APK包进行解析确认后面是否可以安装；
的注释已经写得非常详细了，直接看原生代码注释就好，我就不多赘述了。
/*
* 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;
// If we're already staged, we've firmly committed to an install location
if (origin.staged) {
if (origin.file != null) {
installFlags |= PackageManager.INSTALL_INTERNAL;
installFlags &= ~PackageManager.INSTALL_EXTERNAL;
} else if (origin.cid != null) {
installFlags |= PackageManager.INSTALL_EXTERNAL;
installFlags &= ~PackageManager.INSTALL_INTERNAL;
} else {
throw new IllegalStateException("Invalid stage location");
}
}
final boolean onSd = (installFlags & PackageManager.INSTALL_EXTERNAL) != 0;
final boolean onInt = (installFlags & PackageManager.INSTALL_INTERNAL) != 0;
final boolean ephemeral = (installFlags & PackageManager.INSTALL_EPHEMERAL) != 0;
PackageInfoLite pkgLite = null;
if (onInt && onSd) {
// Check if both bits are set.
Slog.w(TAG, "Conflicting flags specified for installing on both internal and external");
ret = PackageManager.INSTALL_FAILED_INVALID_INSTALL_LOCATION;
} else if (onSd && ephemeral) {
Slog.w(TAG, "Conflicting flags specified for installing ephemeral on external");
ret = PackageManager.INSTALL_FAILED_INVALID_INSTALL_LOCATION;
} else {
pkgLite = mContainerService.getMinimalPackageInfo(origin.resolvedPath, installFlags,
packageAbiOverride);
if (DEBUG_EPHEMERAL && ephemeral) {
Slog.v(TAG, "pkgLite for install: " + pkgLite);
}
/*
* If we have too little free space, try to free cache
* before giving up.
*/
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 = mContainerService.calculateInstalledSize(
origin.resolvedPath, isForwardLocked(), packageAbiOverride);
try {
mInstaller.freeCache(null, sizeBytes + lowThreshold);
pkgLite = mContainerService.getMinimalPackageInfo(origin.resolvedPath,
installFlags, packageAbiOverride);
} catch (InstallerException e) {
Slog.w(TAG, "Failed to free cache", e);
}
/*
* The cache free must have deleted the file we
* downloaded to install.
*
* TODO: fix the "freeCache" call to not delete
* the file we care about.
*/
if (pkgLite.recommendedInstallLocation
== PackageHelper.RECOMMEND_FAILED_INVALID_URI) {
pkgLite.recommendedInstallLocation
= PackageHelper.RECOMMEND_FAILED_INSUFFICIENT_STORAGE;
}
}
}
if (ret == PackageManager.INSTALL_SUCCEEDED) {
int loc = pkgLite.recommendedInstallLocation;
if (loc == PackageHelper.RECOMMEND_FAILED_INVALID_LOCATION) {
ret = PackageManager.INSTALL_FAILED_INVALID_INSTALL_LOCATION;
} else if (loc == PackageHelper.RECOMMEND_FAILED_ALREADY_EXISTS) {
ret = PackageManager.INSTALL_FAILED_ALREADY_EXISTS;
} else if (loc == PackageHelper.RECOMMEND_FAILED_INSUFFICIENT_STORAGE) {
ret = PackageManager.INSTALL_FAILED_INSUFFICIENT_STORAGE;
} else if (loc == PackageHelper.RECOMMEND_FAILED_INVALID_APK) {
ret = PackageManager.INSTALL_FAILED_INVALID_APK;
} else if (loc == PackageHelper.RECOMMEND_FAILED_INVALID_URI) {
ret = PackageManager.INSTALL_FAILED_INVALID_URI;
} else if (loc == PackageHelper.RECOMMEND_MEDIA_UNAVAILABLE) {
ret = PackageManager.INSTALL_FAILED_MEDIA_UNAVAILABLE;
} else {
// Override with defaults if needed.
loc = installLocationPolicy(pkgLite);
if (loc == PackageHelper.RECOMMEND_FAILED_VERSION_DOWNGRADE) {
ret = PackageManager.INSTALL_FAILED_VERSION_DOWNGRADE;
} else if (!onSd && !onInt) {
// Override install location with flags
if (loc == PackageHelper.RECOMMEND_INSTALL_EXTERNAL) {
// Set the flag to install on external media.
installFlags |= PackageManager.INSTALL_EXTERNAL;
installFlags &= ~PackageManager.INSTALL_INTERNAL;
} else if (loc == PackageHelper.RECOMMEND_INSTALL_EPHEMERAL) {
if (DEBUG_EPHEMERAL) {
Slog.v(TAG, "...setting INSTALL_EPHEMERAL install flag");
}
installFlags |= PackageManager.INSTALL_EPHEMERAL;
installFlags &= ~(PackageManager.INSTALL_EXTERNAL
|PackageManager.INSTALL_INTERNAL);
} else {
// Make sure the flag for installing on external
// media is unset
installFlags |= PackageManager.INSTALL_INTERNAL;
installFlags &= ~PackageManager.INSTALL_EXTERNAL;
}
}
}
}
final InstallArgs args = createInstallArgs(this);
mArgs = args;
if (ret == PackageManager.INSTALL_SUCCEEDED) {
// Apps installed for "all" users use the device owner to verify the app
UserHandle verifierUser = getUser();
if (verifierUser == UserHandle.ALL) {
verifierUser = UserHandle.SYSTEM;
}
/*
* Determine if we have any installed package verifiers. If we
* do, then we'll defer to them to verify the packages.
*/
final int requiredUid = mRequiredVerifierPackage == null ? -1
: getPackageUid(mRequiredVerifierPackage, MATCH_DEBUG_TRIAGED_MISSING,
verifierUser.getIdentifier());
if (!origin.existing && requiredUid != -1
&& isVerificationEnabled(verifierUser.getIdentifier(), installFlags)) {
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);
// Query all live verifiers based on current user state
final List<ResolveInfo> receivers = queryIntentReceiversInternal(verification,
PACKAGE_MIME_TYPE, 0, verifierUser.getIdentifier());
if (DEBUG_VERIFY) {
Slog.d(TAG, "Found " + receivers.size() + " verifiers for intent "
+ verification.toString() + " with " + pkgLite.verifiers.length
+ " optional verifiers");
}
final int verificationId = mPendingVerificationToken++;
verification.putExtra(PackageManager.EXTRA_VERIFICATION_ID, verificationId);
verification.putExtra(PackageManager.EXTRA_VERIFICATION_INSTALLER_PACKAGE,
installerPackageName);
verification.putExtra(PackageManager.EXTRA_VERIFICATION_INSTALL_FLAGS,
installFlags);
verification.putExtra(PackageManager.EXTRA_VERIFICATION_PACKAGE_NAME,
pkgLite.packageName);
verification.putExtra(PackageManager.EXTRA_VERIFICATION_VERSION_CODE,
pkgLite.versionCode);
if (verificationInfo != null) {
if (verificationInfo.originatingUri != null) {
verification.putExtra(Intent.EXTRA_ORIGINATING_URI,
verificationInfo.originatingUri);
}
if (verificationInfo.referrer != null) {
verification.putExtra(Intent.EXTRA_REFERRER,
verificationInfo.referrer);
}
if (verificationInfo.originatingUid >= 0) {
verification.putExtra(Intent.EXTRA_ORIGINATING_UID,
verificationInfo.originatingUid);
}
if (verificationInfo.installerUid >= 0) {
verification.putExtra(PackageManager.EXTRA_VERIFICATION_INSTALLER_UID,
verificationInfo.installerUid);
}
}
final PackageVerificationState verificationState = new PackageVerificationState(
requiredUid, args);
mPendingVerification.append(verificationId, verificationState);
final List<ComponentName> sufficientVerifiers = matchVerifiers(pkgLite,
receivers, verificationState);
/*
* 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);
final Intent sufficientIntent = new Intent(verification);
sufficientIntent.setComponent(verifierComponent);
mContext.sendBroadcastAsUser(sufficientIntent, verifierUser);
}
}
}
final ComponentName requiredVerifierComponent = matchComponentForVerifier(
mRequiredVerifierPackage, receivers);
if (ret == PackageManager.INSTALL_SUCCEEDED
&& mRequiredVerifierPackage != null) {
Trace.asyncTraceBegin(
TRACE_TAG_PACKAGE_MANAGER, "verification", verificationId);
/*
* Send the intent to the required verification agent,
* but only start the verification timeout after the
* target BroadcastReceivers have run.
*/
verification.setComponent(requiredVerifierComponent);
mContext.sendOrderedBroadcastAsUser(verification, verifierUser,
android.Manifest.permission.PACKAGE_VERIFICATION_AGENT,
new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
final Message msg = mHandler
.obtainMessage(CHECK_PENDING_VERIFICATION);
msg.arg1 = verificationId;
mHandler.sendMessageDelayed(msg, getVerificationTimeout());
}
}, null, 0, null, null);
/*
* We don't want the copy to proceed until verification
* succeeds, so null out this field.
*/
mArgs = null;
}
} else {
/*
* No package verification is enabled, so immediately start
* the remote call to initiate copy using temporary file.
*/
ret = args.copyApk(mContainerService, true);
}
}
mRet = ret;
}
handleReturnCode方法有两处重载了，一个是删除时调用的，一个是安装时调用的，下面列出安装的地方：
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);
}
}
调用 processPendingInstall 方法：
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.setReturnCode(currentStatus);
res.uid = -1;
res.pkg = null;
res.removedInfo = null;
if (res.returnCode == PackageManager.INSTALL_SUCCEEDED) {
args.doPreInstall(res.returnCode);
synchronized (mInstallLock) {
installPackageTracedLI(args, res);
}
args.doPostInstall(res.returnCode, res.uid);
}
......
这个方法主要调用的是installPackageTracedLI 方法：
private void installPackageTracedLI(InstallArgs args, PackageInstalledInfo res) {
try {
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "installPackage");
installPackageLI(args, res);
} finally {
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
}
}
调用到installPackageLI中：
private void installPackageLI(InstallArgs args, PackageInstalledInfo res) {
final int installFlags = args.installFlags;
final String installerPackageName = args.installerPackageName;
final String volumeUuid = args.volumeUuid;
final File tmpPackageFile = new File(args.getCodePath());
final boolean forwardLocked = ((installFlags & PackageManager.INSTALL_FORWARD_LOCK) != 0);
final boolean onExternal = (((installFlags & PackageManager.INSTALL_EXTERNAL) != 0)
|| (args.volumeUuid != null));
final boolean ephemeral = ((installFlags & PackageManager.INSTALL_EPHEMERAL) != 0);
final boolean forceSdk = ((installFlags & PackageManager.INSTALL_FORCE_SDK) != 0);
boolean replace = false;
int scanFlags = SCAN_NEW_INSTALL | SCAN_UPDATE_SIGNATURE;
if (args.move != null) {
// moving a complete application; perform an initial scan on the new install location
scanFlags |= SCAN_INITIAL;
}
if ((installFlags & PackageManager.INSTALL_DONT_KILL_APP) != 0) {
scanFlags |= SCAN_DONT_KILL_APP;
}
// Result object to be returned
res.setReturnCode(PackageManager.INSTALL_SUCCEEDED);
if (DEBUG_INSTALL) Slog.d(TAG, "installPackageLI: path=" + tmpPackageFile);
// Sanity check
if (ephemeral && (forwardLocked || onExternal)) {
Slog.i(TAG, "Incompatible ephemeral install; fwdLocked=" + forwardLocked
+ " external=" + onExternal);
res.setReturnCode(PackageManager.INSTALL_FAILED_EPHEMERAL_INVALID);
return;
}
// Retrieve PackageSettings and parse package
final int parseFlags = mDefParseFlags | PackageParser.PARSE_CHATTY
| PackageParser.PARSE_ENFORCE_CODE
| (forwardLocked ? PackageParser.PARSE_FORWARD_LOCK : 0)
| (onExternal ? PackageParser.PARSE_EXTERNAL_STORAGE : 0)
| (ephemeral ? PackageParser.PARSE_IS_EPHEMERAL : 0)
| (forceSdk ? PackageParser.PARSE_FORCE_SDK : 0);
PackageParser pp = new PackageParser();
pp.setSeparateProcesses(mSeparateProcesses);
pp.setDisplayMetrics(mMetrics);
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "parsePackage");
final PackageParser.Package pkg;
try {
pkg = pp.parsePackage(tmpPackageFile, parseFlags);
} catch (PackageParserException e) {
res.setError("Failed parse during installPackageLI", e);
return;
} finally {
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
}
// If we are installing a clustered package add results for the children
if (pkg.childPackages != null) {
synchronized (mPackages) {
final int childCount = pkg.childPackages.size();
for (int i = 0; i < childCount; i++) {
PackageParser.Package childPkg = pkg.childPackages.get(i);
PackageInstalledInfo childRes = new PackageInstalledInfo();
childRes.setReturnCode(PackageManager.INSTALL_SUCCEEDED);
childRes.pkg = childPkg;
childRes.name = childPkg.packageName;
PackageSetting childPs = mSettings.peekPackageLPr(childPkg.packageName);
if (childPs != null) {
childRes.origUsers = childPs.queryInstalledUsers(
sUserManager.getUserIds(), true);
}
if ((mPackages.containsKey(childPkg.packageName))) {
childRes.removedInfo = new PackageRemovedInfo();
childRes.removedInfo.removedPackage = childPkg.packageName;
}
if (res.addedChildPackages == null) {
res.addedChildPackages = new ArrayMap<>();
}
res.addedChildPackages.put(childPkg.packageName, childRes);
}
}
}
// If package doesn't declare API override, mark that we have an install
// time CPU ABI override.
if (TextUtils.isEmpty(pkg.cpuAbiOverride)) {
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;
}
}
try {
// either use what we've been given or parse directly from the APK
if (args.certificates != null) {
try {
PackageParser.populateCertificates(pkg, args.certificates);
} catch (PackageParserException e) {
// there was something wrong with the certificates we were given;
// try to pull them from the APK
PackageParser.collectCertificates(pkg, parseFlags);
}
} else {
PackageParser.collectCertificates(pkg, parseFlags);
}
} catch (PackageParserException e) {
res.setError("Failed collect during installPackageLI", e);
return;
}
// Get rid of all references to package scan path via parser.
pp = null;
String oldCodePath = null;
boolean systemApp = false;
synchronized (mPackages) {
// Check if installing already existing package
if ((installFlags & PackageManager.INSTALL_REPLACE_EXISTING) != 0) {
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);
}
// Child packages are installed through the parent package
if (pkg.parentPackage != null) {
res.setError(PackageManager.INSTALL_PARSE_FAILED_BAD_PACKAGE_NAME,
"Package " + pkg.packageName + " is child of package "
+ pkg.parentPackage.parentPackage + ". Child packages "
+ "can be updated only through the parent package.");
return;
}
if (replace) {
// Prevent apps opting out from runtime permissions
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;
}
// Prevent installing of child packages
if (oldPackage.parentPackage != null) {
res.setError(PackageManager.INSTALL_PARSE_FAILED_BAD_PACKAGE_NAME,
"Package " + pkg.packageName + " is child of package "
+ oldPackage.parentPackage + ". Child packages "
+ "can be updated only through the parent package.");
return;
}
}
}
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);
}
// 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);
}
}
}
}
}
if (systemApp) {
if (onExternal) {
// Abort update; system app can't be replaced with app on sdcard
res.setError(INSTALL_FAILED_INVALID_INSTALL_LOCATION,
"Cannot install updates to system apps on sdcard");
return;
} else if (ephemeral) {
// Abort update; system app can't be replaced with an ephemeral app
res.setError(INSTALL_FAILED_EPHEMERAL_INVALID,
"Cannot update a system app with an ephemeral app");
return;
}
}
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()) {
// Enable SCAN_NO_DEX flag to skip dexopt at a later stage
scanFlags |= SCAN_NO_DEX;
try {
String abiOverride = (TextUtils.isEmpty(pkg.cpuAbiOverride) ?
args.abiOverride : pkg.cpuAbiOverride);
derivePackageAbi(pkg, new File(pkg.codePath), abiOverride,
true /* extract libs */,parseFlags);
} catch (PackageManagerException pme) {
Slog.e(TAG, "Error deriving application ABI", pme);
res.setError(INSTALL_FAILED_INTERNAL_ERROR, "Error deriving application ABI");
return;
}
// Shared libraries for the package need to be updated.
synchronized (mPackages) {
try {
updateSharedLibrariesLPw(pkg, null);
} catch (PackageManagerException e) {
Slog.e(TAG, "updateSharedLibrariesLPw failed: " + e.getMessage());
}
}
Trace.traceBegin(TRACE_TAG_PACKAGE_MANAGER, "dexopt");
// Do not run PackageDexOptimizer through the local performDexOpt
// method because `pkg` may not be in `mPackages` yet.
//
// Also, don't fail application installs if the dexopt step fails.
mPackageDexOptimizer.performDexOpt(pkg, pkg.usesLibraryFiles,
null /* instructionSets */, false /* checkProfiles */,
getCompilerFilterForReason(REASON_INSTALL),
getOrCreateCompilerPackageStats(pkg));
Trace.traceEnd(TRACE_TAG_PACKAGE_MANAGER);
// Notify BackgroundDexOptService that the package has been changed.
// If this is an update of a package which used to fail to compile,
// BDOS will remove it from its blacklist.
BackgroundDexOptService.notifyPackageChanged(pkg.packageName);
}
if (!args.doRename(res.returnCode, pkg, oldCodePath)) {
res.setError(INSTALL_FAILED_INSUFFICIENT_STORAGE, "Failed rename");
return;
}
startIntentFilterVerifications(args.user.getIdentifier(), replace, pkg);
try (PackageFreezer freezer = freezePackageForInstall(pkgName, installFlags,
"installPackageLI")) {
if (replace) {
replacePackageLIF(pkg, parseFlags, scanFlags | SCAN_REPLACING, args.user,
installerPackageName, res);
} else {
installNewPackageLIF(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);
}
final int childCount = (pkg.childPackages != null) ? pkg.childPackages.size() : 0;
for (int i = 0; i < childCount; i++) {
PackageParser.Package childPkg = pkg.childPackages.get(i);
PackageInstalledInfo childRes = res.addedChildPackages.get(childPkg.packageName);
PackageSetting childPs = mSettings.peekPackageLPr(childPkg.packageName);
if (childPs != null) {
childRes.newUsers = childPs.queryInstalledUsers(
sUserManager.getUserIds(), true);
}
}
}
}
这个方法是真正的安装了，会判断安装的APP是否为系统APP，同时会判断安装的APK 包里面的信息是否完整，否则不允许安装。
4、通过PackageInstaller安装
下面我们说说另一种安装方式，使用packageInstallerSession来进行安装
从前面的doPackageStage函数中，我们截取几个关键操作进行说明：
PackageInstaller.Session session = null;
通过PackageInstaller的createSession来创建一个安装session
final int sessionId = packageInstaller.createSession(params);
frameworks/base/core/java/android/content/pm/PackageInstaller.java
public int createSession(@NonNull SessionParams params) throws IOException {
try {
return mInstaller.createSession(params, mInstallerPackageName, mUserId);
} catch (RuntimeException e) {
ExceptionUtils.maybeUnwrapIOException(e);
throw e;
} catch (RemoteException e) {
throw e.rethrowFromSystemServer();
然后调用的是PackageInstallerService的createSession
frameworks/base/services/core/java/com/android/server/pm/PackageInstallerService.java
public int createSession(SessionParams params, String installerPackageName, int userId) {
try {
return createSessionInternal(params, installerPackageName, userId);
} catch (IOException e) {
throw ExceptionUtils.wrap(e);
}
}
private int createSessionInternal(SessionParams params, String installerPackageName, int userId)
throws IOException {
final int callingUid = Binder.getCallingUid();
mPm.enforceCrossUserPermission(callingUid, userId, true, true, "createSession");
if (mPm.isUserRestricted(userId, UserManager.DISALLOW_INSTALL_APPS)) {
throw new SecurityException("User restriction prevents installing");
}
if ((callingUid == Process.SHELL_UID) || (callingUid == Process.ROOT_UID)) {
params.installFlags |= PackageManager.INSTALL_FROM_ADB;
} else {
mAppOps.checkPackage(callingUid, installerPackageName);
params.installFlags &= ~PackageManager.INSTALL_FROM_ADB;
params.installFlags &= ~PackageManager.INSTALL_ALL_USERS;
params.installFlags |= PackageManager.INSTALL_REPLACE_EXISTING;
}
// Only system components can circumvent runtime permissions when installing.
if ((params.installFlags & PackageManager.INSTALL_GRANT_RUNTIME_PERMISSIONS) != 0
&& mContext.checkCallingOrSelfPermission(Manifest.permission
.INSTALL_GRANT_RUNTIME_PERMISSIONS) == PackageManager.PERMISSION_DENIED) {
throw new SecurityException("You need the "
+ "android.permission.INSTALL_GRANT_RUNTIME_PERMISSIONS permission "
+ "to use the PackageManager.INSTALL_GRANT_RUNTIME_PERMISSIONS flag");
}
// Defensively resize giant app icons
if (params.appIcon != null) {
final ActivityManager am = (ActivityManager) mContext.getSystemService(
Context.ACTIVITY_SERVICE);
final int iconSize = am.getLauncherLargeIconSize();
if ((params.appIcon.getWidth() > iconSize * 2)
|| (params.appIcon.getHeight() > iconSize * 2)) {
params.appIcon = Bitmap.createScaledBitmap(params.appIcon, iconSize, iconSize,
true);
}
}
switch (params.mode) {
case SessionParams.MODE_FULL_INSTALL:
case SessionParams.MODE_INHERIT_EXISTING:
break;
default:
throw new IllegalArgumentException("Invalid install mode: " + params.mode);
}
// If caller requested explicit location, sanity check it, otherwise
// resolve the best internal or adopted location.
if ((params.installFlags & PackageManager.INSTALL_INTERNAL) != 0) {
if (!PackageHelper.fitsOnInternal(mContext, params.sizeBytes)) {
throw new IOException("No suitable internal storage available");
}
} else if ((params.installFlags & PackageManager.INSTALL_EXTERNAL) != 0) {
if (!PackageHelper.fitsOnExternal(mContext, params.sizeBytes)) {
throw new IOException("No suitable external storage available");
}
} else if ((params.installFlags & PackageManager.INSTALL_FORCE_VOLUME_UUID) != 0) {
// For now, installs to adopted media are treated as internal from
// an install flag point-of-view.
params.setInstallFlagsInternal();
} else {
// For now, installs to adopted media are treated as internal from
// an install flag point-of-view.
params.setInstallFlagsInternal();
// Resolve best location for install, based on combination of
// requested install flags, delta size, and manifest settings.
final long ident = Binder.clearCallingIdentity();
try {
params.volumeUuid = PackageHelper.resolveInstallVolume(mContext,
params.appPackageName, params.installLocation, params.sizeBytes);
} finally {
Binder.restoreCallingIdentity(ident);
}
}
final int sessionId;
final PackageInstallerSession session;
synchronized (mSessions) {
// Sanity check that installer isn't going crazy
final int activeCount = getSessionCount(mSessions, callingUid);
if (activeCount >= MAX_ACTIVE_SESSIONS) {
throw new IllegalStateException(
"Too many active sessions for UID " + callingUid);
}
final int historicalCount = getSessionCount(mHistoricalSessions, callingUid);
if (historicalCount >= MAX_HISTORICAL_SESSIONS) {
throw new IllegalStateException(
"Too many historical sessions for UID " + callingUid);
}
sessionId = allocateSessionIdLocked();
}
final long createdMillis = System.currentTimeMillis();
// We're staging to exactly one location
File stageDir = null;
String stageCid = null;
if ((params.installFlags & PackageManager.INSTALL_INTERNAL) != 0) {
final boolean isEphemeral =
(params.installFlags & PackageManager.INSTALL_EPHEMERAL) != 0;
stageDir = buildStageDir(params.volumeUuid, sessionId, isEphemeral);
} else {
stageCid = buildExternalStageCid(sessionId);
}
//最终调用PackageInstallerSession 的构造方法来创建session
session = new PackageInstallerSession(mInternalCallback, mContext, mPm,
mInstallThread.getLooper(), sessionId, userId, installerPackageName, callingUid,
params, createdMillis, stageDir, stageCid, false, false);
synchronized (mSessions) {
mSessions.put(sessionId, session);
}
mCallbacks.notifySessionCreated(session.sessionId, session.userId);
writeSessionsAsync();
return sessionId;
}
这个函数主要是为创建一个安装session，同时准备一些安装临时文件所需要的环境，重点关注这步：
stageDir = buildStageDir(params.volumeUuid, sessionId, isEphemeral);
这里会创建一个存储APP安装的临时文件夹，在/data/app/目录下类似vmdlxxxxxx.tmp的目录，其中xxxxxx是本次创建的session ID。
打开这个session：
session = packageInstaller.openSession(sessionId);
最后通过commit操作来完成真正的安
session.commit(pendingIntent.getIntentSender());
我们来分析一下这个commit操作，看看它的最后实现是怎么样了
frameworks/base/services/core/java/com/android/server/pm/PackageInstallerSession.java
@Override
public void commit(IntentSender statusReceiver) {
Preconditions.checkNotNull(statusReceiver);
final boolean wasSealed;
synchronized (mLock) {
wasSealed = mSealed;
if (!mSealed) {
// Verify that all writers are hands-off
for (FileBridge bridge : mBridges) {
if (!bridge.isClosed()) {
throw new SecurityException("Files still open");
}
}
mSealed = true;
}
// Client staging is fully done at this point
mClientProgress = 1f;
computeProgressLocked(true);
}
if (!wasSealed) {
// Persist the fact that we've sealed ourselves to prevent
// mutations of any hard links we create. We do this without holding
// the session lock, since otherwise it's a lock inversion.
mCallback.onSessionSealedBlocking(this);
}
// This ongoing commit should keep session active, even though client
// will probably close their end.
mActiveCount.incrementAndGet();
final PackageInstallObserverAdapter adapter = new PackageInstallObserverAdapter(mContext,
statusReceiver, sessionId, mIsInstallerDeviceOwner, userId);
mHandler.obtainMessage(MSG_COMMIT, adapter.getBinder()).sendToTarget();
然后会调用到：
private void commitLocked(PackageInfo pkgInfo, ApplicationInfo appInfo)
throws PackageManagerException {
//...... 省略部分
final UserHandle user;
if ((params.installFlags & PackageManager.INSTALL_ALL_USERS) != 0) {
user = UserHandle.ALL;
} else {
user = new UserHandle(userId);
}
mRelinquished = true;
mPm.installStage(mPackageName, stageDir, stageCid, localObserver, params,
installerPackageName, installerUid, user, mCertificates);
}
我们发现这个函数最后还是会调用到PackageManagerService，并调用它的installStage，
services/core/java/com/android/server/pm/PackageManagerService.java
void installStage(String packageName, File stagedDir, String stagedCid,
IPackageInstallObserver2 observer, PackageInstaller.SessionParams sessionParams,
String installerPackageName, int installerUid, UserHandle user,
Certificate[][] certificates) {
if (DEBUG_EPHEMERAL) {
if ((sessionParams.installFlags & PackageManager.INSTALL_EPHEMERAL) != 0) {
Slog.d(TAG, "Ephemeral install of " + packageName);
}
}
final VerificationInfo verificationInfo = new VerificationInfo(
sessionParams.originatingUri, sessionParams.referrerUri,
sessionParams.originatingUid, installerUid);
final OriginInfo origin;
if (stagedDir != null) {
origin = OriginInfo.fromStagedFile(stagedDir);
} else {
origin = OriginInfo.fromStagedContainer(stagedCid);
}
final Message msg = mHandler.obtainMessage(INIT_COPY);
final InstallParams params = new InstallParams(origin, null, observer,
sessionParams.installFlags, installerPackageName, sessionParams.volumeUuid,
verificationInfo, user, sessionParams.abiOverride,
sessionParams.grantedRuntimePermissions, certificates);
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));
mHandler.sendMessage(msg);
到这个函数里面，就很熟悉了，这里同样会发送我们之前分析的第一种方法的INIT_COPY 这个message来进行真正的安装操作，
后面的操作就跟第一种方法是一样的了。
所以分析到这里，你就能对比第一种和第二种方法的区别了，其实第二种方法就相当于是多创建了一个session来进行APP的安装，这样有个好处就在于每个APP的安装都是创建一个session来完成，这样就可以进行异步多个安装，而不会冲突。 而第一种方法
在有多个APP同步安装的情况下，就得进行排队一个个安装，但是第一种方法存在风险：如果创建了这个session之后，这个session并没有完成，或者被异常打断（比如安装过程中强制关机重启），那么这个session就是是一个hang或die的状态，然后被中断，那么它的
所有的中间文件，比如上面分析的vmdlxxxxxxx.tmp 临时安装文件夹就不会被删除，因为这个临时文件只有在正常session安装完成之后才会被删除。
