android ActivityManagerService 学习 （三）
继续上一个 http://blog.csdn.net/jianguo_liao19840726/article/details/12753701 即android ActivityManagerService 学习 （二）的学习
在SystemService里面的ServerThread类中的run方法中，有关ActivityManagerService的还有一行代码如下：
ActivityManagerService.installSystemProviders();进入该方法
public static final void installSystemProviders() {
List providers;
synchronized (mSelf) {
ProcessRecord app = mSelf.mProcessNames.get("system", Process.SYSTEM_UID);
providers = mSelf.generateApplicationProvidersLocked(app);
if (providers != null) {
for (int i=providers.size()-1; i>=0; i--) {
ProviderInfo pi = (ProviderInfo)providers.get(i);
if ((pi.applicationInfo.flags&ApplicationInfo.FLAG_SYSTEM) == 0) {
Slog.w(TAG, "Not installing system proc provider " + pi.name
+ ": not system .apk");
providers.remove(i);
}
}
}
}
if (providers != null) {
mSystemThread.installSystemProviders(providers);
}
}我们先看下面这行代码
ProcessRecord app = mSelf.mProcessNames.get("system", Process.SYSTEM_UID);从ActivityManagerService中的mProcessNames取出进程为“system”，再开始查询这个进程名为“system”的Provider，看下面查询
try {
providers = AppGlobals.getPackageManager().
queryContentProviders(app.processName, app.info.uid,
STOCK_PM_FLAGS | PackageManager.GET_URI_PERMISSION_PATTERNS);
} catch (RemoteException ex) {
}主要通过PackageManagerService来获取相应的ContentProvider，现在我们看下这个是什么什么Provider，这里是SettingsProvider
位于：frameworks/base/packages/settingsprovider下的AandroidManifest.xml中的关联的一句： android:process="system"
看下面代码，查询出了结果，然后将查询出的List
if (providers != null) {
final int N = providers.size();
for (int i=0; i回到之前
public static final void installSystemProviders() {
List providers;
synchronized (mSelf) {
ProcessRecord app = mSelf.mProcessNames.get("system", Process.SYSTEM_UID);
providers = mSelf.generateApplicationProvidersLocked(app);
if (providers != null) {
for (int i=providers.size()-1; i>=0; i--) {
ProviderInfo pi = (ProviderInfo)providers.get(i);
if ((pi.applicationInfo.flags&ApplicationInfo.FLAG_SYSTEM) == 0) {
Slog.w(TAG, "Not installing system proc provider " + pi.name
+ ": not system .apk");
providers.remove(i);
}
}
}
}
if (providers != null) {
mSystemThread.installSystemProviders(providers);
}
}我们看有关
mSystemThread.installSystemProviders(providers);进入该方法
private final void installContentProviders(
Context context, List providers) {
final ArrayList results =
new ArrayList();
Iterator i = providers.iterator();
while (i.hasNext()) {
ProviderInfo cpi = i.next();
StringBuilder buf = new StringBuilder(128);
buf.append("Pub ");
buf.append(cpi.authority);
buf.append(": ");
buf.append(cpi.name);
Log.i(TAG, buf.toString());
IContentProvider cp = installProvider(context, null, cpi, false);
if (cp != null) {
IActivityManager.ContentProviderHolder cph =
new IActivityManager.ContentProviderHolder(cpi);
cph.provider = cp;
results.add(cph);
// Don't ever unload this provider from the process.
synchronized(mProviderMap) {
mProviderRefCountMap.put(cp.asBinder(), new ProviderRefCount(10000));
}
}
}
try {
ActivityManagerNative.getDefault().publishContentProviders(
getApplicationThread(), results);
} catch (RemoteException ex) {
}
} 我们看其中两行重要的代码
IContentProvider cp = installProvider(context, null, cpi, false);
ActivityManagerNative.getDefault().publishContentProviders(
getApplicationThread(), results);其中主要实现为
1、创建ContentProvider，存入ContentProviderHolder的属性provider中
2、发布ContentProvider
进入创建方法
private final IContentProvider installProvider(Context context,
IContentProvider provider, ProviderInfo info, boolean noisy) {
ContentProvider localProvider = null;
if (provider == null) {
if (noisy) {
Slog.d(TAG, "Loading provider " + info.authority + ": "
+ info.name);
}
Context c = null;
ApplicationInfo ai = info.applicationInfo;
if (context.getPackageName().equals(ai.packageName)) {
c = context;
} else if (mInitialApplication != null &&
mInitialApplication.getPackageName().equals(ai.packageName)) {
c = mInitialApplication;
} else {
try {
c = context.createPackageContext(ai.packageName,
Context.CONTEXT_INCLUDE_CODE);
} catch (PackageManager.NameNotFoundException e) {
}
}
if (c == null) {
Slog.w(TAG, "Unable to get context for package " +
ai.packageName +
" while loading content provider " +
info.name);
return null;
}
try {
final java.lang.ClassLoader cl = c.getClassLoader();
localProvider = (ContentProvider)cl.
loadClass(info.name).newInstance();
provider = localProvider.getIContentProvider();
if (provider == null) {
Slog.e(TAG, "Failed to instantiate class " +
info.name + " from sourceDir " +
info.applicationInfo.sourceDir);
return null;
}
if (Config.LOGV) Slog.v(
TAG, "Instantiating local provider " + info.name);
// XXX Need to create the correct context for this provider.
localProvider.attachInfo(c, info);
} catch (java.lang.Exception e) {
if (!mInstrumentation.onException(null, e)) {
throw new RuntimeException(
"Unable to get provider " + info.name
+ ": " + e.toString(), e);
}
return null;
}
} else if (localLOGV) {
Slog.v(TAG, "Installing external provider " + info.authority + ": "
+ info.name);
}
synchronized (mProviderMap) {
// Cache the pointer for the remote provider.
String names[] = PATTERN_SEMICOLON.split(info.authority);
for (int i=0; i进入发布方法
public final void publishContentProviders(IApplicationThread caller,
List providers) {
if (providers == null) {
return;
}
synchronized(this) {
final ProcessRecord r = getRecordForAppLocked(caller);
if (r == null) {
throw new SecurityException(
"Unable to find app for caller " + caller
+ " (pid=" + Binder.getCallingPid()
+ ") when publishing content providers");
}
final long origId = Binder.clearCallingIdentity();
final int N = providers.size();
for (int i=0; i