android----ServiceManager

serviceManager


在c++层如何使用serviceManager


frameworks\base\services\camera\tests\CameraServiceTest,示例代码如下：


sp<ICameraService> getCameraService() {
//取得serviceManager
sp<IServiceManager> sm = defaultServiceManager();


ASSERT(sm != 0);
sp<IBinder> binder = sm->getService(String16("media.camera"));
ASSERT(binder != 0);
sp<ICameraService> cs = interface_cast<ICameraService>(binder);
ASSERT(cs != 0);
return cs;
}
\frameworks\base\services\java\com\android\server\am


在java层使用serviceManager
\frameworks\base\services\java\com\android\server\am\
AtcitiveyManagerService.java 示例代码：
public static void setSystemProcess() {
try {
//以下语句相当于上面c++层的，
//defaultServiceManager()->addService()


ActivityManagerService m = mSelf;
ServiceManager.addService("activity", m);



ServiceManager.addService("meminfo", new MemBinder(m));
if (MONITOR_CPU_USAGE) {
ServiceManager.addService("cpuinfo", new CpuBinder


(m));
}
ServiceManager.addService("activity.broadcasts", new


BroadcastsBinder(m));
ServiceManager.addService("activity.services", new


ServicesBinder(m));
ServiceManager.addService("activity.senders",new


SendersBinder(m));
ServiceManager.addService("activity.providers",
new ProvidersBinder(m));
ServiceManager.addService("permission",
new PermissionController(m));
ApplicationInfo info =
mSelf.mContext.getPackageManager


().getApplicationInfo(
"android",
PackageManager.GET_SHARED_LIBRARY_FILES);
synchronized (mSelf) {
ProcessRecord app = mSelf.newProcessRecordLocked(
mSystemThread.getApplicationThread(),


info,
info.processName);
app.persistent = true;
app.pid = Process.myPid();
app.maxAdj = SYSTEM_ADJ;
mSelf.mProcessNames.put(app.processName,


app.info.uid, app);
synchronized (mSelf.mPidsSelfLocked) {
mSelf.mPidsSelfLocked.put(app.pid, app);
}
mSelf.updateLRUListLocked(app, true);
}
} catch (PackageManager.NameNotFoundException e) {
throw new RuntimeException("Unable to find android system


package", e);
}
}






serviceManager 在c++层


\frameworks\base\libs\binder
IServiceManager.cpp文件部分代码如下：

sp<IServiceManager> defaultServiceManager()
{
if (gDefaultServiceManager != NULL) return gDefaultServiceManager;

{
AutoMutex _l(gDefaultServiceManagerLock);
if (gDefaultServiceManager == NULL) {
gDefaultServiceManager = interface_cast<IServiceManager>(
//产生一个bpServicManager对象，提代iServiceManager接口,让


defaultServiceManager来回调这个接口
ProcessState::self()->getContextObject(NULL));
}
}

return gDefaultServiceManager;
}


serviceManager 在 java层
\frameworks\base\core\java\android\os
public final class ServiceManager {
.....
private static IServiceManager getIServiceManager() {
if (sServiceManager != null) {
return sServiceManager;
}
// Find the service manager
//产生一个serviceManagerProxy,提供IServiceManager接口，


getiServiceManager回调IServiceManager接口
sServiceManager = ServiceManagerNative.asInterface


(BinderInternal.getContextObject());
return sServiceManager;
}


public static IBinder getService(String name) {
try {
IBinder service = sCache.get(name);
if (service != null) {
return service;
} else {
//调用底层serviceManager
return getIServiceManager().getService(name);
}
} catch (RemoteException e) {
Log.e(TAG, "error in getService", e); }
return null;
}


public static void addService(String name, IBinder service) {
try {
//调用底层serviceManager
getIServiceManager().addService(name, service);
} catch (RemoteException e) {
Log.e(TAG, "error in addService", e);
}
}






.....
}