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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.os;
     18 
     19 import com.android.internal.os.BinderInternal;
     20 
     21 import android.util.Log;
     22 
     23 import java.util.HashMap;
     24 import java.util.Map;
     25 
     26 /** @hide */
     27 public final class ServiceManager {
     28     private static final String TAG = "ServiceManager";
     29 
     30     private static IServiceManager sServiceManager;
     31     private static HashMap<String, IBinder> sCache = new HashMap<String, IBinder>();
     32 
     33     private static IServiceManager getIServiceManager() {
     34         if (sServiceManager != null) {
     35             return sServiceManager;
     36         }
     37 
     38         // Find the service manager
     39         sServiceManager = ServiceManagerNative.asInterface(BinderInternal.getContextObject());
     40         return sServiceManager;
     41     }
     42 
     43     /**
     44      * Returns a reference to a service with the given name.
     45      *
     46      * @param name the name of the service to get
     47      * @return a reference to the service, or <code>null</code> if the service doesn't exist
     48      */
     49     public static IBinder getService(String name) {
     50         try {
     51             IBinder service = sCache.get(name);
     52             if (service != null) {
     53                 return service;
     54             } else {
     55                 return getIServiceManager().getService(name);
     56             }
     57         } catch (RemoteException e) {
     58             Log.e(TAG, "error in getService", e);
     59         }
     60         return null;
     61     }
     62 
     63     /**
     64      * Place a new @a service called @a name into the service
     65      * manager.
     66      *
     67      * @param name the name of the new service
     68      * @param service the service object
     69      */
     70     public static void addService(String name, IBinder service) {
     71         try {
     72             getIServiceManager().addService(name, service, false);
     73         } catch (RemoteException e) {
     74             Log.e(TAG, "error in addService", e);
     75         }
     76     }
     77 
     78     /**
     79      * Place a new @a service called @a name into the service
     80      * manager.
     81      *
     82      * @param name the name of the new service
     83      * @param service the service object
     84      * @param allowIsolated set to true to allow isolated sandboxed processes
     85      * to access this service
     86      */
     87     public static void addService(String name, IBinder service, boolean allowIsolated) {
     88         try {
     89             getIServiceManager().addService(name, service, allowIsolated);
     90         } catch (RemoteException e) {
     91             Log.e(TAG, "error in addService", e);
     92         }
     93     }
     94 
     95     /**
     96      * Retrieve an existing service called @a name from the
     97      * service manager.  Non-blocking.
     98      */
     99     public static IBinder checkService(String name) {
    100         try {
    101             IBinder service = sCache.get(name);
    102             if (service != null) {
    103                 return service;
    104             } else {
    105                 return getIServiceManager().checkService(name);
    106             }
    107         } catch (RemoteException e) {
    108             Log.e(TAG, "error in checkService", e);
    109             return null;
    110         }
    111     }
    112 
    113     /**
    114      * Return a list of all currently running services.
    115      */
    116     public static String[] listServices() throws RemoteException {
    117         try {
    118             return getIServiceManager().listServices();
    119         } catch (RemoteException e) {
    120             Log.e(TAG, "error in listServices", e);
    121             return null;
    122         }
    123     }
    124 
    125     /**
    126      * This is only intended to be called when the process is first being brought
    127      * up and bound by the activity manager. There is only one thread in the process
    128      * at that time, so no locking is done.
    129      *
    130      * @param cache the cache of service references
    131      * @hide
    132      */
    133     public static void initServiceCache(Map<String, IBinder> cache) {
    134         if (sCache.size() != 0) {
    135             throw new IllegalStateException("setServiceCache may only be called once");
    136         }
    137         sCache.putAll(cache);
    138     }
    139 }
    140