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 android.util.Log; 20 21 import com.android.internal.os.BinderInternal; 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 getIServiceManager()33 private static IServiceManager getIServiceManager() { 34 if (sServiceManager != null) { 35 return sServiceManager; 36 } 37 38 // Find the service manager 39 sServiceManager = ServiceManagerNative 40 .asInterface(Binder.allowBlocking(BinderInternal.getContextObject())); 41 return sServiceManager; 42 } 43 44 /** 45 * Returns a reference to a service with the given name. 46 * 47 * @param name the name of the service to get 48 * @return a reference to the service, or <code>null</code> if the service doesn't exist 49 */ getService(String name)50 public static IBinder getService(String name) { 51 try { 52 IBinder service = sCache.get(name); 53 if (service != null) { 54 return service; 55 } else { 56 return Binder.allowBlocking(getIServiceManager().getService(name)); 57 } 58 } catch (RemoteException e) { 59 Log.e(TAG, "error in getService", e); 60 } 61 return null; 62 } 63 64 /** 65 * Returns a reference to a service with the given name, or throws 66 * {@link NullPointerException} if none is found. 67 * 68 * @hide 69 */ getServiceOrThrow(String name)70 public static IBinder getServiceOrThrow(String name) throws ServiceNotFoundException { 71 final IBinder binder = getService(name); 72 if (binder != null) { 73 return binder; 74 } else { 75 throw new ServiceNotFoundException(name); 76 } 77 } 78 79 /** 80 * Place a new @a service called @a name into the service 81 * manager. 82 * 83 * @param name the name of the new service 84 * @param service the service object 85 */ addService(String name, IBinder service)86 public static void addService(String name, IBinder service) { 87 try { 88 getIServiceManager().addService(name, service, false); 89 } catch (RemoteException e) { 90 Log.e(TAG, "error in addService", e); 91 } 92 } 93 94 /** 95 * Place a new @a service called @a name into the service 96 * manager. 97 * 98 * @param name the name of the new service 99 * @param service the service object 100 * @param allowIsolated set to true to allow isolated sandboxed processes 101 * to access this service 102 */ addService(String name, IBinder service, boolean allowIsolated)103 public static void addService(String name, IBinder service, boolean allowIsolated) { 104 try { 105 getIServiceManager().addService(name, service, allowIsolated); 106 } catch (RemoteException e) { 107 Log.e(TAG, "error in addService", e); 108 } 109 } 110 111 /** 112 * Retrieve an existing service called @a name from the 113 * service manager. Non-blocking. 114 */ checkService(String name)115 public static IBinder checkService(String name) { 116 try { 117 IBinder service = sCache.get(name); 118 if (service != null) { 119 return service; 120 } else { 121 return Binder.allowBlocking(getIServiceManager().checkService(name)); 122 } 123 } catch (RemoteException e) { 124 Log.e(TAG, "error in checkService", e); 125 return null; 126 } 127 } 128 129 /** 130 * Return a list of all currently running services. 131 * @return an array of all currently running services, or <code>null</code> in 132 * case of an exception 133 */ listServices()134 public static String[] listServices() { 135 try { 136 return getIServiceManager().listServices(); 137 } catch (RemoteException e) { 138 Log.e(TAG, "error in listServices", e); 139 return null; 140 } 141 } 142 143 /** 144 * This is only intended to be called when the process is first being brought 145 * up and bound by the activity manager. There is only one thread in the process 146 * at that time, so no locking is done. 147 * 148 * @param cache the cache of service references 149 * @hide 150 */ initServiceCache(Map<String, IBinder> cache)151 public static void initServiceCache(Map<String, IBinder> cache) { 152 if (sCache.size() != 0) { 153 throw new IllegalStateException("setServiceCache may only be called once"); 154 } 155 sCache.putAll(cache); 156 } 157 158 /** 159 * Exception thrown when no service published for given name. This might be 160 * thrown early during boot before certain services have published 161 * themselves. 162 * 163 * @hide 164 */ 165 public static class ServiceNotFoundException extends Exception { ServiceNotFoundException(String name)166 public ServiceNotFoundException(String name) { 167 super("No service published for: " + name); 168 } 169 } 170 } 171