1 /* 2 * Copyright (C) 2014 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.app.stubs;; 18 19 import android.app.Service; 20 import android.content.ComponentName; 21 import android.content.Context; 22 import android.content.Intent; 23 import android.content.ServiceConnection; 24 import android.os.AsyncTask; 25 import android.os.Binder; 26 import android.os.Bundle; 27 import android.os.IBinder; 28 import android.os.Parcel; 29 import android.os.RemoteException; 30 31 import java.util.concurrent.CountDownLatch; 32 33 public class TrimMemService extends Service { 34 private static final int COMMAND_TRIM_MEMORY_LEVEL = IBinder.FIRST_CALL_TRANSACTION; 35 private Binder mRemote = new Binder(); 36 private IBinder mCallback; 37 38 @Override onBind(Intent intent)39 public IBinder onBind(Intent intent) { 40 final Bundle extras = intent.getExtras(); 41 mCallback = extras.getBinder(CommandReceiver.EXTRA_CALLBACK); 42 return mRemote; 43 } 44 45 @Override onTrimMemory(int level)46 public void onTrimMemory(int level) { 47 if (mCallback != null) { 48 Parcel data = Parcel.obtain(); 49 Parcel reply = Parcel.obtain(); 50 data.writeInt(level); 51 try { 52 mCallback.transact(COMMAND_TRIM_MEMORY_LEVEL, data, reply, 0); 53 } catch (RemoteException e) { 54 } finally { 55 data.recycle(); 56 reply.recycle(); 57 } 58 } 59 } 60 61 private static class MyMemFactorCallback extends Binder { 62 private CountDownLatch[] mLatchHolder; 63 private int[] mLevelHolder; 64 MyMemFactorCallback(CountDownLatch[] latchHolder, int[] levelHolder)65 MyMemFactorCallback(CountDownLatch[] latchHolder, int[] levelHolder) { 66 mLatchHolder = latchHolder; 67 mLevelHolder = levelHolder; 68 } 69 70 @Override onTransact(int code, Parcel data, Parcel reply, int flags)71 protected boolean onTransact(int code, Parcel data, Parcel reply, int flags) 72 throws RemoteException { 73 switch (code) { 74 case COMMAND_TRIM_MEMORY_LEVEL: 75 mLevelHolder[0] = data.readInt(); 76 mLatchHolder[0].countDown(); 77 return true; 78 default: 79 return false; 80 } 81 } 82 } 83 84 private static class MyServiceConnection implements ServiceConnection { 85 private CountDownLatch mLatch; 86 MyServiceConnection(CountDownLatch latch)87 MyServiceConnection(CountDownLatch latch) { 88 mLatch = latch; 89 } 90 91 @Override onServiceConnected(ComponentName name, IBinder service)92 public void onServiceConnected(ComponentName name, IBinder service) { 93 mLatch.countDown(); 94 } 95 96 @Override onServiceDisconnected(ComponentName name)97 public void onServiceDisconnected(ComponentName name) { 98 } 99 } 100 bindToTrimMemService(String packageName, String instanceName, CountDownLatch[] latchHolder, int[] levelHolder, Context context)101 public static ServiceConnection bindToTrimMemService(String packageName, String instanceName, 102 CountDownLatch[] latchHolder, int[] levelHolder, Context context) throws Exception { 103 final Intent intent = new Intent(); 104 intent.setClassName(packageName, "android.app.stubs.TrimMemService"); 105 final Bundle extras = new Bundle(); 106 extras.putBinder(CommandReceiver.EXTRA_CALLBACK, 107 new MyMemFactorCallback(latchHolder, levelHolder)); 108 intent.putExtras(extras); 109 final CountDownLatch latch = new CountDownLatch(1); 110 final MyServiceConnection conn = new MyServiceConnection(latch); 111 context.bindIsolatedService(intent, Context.BIND_AUTO_CREATE | Context.BIND_WAIVE_PRIORITY, 112 instanceName, AsyncTask.THREAD_POOL_EXECUTOR, conn); 113 latch.await(); 114 return conn; 115 } 116 } 117 118