TaskPersister.java revision e0129b3c672f5555deb75366b1a7159f41737874
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 17package com.android.server.am; 18 19import android.graphics.Bitmap; 20import android.graphics.BitmapFactory; 21import android.os.Debug; 22import android.os.SystemClock; 23import android.util.ArraySet; 24import android.util.AtomicFile; 25import android.util.Slog; 26import android.util.Xml; 27import com.android.internal.util.FastXmlSerializer; 28import com.android.internal.util.XmlUtils; 29import org.xmlpull.v1.XmlPullParser; 30import org.xmlpull.v1.XmlPullParserException; 31import org.xmlpull.v1.XmlSerializer; 32 33import java.io.BufferedReader; 34import java.io.File; 35import java.io.FileOutputStream; 36import java.io.FileReader; 37import java.io.IOException; 38import java.io.StringWriter; 39import java.util.ArrayList; 40import java.util.Arrays; 41import java.util.Comparator; 42 43public class TaskPersister { 44 static final String TAG = "TaskPersister"; 45 static final boolean DEBUG = false; 46 47 /** When in slow mode don't write tasks out faster than this */ 48 private static final long INTER_TASK_DELAY_MS = 60000; 49 private static final long DEBUG_INTER_TASK_DELAY_MS = 5000; 50 51 private static final String RECENTS_FILENAME = "_task"; 52 private static final String TASKS_DIRNAME = "recent_tasks"; 53 private static final String TASK_EXTENSION = ".xml"; 54 private static final String IMAGES_DIRNAME = "recent_images"; 55 private static final String IMAGE_EXTENSION = ".png"; 56 57 private static final String TAG_TASK = "task"; 58 59 private static File sImagesDir; 60 private static File sTasksDir; 61 62 private final ActivityManagerService mService; 63 private final ActivityStackSupervisor mStackSupervisor; 64 65 private boolean mRecentsChanged = false; 66 67 private final LazyTaskWriterThread mLazyTaskWriterThread; 68 69 TaskPersister(File systemDir, ActivityStackSupervisor stackSupervisor) { 70 sTasksDir = new File(systemDir, TASKS_DIRNAME); 71 if (!sTasksDir.exists()) { 72 if (!sTasksDir.mkdir()) { 73 Slog.e(TAG, "Failure creating tasks directory " + sTasksDir); 74 } 75 } 76 77 sImagesDir = new File(systemDir, IMAGES_DIRNAME); 78 if (!sImagesDir.exists()) { 79 if (!sImagesDir.mkdir()) { 80 Slog.e(TAG, "Failure creating images directory " + sImagesDir); 81 } 82 } 83 84 mStackSupervisor = stackSupervisor; 85 mService = stackSupervisor.mService; 86 87 mLazyTaskWriterThread = new LazyTaskWriterThread("LazyTaskWriterThread"); 88 } 89 90 void startPersisting() { 91 mLazyTaskWriterThread.start(); 92 } 93 94 public void notify(TaskRecord task, boolean flush) { 95 if (DEBUG) Slog.d(TAG, "notify: task=" + task + " flush=" + flush + 96 " Callers=" + Debug.getCallers(4)); 97 if (task != null) { 98 task.needsPersisting = true; 99 } 100 synchronized (this) { 101 mLazyTaskWriterThread.mSlow = !flush; 102 mRecentsChanged = true; 103 notifyAll(); 104 } 105 } 106 107 private StringWriter saveToXml(TaskRecord task) throws IOException, XmlPullParserException { 108 if (DEBUG) Slog.d(TAG, "saveToXml: task=" + task); 109 final XmlSerializer xmlSerializer = new FastXmlSerializer(); 110 StringWriter stringWriter = new StringWriter(); 111 xmlSerializer.setOutput(stringWriter); 112 113 if (DEBUG) xmlSerializer.setFeature( 114 "http://xmlpull.org/v1/doc/features.html#indent-output", true); 115 116 // save task 117 xmlSerializer.startDocument(null, true); 118 119 xmlSerializer.startTag(null, TAG_TASK); 120 task.saveToXml(xmlSerializer); 121 xmlSerializer.endTag(null, TAG_TASK); 122 123 xmlSerializer.endDocument(); 124 xmlSerializer.flush(); 125 126 return stringWriter; 127 } 128 129 static void saveImage(Bitmap image, String filename) throws IOException { 130 if (DEBUG) Slog.d(TAG, "saveImage: filename=" + filename); 131 FileOutputStream imageFile = null; 132 try { 133 imageFile = new FileOutputStream(new File(sImagesDir, filename + IMAGE_EXTENSION)); 134 image.compress(Bitmap.CompressFormat.PNG, 100, imageFile); 135 } catch (Exception e) { 136 Slog.e(TAG, "saveImage: unable to save " + filename, e); 137 } finally { 138 if (imageFile != null) { 139 imageFile.close(); 140 } 141 } 142 } 143 144 ArrayList<TaskRecord> restoreTasksLocked() { 145 final ArrayList<TaskRecord> tasks = new ArrayList<TaskRecord>(); 146 ArraySet<Integer> recoveredTaskIds = new ArraySet<Integer>(); 147 148 File[] recentFiles = sTasksDir.listFiles(); 149 if (recentFiles == null) { 150 Slog.e(TAG, "Unable to list files from " + sTasksDir); 151 return tasks; 152 } 153 154 for (int taskNdx = 0; taskNdx < recentFiles.length; ++taskNdx) { 155 File taskFile = recentFiles[taskNdx]; 156 if (DEBUG) Slog.d(TAG, "restoreTasksLocked: taskFile=" + taskFile.getName()); 157 BufferedReader reader = null; 158 boolean deleteFile = false; 159 try { 160 reader = new BufferedReader(new FileReader(taskFile)); 161 final XmlPullParser in = Xml.newPullParser(); 162 in.setInput(reader); 163 164 int event; 165 while (((event = in.next()) != XmlPullParser.END_DOCUMENT) && 166 event != XmlPullParser.END_TAG) { 167 final String name = in.getName(); 168 if (event == XmlPullParser.START_TAG) { 169 if (DEBUG) Slog.d(TAG, "restoreTasksLocked: START_TAG name=" + name); 170 if (TAG_TASK.equals(name)) { 171 final TaskRecord task = 172 TaskRecord.restoreFromXml(in, mStackSupervisor); 173 if (DEBUG) Slog.d(TAG, "restoreTasksLocked: restored task=" + task); 174 if (task != null) { 175 tasks.add(task); 176 final int taskId = task.taskId; 177 recoveredTaskIds.add(taskId); 178 mStackSupervisor.setNextTaskId(taskId); 179 } 180 } else { 181 Slog.e(TAG, "restoreTasksLocked Unknown xml event=" + event + " name=" 182 + name); 183 } 184 } 185 XmlUtils.skipCurrentTag(in); 186 } 187 } catch (Exception e) { 188 Slog.wtf(TAG, "Unable to parse " + taskFile + ". Error " + e); 189 deleteFile = true; 190 } finally { 191 if (reader != null) { 192 try { 193 reader.close(); 194 } catch (IOException e) { 195 } 196 } 197 if (!DEBUG && deleteFile) { 198 taskFile.delete(); 199 } 200 } 201 } 202 203 if (!DEBUG) { 204 removeObsoleteFiles(recoveredTaskIds); 205 } 206 207 TaskRecord[] tasksArray = new TaskRecord[tasks.size()]; 208 tasks.toArray(tasksArray); 209 Arrays.sort(tasksArray, new Comparator<TaskRecord>() { 210 @Override 211 public int compare(TaskRecord lhs, TaskRecord rhs) { 212 final long diff = lhs.mLastTimeMoved - rhs.mLastTimeMoved; 213 if (diff < 0) { 214 return -1; 215 } else if (diff > 0) { 216 return +1; 217 } else { 218 return 0; 219 } 220 } 221 }); 222 223 return new ArrayList<TaskRecord>(Arrays.asList(tasksArray)); 224 } 225 226 private static void removeObsoleteFiles(ArraySet<Integer> persistentTaskIds, File[] files) { 227 for (int fileNdx = 0; fileNdx < files.length; ++fileNdx) { 228 File file = files[fileNdx]; 229 String filename = file.getName(); 230 final int taskIdEnd = filename.indexOf('_') + 1; 231 if (taskIdEnd > 0) { 232 final int taskId; 233 try { 234 taskId = Integer.valueOf(filename.substring(0, taskIdEnd)); 235 } catch (Exception e) { 236 if (DEBUG) Slog.d(TAG, "removeObsoleteFile: Can't parse file=" + 237 file.getName()); 238 file.delete(); 239 continue; 240 } 241 if (!persistentTaskIds.contains(taskId)) { 242 if (DEBUG) Slog.d(TAG, "removeObsoleteFile: deleting file=" + file.getName()); 243 file.delete(); 244 } 245 } 246 } 247 } 248 249 private void removeObsoleteFiles(ArraySet<Integer> persistentTaskIds) { 250 removeObsoleteFiles(persistentTaskIds, sTasksDir.listFiles()); 251 removeObsoleteFiles(persistentTaskIds, sImagesDir.listFiles()); 252 } 253 254 static Bitmap restoreImage(String filename) { 255 if (DEBUG) Slog.d(TAG, "restoreImage: restoring " + filename); 256 return BitmapFactory.decodeFile(sImagesDir + File.separator + filename + IMAGE_EXTENSION); 257 } 258 259 private class LazyTaskWriterThread extends Thread { 260 boolean mSlow = true; 261 262 LazyTaskWriterThread(String name) { 263 super(name); 264 } 265 266 @Override 267 public void run() { 268 ArraySet<Integer> persistentTaskIds = new ArraySet<Integer>(); 269 while (true) { 270 // If mSlow, then delay between each call to saveToXml(). 271 synchronized (TaskPersister.this) { 272 long now = SystemClock.uptimeMillis(); 273 final long releaseTime = 274 now + (DEBUG ? DEBUG_INTER_TASK_DELAY_MS: INTER_TASK_DELAY_MS); 275 while (mSlow && now < releaseTime) { 276 try { 277 if (DEBUG) Slog.d(TAG, "LazyTaskWriter: waiting " + 278 (releaseTime - now)); 279 TaskPersister.this.wait(releaseTime - now); 280 } catch (InterruptedException e) { 281 } 282 now = SystemClock.uptimeMillis(); 283 } 284 } 285 286 StringWriter stringWriter = null; 287 TaskRecord task = null; 288 synchronized(mService) { 289 final ArrayList<TaskRecord> tasks = mService.mRecentTasks; 290 persistentTaskIds.clear(); 291 for (int taskNdx = tasks.size() - 1; taskNdx >= 0; --taskNdx) { 292 task = tasks.get(taskNdx); 293 if (DEBUG) Slog.d(TAG, "LazyTaskWriter: task=" + task + " persistable=" + 294 task.isPersistable + " needsPersisting=" + task.needsPersisting); 295 if (task.isPersistable) { 296 persistentTaskIds.add(task.taskId); 297 298 if (task.needsPersisting) { 299 try { 300 stringWriter = saveToXml(task); 301 break; 302 } catch (IOException e) { 303 } catch (XmlPullParserException e) { 304 } finally { 305 task.needsPersisting = false; 306 } 307 } 308 } 309 } 310 } 311 312 if (stringWriter != null) { 313 // Write out xml file while not holding mService lock. 314 FileOutputStream file = null; 315 AtomicFile atomicFile = null; 316 try { 317 atomicFile = new AtomicFile(new File(sTasksDir, 318 String.valueOf(task.taskId) + RECENTS_FILENAME + TASK_EXTENSION)); 319 file = atomicFile.startWrite(); 320 file.write(stringWriter.toString().getBytes()); 321 file.write('\n'); 322 atomicFile.finishWrite(file); 323 } catch (IOException e) { 324 if (file != null) { 325 atomicFile.failWrite(file); 326 } 327 Slog.e(TAG, "Unable to open " + atomicFile + " for persisting. " + e); 328 } 329 } else { 330 // Made it through the entire list and didn't find anything new that needed 331 // persisting. 332 if (!DEBUG) { 333 removeObsoleteFiles(persistentTaskIds); 334 } 335 336 // Wait here for someone to call setRecentsChanged(). 337 synchronized (TaskPersister.this) { 338 while (!mRecentsChanged) { 339 if (DEBUG) Slog.d(TAG, "LazyTaskWriter: Waiting."); 340 try { 341 TaskPersister.this.wait(); 342 } catch (InterruptedException e) { 343 } 344 } 345 mRecentsChanged = false; 346 if (DEBUG) Slog.d(TAG, "LazyTaskWriter: Awake"); 347 } 348 } 349 // Some recents file needs to be written. 350 } 351 } 352 } 353} 354