| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License |
| */ |
| |
| package com.android.server.wm; |
| |
| import android.annotation.Nullable; |
| import android.app.ActivityManager.TaskSnapshot; |
| import android.util.ArrayMap; |
| import android.util.LruCache; |
| |
| import java.io.PrintWriter; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| |
| /** |
| * Caches snapshots. See {@link TaskSnapshotController}. |
| * <p> |
| * Access to this class should be guarded by the global window manager lock. |
| */ |
| class TaskSnapshotCache { |
| |
| // TODO: Make this more dynamic to accomodate for different clients. |
| private static final int RETRIEVAL_CACHE_SIZE = 4; |
| |
| private final WindowManagerService mService; |
| private final TaskSnapshotLoader mLoader; |
| private final ArrayMap<AppWindowToken, Integer> mAppTaskMap = new ArrayMap<>(); |
| private final ArrayMap<Integer, CacheEntry> mRunningCache = new ArrayMap<>(); |
| private final LruCache<Integer, TaskSnapshot> mRetrievalCache = |
| new LruCache<>(RETRIEVAL_CACHE_SIZE); |
| |
| TaskSnapshotCache(WindowManagerService service, TaskSnapshotLoader loader) { |
| mService = service; |
| mLoader = loader; |
| } |
| |
| void putSnapshot(Task task, TaskSnapshot snapshot) { |
| final CacheEntry entry = mRunningCache.get(task.mTaskId); |
| if (entry != null) { |
| mAppTaskMap.remove(entry.topApp); |
| } |
| final AppWindowToken top = task.getTopChild(); |
| mAppTaskMap.put(top, task.mTaskId); |
| mRunningCache.put(task.mTaskId, new CacheEntry(snapshot, task.getTopChild())); |
| mRetrievalCache.put(task.mTaskId, snapshot); |
| } |
| |
| /** |
| * If {@param restoreFromDisk} equals {@code true}, DO NOT HOLD THE WINDOW MANAGER LOCK! |
| */ |
| @Nullable TaskSnapshot getSnapshot(int taskId, int userId, boolean restoreFromDisk) { |
| |
| synchronized (mService.mWindowMap) { |
| // Try the running cache. |
| final CacheEntry entry = mRunningCache.get(taskId); |
| if (entry != null) { |
| return entry.snapshot; |
| } |
| |
| // Try the retrieval cache. |
| final TaskSnapshot snapshot = mRetrievalCache.get(taskId); |
| if (snapshot != null) { |
| return snapshot; |
| } |
| } |
| |
| // Try to restore from disk if asked. |
| if (!restoreFromDisk) { |
| return null; |
| } |
| return tryRestoreFromDisk(taskId, userId); |
| } |
| |
| /** |
| * DO NOT HOLD THE WINDOW MANAGER LOCK WHEN CALLING THIS METHOD! |
| */ |
| private TaskSnapshot tryRestoreFromDisk(int taskId, int userId) { |
| final TaskSnapshot snapshot = mLoader.loadTask(taskId, userId); |
| if (snapshot == null) { |
| return null; |
| } |
| synchronized (mService.mWindowMap) { |
| mRetrievalCache.put(taskId, snapshot); |
| } |
| return snapshot; |
| } |
| |
| /** |
| * Called when an app token has been removed |
| */ |
| void onAppRemoved(AppWindowToken wtoken) { |
| final Integer taskId = mAppTaskMap.get(wtoken); |
| if (taskId != null) { |
| removeRunningEntry(taskId); |
| } |
| if (wtoken.getTask() != null) { |
| mRetrievalCache.remove(wtoken.getTask().mTaskId); |
| } |
| } |
| |
| /** |
| * Callend when an app window token's process died. |
| */ |
| void onAppDied(AppWindowToken wtoken) { |
| final Integer taskId = mAppTaskMap.get(wtoken); |
| if (taskId != null) { |
| removeRunningEntry(taskId); |
| } |
| } |
| |
| void onTaskRemoved(int taskId) { |
| removeRunningEntry(taskId); |
| mRetrievalCache.remove(taskId); |
| } |
| |
| private void removeRunningEntry(int taskId) { |
| final CacheEntry entry = mRunningCache.get(taskId); |
| if (entry != null) { |
| mAppTaskMap.remove(entry.topApp); |
| mRunningCache.remove(taskId); |
| } |
| } |
| |
| void dump(PrintWriter pw, String prefix) { |
| final String doublePrefix = prefix + " "; |
| final String triplePrefix = doublePrefix + " "; |
| final String quadruplePrefix = triplePrefix + " "; |
| pw.println(prefix + "SnapshotCache"); |
| pw.println(doublePrefix + "RunningCache"); |
| for (int i = mRunningCache.size() - 1; i >= 0; i--) { |
| final CacheEntry entry = mRunningCache.valueAt(i); |
| pw.println(triplePrefix + "Entry taskId=" + mRunningCache.keyAt(i)); |
| pw.println(quadruplePrefix + "topApp=" + entry.topApp); |
| pw.println(quadruplePrefix + "snapshot=" + entry.snapshot); |
| } |
| pw.println(doublePrefix + "RetrievalCache"); |
| final Map<Integer, TaskSnapshot> retrievalSnapshot = mRetrievalCache.snapshot(); |
| for (Entry<Integer, TaskSnapshot> entry : retrievalSnapshot.entrySet()) { |
| pw.println(triplePrefix + "Entry taskId=" + entry.getKey()); |
| pw.println(quadruplePrefix + "snapshot=" + entry.getValue()); |
| } |
| } |
| |
| private static final class CacheEntry { |
| |
| /** The snapshot. */ |
| final TaskSnapshot snapshot; |
| |
| /** The app token that was on top of the task when the snapshot was taken */ |
| final AppWindowToken topApp; |
| |
| CacheEntry(TaskSnapshot snapshot, AppWindowToken topApp) { |
| this.snapshot = snapshot; |
| this.topApp = topApp; |
| } |
| } |
| } |