1 /*
2  * Copyright (C) 2017 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 com.android.server.wm;
18 
19 import android.app.ActivityManager.RunningTaskInfo;
20 import android.app.WindowConfiguration.ActivityType;
21 import android.app.WindowConfiguration.WindowingMode;
22 import android.util.ArraySet;
23 
24 import java.util.ArrayList;
25 import java.util.Comparator;
26 import java.util.Iterator;
27 import java.util.List;
28 import java.util.TreeSet;
29 
30 /**
31  * Class for resolving the set of running tasks in the system.
32  */
33 class RunningTasks {
34 
35     // Comparator to sort by last active time (descending)
36     private static final Comparator<TaskRecord> LAST_ACTIVE_TIME_COMPARATOR =
37             (o1, o2) -> Long.signum(o2.lastActiveTime - o1.lastActiveTime);
38 
39     private final TreeSet<TaskRecord> mTmpSortedSet = new TreeSet<>(LAST_ACTIVE_TIME_COMPARATOR);
40     private final ArrayList<TaskRecord> mTmpStackTasks = new ArrayList<>();
41 
getTasks(int maxNum, List<RunningTaskInfo> list, @ActivityType int ignoreActivityType, @WindowingMode int ignoreWindowingMode, ArrayList<ActivityDisplay> activityDisplays, int callingUid, boolean allowed, boolean crossUser, ArraySet<Integer> profileIds)42     void getTasks(int maxNum, List<RunningTaskInfo> list, @ActivityType int ignoreActivityType,
43             @WindowingMode int ignoreWindowingMode, ArrayList<ActivityDisplay> activityDisplays,
44             int callingUid, boolean allowed, boolean crossUser, ArraySet<Integer> profileIds) {
45         // Return early if there are no tasks to fetch
46         if (maxNum <= 0) {
47             return;
48         }
49 
50         // Gather all of the tasks across all of the tasks, and add them to the sorted set
51         mTmpSortedSet.clear();
52         final int numDisplays = activityDisplays.size();
53         for (int displayNdx = 0; displayNdx < numDisplays; ++displayNdx) {
54             final ActivityDisplay display = activityDisplays.get(displayNdx);
55             for (int stackNdx = display.getChildCount() - 1; stackNdx >= 0; --stackNdx) {
56                 final ActivityStack stack = display.getChildAt(stackNdx);
57                 mTmpStackTasks.clear();
58                 stack.getRunningTasks(mTmpStackTasks, ignoreActivityType, ignoreWindowingMode,
59                         callingUid, allowed, crossUser, profileIds);
60                 mTmpSortedSet.addAll(mTmpStackTasks);
61             }
62         }
63 
64         // Take the first {@param maxNum} tasks and create running task infos for them
65         final Iterator<TaskRecord> iter = mTmpSortedSet.iterator();
66         while (iter.hasNext()) {
67             if (maxNum == 0) {
68                 break;
69             }
70 
71             final TaskRecord task = iter.next();
72             list.add(createRunningTaskInfo(task));
73             maxNum--;
74         }
75     }
76 
77     /**
78      * Constructs a {@link RunningTaskInfo} from a given {@param task}.
79      */
createRunningTaskInfo(TaskRecord task)80     private RunningTaskInfo createRunningTaskInfo(TaskRecord task) {
81         final RunningTaskInfo rti = new RunningTaskInfo();
82         task.fillTaskInfo(rti);
83         // Fill in some deprecated values
84         rti.id = rti.taskId;
85         return rti;
86     }
87 }
88