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 static android.os.Process.THREAD_PRIORITY_DISPLAY;
20 import static android.os.Process.myTid;
21 import static android.os.Process.setThreadPriority;
22 
23 import static com.android.server.LockGuard.INDEX_WINDOW;
24 import static com.android.server.am.ActivityManagerService.TOP_APP_PRIORITY_BOOST;
25 
26 import com.android.internal.annotations.GuardedBy;
27 import com.android.server.AnimationThread;
28 import com.android.server.ThreadPriorityBooster;
29 
30 /**
31  * Window manager version of {@link ThreadPriorityBooster} that boosts even more during app
32  * transitions.
33  */
34 class WindowManagerThreadPriorityBooster extends ThreadPriorityBooster {
35 
36     private final Object mLock = new Object();
37 
38     private final int mAnimationThreadId;
39 
40     @GuardedBy("mLock")
41     private boolean mAppTransitionRunning;
42     @GuardedBy("mLock")
43     private boolean mBoundsAnimationRunning;
44 
WindowManagerThreadPriorityBooster()45     WindowManagerThreadPriorityBooster() {
46         super(THREAD_PRIORITY_DISPLAY, INDEX_WINDOW);
47         mAnimationThreadId = AnimationThread.get().getThreadId();
48     }
49 
50     @Override
boost()51     public void boost() {
52 
53         // Do not boost the animation thread. As the animation thread is changing priorities,
54         // boosting it might mess up the priority because we reset it the the previous priority.
55         if (myTid() == mAnimationThreadId) {
56             return;
57         }
58         super.boost();
59     }
60 
61     @Override
reset()62     public void reset() {
63 
64         // See comment in boost().
65         if (myTid() == mAnimationThreadId) {
66             return;
67         }
68         super.reset();
69     }
70 
setAppTransitionRunning(boolean running)71     void setAppTransitionRunning(boolean running) {
72         synchronized (mLock) {
73             if (mAppTransitionRunning != running) {
74                 mAppTransitionRunning = running;
75                 updatePriorityLocked();
76             }
77         }
78     }
79 
setBoundsAnimationRunning(boolean running)80     void setBoundsAnimationRunning(boolean running) {
81         synchronized (mLock) {
82             if (mBoundsAnimationRunning != running) {
83                 mBoundsAnimationRunning = running;
84                 updatePriorityLocked();
85             }
86         }
87     }
88 
89     @GuardedBy("mLock")
updatePriorityLocked()90     private void updatePriorityLocked() {
91         int priority = (mAppTransitionRunning || mBoundsAnimationRunning)
92                 ? TOP_APP_PRIORITY_BOOST : THREAD_PRIORITY_DISPLAY;
93         setBoostToPriority(priority);
94         setThreadPriority(mAnimationThreadId, priority);
95     }
96 }
97