WindowManagerThreadPriorityBooster.java revision 1ec3e26c087ce69134631cbcdf5c38f7ebdd63e7 
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
17package com.android.server.wm;
18
19import static android.os.Process.THREAD_PRIORITY_DISPLAY;
20import static android.os.Process.myTid;
21import static android.os.Process.setThreadPriority;
22
23import static com.android.server.LockGuard.INDEX_WINDOW;
24import static com.android.server.am.ActivityManagerService.TOP_APP_PRIORITY_BOOST;
25
26import com.android.internal.annotations.GuardedBy;
27import com.android.server.AnimationThread;
28import com.android.server.ThreadPriorityBooster;
29
30/**
31 * Window manager version of {@link ThreadPriorityBooster} that boosts even more during app
32 * transitions.
33 */
34class 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
45    WindowManagerThreadPriorityBooster() {
46        super(THREAD_PRIORITY_DISPLAY, INDEX_WINDOW);
47        mAnimationThreadId = AnimationThread.get().getThreadId();
48    }
49
50    @Override
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
62    public void reset() {
63
64        // See comment in boost().
65        if (myTid() == mAnimationThreadId) {
66            return;
67        }
68        super.reset();
69    }
70
71    void setAppTransitionRunning(boolean running) {
72        synchronized (mLock) {
73            if (mAppTransitionRunning != running) {
74                mAppTransitionRunning = running;
75                updatePriorityLocked();
76            }
77        }
78    }
79
80    void setBoundsAnimationRunning(boolean running) {
81        synchronized (mLock) {
82            if (mBoundsAnimationRunning != running) {
83                mBoundsAnimationRunning = running;
84                updatePriorityLocked();
85            }
86        }
87    }
88
89    @GuardedBy("mLock")
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