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Kevin DuBois305bef12019-10-09 13:23:27 -07001/*
2 * Copyright 2019 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#pragma once
18
19#include <utils/Timers.h>
Dominik Laskowskif6b4ba62021-11-09 12:46:10 -080020
21#include <scheduler/Fps.h>
22
Kevin DuBois305bef12019-10-09 13:23:27 -070023#include "VSyncDispatch.h"
24
25namespace android::scheduler {
26/*
27 * VSyncTracker is an interface for providing estimates on future Vsync signal times based on
28 * historical vsync timing data.
29 */
30class VSyncTracker {
31public:
32 virtual ~VSyncTracker();
33
34 /*
35 * Adds a known timestamp from a vsync timing source (HWVsync signal, present fence)
36 * to the model.
37 *
38 * \param [in] timestamp The timestamp when the vsync signal was.
Kevin DuBois02d5ed92020-01-27 11:05:46 -080039 * \return True if the timestamp was consistent with the internal model,
40 * False otherwise
Kevin DuBois305bef12019-10-09 13:23:27 -070041 */
Kevin DuBois02d5ed92020-01-27 11:05:46 -080042 virtual bool addVsyncTimestamp(nsecs_t timestamp) = 0;
Kevin DuBois305bef12019-10-09 13:23:27 -070043
44 /*
45 * Access the next anticipated vsync time such that the anticipated time >= timePoint.
46 * This will always give the best accurate at the time of calling; multiple
47 * calls with the same timePoint might give differing values if the internal model
48 * is updated.
49 *
50 * \param [in] timePoint The point in time after which to estimate a vsync event.
51 * \return A prediction of the timestamp of a vsync event.
52 */
53 virtual nsecs_t nextAnticipatedVSyncTimeFrom(nsecs_t timePoint) const = 0;
54
Kevin DuBois2fd3cea2019-11-14 08:52:45 -080055 /*
56 * The current period of the vsync signal.
57 *
58 * \return The current period of the vsync signal
59 */
60 virtual nsecs_t currentPeriod() const = 0;
61
Kevin DuBoisee2ad9f2019-11-21 11:10:57 -080062 /*
63 * Inform the tracker that the period is changing and the tracker needs to recalibrate itself.
64 *
65 * \param [in] period The period that the system is changing into.
66 */
67 virtual void setPeriod(nsecs_t period) = 0;
68
Kevin DuBoisc3e9e8e2020-01-07 09:06:52 -080069 /* Inform the tracker that the samples it has are not accurate for prediction. */
70 virtual void resetModel() = 0;
71
Kevin DuBoisb818bfa2020-07-10 14:29:36 -070072 virtual bool needsMoreSamples() const = 0;
73
Ady Abraham0bb6a472020-10-12 10:22:13 -070074 /*
Ady Abraham5cc2e262021-03-25 13:09:17 -070075 * Checks if a vsync timestamp is in phase for a frame rate
Ady Abraham0bb6a472020-10-12 10:22:13 -070076 *
77 * \param [in] timePoint A vsync timestamp
Ady Abraham5cc2e262021-03-25 13:09:17 -070078 * \param [in] frameRate The frame rate to check for
Ady Abraham0bb6a472020-10-12 10:22:13 -070079 */
Ady Abraham5cc2e262021-03-25 13:09:17 -070080 virtual bool isVSyncInPhase(nsecs_t timePoint, Fps frameRate) const = 0;
Ady Abraham0bb6a472020-10-12 10:22:13 -070081
Ady Abrahamace3d052022-11-17 16:25:05 -080082 /*
Ady Abrahamfdc049c2023-02-17 14:52:05 +000083 * Sets a render rate on the tracker. If the render rate is not a divisor
84 * of the period, the render rate is ignored until the period changes.
Ady Abrahamace3d052022-11-17 16:25:05 -080085 * The tracker will continue to track the vsync timeline and expect it
86 * to match the current period, however, nextAnticipatedVSyncTimeFrom will
Ady Abrahamfdc049c2023-02-17 14:52:05 +000087 * return vsyncs according to the render rate set. Setting a render rate is useful
Ady Abrahamace3d052022-11-17 16:25:05 -080088 * when a display is running at 120Hz but the render frame rate is 60Hz.
89 *
Ady Abrahamfdc049c2023-02-17 14:52:05 +000090 * \param [in] Fps The render rate the tracker should operate at.
Ady Abrahamace3d052022-11-17 16:25:05 -080091 */
Ady Abrahamfdc049c2023-02-17 14:52:05 +000092 virtual void setRenderRate(Fps) = 0;
Ady Abrahamace3d052022-11-17 16:25:05 -080093
Ady Abraham5e7371c2020-03-24 14:47:24 -070094 virtual void dump(std::string& result) const = 0;
95
Kevin DuBois305bef12019-10-09 13:23:27 -070096protected:
97 VSyncTracker(VSyncTracker const&) = delete;
98 VSyncTracker& operator=(VSyncTracker const&) = delete;
99 VSyncTracker() = default;
100};
101
102} // namespace android::scheduler