TimeLord.h revision d5a4a1aac980c304d6f46f07f15bfc5c94d8f9d0 
1/*
2 * Copyright (C) 2014 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#ifndef TIMELORD_H
17#define TIMELORD_H
18
19#include <utils/Timers.h>
20
21namespace android {
22namespace uirenderer {
23namespace renderthread {
24
25class RenderThread;
26
27// This class serves as a helper to filter & manage frame times from multiple sources
28// ensuring that time flows linearly and smoothly
29class TimeLord {
30public:
31    void setFrameInterval(nsecs_t intervalNanos) { mFrameIntervalNanos = intervalNanos; }
32    nsecs_t frameIntervalNanos() const { return mFrameIntervalNanos; }
33
34    // returns true if the vsync is newer, false if it was rejected for staleness
35    bool vsyncReceived(nsecs_t vsync);
36    nsecs_t latestVsync() { return mFrameTimeNanos; }
37    nsecs_t computeFrameTimeMs();
38    nsecs_t computeFrameTimeNanos();
39
40private:
41    friend class RenderThread;
42
43    TimeLord();
44    ~TimeLord() {}
45
46    nsecs_t mFrameIntervalNanos;
47    nsecs_t mFrameTimeNanos;
48};
49
50} /* namespace renderthread */
51} /* namespace uirenderer */
52} /* namespace android */
53
54#endif /* TIMELORD_H */
55