TimeLord.h revision 0e40462e11d27eb859b829b112cecb8c6f0d7afb 
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    // returns true if the vsync is newer, false if it was rejected for staleness
33    bool vsyncReceived(nsecs_t vsync);
34    nsecs_t computeFrameTimeMs();
35
36private:
37    friend class RenderThread;
38
39    TimeLord();
40    ~TimeLord() {}
41
42    nsecs_t mFrameIntervalNanos;
43    nsecs_t mFrameTimeNanos;
44};
45
46} /* namespace renderthread */
47} /* namespace uirenderer */
48} /* namespace android */
49
50#endif /* TIMELORD_H */
51