1/*
2 * Copyright 2016 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#undef LOG_TAG
18#define LOG_TAG "OccupancyTracker"
19
20#include <gui/OccupancyTracker.h>
21#include <binder/Parcel.h>
22#include <utils/String8.h>
23#include <utils/Trace.h>
24
25#include <inttypes.h>
26
27namespace android {
28
29status_t OccupancyTracker::Segment::writeToParcel(Parcel* parcel) const {
30    status_t result = parcel->writeInt64(totalTime);
31    if (result != OK) {
32        return result;
33    }
34    result = parcel->writeUint64(static_cast<uint64_t>(numFrames));
35    if (result != OK) {
36        return result;
37    }
38    result = parcel->writeFloat(occupancyAverage);
39    if (result != OK) {
40        return result;
41    }
42    return parcel->writeBool(usedThirdBuffer);
43}
44
45status_t OccupancyTracker::Segment::readFromParcel(const Parcel* parcel) {
46    status_t result = parcel->readInt64(&totalTime);
47    if (result != OK) {
48        return result;
49    }
50    uint64_t uintNumFrames = 0;
51    result = parcel->readUint64(&uintNumFrames);
52    if (result != OK) {
53        return result;
54    }
55    numFrames = static_cast<size_t>(uintNumFrames);
56    result = parcel->readFloat(&occupancyAverage);
57    if (result != OK) {
58        return result;
59    }
60    return parcel->readBool(&usedThirdBuffer);
61}
62
63void OccupancyTracker::registerOccupancyChange(size_t occupancy) {
64    ATRACE_CALL();
65    nsecs_t now = systemTime();
66    nsecs_t delta = now - mLastOccupancyChangeTime;
67    if (delta > NEW_SEGMENT_DELAY) {
68        recordPendingSegment();
69    } else {
70        mPendingSegment.totalTime += delta;
71        if (mPendingSegment.mOccupancyTimes.count(mLastOccupancy)) {
72            mPendingSegment.mOccupancyTimes[mLastOccupancy] += delta;
73        } else {
74            mPendingSegment.mOccupancyTimes[mLastOccupancy] = delta;
75        }
76    }
77    if (occupancy > mLastOccupancy) {
78        ++mPendingSegment.numFrames;
79    }
80    mLastOccupancyChangeTime = now;
81    mLastOccupancy = occupancy;
82}
83
84std::vector<OccupancyTracker::Segment> OccupancyTracker::getSegmentHistory(
85        bool forceFlush) {
86    if (forceFlush) {
87        recordPendingSegment();
88    }
89    std::vector<Segment> segments(mSegmentHistory.cbegin(),
90            mSegmentHistory.cend());
91    mSegmentHistory.clear();
92    return segments;
93}
94
95void OccupancyTracker::recordPendingSegment() {
96    // Only record longer segments to get a better measurement of actual double-
97    // vs. triple-buffered time
98    if (mPendingSegment.numFrames > LONG_SEGMENT_THRESHOLD) {
99        float occupancyAverage = 0.0f;
100        bool usedThirdBuffer = false;
101        for (const auto& timePair : mPendingSegment.mOccupancyTimes) {
102            size_t occupancy = timePair.first;
103            float timeRatio = static_cast<float>(timePair.second) /
104                    mPendingSegment.totalTime;
105            occupancyAverage += timeRatio * occupancy;
106            usedThirdBuffer = usedThirdBuffer || (occupancy > 1);
107        }
108        mSegmentHistory.push_front({mPendingSegment.totalTime,
109                mPendingSegment.numFrames, occupancyAverage, usedThirdBuffer});
110        if (mSegmentHistory.size() > MAX_HISTORY_SIZE) {
111            mSegmentHistory.pop_back();
112        }
113    }
114    mPendingSegment.clear();
115}
116
117} // namespace android
118