libhistogram/histogram_collector.h

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef HISTOGRAM_HISTOGRAM_COLLECTOR_H_
#define HISTOGRAM_HISTOGRAM_COLLECTOR_H_
#include <string>
#include <thread>
#define HWC2_INCLUDE_STRINGIFICATION
#define HWC2_USE_CPP11
#include <hardware/hwcomposer2.h>
#undef HWC2_INCLUDE_STRINGIFICATION
#undef HWC2_USE_CPP11

//number of enums in hwc2_format_color_component_t;
#define NUM_HISTOGRAM_COLOR_COMPONENTS 4

namespace histogram {

class Ringbuffer;
class HistogramCollector
{
public:
    HistogramCollector();
    ~HistogramCollector();

    void start();
    void start(uint64_t max_frames);
    void stop();

    std::string Dump() const;

    HWC2::Error collect(uint64_t max_frames,
                        uint64_t timestamp,
                        int32_t samples_size[NUM_HISTOGRAM_COLOR_COMPONENTS],
                        uint64_t* samples[NUM_HISTOGRAM_COLOR_COMPONENTS],
                        uint64_t* numFrames) const;
    HWC2::Error getAttributes(int32_t* format,
                              int32_t* dataspace,
                              uint8_t* supported_components) const;

private:
    HistogramCollector(HistogramCollector const&) = delete;
    HistogramCollector& operator=(HistogramCollector const&) = delete;
    void collecting_thread(int pipe);

    std::mutex thread_control;
    bool started = false;
    std::thread monitoring_thread;
    int selfpipe[2];

    std::unique_ptr<histogram::Ringbuffer> histogram;

};

}  // namespace histogram

#endif  // HISTOGRAM_HISTOGRAM_COLLECTOR_H_