Merge "sf: reuse luma sampling buffer when available" into qt-dev

        mFlinger.traverseLayersInDisplay(device, filterVisitor);

    };

    sp<GraphicBuffer> buffer = nullptr;

    if (mCachedBuffer && mCachedBuffer->getWidth() == sampledArea.getWidth() &&

        mCachedBuffer->getHeight() == sampledArea.getHeight()) {

        buffer = mCachedBuffer;

    } else {

        const uint32_t usage = GRALLOC_USAGE_SW_READ_OFTEN | GRALLOC_USAGE_HW_RENDER;

    sp<GraphicBuffer> buffer =

            new GraphicBuffer(sampledArea.getWidth(), sampledArea.getHeight(),

        buffer = new GraphicBuffer(sampledArea.getWidth(), sampledArea.getHeight(),

                                   PIXEL_FORMAT_RGBA_8888, 1, usage, "RegionSamplingThread");

    }

    // When calling into SF, we post a message into the SF message queue (so the

    // screen capture runs on the main thread). This message blocks until the

    for (size_t d = 0; d < activeDescriptors.size(); ++d) {

        activeDescriptors[d].listener->onSampleCollected(lumas[d]);

    }

    // Extend the lifetime of mCachedBuffer from the previous frame to here to ensure that:

    // 1) The region sampling thread is the last owner of the buffer, and the freeing of the buffer

    // happens in this thread, as opposed to the main thread.

    // 2) The listener(s) receive their notifications prior to freeing the buffer.

    mCachedBuffer = buffer;

    ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::noWorkNeeded));

}

#include <android-base/thread_annotations.h>

#include <binder/IBinder.h>

#include <ui/GraphicBuffer.h>

#include <ui/Rect.h>

#include <utils/StrongPointer.h>

#include "Scheduler/IdleTimer.h"

namespace android {

class GraphicBuffer;

class IRegionSamplingListener;

class Layer;

class Scheduler;

    std::unordered_map<wp<IBinder>, Descriptor, WpHash> mDescriptors GUARDED_BY(mMutex);

    std::chrono::nanoseconds lastSampleTime GUARDED_BY(mMutex);

    bool mDiscardedFrames GUARDED_BY(mMutex) = false;

    sp<GraphicBuffer> mCachedBuffer GUARDED_BY(mMutex) = nullptr;

};

} // namespace android