Home | History | Annotate | Download | only in surfaceflinger 
      1 /*
      2  * Copyright 2019 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 #pragma once
     18 
     19 #include <chrono>
     20 #include <condition_variable>
     21 #include <mutex>
     22 #include <thread>
     23 #include <unordered_map>
     24 
     25 #include <android-base/thread_annotations.h>
     26 #include <binder/IBinder.h>
     27 #include <ui/GraphicBuffer.h>
     28 #include <ui/Rect.h>
     29 #include <utils/StrongPointer.h>
     30 #include "Scheduler/IdleTimer.h"
     31 
     32 namespace android {
     33 
     34 class IRegionSamplingListener;
     35 class Layer;
     36 class Scheduler;
     37 class SurfaceFlinger;
     38 struct SamplingOffsetCallback;
     39 
     40 float sampleArea(const uint32_t* data, int32_t width, int32_t height, int32_t stride,
     41                  uint32_t orientation, const Rect& area);
     42 
     43 class RegionSamplingThread : public IBinder::DeathRecipient {
     44 public:
     45     struct TimingTunables {
     46         // debug.sf.sampling_offset_ns
     47         // When asynchronously collecting sample, the offset, from zero phase in the vsync timeline
     48         // at which the sampling should start.
     49         std::chrono::nanoseconds mSamplingOffset;
     50         // debug.sf.sampling_period_ns
     51         // This is the maximum amount of time the luma recieving client
     52         // should have to wait for a new luma value after a frame is updated. The inverse of this is
     53         // roughly the sampling rate. Sampling system rounds up sub-vsync sampling period to vsync
     54         // period.
     55         std::chrono::nanoseconds mSamplingPeriod;
     56         // debug.sf.sampling_timer_timeout_ns
     57         // This is the interval at which the luma sampling system will check that the luma clients
     58         // have up to date information. It defaults to the mSamplingPeriod.
     59         std::chrono::nanoseconds mSamplingTimerTimeout;
     60     };
     61     struct EnvironmentTimingTunables : TimingTunables {
     62         EnvironmentTimingTunables();
     63     };
     64     explicit RegionSamplingThread(SurfaceFlinger& flinger, Scheduler& scheduler,
     65                                   const TimingTunables& tunables);
     66     explicit RegionSamplingThread(SurfaceFlinger& flinger, Scheduler& scheduler);
     67 
     68     ~RegionSamplingThread();
     69 
     70     // Add a listener to receive luma notifications. The luma reported via listener will
     71     // report the median luma for the layers under the stopLayerHandle, in the samplingArea region.
     72     void addListener(const Rect& samplingArea, const sp<IBinder>& stopLayerHandle,
     73                      const sp<IRegionSamplingListener>& listener);
     74     // Remove the listener to stop receiving median luma notifications.
     75     void removeListener(const sp<IRegionSamplingListener>& listener);
     76 
     77     // Notifies sampling engine that new content is available. This will trigger a sampling
     78     // pass at some point in the future.
     79     void notifyNewContent();
     80 
     81     // Notifies the sampling engine that it has a good timing window in which to sample.
     82     void notifySamplingOffset();
     83 
     84 private:
     85     struct Descriptor {
     86         Rect area = Rect::EMPTY_RECT;
     87         wp<Layer> stopLayer;
     88         sp<IRegionSamplingListener> listener;
     89     };
     90 
     91     struct WpHash {
     92         size_t operator()(const wp<IBinder>& p) const {
     93             return std::hash<IBinder*>()(p.unsafe_get());
     94         }
     95     };
     96     std::vector<float> sampleBuffer(
     97             const sp<GraphicBuffer>& buffer, const Point& leftTop,
     98             const std::vector<RegionSamplingThread::Descriptor>& descriptors, uint32_t orientation);
     99 
    100     void doSample();
    101     void binderDied(const wp<IBinder>& who) override;
    102     void checkForStaleLuma();
    103 
    104     void captureSample();
    105     void threadMain();
    106 
    107     SurfaceFlinger& mFlinger;
    108     Scheduler& mScheduler;
    109     const TimingTunables mTunables;
    110     scheduler::IdleTimer mIdleTimer;
    111 
    112     std::unique_ptr<SamplingOffsetCallback> const mPhaseCallback;
    113 
    114     std::thread mThread;
    115 
    116     std::mutex mThreadControlMutex;
    117     std::condition_variable_any mCondition;
    118     bool mRunning GUARDED_BY(mThreadControlMutex) = true;
    119     bool mSampleRequested GUARDED_BY(mThreadControlMutex) = false;
    120     bool mDiscardedFrames GUARDED_BY(mThreadControlMutex) = false;
    121     std::chrono::nanoseconds lastSampleTime GUARDED_BY(mThreadControlMutex);
    122 
    123     std::mutex mSamplingMutex;
    124     std::unordered_map<wp<IBinder>, Descriptor, WpHash> mDescriptors GUARDED_BY(mSamplingMutex);
    125     sp<GraphicBuffer> mCachedBuffer GUARDED_BY(mSamplingMutex) = nullptr;
    126 };
    127 
    128 } // namespace android
    129