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 <android-base/thread_annotations.h>
20 #include <android/gui/IRegionSamplingListener.h>
21 #include <binder/IBinder.h>
22 #include <renderengine/ExternalTexture.h>
23 #include <ui/GraphicBuffer.h>
24 #include <ui/Rect.h>
25 #include <utils/StrongPointer.h>
26 
27 #include <chrono>
28 #include <condition_variable>
29 #include <cstdint>
30 #include <mutex>
31 #include <thread>
32 #include <unordered_map>
33 
34 #include "Scheduler/OneShotTimer.h"
35 #include "WpHash.h"
36 
37 namespace android {
38 
39 class Layer;
40 class SurfaceFlinger;
41 struct SamplingOffsetCallback;
42 
43 using gui::IRegionSamplingListener;
44 
45 float sampleArea(const uint32_t* data, int32_t width, int32_t height, int32_t stride,
46                  uint32_t orientation, const Rect& area);
47 
48 class RegionSamplingThread : public IBinder::DeathRecipient {
49 public:
50     struct TimingTunables {
51         // debug.sf.sampling_duration_ns
52         // When asynchronously collecting sample, the duration, at which the sampling should start
53         // before a vsync
54         std::chrono::nanoseconds mSamplingDuration;
55         // debug.sf.sampling_period_ns
56         // This is the maximum amount of time the luma recieving client
57         // should have to wait for a new luma value after a frame is updated. The inverse of this is
58         // roughly the sampling rate. Sampling system rounds up sub-vsync sampling period to vsync
59         // period.
60         std::chrono::nanoseconds mSamplingPeriod;
61         // debug.sf.sampling_timer_timeout_ns
62         // This is the interval at which the luma sampling system will check that the luma clients
63         // have up to date information. It defaults to the mSamplingPeriod.
64         std::chrono::nanoseconds mSamplingTimerTimeout;
65     };
66     struct EnvironmentTimingTunables : TimingTunables {
67         EnvironmentTimingTunables();
68     };
69     explicit RegionSamplingThread(SurfaceFlinger& flinger, const TimingTunables& tunables);
70     explicit RegionSamplingThread(SurfaceFlinger& flinger);
71 
72     ~RegionSamplingThread();
73 
74     // Add a listener to receive luma notifications. The luma reported via listener will
75     // report the median luma for the layers under the stopLayerHandle, in the samplingArea region.
76     void addListener(const Rect& samplingArea, uint32_t stopLayerId,
77                      const sp<IRegionSamplingListener>& listener);
78     // Remove the listener to stop receiving median luma notifications.
79     void removeListener(const sp<IRegionSamplingListener>& listener);
80 
81     // Notifies sampling engine that composition is done and new content is
82     // available, and the deadline for the sampling work on the main thread to
83     // be completed without eating the budget of another frame.
84     void onCompositionComplete(
85             std::optional<std::chrono::steady_clock::time_point> samplingDeadline);
86 
87 private:
88     struct Descriptor {
89         Rect area = Rect::EMPTY_RECT;
90         uint32_t stopLayerId;
91         sp<IRegionSamplingListener> listener;
92     };
93 
94     std::vector<float> sampleBuffer(
95             const sp<GraphicBuffer>& buffer, const Point& leftTop,
96             const std::vector<RegionSamplingThread::Descriptor>& descriptors, uint32_t orientation);
97 
98     void doSample(std::optional<std::chrono::steady_clock::time_point> samplingDeadline);
99     void binderDied(const wp<IBinder>& who) override;
100     void checkForStaleLuma();
101 
102     void captureSample();
103     void threadMain();
104 
105     SurfaceFlinger& mFlinger;
106     const TimingTunables mTunables;
107     scheduler::OneShotTimer mIdleTimer;
108 
109     std::thread mThread;
110 
111     std::mutex mThreadControlMutex;
112     std::condition_variable_any mCondition;
113     bool mRunning GUARDED_BY(mThreadControlMutex) = true;
114     bool mSampleRequested GUARDED_BY(mThreadControlMutex) = false;
115     std::optional<std::chrono::steady_clock::time_point> mSampleRequestTime
116             GUARDED_BY(mThreadControlMutex);
117     std::chrono::steady_clock::time_point mLastSampleTime GUARDED_BY(mThreadControlMutex);
118 
119     std::mutex mSamplingMutex;
120     std::unordered_map<wp<IBinder>, Descriptor, WpHash> mDescriptors GUARDED_BY(mSamplingMutex);
121     std::shared_ptr<renderengine::ExternalTexture> mCachedBuffer GUARDED_BY(mSamplingMutex) =
122             nullptr;
123 };
124 
125 } // namespace android
126