SF: rate-limit luma sampling (413287fa) · Commits · e / os / android_frameworks_native-old

services/surfaceflinger/RegionSamplingThread.cpp

+180 −5

Original line number	Diff line number	Diff line
		@@ -21,27 +21,168 @@

		#include "RegionSamplingThread.h"

		#include <cutils/properties.h>
		#include <gui/IRegionSamplingListener.h>
		#include <utils/Trace.h>
		#include <string>

		#include "DisplayDevice.h"
		#include "Layer.h"
		#include "SurfaceFlinger.h"

		namespace android {
		using namespace std::chrono_literals;

		template <typename T>
		struct SpHash {
		size_t operator()(const sp<T>& p) const { return std::hash<T*>()(p.get()); }
		};

		RegionSamplingThread::RegionSamplingThread(SurfaceFlinger& flinger) : mFlinger(flinger) {
		constexpr auto lumaSamplingStepTag = "LumaSamplingStep";
		enum class samplingStep {
		noWorkNeeded,
		idleTimerWaiting,
		waitForZeroPhase,
		waitForSamplePhase,
		sample
		};

		constexpr auto defaultRegionSamplingOffset = -3ms;
		constexpr auto defaultRegionSamplingPeriod = 100ms;
		constexpr auto defaultRegionSamplingTimerTimeout = 100ms;
		// TODO: (b/127403193) duration to string conversion could probably be constexpr
		template <typename Rep, typename Per>
		inline std::string toNsString(std::chrono::duration<Rep, Per> t) {
		return std::to_string(std::chrono::duration_cast<std::chrono::nanoseconds>(t).count());
		}

		RegionSamplingThread::EnvironmentTimingTunables::EnvironmentTimingTunables() {
		char value[PROPERTY_VALUE_MAX] = {};

		property_get("debug.sf.region_sampling_offset_ns", value,
		toNsString(defaultRegionSamplingOffset).c_str());
		int const samplingOffsetNsRaw = atoi(value);

		property_get("debug.sf.region_sampling_period_ns", value,
		toNsString(defaultRegionSamplingPeriod).c_str());
		int const samplingPeriodNsRaw = atoi(value);

		property_get("debug.sf.region_sampling_timer_timeout_ns", value,
		toNsString(defaultRegionSamplingTimerTimeout).c_str());
		int const samplingTimerTimeoutNsRaw = atoi(value);

		if ((samplingPeriodNsRaw < 0) \|\| (samplingTimerTimeoutNsRaw < 0)) {
		ALOGW("User-specified sampling tuning options nonsensical. Using defaults");
		mSamplingOffset = defaultRegionSamplingOffset;
		mSamplingPeriod = defaultRegionSamplingPeriod;
		mSamplingTimerTimeout = defaultRegionSamplingTimerTimeout;
		} else {
		mSamplingOffset = std::chrono::nanoseconds(samplingOffsetNsRaw);
		mSamplingPeriod = std::chrono::nanoseconds(samplingPeriodNsRaw);
		mSamplingTimerTimeout = std::chrono::nanoseconds(samplingTimerTimeoutNsRaw);
		}
		}

		struct SamplingOffsetCallback : DispSync::Callback {
		SamplingOffsetCallback(RegionSamplingThread& samplingThread, Scheduler& scheduler,
		std::chrono::nanoseconds targetSamplingOffset)
		: mRegionSamplingThread(samplingThread),
		mScheduler(scheduler),
		mTargetSamplingOffset(targetSamplingOffset) {}

		~SamplingOffsetCallback() { stopVsyncListener(); }

		SamplingOffsetCallback(const SamplingOffsetCallback&) = delete;
		SamplingOffsetCallback& operator=(const SamplingOffsetCallback&) = delete;

		void startVsyncListener() {
		std::lock_guard lock(mMutex);
		if (mVsyncListening) return;

		mPhaseIntervalSetting = Phase::ZERO;
		mScheduler.withPrimaryDispSync([this](android::DispSync& sync) {
		sync.addEventListener("SamplingThreadDispSyncListener", 0, this);
		});
		mVsyncListening = true;
		}

		void stopVsyncListener() {
		std::lock_guard lock(mMutex);
		stopVsyncListenerLocked();
		}

		private:
		void stopVsyncListenerLocked() /REQUIRES(mMutex)/ {
		if (!mVsyncListening) return;

		mScheduler.withPrimaryDispSync(
		[this](android::DispSync& sync) { sync.removeEventListener(this); });
		mVsyncListening = false;
		}

		void onDispSyncEvent(nsecs_t /* when */) final {
		std::unique_lock<decltype(mMutex)> lock(mMutex);

		if (mPhaseIntervalSetting == Phase::ZERO) {
		ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::waitForSamplePhase));
		mPhaseIntervalSetting = Phase::SAMPLING;
		mScheduler.withPrimaryDispSync([this](android::DispSync& sync) {
		sync.changePhaseOffset(this, mTargetSamplingOffset.count());
		});
		return;
		}

		if (mPhaseIntervalSetting == Phase::SAMPLING) {
		mPhaseIntervalSetting = Phase::ZERO;
		mScheduler.withPrimaryDispSync(
		[this](android::DispSync& sync) { sync.changePhaseOffset(this, 0); });
		stopVsyncListenerLocked();
		lock.unlock();
		mRegionSamplingThread.notifySamplingOffset();
		return;
		}
		}

		RegionSamplingThread& mRegionSamplingThread;
		Scheduler& mScheduler;
		const std::chrono::nanoseconds mTargetSamplingOffset;
		mutable std::mutex mMutex;
		enum class Phase {
		ZERO,
		SAMPLING
		} mPhaseIntervalSetting /GUARDED_BY(mMutex) macro doesnt work with unique_lock?/
		= Phase::ZERO;
		bool mVsyncListening /GUARDED_BY(mMutex)/ = false;
		};

		RegionSamplingThread::RegionSamplingThread(SurfaceFlinger& flinger, Scheduler& scheduler,
		const TimingTunables& tunables)
		: mFlinger(flinger),
		mScheduler(scheduler),
		mTunables(tunables),
		mIdleTimer(std::chrono::duration_cast<std::chrono::milliseconds>(
		mTunables.mSamplingTimerTimeout),
		[] {}, [this] { checkForStaleLuma(); }),
		mPhaseCallback(std::make_unique<SamplingOffsetCallback>(*this, mScheduler,
		tunables.mSamplingOffset)),
		lastSampleTime(0ns) {
		{
		std::lock_guard threadLock(mThreadMutex);
		mThread = std::thread([this]() { threadMain(); });
		pthread_setname_np(mThread.native_handle(), "RegionSamplingThread");
		}
		mIdleTimer.start();
		}

		RegionSamplingThread::RegionSamplingThread(SurfaceFlinger& flinger, Scheduler& scheduler)
		: RegionSamplingThread(flinger, scheduler,
		TimingTunables{defaultRegionSamplingOffset,
		defaultRegionSamplingPeriod,
		defaultRegionSamplingTimerTimeout}) {}

		RegionSamplingThread::~RegionSamplingThread() {
		mIdleTimer.stop();

		{
		std::lock_guard lock(mMutex);
		mRunning = false;
		@@ -71,8 +212,41 @@ void RegionSamplingThread::removeListener(const sp<IRegionSamplingListener>& lis
		mDescriptors.erase(wp<IBinder>(IInterface::asBinder(listener)));
		}

		void RegionSamplingThread::sampleNow() {
		void RegionSamplingThread::checkForStaleLuma() {
		std::lock_guard lock(mMutex);

		if (mDiscardedFrames) {
		ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::waitForZeroPhase));
		mDiscardedFrames = false;
		mPhaseCallback->startVsyncListener();
		}
		}

		void RegionSamplingThread::notifyNewContent() {
		doSample();
		}

		void RegionSamplingThread::notifySamplingOffset() {
		doSample();
		}

		void RegionSamplingThread::doSample() {
		std::lock_guard lock(mMutex);
		auto now = std::chrono::nanoseconds(systemTime(SYSTEM_TIME_MONOTONIC));
		if (lastSampleTime + mTunables.mSamplingPeriod > now) {
		ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::idleTimerWaiting));
		mDiscardedFrames = true;
		return;
		}

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

		mDiscardedFrames = false;
		lastSampleTime = now;

		mIdleTimer.reset();
		mPhaseCallback->stopVsyncListener();

		mSampleRequested = true;
		mCondition.notify_one();
		}
		@@ -238,6 +412,7 @@ void RegionSamplingThread::captureSample() {
		for (size_t d = 0; d < activeDescriptors.size(); ++d) {
		activeDescriptors[d].listener->onSampleCollected(lumas[d]);
		}
		ATRACE_INT(lumaSamplingStepTag, static_cast<int>(samplingStep::noWorkNeeded));
		}

		void RegionSamplingThread::threadMain() {

services/surfaceflinger/RegionSamplingThread.h

+43 −3

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@

		#pragma once

		#include <chrono>
		#include <condition_variable>
		#include <mutex>
		#include <thread>
		@@ -25,17 +26,42 @@
		#include <binder/IBinder.h>
		#include <ui/Rect.h>
		#include <utils/StrongPointer.h>
		#include "Scheduler/IdleTimer.h"

		namespace android {

		class GraphicBuffer;
		class IRegionSamplingListener;
		class Layer;
		class Scheduler;
		class SurfaceFlinger;
		struct SamplingOffsetCallback;

		class RegionSamplingThread : public IBinder::DeathRecipient {
		public:
		explicit RegionSamplingThread(SurfaceFlinger& flinger);
		struct TimingTunables {
		// debug.sf.sampling_offset_ns
		// When asynchronously collecting sample, the offset, from zero phase in the vsync timeline
		// at which the sampling should start.
		std::chrono::nanoseconds mSamplingOffset;
		// debug.sf.sampling_period_ns
		// This is the maximum amount of time the luma recieving client
		// should have to wait for a new luma value after a frame is updated. The inverse of this is
		// roughly the sampling rate. Sampling system rounds up sub-vsync sampling period to vsync
		// period.
		std::chrono::nanoseconds mSamplingPeriod;
		// debug.sf.sampling_timer_timeout_ns
		// This is the interval at which the luma sampling system will check that the luma clients
		// have up to date information. It defaults to the mSamplingPeriod.
		std::chrono::nanoseconds mSamplingTimerTimeout;
		};
		struct EnvironmentTimingTunables : TimingTunables {
		EnvironmentTimingTunables();
		};
		explicit RegionSamplingThread(SurfaceFlinger& flinger, Scheduler& scheduler,
		const TimingTunables& tunables);
		explicit RegionSamplingThread(SurfaceFlinger& flinger, Scheduler& scheduler);

		~RegionSamplingThread();

		// Add a listener to receive luma notifications. The luma reported via listener will
		@@ -44,8 +70,13 @@ public:
		const sp<IRegionSamplingListener>& listener);
		// Remove the listener to stop receiving median luma notifications.
		void removeListener(const sp<IRegionSamplingListener>& listener);
		// Instruct the thread to perform a median luma sampling on the layers.
		void sampleNow();

		// Notifies sampling engine that new content is available. This will trigger a sampling
		// pass at some point in the future.
		void notifyNewContent();

		// Notifies the sampling engine that it has a good timing window in which to sample.
		void notifySamplingOffset();

		private:
		struct Descriptor {
		@@ -63,12 +94,19 @@ private:
		const sp<GraphicBuffer>& buffer, const Point& leftTop,
		const std::vector<RegionSamplingThread::Descriptor>& descriptors);

		void doSample();
		void binderDied(const wp<IBinder>& who) override;
		void checkForStaleLuma();

		void captureSample() REQUIRES(mMutex);
		void threadMain();

		SurfaceFlinger& mFlinger;
		Scheduler& mScheduler;
		const TimingTunables mTunables;
		scheduler::IdleTimer mIdleTimer;

		std::unique_ptr<SamplingOffsetCallback> const mPhaseCallback;

		std::mutex mThreadMutex;
		std::thread mThread GUARDED_BY(mThreadMutex);
		@@ -79,6 +117,8 @@ private:
		bool mSampleRequested GUARDED_BY(mMutex) = false;

		std::unordered_map<wp<IBinder>, Descriptor, WpHash> mDescriptors GUARDED_BY(mMutex);
		std::chrono::nanoseconds lastSampleTime GUARDED_BY(mMutex);
		bool mDiscardedFrames GUARDED_BY(mMutex) = false;
		};

		} // namespace android

services/surfaceflinger/Scheduler/Scheduler.cpp

+4 −0

Original line number	Diff line number	Diff line
		@@ -304,6 +304,10 @@ void Scheduler::addNativeWindowApi(int apiId) {
		mApiHistoryCounter = mApiHistoryCounter % scheduler::ARRAY_SIZE;
		}

		void Scheduler::withPrimaryDispSync(std::function<void(DispSync&)> const& fn) {
		fn(*mPrimaryDispSync);
		}

		void Scheduler::updateFpsBasedOnNativeWindowApi() {
		int mode;
		{

services/surfaceflinger/Scheduler/Scheduler.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		#pragma once

		#include <cstdint>
		#include <functional>
		#include <memory>

		#include <ui/DisplayStatInfo.h>
		@@ -104,6 +105,9 @@ public:
		// Getter methods.
		EventThread* getEventThread(const sp<ConnectionHandle>& handle);

		// Provides access to the DispSync object for the primary display.
		void withPrimaryDispSync(std::function<void(DispSync&)> const& fn);

		sp<EventThreadConnection> getEventConnection(const sp<ConnectionHandle>& handle);

		// Should be called when receiving a hotplug event.

services/surfaceflinger/SurfaceFlinger.cpp

+6 −2

Original line number	Diff line number	Diff line
		@@ -637,6 +637,10 @@ void SurfaceFlinger::init() {
		mVsyncModulator.setSchedulerAndHandles(mScheduler.get(), mAppConnectionHandle.get(),
		mSfConnectionHandle.get());

		mRegionSamplingThread =
		new RegionSamplingThread(this, mScheduler,
		RegionSamplingThread::EnvironmentTimingTunables());

		// Get a RenderEngine for the given display / config (can't fail)
		int32_t renderEngineFeature = 0;
		renderEngineFeature \|= (useColorManagement ?
		@@ -2063,8 +2067,8 @@ void SurfaceFlinger::postComposition()
		mTransactionCompletedThread.addPresentFence(mPreviousPresentFence);
		mTransactionCompletedThread.sendCallbacks();

		if (mLumaSampling) {
		mRegionSamplingThread->sampleNow();
		if (mLumaSampling && mRegionSamplingThread) {
		mRegionSamplingThread->notifyNewContent();
		}
		}