services/surfaceflinger/Scheduler/VSyncReactor.cpp - android_frameworks_native - Gitiles

 /*
  * Copyright 2019 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.
  */

 #undef LOG_TAG
 #define LOG_TAG "VSyncReactor"
 //#define LOG_NDEBUG 0
 #include "VSyncReactor.h"
 #include <log/log.h>
 #include "TimeKeeper.h"
 #include "VSyncDispatch.h"
 #include "VSyncTracker.h"

 namespace android::scheduler {

 Clock::~Clock() = default;
 nsecs_t SystemClock::now() const {
     return systemTime(SYSTEM_TIME_MONOTONIC);
 }

 VSyncReactor::VSyncReactor(std::unique_ptr<Clock> clock, std::unique_ptr<VSyncDispatch> dispatch,
                            std::unique_ptr<VSyncTracker> tracker, size_t pendingFenceLimit)
       : mClock(std::move(clock)),
         mTracker(std::move(tracker)),
         mDispatch(std::move(dispatch)),
         mPendingLimit(pendingFenceLimit) {}

 VSyncReactor::~VSyncReactor() = default;

 // The DispSync interface has a 'repeat this callback at rate' semantic. This object adapts
 // VSyncDispatch's individually-scheduled callbacks so as to meet DispSync's existing semantic
 // for now.
 class CallbackRepeater {
 public:
     CallbackRepeater(VSyncDispatch& dispatch, DispSync::Callback* cb, const char* name,
                      nsecs_t period, nsecs_t offset, nsecs_t notBefore)
           : mCallback(cb),
             mRegistration(dispatch,
                           std::bind(&CallbackRepeater::callback, this, std::placeholders::_1),
                           std::string(name)),
             mPeriod(period),
             mOffset(offset),
             mLastCallTime(notBefore) {}

     ~CallbackRepeater() {
         std::lock_guard<std::mutex> lk(mMutex);
         mRegistration.cancel();
     }

     void start(nsecs_t offset) {
         std::lock_guard<std::mutex> lk(mMutex);
         mStopped = false;
         mOffset = offset;

         auto const schedule_result = mRegistration.schedule(calculateWorkload(), mLastCallTime);
         LOG_ALWAYS_FATAL_IF((schedule_result != ScheduleResult::Scheduled),
                             "Error scheduling callback: rc %X", schedule_result);
     }

     void setPeriod(nsecs_t period) {
         std::lock_guard<std::mutex> lk(mMutex);
         if (period == mPeriod) {
             return;
         }
         mPeriod = period;
     }

     void stop() {
         std::lock_guard<std::mutex> lk(mMutex);
         LOG_ALWAYS_FATAL_IF(mStopped, "DispSyncInterface misuse: callback already stopped");
         mStopped = true;
         mRegistration.cancel();
     }

 private:
     void callback(nsecs_t vsynctime) {
         nsecs_t period = 0;
         {
             std::lock_guard<std::mutex> lk(mMutex);
             period = mPeriod;
             mLastCallTime = vsynctime;
         }

         mCallback->onDispSyncEvent(vsynctime - period);

         {
             std::lock_guard<std::mutex> lk(mMutex);
             auto const schedule_result = mRegistration.schedule(calculateWorkload(), vsynctime);
             LOG_ALWAYS_FATAL_IF((schedule_result != ScheduleResult::Scheduled),
                                 "Error rescheduling callback: rc %X", schedule_result);
         }
     }

     // DispSync offsets are defined as time after the vsync before presentation.
     // VSyncReactor workloads are defined as time before the intended presentation vsync.
     // Note change in sign between the two defnitions.
     nsecs_t calculateWorkload() REQUIRES(mMutex) { return mPeriod - mOffset; }

     DispSync::Callback* const mCallback;

     std::mutex mutable mMutex;
     VSyncCallbackRegistration mRegistration GUARDED_BY(mMutex);
     bool mStopped GUARDED_BY(mMutex) = false;
     nsecs_t mPeriod GUARDED_BY(mMutex);
     nsecs_t mOffset GUARDED_BY(mMutex);
     nsecs_t mLastCallTime GUARDED_BY(mMutex);
 };

 bool VSyncReactor::addPresentFence(const std::shared_ptr<FenceTime>& fence) {
     if (!fence) {
         return false;
     }

     nsecs_t const signalTime = fence->getCachedSignalTime();
     if (signalTime == Fence::SIGNAL_TIME_INVALID) {
         return true;
     }

     std::lock_guard<std::mutex> lk(mMutex);
     if (mIgnorePresentFences) {
         return true;
     }

     for (auto it = mUnfiredFences.begin(); it != mUnfiredFences.end();) {
         auto const time = (*it)->getCachedSignalTime();
         if (time == Fence::SIGNAL_TIME_PENDING) {
             it++;
         } else if (time == Fence::SIGNAL_TIME_INVALID) {
             it = mUnfiredFences.erase(it);
         } else {
             mTracker->addVsyncTimestamp(time);
             it = mUnfiredFences.erase(it);
         }
     }

     if (signalTime == Fence::SIGNAL_TIME_PENDING) {
         if (mPendingLimit == mUnfiredFences.size()) {
             mUnfiredFences.erase(mUnfiredFences.begin());
         }
         mUnfiredFences.push_back(fence);
     } else {
         mTracker->addVsyncTimestamp(signalTime);
     }

     return mMoreSamplesNeeded;
 }

 void VSyncReactor::setIgnorePresentFences(bool ignoration) {
     std::lock_guard<std::mutex> lk(mMutex);
     mIgnorePresentFences = ignoration;
     if (mIgnorePresentFences == true) {
         mUnfiredFences.clear();
     }
 }

 nsecs_t VSyncReactor::computeNextRefresh(int periodOffset) const {
     auto const now = mClock->now();
     auto const currentPeriod = periodOffset ? mTracker->currentPeriod() : 0;
     return mTracker->nextAnticipatedVSyncTimeFrom(now + periodOffset * currentPeriod);
 }

 nsecs_t VSyncReactor::expectedPresentTime() {
     return mTracker->nextAnticipatedVSyncTimeFrom(mClock->now());
 }

 void VSyncReactor::setPeriod(nsecs_t period) {
     std::lock_guard lk(mMutex);
     mLastHwVsync.reset();
     mPeriodTransitioningTo = period;
 }

 nsecs_t VSyncReactor::getPeriod() {
     return mTracker->currentPeriod();
 }

 void VSyncReactor::beginResync() {}

 void VSyncReactor::endResync() {}

 bool VSyncReactor::periodChangeDetected(nsecs_t vsync_timestamp) {
     if (!mLastHwVsync || !mPeriodTransitioningTo) {
         return false;
     }
     auto const distance = vsync_timestamp - *mLastHwVsync;
     return std::abs(distance - *mPeriodTransitioningTo) < std::abs(distance - getPeriod());
 }

 bool VSyncReactor::addResyncSample(nsecs_t timestamp, bool* periodFlushed) {
     assert(periodFlushed);

     std::lock_guard<std::mutex> lk(mMutex);
     if (periodChangeDetected(timestamp)) {
         mMoreSamplesNeeded = false;
         *periodFlushed = true;

         mTracker->setPeriod(*mPeriodTransitioningTo);
         for (auto& entry : mCallbacks) {
             entry.second->setPeriod(*mPeriodTransitioningTo);
         }

         mPeriodTransitioningTo.reset();
         mLastHwVsync.reset();
     } else if (mPeriodTransitioningTo) {
         mLastHwVsync = timestamp;
         mMoreSamplesNeeded = true;
         *periodFlushed = false;
     } else {
         mMoreSamplesNeeded = false;
         *periodFlushed = false;
     }

     mTracker->addVsyncTimestamp(timestamp);
     return mMoreSamplesNeeded;
 }

 status_t VSyncReactor::addEventListener(const char* name, nsecs_t phase,
                                         DispSync::Callback* callback,
                                         nsecs_t /* lastCallbackTime */) {
     std::lock_guard<std::mutex> lk(mMutex);
     auto it = mCallbacks.find(callback);
     if (it == mCallbacks.end()) {
         // TODO (b/146557561): resolve lastCallbackTime semantics in DispSync i/f.
         static auto constexpr maxListeners = 3;
         if (mCallbacks.size() >= maxListeners) {
             ALOGE("callback %s not added, exceeded callback limit of %i (currently %zu)", name,
                   maxListeners, mCallbacks.size());
             return NO_MEMORY;
         }

         auto const period = mTracker->currentPeriod();
         auto repeater = std::make_unique<CallbackRepeater>(*mDispatch, callback, name, period,
                                                            phase, mClock->now());
         it = mCallbacks.emplace(std::pair(callback, std::move(repeater))).first;
     }

     it->second->start(phase);
     return NO_ERROR;
 }

 status_t VSyncReactor::removeEventListener(DispSync::Callback* callback,
                                            nsecs_t* /* outLastCallback */) {
     std::lock_guard<std::mutex> lk(mMutex);
     auto const it = mCallbacks.find(callback);
     LOG_ALWAYS_FATAL_IF(it == mCallbacks.end(), "callback %p not registered", callback);

     it->second->stop();
     return NO_ERROR;
 }

 status_t VSyncReactor::changePhaseOffset(DispSync::Callback* callback, nsecs_t phase) {
     std::lock_guard<std::mutex> lk(mMutex);
     auto const it = mCallbacks.find(callback);
     LOG_ALWAYS_FATAL_IF(it == mCallbacks.end(), "callback was %p not registered", callback);

     it->second->start(phase);
     return NO_ERROR;
 }

 void VSyncReactor::dump(std::string& result) const {
     result += "VsyncReactor in use\n"; // TODO (b/144927823): add more information!
 }

 void VSyncReactor::reset() {}

 } // namespace android::scheduler
	/*
	* Copyright 2019 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.
	*/

	#undef LOG_TAG
	#define LOG_TAG "VSyncReactor"
	//#define LOG_NDEBUG 0
	#include "VSyncReactor.h"
	#include <log/log.h>
	#include "TimeKeeper.h"
	#include "VSyncDispatch.h"
	#include "VSyncTracker.h"

	namespace android::scheduler {

	Clock::~Clock() = default;
	nsecs_t SystemClock::now() const {
	return systemTime(SYSTEM_TIME_MONOTONIC);
	}

	VSyncReactor::VSyncReactor(std::unique_ptr<Clock> clock, std::unique_ptr<VSyncDispatch> dispatch,
	std::unique_ptr<VSyncTracker> tracker, size_t pendingFenceLimit)
	: mClock(std::move(clock)),
	mTracker(std::move(tracker)),
	mDispatch(std::move(dispatch)),
	mPendingLimit(pendingFenceLimit) {}

	VSyncReactor::~VSyncReactor() = default;

	// The DispSync interface has a 'repeat this callback at rate' semantic. This object adapts
	// VSyncDispatch's individually-scheduled callbacks so as to meet DispSync's existing semantic
	// for now.
	class CallbackRepeater {
	public:
	CallbackRepeater(VSyncDispatch& dispatch, DispSync::Callback* cb, const char* name,
	nsecs_t period, nsecs_t offset, nsecs_t notBefore)
	: mCallback(cb),
	mRegistration(dispatch,
	std::bind(&CallbackRepeater::callback, this, std::placeholders::_1),
	std::string(name)),
	mPeriod(period),
	mOffset(offset),
	mLastCallTime(notBefore) {}

	~CallbackRepeater() {
	std::lock_guard<std::mutex> lk(mMutex);
	mRegistration.cancel();
	}

	void start(nsecs_t offset) {
	std::lock_guard<std::mutex> lk(mMutex);
	mStopped = false;
	mOffset = offset;

	auto const schedule_result = mRegistration.schedule(calculateWorkload(), mLastCallTime);
	LOG_ALWAYS_FATAL_IF((schedule_result != ScheduleResult::Scheduled),
	"Error scheduling callback: rc %X", schedule_result);
	}

	void setPeriod(nsecs_t period) {
	std::lock_guard<std::mutex> lk(mMutex);
	if (period == mPeriod) {
	return;
	}
	mPeriod = period;
	}

	void stop() {
	std::lock_guard<std::mutex> lk(mMutex);
	LOG_ALWAYS_FATAL_IF(mStopped, "DispSyncInterface misuse: callback already stopped");
	mStopped = true;
	mRegistration.cancel();
	}

	private:
	void callback(nsecs_t vsynctime) {
	nsecs_t period = 0;
	{
	std::lock_guard<std::mutex> lk(mMutex);
	period = mPeriod;
	mLastCallTime = vsynctime;
	}

	mCallback->onDispSyncEvent(vsynctime - period);

	{
	std::lock_guard<std::mutex> lk(mMutex);
	auto const schedule_result = mRegistration.schedule(calculateWorkload(), vsynctime);
	LOG_ALWAYS_FATAL_IF((schedule_result != ScheduleResult::Scheduled),
	"Error rescheduling callback: rc %X", schedule_result);
	}
	}

	// DispSync offsets are defined as time after the vsync before presentation.
	// VSyncReactor workloads are defined as time before the intended presentation vsync.
	// Note change in sign between the two defnitions.
	nsecs_t calculateWorkload() REQUIRES(mMutex) { return mPeriod - mOffset; }

	DispSync::Callback* const mCallback;

	std::mutex mutable mMutex;
	VSyncCallbackRegistration mRegistration GUARDED_BY(mMutex);
	bool mStopped GUARDED_BY(mMutex) = false;
	nsecs_t mPeriod GUARDED_BY(mMutex);
	nsecs_t mOffset GUARDED_BY(mMutex);
	nsecs_t mLastCallTime GUARDED_BY(mMutex);
	};

	bool VSyncReactor::addPresentFence(const std::shared_ptr<FenceTime>& fence) {
	if (!fence) {
	return false;
	}

	nsecs_t const signalTime = fence->getCachedSignalTime();
	if (signalTime == Fence::SIGNAL_TIME_INVALID) {
	return true;
	}

	std::lock_guard<std::mutex> lk(mMutex);
	if (mIgnorePresentFences) {
	return true;
	}

	for (auto it = mUnfiredFences.begin(); it != mUnfiredFences.end();) {
	auto const time = (*it)->getCachedSignalTime();
	if (time == Fence::SIGNAL_TIME_PENDING) {
	it++;
	} else if (time == Fence::SIGNAL_TIME_INVALID) {
	it = mUnfiredFences.erase(it);
	} else {
	mTracker->addVsyncTimestamp(time);
	it = mUnfiredFences.erase(it);
	}
	}

	if (signalTime == Fence::SIGNAL_TIME_PENDING) {
	if (mPendingLimit == mUnfiredFences.size()) {
	mUnfiredFences.erase(mUnfiredFences.begin());
	}
	mUnfiredFences.push_back(fence);
	} else {
	mTracker->addVsyncTimestamp(signalTime);
	}

	return mMoreSamplesNeeded;
	}

	void VSyncReactor::setIgnorePresentFences(bool ignoration) {
	std::lock_guard<std::mutex> lk(mMutex);
	mIgnorePresentFences = ignoration;
	if (mIgnorePresentFences == true) {
	mUnfiredFences.clear();
	}
	}

	nsecs_t VSyncReactor::computeNextRefresh(int periodOffset) const {
	auto const now = mClock->now();
	auto const currentPeriod = periodOffset ? mTracker->currentPeriod() : 0;
	return mTracker->nextAnticipatedVSyncTimeFrom(now + periodOffset * currentPeriod);
	}

	nsecs_t VSyncReactor::expectedPresentTime() {
	return mTracker->nextAnticipatedVSyncTimeFrom(mClock->now());
	}

	void VSyncReactor::setPeriod(nsecs_t period) {
	std::lock_guard lk(mMutex);
	mLastHwVsync.reset();
	mPeriodTransitioningTo = period;
	}

	nsecs_t VSyncReactor::getPeriod() {
	return mTracker->currentPeriod();
	}

	void VSyncReactor::beginResync() {}

	void VSyncReactor::endResync() {}

	bool VSyncReactor::periodChangeDetected(nsecs_t vsync_timestamp) {
	if (!mLastHwVsync \|\| !mPeriodTransitioningTo) {
	return false;
	}
	auto const distance = vsync_timestamp - *mLastHwVsync;
	return std::abs(distance - *mPeriodTransitioningTo) < std::abs(distance - getPeriod());
	}

	bool VSyncReactor::addResyncSample(nsecs_t timestamp, bool* periodFlushed) {
	assert(periodFlushed);

	std::lock_guard<std::mutex> lk(mMutex);
	if (periodChangeDetected(timestamp)) {
	mMoreSamplesNeeded = false;
	*periodFlushed = true;

	mTracker->setPeriod(*mPeriodTransitioningTo);
	for (auto& entry : mCallbacks) {
	entry.second->setPeriod(*mPeriodTransitioningTo);
	}

	mPeriodTransitioningTo.reset();
	mLastHwVsync.reset();
	} else if (mPeriodTransitioningTo) {
	mLastHwVsync = timestamp;
	mMoreSamplesNeeded = true;
	*periodFlushed = false;
	} else {
	mMoreSamplesNeeded = false;
	*periodFlushed = false;
	}

	mTracker->addVsyncTimestamp(timestamp);
	return mMoreSamplesNeeded;
	}

	status_t VSyncReactor::addEventListener(const char* name, nsecs_t phase,
	DispSync::Callback* callback,
	nsecs_t /* lastCallbackTime */) {
	std::lock_guard<std::mutex> lk(mMutex);
	auto it = mCallbacks.find(callback);
	if (it == mCallbacks.end()) {
	// TODO (b/146557561): resolve lastCallbackTime semantics in DispSync i/f.
	static auto constexpr maxListeners = 3;
	if (mCallbacks.size() >= maxListeners) {
	ALOGE("callback %s not added, exceeded callback limit of %i (currently %zu)", name,
	maxListeners, mCallbacks.size());
	return NO_MEMORY;
	}

	auto const period = mTracker->currentPeriod();
	auto repeater = std::make_unique<CallbackRepeater>(*mDispatch, callback, name, period,
	phase, mClock->now());
	it = mCallbacks.emplace(std::pair(callback, std::move(repeater))).first;
	}

	it->second->start(phase);
	return NO_ERROR;
	}

	status_t VSyncReactor::removeEventListener(DispSync::Callback* callback,
	nsecs_t* /* outLastCallback */) {
	std::lock_guard<std::mutex> lk(mMutex);
	auto const it = mCallbacks.find(callback);
	LOG_ALWAYS_FATAL_IF(it == mCallbacks.end(), "callback %p not registered", callback);

	it->second->stop();
	return NO_ERROR;
	}

	status_t VSyncReactor::changePhaseOffset(DispSync::Callback* callback, nsecs_t phase) {
	std::lock_guard<std::mutex> lk(mMutex);
	auto const it = mCallbacks.find(callback);
	LOG_ALWAYS_FATAL_IF(it == mCallbacks.end(), "callback was %p not registered", callback);

	it->second->start(phase);
	return NO_ERROR;
	}

	void VSyncReactor::dump(std::string& result) const {
	result += "VsyncReactor in use\n"; // TODO (b/144927823): add more information!
	}

	void VSyncReactor::reset() {}

	} // namespace android::scheduler