services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.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.
  */

 #define ATRACE_TAG ATRACE_TAG_GRAPHICS
 #include <utils/Trace.h>
 #include <vector>

 #include "TimeKeeper.h"
 #include "VSyncDispatchTimerQueue.h"
 #include "VSyncTracker.h"

 namespace android::scheduler {

 VSyncDispatch::~VSyncDispatch() = default;
 VSyncTracker::~VSyncTracker() = default;
 TimeKeeper::~TimeKeeper() = default;

 VSyncDispatchTimerQueueEntry::VSyncDispatchTimerQueueEntry(std::string const& name,
                                                            std::function<void(nsecs_t)> const& cb,
                                                            nsecs_t minVsyncDistance)
       : mName(name),
         mCallback(cb),
         mWorkDuration(0),
         mEarliestVsync(0),
         mMinVsyncDistance(minVsyncDistance) {}

 std::optional<nsecs_t> VSyncDispatchTimerQueueEntry::lastExecutedVsyncTarget() const {
     return mLastDispatchTime;
 }

 std::string_view VSyncDispatchTimerQueueEntry::name() const {
     return mName;
 }

 std::optional<nsecs_t> VSyncDispatchTimerQueueEntry::wakeupTime() const {
     if (!mArmedInfo) {
         return {};
     }
     return {mArmedInfo->mActualWakeupTime};
 }

 ScheduleResult VSyncDispatchTimerQueueEntry::schedule(nsecs_t workDuration, nsecs_t earliestVsync,
                                                       VSyncTracker& tracker, nsecs_t now) {
     auto nextVsyncTime =
             tracker.nextAnticipatedVSyncTimeFrom(std::max(earliestVsync, now + workDuration));

     bool const wouldSkipAVsyncTarget =
             mArmedInfo && (nextVsyncTime > (mArmedInfo->mActualVsyncTime + mMinVsyncDistance));
     if (wouldSkipAVsyncTarget) {
         return ScheduleResult::Scheduled;
     }

     bool const alreadyDispatchedForVsync = mLastDispatchTime &&
             ((*mLastDispatchTime + mMinVsyncDistance) >= nextVsyncTime &&
              (*mLastDispatchTime - mMinVsyncDistance) <= nextVsyncTime);
     if (alreadyDispatchedForVsync) {
         nextVsyncTime =
                 tracker.nextAnticipatedVSyncTimeFrom(*mLastDispatchTime + mMinVsyncDistance);
     }

     auto const nextWakeupTime = nextVsyncTime - workDuration;
     mWorkDuration = workDuration;
     mEarliestVsync = earliestVsync;
     mArmedInfo = {nextWakeupTime, nextVsyncTime};
     return ScheduleResult::Scheduled;
 }

 void VSyncDispatchTimerQueueEntry::update(VSyncTracker& tracker, nsecs_t now) {
     if (!mArmedInfo) {
         return;
     }
     auto const nextVsyncTime =
             tracker.nextAnticipatedVSyncTimeFrom(std::max(mEarliestVsync, now + mWorkDuration));
     mArmedInfo = {nextVsyncTime - mWorkDuration, nextVsyncTime};
 }

 void VSyncDispatchTimerQueueEntry::disarm() {
     mArmedInfo.reset();
 }

 nsecs_t VSyncDispatchTimerQueueEntry::executing() {
     mLastDispatchTime = mArmedInfo->mActualVsyncTime;
     disarm();
     return *mLastDispatchTime;
 }

 void VSyncDispatchTimerQueueEntry::callback(nsecs_t t) {
     {
         std::lock_guard<std::mutex> lk(mRunningMutex);
         mRunning = true;
     }

     mCallback(t);

     std::lock_guard<std::mutex> lk(mRunningMutex);
     mRunning = false;
     mCv.notify_all();
 }

 void VSyncDispatchTimerQueueEntry::ensureNotRunning() {
     std::unique_lock<std::mutex> lk(mRunningMutex);
     mCv.wait(lk, [this]() REQUIRES(mRunningMutex) { return !mRunning; });
 }

 VSyncDispatchTimerQueue::VSyncDispatchTimerQueue(std::unique_ptr<TimeKeeper> tk,
                                                  VSyncTracker& tracker, nsecs_t timerSlack,
                                                  nsecs_t minVsyncDistance)
       : mTimeKeeper(std::move(tk)),
         mTracker(tracker),
         mTimerSlack(timerSlack),
         mMinVsyncDistance(minVsyncDistance) {}

 VSyncDispatchTimerQueue::~VSyncDispatchTimerQueue() {
     std::lock_guard<decltype(mMutex)> lk(mMutex);
     cancelTimer();
 }

 void VSyncDispatchTimerQueue::cancelTimer() {
     mIntendedWakeupTime = kInvalidTime;
     mTimeKeeper->alarmCancel();
 }

 void VSyncDispatchTimerQueue::setTimer(nsecs_t targetTime, nsecs_t now) {
     mIntendedWakeupTime = targetTime;
     mTimeKeeper->alarmIn(std::bind(&VSyncDispatchTimerQueue::timerCallback, this),
                          targetTime - now);
 }

 void VSyncDispatchTimerQueue::rearmTimer(nsecs_t now) {
     rearmTimerSkippingUpdateFor(now, mCallbacks.end());
 }

 void VSyncDispatchTimerQueue::rearmTimerSkippingUpdateFor(
         nsecs_t now, CallbackMap::iterator const& skipUpdateIt) {
     std::optional<nsecs_t> min;
     for (auto it = mCallbacks.begin(); it != mCallbacks.end(); it++) {
         auto& callback = it->second;
         if (!callback->wakeupTime()) {
             continue;
         }

         if (it != skipUpdateIt) {
             callback->update(mTracker, now);
         }
         auto const wakeupTime = *callback->wakeupTime();
         if (!min || (min && *min > wakeupTime)) {
             min = wakeupTime;
         }
     }

     if (min && (min < mIntendedWakeupTime)) {
         setTimer(*min, now);
     } else {
         cancelTimer();
     }
 }

 void VSyncDispatchTimerQueue::timerCallback() {
     struct Invocation {
         std::shared_ptr<VSyncDispatchTimerQueueEntry> callback;
         nsecs_t timestamp;
     };
     std::vector<Invocation> invocations;
     {
         std::lock_guard<decltype(mMutex)> lk(mMutex);
         for (auto it = mCallbacks.begin(); it != mCallbacks.end(); it++) {
             auto& callback = it->second;
             auto const wakeupTime = callback->wakeupTime();
             if (!wakeupTime) {
                 continue;
             }

             if (*wakeupTime < mIntendedWakeupTime + mTimerSlack) {
                 callback->executing();
                 invocations.emplace_back(
                         Invocation{callback, *callback->lastExecutedVsyncTarget()});
             }
         }

         mIntendedWakeupTime = kInvalidTime;
         rearmTimer(mTimeKeeper->now());
     }

     for (auto const& invocation : invocations) {
         invocation.callback->callback(invocation.timestamp);
     }
 }

 VSyncDispatchTimerQueue::CallbackToken VSyncDispatchTimerQueue::registerCallback(
         std::function<void(nsecs_t)> const& callbackFn, std::string callbackName) {
     std::lock_guard<decltype(mMutex)> lk(mMutex);
     return CallbackToken{
             mCallbacks
                     .emplace(++mCallbackToken,
                              std::make_shared<VSyncDispatchTimerQueueEntry>(callbackName,
                                                                             callbackFn,
                                                                             mMinVsyncDistance))
                     .first->first};
 }

 void VSyncDispatchTimerQueue::unregisterCallback(CallbackToken token) {
     std::shared_ptr<VSyncDispatchTimerQueueEntry> entry = nullptr;
     {
         std::lock_guard<decltype(mMutex)> lk(mMutex);
         auto it = mCallbacks.find(token);
         if (it != mCallbacks.end()) {
             entry = it->second;
             mCallbacks.erase(it);
         }
     }

     if (entry) {
         entry->ensureNotRunning();
     }
 }

 ScheduleResult VSyncDispatchTimerQueue::schedule(CallbackToken token, nsecs_t workDuration,
                                                  nsecs_t earliestVsync) {
     auto result = ScheduleResult::Error;
     {
         std::lock_guard<decltype(mMutex)> lk(mMutex);

         auto it = mCallbacks.find(token);
         if (it == mCallbacks.end()) {
             return result;
         }
         auto& callback = it->second;
         auto const now = mTimeKeeper->now();
         result = callback->schedule(workDuration, earliestVsync, mTracker, now);
         if (result == ScheduleResult::CannotSchedule) {
             return result;
         }

         if (callback->wakeupTime() < mIntendedWakeupTime - mTimerSlack) {
             rearmTimerSkippingUpdateFor(now, it);
         }
     }

     return result;
 }

 CancelResult VSyncDispatchTimerQueue::cancel(CallbackToken token) {
     std::lock_guard<decltype(mMutex)> lk(mMutex);

     auto it = mCallbacks.find(token);
     if (it == mCallbacks.end()) {
         return CancelResult::Error;
     }
     auto& callback = it->second;

     if (callback->wakeupTime()) {
         callback->disarm();
         mIntendedWakeupTime = kInvalidTime;
         rearmTimer(mTimeKeeper->now());
         return CancelResult::Cancelled;
     }
     return CancelResult::TooLate;
 }

 VSyncCallbackRegistration::VSyncCallbackRegistration(VSyncDispatch& dispatch,
                                                      std::function<void(nsecs_t)> const& callbackFn,
                                                      std::string const& callbackName)
       : mDispatch(dispatch),
         mToken(dispatch.registerCallback(callbackFn, callbackName)),
         mValidToken(true) {}

 VSyncCallbackRegistration::VSyncCallbackRegistration(VSyncCallbackRegistration&& other)
       : mDispatch(other.mDispatch),
         mToken(std::move(other.mToken)),
         mValidToken(std::move(other.mValidToken)) {
     other.mValidToken = false;
 }

 VSyncCallbackRegistration& VSyncCallbackRegistration::operator=(VSyncCallbackRegistration&& other) {
     mDispatch = std::move(other.mDispatch);
     mToken = std::move(other.mToken);
     mValidToken = std::move(other.mValidToken);
     other.mValidToken = false;
     return *this;
 }

 VSyncCallbackRegistration::~VSyncCallbackRegistration() {
     if (mValidToken) mDispatch.get().unregisterCallback(mToken);
 }

 ScheduleResult VSyncCallbackRegistration::schedule(nsecs_t workDuration, nsecs_t earliestVsync) {
     if (!mValidToken) {
         return ScheduleResult::Error;
     }
     return mDispatch.get().schedule(mToken, workDuration, earliestVsync);
 }

 CancelResult VSyncCallbackRegistration::cancel() {
     if (!mValidToken) {
         return CancelResult::Error;
     }
     return mDispatch.get().cancel(mToken);
 }

 } // 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.
	*/

	#define ATRACE_TAG ATRACE_TAG_GRAPHICS
	#include <utils/Trace.h>
	#include <vector>

	#include "TimeKeeper.h"
	#include "VSyncDispatchTimerQueue.h"
	#include "VSyncTracker.h"

	namespace android::scheduler {

	VSyncDispatch::~VSyncDispatch() = default;
	VSyncTracker::~VSyncTracker() = default;
	TimeKeeper::~TimeKeeper() = default;

	VSyncDispatchTimerQueueEntry::VSyncDispatchTimerQueueEntry(std::string const& name,
	std::function<void(nsecs_t)> const& cb,
	nsecs_t minVsyncDistance)
	: mName(name),
	mCallback(cb),
	mWorkDuration(0),
	mEarliestVsync(0),
	mMinVsyncDistance(minVsyncDistance) {}

	std::optional<nsecs_t> VSyncDispatchTimerQueueEntry::lastExecutedVsyncTarget() const {
	return mLastDispatchTime;
	}

	std::string_view VSyncDispatchTimerQueueEntry::name() const {
	return mName;
	}

	std::optional<nsecs_t> VSyncDispatchTimerQueueEntry::wakeupTime() const {
	if (!mArmedInfo) {
	return {};
	}
	return {mArmedInfo->mActualWakeupTime};
	}

	ScheduleResult VSyncDispatchTimerQueueEntry::schedule(nsecs_t workDuration, nsecs_t earliestVsync,
	VSyncTracker& tracker, nsecs_t now) {
	auto nextVsyncTime =
	tracker.nextAnticipatedVSyncTimeFrom(std::max(earliestVsync, now + workDuration));

	bool const wouldSkipAVsyncTarget =
	mArmedInfo && (nextVsyncTime > (mArmedInfo->mActualVsyncTime + mMinVsyncDistance));
	if (wouldSkipAVsyncTarget) {
	return ScheduleResult::Scheduled;
	}

	bool const alreadyDispatchedForVsync = mLastDispatchTime &&
	((*mLastDispatchTime + mMinVsyncDistance) >= nextVsyncTime &&
	(*mLastDispatchTime - mMinVsyncDistance) <= nextVsyncTime);
	if (alreadyDispatchedForVsync) {
	nextVsyncTime =
	tracker.nextAnticipatedVSyncTimeFrom(*mLastDispatchTime + mMinVsyncDistance);
	}

	auto const nextWakeupTime = nextVsyncTime - workDuration;
	mWorkDuration = workDuration;
	mEarliestVsync = earliestVsync;
	mArmedInfo = {nextWakeupTime, nextVsyncTime};
	return ScheduleResult::Scheduled;
	}

	void VSyncDispatchTimerQueueEntry::update(VSyncTracker& tracker, nsecs_t now) {
	if (!mArmedInfo) {
	return;
	}
	auto const nextVsyncTime =
	tracker.nextAnticipatedVSyncTimeFrom(std::max(mEarliestVsync, now + mWorkDuration));
	mArmedInfo = {nextVsyncTime - mWorkDuration, nextVsyncTime};
	}

	void VSyncDispatchTimerQueueEntry::disarm() {
	mArmedInfo.reset();
	}

	nsecs_t VSyncDispatchTimerQueueEntry::executing() {
	mLastDispatchTime = mArmedInfo->mActualVsyncTime;
	disarm();
	return *mLastDispatchTime;
	}

	void VSyncDispatchTimerQueueEntry::callback(nsecs_t t) {
	{
	std::lock_guard<std::mutex> lk(mRunningMutex);
	mRunning = true;
	}

	mCallback(t);

	std::lock_guard<std::mutex> lk(mRunningMutex);
	mRunning = false;
	mCv.notify_all();
	}

	void VSyncDispatchTimerQueueEntry::ensureNotRunning() {
	std::unique_lock<std::mutex> lk(mRunningMutex);
	mCv.wait(lk, [this]() REQUIRES(mRunningMutex) { return !mRunning; });
	}

	VSyncDispatchTimerQueue::VSyncDispatchTimerQueue(std::unique_ptr<TimeKeeper> tk,
	VSyncTracker& tracker, nsecs_t timerSlack,
	nsecs_t minVsyncDistance)
	: mTimeKeeper(std::move(tk)),
	mTracker(tracker),
	mTimerSlack(timerSlack),
	mMinVsyncDistance(minVsyncDistance) {}

	VSyncDispatchTimerQueue::~VSyncDispatchTimerQueue() {
	std::lock_guard<decltype(mMutex)> lk(mMutex);
	cancelTimer();
	}

	void VSyncDispatchTimerQueue::cancelTimer() {
	mIntendedWakeupTime = kInvalidTime;
	mTimeKeeper->alarmCancel();
	}

	void VSyncDispatchTimerQueue::setTimer(nsecs_t targetTime, nsecs_t now) {
	mIntendedWakeupTime = targetTime;
	mTimeKeeper->alarmIn(std::bind(&VSyncDispatchTimerQueue::timerCallback, this),
	targetTime - now);
	}

	void VSyncDispatchTimerQueue::rearmTimer(nsecs_t now) {
	rearmTimerSkippingUpdateFor(now, mCallbacks.end());
	}

	void VSyncDispatchTimerQueue::rearmTimerSkippingUpdateFor(
	nsecs_t now, CallbackMap::iterator const& skipUpdateIt) {
	std::optional<nsecs_t> min;
	for (auto it = mCallbacks.begin(); it != mCallbacks.end(); it++) {
	auto& callback = it->second;
	if (!callback->wakeupTime()) {
	continue;
	}

	if (it != skipUpdateIt) {
	callback->update(mTracker, now);
	}
	auto const wakeupTime = *callback->wakeupTime();
	if (!min \|\| (min && *min > wakeupTime)) {
	min = wakeupTime;
	}
	}

	if (min && (min < mIntendedWakeupTime)) {
	setTimer(*min, now);
	} else {
	cancelTimer();
	}
	}

	void VSyncDispatchTimerQueue::timerCallback() {
	struct Invocation {
	std::shared_ptr<VSyncDispatchTimerQueueEntry> callback;
	nsecs_t timestamp;
	};
	std::vector<Invocation> invocations;
	{
	std::lock_guard<decltype(mMutex)> lk(mMutex);
	for (auto it = mCallbacks.begin(); it != mCallbacks.end(); it++) {
	auto& callback = it->second;
	auto const wakeupTime = callback->wakeupTime();
	if (!wakeupTime) {
	continue;
	}

	if (*wakeupTime < mIntendedWakeupTime + mTimerSlack) {
	callback->executing();
	invocations.emplace_back(
	Invocation{callback, *callback->lastExecutedVsyncTarget()});
	}
	}

	mIntendedWakeupTime = kInvalidTime;
	rearmTimer(mTimeKeeper->now());
	}

	for (auto const& invocation : invocations) {
	invocation.callback->callback(invocation.timestamp);
	}
	}

	VSyncDispatchTimerQueue::CallbackToken VSyncDispatchTimerQueue::registerCallback(
	std::function<void(nsecs_t)> const& callbackFn, std::string callbackName) {
	std::lock_guard<decltype(mMutex)> lk(mMutex);
	return CallbackToken{
	mCallbacks
	.emplace(++mCallbackToken,
	std::make_shared<VSyncDispatchTimerQueueEntry>(callbackName,
	callbackFn,
	mMinVsyncDistance))
	.first->first};
	}

	void VSyncDispatchTimerQueue::unregisterCallback(CallbackToken token) {
	std::shared_ptr<VSyncDispatchTimerQueueEntry> entry = nullptr;
	{
	std::lock_guard<decltype(mMutex)> lk(mMutex);
	auto it = mCallbacks.find(token);
	if (it != mCallbacks.end()) {
	entry = it->second;
	mCallbacks.erase(it);
	}
	}

	if (entry) {
	entry->ensureNotRunning();
	}
	}

	ScheduleResult VSyncDispatchTimerQueue::schedule(CallbackToken token, nsecs_t workDuration,
	nsecs_t earliestVsync) {
	auto result = ScheduleResult::Error;
	{
	std::lock_guard<decltype(mMutex)> lk(mMutex);

	auto it = mCallbacks.find(token);
	if (it == mCallbacks.end()) {
	return result;
	}
	auto& callback = it->second;
	auto const now = mTimeKeeper->now();
	result = callback->schedule(workDuration, earliestVsync, mTracker, now);
	if (result == ScheduleResult::CannotSchedule) {
	return result;
	}

	if (callback->wakeupTime() < mIntendedWakeupTime - mTimerSlack) {
	rearmTimerSkippingUpdateFor(now, it);
	}
	}

	return result;
	}

	CancelResult VSyncDispatchTimerQueue::cancel(CallbackToken token) {
	std::lock_guard<decltype(mMutex)> lk(mMutex);

	auto it = mCallbacks.find(token);
	if (it == mCallbacks.end()) {
	return CancelResult::Error;
	}
	auto& callback = it->second;

	if (callback->wakeupTime()) {
	callback->disarm();
	mIntendedWakeupTime = kInvalidTime;
	rearmTimer(mTimeKeeper->now());
	return CancelResult::Cancelled;
	}
	return CancelResult::TooLate;
	}

	VSyncCallbackRegistration::VSyncCallbackRegistration(VSyncDispatch& dispatch,
	std::function<void(nsecs_t)> const& callbackFn,
	std::string const& callbackName)
	: mDispatch(dispatch),
	mToken(dispatch.registerCallback(callbackFn, callbackName)),
	mValidToken(true) {}

	VSyncCallbackRegistration::VSyncCallbackRegistration(VSyncCallbackRegistration&& other)
	: mDispatch(other.mDispatch),
	mToken(std::move(other.mToken)),
	mValidToken(std::move(other.mValidToken)) {
	other.mValidToken = false;
	}

	VSyncCallbackRegistration& VSyncCallbackRegistration::operator=(VSyncCallbackRegistration&& other) {
	mDispatch = std::move(other.mDispatch);
	mToken = std::move(other.mToken);
	mValidToken = std::move(other.mValidToken);
	other.mValidToken = false;
	return *this;
	}

	VSyncCallbackRegistration::~VSyncCallbackRegistration() {
	if (mValidToken) mDispatch.get().unregisterCallback(mToken);
	}

	ScheduleResult VSyncCallbackRegistration::schedule(nsecs_t workDuration, nsecs_t earliestVsync) {
	if (!mValidToken) {
	return ScheduleResult::Error;
	}
	return mDispatch.get().schedule(mToken, workDuration, earliestVsync);
	}

	CancelResult VSyncCallbackRegistration::cancel() {
	if (!mValidToken) {
	return CancelResult::Error;
	}
	return mDispatch.get().cancel(mToken);
	}

	} // namespace android::scheduler