File indexing completed on 2024-05-12 05:31:23

 /*
     SPDX-FileCopyrightText: 2020 Vlad Zahorodnii <vlad.zahorodnii@kde.org>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "renderloop.h"
 #include "options.h"
 #include "renderloop_p.h"
 #include "scene/surfaceitem.h"
 #include "utils/common.h"
 #include "window.h"
 #include "workspace.h"
 
 namespace KWin
 {
 
 template<typename T>
 T alignTimestamp(const T &timestamp, const T &alignment)
 {
     return timestamp + ((alignment - (timestamp % alignment)) % alignment);
 }
 
 RenderLoopPrivate *RenderLoopPrivate::get(RenderLoop *loop)
 {
     return loop->d.get();
 }
 
 RenderLoopPrivate::RenderLoopPrivate(RenderLoop *q, Output *output)
     : q(q)
     , output(output)
 {
     compositeTimer.setSingleShot(true);
     QObject::connect(&compositeTimer, &QTimer::timeout, q, [this]() {
         dispatch();
     });
 }
 
 void RenderLoopPrivate::scheduleRepaint()
 {
     if (kwinApp()->isTerminating() || compositeTimer.isActive()) {
         return;
     }
     const std::chrono::nanoseconds vblankInterval(1'000'000'000'000ull / refreshRate);
     const std::chrono::nanoseconds currentTime(std::chrono::steady_clock::now().time_since_epoch());
 
     // Estimate when the next presentation will occur. Note that this is a prediction.
     nextPresentationTimestamp = lastPresentationTimestamp + vblankInterval;
     if (nextPresentationTimestamp < currentTime && presentationMode == PresentationMode::VSync) {
         nextPresentationTimestamp = lastPresentationTimestamp
             + alignTimestamp(currentTime - lastPresentationTimestamp, vblankInterval);
     }
 
     // Estimate when it's a good time to perform the next compositing cycle.
     // the 1ms on top of the safety margin is required for timer and scheduler inaccuracies
     std::chrono::nanoseconds nextRenderTimestamp = nextPresentationTimestamp - renderJournal.result() - safetyMargin - std::chrono::milliseconds(1);
 
     // If we can't render the frame before the deadline, start compositing immediately.
     if (nextRenderTimestamp < currentTime) {
         nextRenderTimestamp = currentTime;
     }
 
     if (presentationMode == PresentationMode::Async || presentationMode == PresentationMode::AdaptiveAsync) {
         compositeTimer.start(0);
     } else {
         const std::chrono::nanoseconds waitInterval = nextRenderTimestamp - currentTime;
         compositeTimer.start(std::chrono::duration_cast<std::chrono::milliseconds>(waitInterval));
     }
 }
 
 void RenderLoopPrivate::delayScheduleRepaint()
 {
     pendingReschedule = true;
 }
 
 void RenderLoopPrivate::maybeScheduleRepaint()
 {
     if (pendingReschedule) {
         scheduleRepaint();
         pendingReschedule = false;
     }
 }
 
 void RenderLoopPrivate::notifyFrameFailed()
 {
     Q_ASSERT(pendingFrameCount > 0);
     pendingFrameCount--;
 
     if (!inhibitCount) {
         maybeScheduleRepaint();
     }
 }
 
 void RenderLoopPrivate::notifyFrameCompleted(std::chrono::nanoseconds timestamp, std::chrono::nanoseconds renderTime, PresentationMode mode)
 {
     Q_ASSERT(pendingFrameCount > 0);
     pendingFrameCount--;
 
     notifyVblank(timestamp);
 
     renderJournal.add(renderTime, timestamp);
     if (!inhibitCount) {
         maybeScheduleRepaint();
     }
 
     Q_EMIT q->framePresented(q, timestamp, mode);
 }
 
 void RenderLoopPrivate::notifyVblank(std::chrono::nanoseconds timestamp)
 {
     if (lastPresentationTimestamp <= timestamp) {
         lastPresentationTimestamp = timestamp;
     } else {
         qCDebug(KWIN_CORE,
                 "Got invalid presentation timestamp: %lld (current %lld)",
                 static_cast<long long>(timestamp.count()),
                 static_cast<long long>(lastPresentationTimestamp.count()));
         lastPresentationTimestamp = std::chrono::steady_clock::now().time_since_epoch();
     }
 }
 
 void RenderLoopPrivate::dispatch()
 {
     // On X11, we want to ignore repaints that are scheduled by windows right before
     // the Compositor starts repainting.
     pendingRepaint = true;
 
     Q_EMIT q->frameRequested(q);
 
     // The Compositor may decide to not repaint when the frameRequested() signal is
     // emitted, in which case the pending repaint flag has to be reset manually.
     pendingRepaint = false;
 }
 
 void RenderLoopPrivate::invalidate()
 {
     pendingReschedule = false;
     pendingFrameCount = 0;
     compositeTimer.stop();
 }
 
 RenderLoop::RenderLoop(Output *output)
     : d(std::make_unique<RenderLoopPrivate>(this, output))
 {
 }
 
 RenderLoop::~RenderLoop()
 {
 }
 
 void RenderLoop::inhibit()
 {
     d->inhibitCount++;
 
     if (d->inhibitCount == 1) {
         d->compositeTimer.stop();
     }
 }
 
 void RenderLoop::uninhibit()
 {
     Q_ASSERT(d->inhibitCount > 0);
     d->inhibitCount--;
 
     if (d->inhibitCount == 0) {
         d->maybeScheduleRepaint();
     }
 }
 
 void RenderLoop::prepareNewFrame()
 {
     d->pendingFrameCount++;
 }
 
 void RenderLoop::beginPaint()
 {
     d->pendingRepaint = false;
 }
 
 int RenderLoop::refreshRate() const
 {
     return d->refreshRate;
 }
 
 void RenderLoop::setRefreshRate(int refreshRate)
 {
     if (d->refreshRate == refreshRate) {
         return;
     }
     d->refreshRate = refreshRate;
     Q_EMIT refreshRateChanged();
 }
 
 void RenderLoop::setPresentationSafetyMargin(std::chrono::nanoseconds safetyMargin)
 {
     d->safetyMargin = safetyMargin;
 }
 
 void RenderLoop::scheduleRepaint(Item *item)
 {
     if (d->pendingRepaint) {
         return;
     }
     const bool vrr = d->presentationMode == PresentationMode::AdaptiveSync || d->presentationMode == PresentationMode::AdaptiveAsync;
     if (vrr && workspace()->activeWindow() && d->output) {
         Window *const activeWindow = workspace()->activeWindow();
         if (activeWindow->isOnOutput(d->output) && activeWindow->surfaceItem() && item != activeWindow->surfaceItem() && activeWindow->surfaceItem()->frameTimeEstimation() <= std::chrono::nanoseconds(1'000'000'000) / 30) {
             return;
         }
     }
     if (!d->pendingFrameCount && !d->inhibitCount) {
         d->scheduleRepaint();
     } else {
         d->delayScheduleRepaint();
     }
 }
 
 std::chrono::nanoseconds RenderLoop::lastPresentationTimestamp() const
 {
     return d->lastPresentationTimestamp;
 }
 
 std::chrono::nanoseconds RenderLoop::nextPresentationTimestamp() const
 {
     return d->nextPresentationTimestamp;
 }
 
 void RenderLoop::setPresentationMode(PresentationMode mode)
 {
     d->presentationMode = mode;
 }
 
 } // namespace KWin
 
 #include "moc_renderloop.cpp"