Web Animations: Overhaul and trace play state in AnimationPlayer

Source/core/animation/AnimationPlayer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 43 matching lines @@
 {
     RefPtrWillBeRawPtr<AnimationPlayer> player = adoptRefWillBeNoop(new AnimationPlayer(executionContext, timeline, content));
     player->uncancel();
     timeline.document()->compositorPendingAnimations().add(player.get());
     player->suspendIfNeeded();
     return player.release();
 }
 
 AnimationPlayer::AnimationPlayer(ExecutionContext* executionContext, AnimationTimeline& timeline, AnimationNode* content)
     : ActiveDOMObject(executionContext)
+    , m_playState(Idle)
     , m_playbackRate(1)
     , m_startTime(nullValue())
     , m_holdTime(0)
     , m_sequenceNumber(nextSequenceNumber())
     , m_content(content)
     , m_timeline(&timeline)
     , m_paused(false)
     , m_held(true)
     , m_isPausedForTesting(false)
     , m_outdated(true)
     , m_finished(true)
     , m_compositorState(nullptr)
     , m_compositorPending(true)
     , m_currentTimePending(false)
-    , m_idle(true)
 {
     if (m_content) {
         if (m_content->player()) {
             m_content->player()->cancel();
             m_content->player()->setSource(0);
         }
         m_content->attach(this);
     }
 }
 
@@ skipping 10 matching lines @@
 double AnimationPlayer::sourceEnd() const
 {
     return m_content ? m_content->endTimeInternal() : 0;
 }
 
 bool AnimationPlayer::limited(double currentTime) const
 {
     return (m_playbackRate < 0 && currentTime <= 0) || (m_playbackRate > 0 && currentTime >= sourceEnd());
 }
 
+void AnimationPlayer::setCurrentTime(double newCurrentTime)
+{
+    UseCounter::count(executionContext(), UseCounter::AnimationPlayerSetCurrentTime);
+    if (!std::isfinite(newCurrentTime))
+        return;
+
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
+    setCompositorPending();
+    m_currentTimePending = false;
+    setCurrentTimeInternal(newCurrentTime / 1000, TimingUpdateOnDemand);
+}
+
 void AnimationPlayer::setCurrentTimeInternal(double newCurrentTime, TimingUpdateReason reason)
 {
     ASSERT(std::isfinite(newCurrentTime));
 
     bool oldHeld = m_held;
     bool outdated = false;
     bool isLimited = limited(newCurrentTime);
     m_held = m_paused || !m_playbackRate || isLimited || std::isnan(m_startTime);
     if (m_held) {
         if (!oldHeld || m_holdTime != newCurrentTime)
             outdated = true;
         m_holdTime = newCurrentTime;
         if (m_paused || !m_playbackRate) {
             m_startTime = nullValue();
         } else if (isLimited && std::isnan(m_startTime) && reason == TimingUpdateForAnimationFrame) {
             m_startTime = calculateStartTime(newCurrentTime);
         }
     } else {
         m_holdTime = nullValue();
         m_startTime = calculateStartTime(newCurrentTime);
-        setFinished(false);
+        m_finished = false;
         outdated = true;
     }
 
     if (outdated) {
         setOutdated();
     }
 }
 
 // Update timing to reflect updated animation clock due to tick
 void AnimationPlayer::updateCurrentTimingState(TimingUpdateReason reason)
@@ skipping 23 matching lines @@
 
 double AnimationPlayer::currentTime(bool& isNull)
 {
     double result = currentTime();
     isNull = std::isnan(result);
     return result;
 }
 
 double AnimationPlayer::currentTime()
 {
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     UseCounter::count(executionContext(), UseCounter::AnimationPlayerGetCurrentTime);
-    if (m_currentTimePending || m_idle)
+    if (m_currentTimePending || playStateInternal() == Idle)
         return std::numeric_limits<double>::quiet_NaN();
+
     return currentTimeInternal() * 1000;
 }
 
-double AnimationPlayer::currentTimeInternal()
+double AnimationPlayer::currentTimeInternal() const
 {
-    updateCurrentTimingState(TimingUpdateOnDemand);
-    if (m_held)
-        return m_holdTime;
-    return calculateCurrentTime();
+    double result = m_held ? m_holdTime : calculateCurrentTime();
+#if ENABLE(ASSERT)

[shans, 2014/10/15 03:38:00]

is ASSERT stronger than DEBUG?

[dstockwell, 2014/10/15 08:30:04]

ASSERT can be enabled outside of a debug build. But this usage is typical.

+    const_cast<AnimationPlayer*>(this)->updateCurrentTimingState(TimingUpdateOnDemand);
+    ASSERT(result == (m_held ? m_holdTime : calculateCurrentTime()));
+#endif
+    return result;
 }
 
 void AnimationPlayer::preCommit(bool startOnCompositor)
 {
     if (m_compositorState && m_compositorState->pendingAction == Start) {
         // Still waiting for a start time.
         return;
     }
 
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     bool softChange = m_compositorState && (paused() || m_compositorState->playbackRate != m_playbackRate);
     bool hardChange = m_compositorState && (m_compositorState->sourceChanged || (m_compositorState->startTime != m_startTime && !std::isnan(m_compositorState->startTime) && !std::isnan(m_startTime)));
 
     // FIXME: softChange && !hardChange should generate a Pause/ThenStart,
     // not a Cancel, but we can't communicate these to the compositor yet.
 
     bool changed = softChange || hardChange;
     bool shouldCancel = (!playing() && m_compositorState) || changed;
     bool shouldStart = playing() && (!m_compositorState || changed);
 
     if (shouldCancel) {
         cancelAnimationOnCompositor();
         m_compositorState = nullptr;
 
     }
 
     if (!shouldStart) {
         m_currentTimePending = false;
     }
 
     if (shouldStart && startOnCompositor && maybeStartAnimationOnCompositor()) {
         m_compositorState = adoptPtr(new CompositorState(*this));
     }
 }
 
 void AnimationPlayer::postCommit(double timelineTime)
 {
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     m_compositorPending = false;
 
     if (!m_compositorState || m_compositorState->pendingAction == None)
         return;
 
     switch (m_compositorState->pendingAction) {
     case Start:
         if (!std::isnan(m_compositorState->startTime)) {
             ASSERT(m_startTime == m_compositorState->startTime);
             m_compositorState->pendingAction = None;
         }
         break;
     case Pause:
     case PauseThenStart:
         ASSERT(std::isnan(m_startTime));
         m_compositorState->pendingAction = None;
         setCurrentTimeInternal((timelineTime - m_compositorState->startTime) * m_playbackRate, TimingUpdateForAnimationFrame);
         m_currentTimePending = false;
         break;
     default:
         ASSERT_NOT_REACHED();
     }
 }
 
 void AnimationPlayer::notifyCompositorStartTime(double timelineTime)
 {
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     if (m_compositorState) {
         ASSERT(m_compositorState->pendingAction == Start);
         ASSERT(std::isnan(m_compositorState->startTime));
 
         double initialCompositorHoldTime = m_compositorState->holdTime;
         m_compositorState->pendingAction = None;
         m_compositorState->startTime = timelineTime;
 
         if (paused() || m_compositorState->playbackRate != m_playbackRate || m_compositorState->sourceChanged) {
             // Paused state, playback rate, or source changed while starting.
@@ skipping 40 matching lines @@
 }
 
 double AnimationPlayer::calculateCurrentTime() const
 {
     ASSERT(!m_held);
     if (isNull(m_startTime) || !m_timeline)
         return 0;
     return (m_timeline->effectiveTime() - m_startTime) * m_playbackRate;
 }
 
-void AnimationPlayer::setCurrentTime(double newCurrentTime)
-{
-    UseCounter::count(executionContext(), UseCounter::AnimationPlayerSetCurrentTime);
-    if (!std::isfinite(newCurrentTime))
-        return;
-
-    setCompositorPending();
-    m_currentTimePending = false;
-    setCurrentTimeInternal(newCurrentTime / 1000, TimingUpdateOnDemand);
-}
-
 void AnimationPlayer::setStartTime(double startTime)
 {
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     UseCounter::count(executionContext(), UseCounter::AnimationPlayerSetStartTime);
-    if (m_paused || m_idle)
+    if (m_paused || playStateInternal() == Idle)
         return;
     if (!std::isfinite(startTime))
         return;
     if (startTime == m_startTime)
         return;
 
     setCompositorPending();
     m_currentTimePending = false;
     setStartTimeInternal(startTime / 1000);
 }
@@ skipping 12 matching lines @@
         // Force a new, limited, current time.
         m_held = false;
         double currentTime = calculateCurrentTime();
         if (m_playbackRate > 0 && currentTime > sourceEnd()) {
             currentTime = sourceEnd();
         } else if (m_playbackRate < 0 && currentTime < 0) {
             currentTime = 0;
         }
         setCurrentTimeInternal(currentTime, TimingUpdateOnDemand);
     }
+    updateCurrentTimingState(TimingUpdateOnDemand);
     double newCurrentTime = currentTimeInternal();
 
     if (previousCurrentTime != newCurrentTime) {
         setOutdated();
     } else if (!hadStartTime && m_timeline) {
         // Even though this player is not outdated, time to effect change is
         // infinity until start time is set.
         m_timeline->wake();
     }
 }
 
 void AnimationPlayer::setSource(AnimationNode* newSource)
 {
     if (m_content == newSource)
         return;
 
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     setCompositorPending(true);
 
     double storedCurrentTime = currentTimeInternal();
     if (m_content)
         m_content->detach();
     m_content = newSource;
     if (newSource) {
         // FIXME: This logic needs to be updated once groups are implemented
         if (newSource->player()) {
             newSource->player()->cancel();
             newSource->player()->setSource(0);
         }
         newSource->attach(this);
         setOutdated();
     }
     setCurrentTimeInternal(storedCurrentTime, TimingUpdateOnDemand);
 }
 
-String AnimationPlayer::playState()
+const char* AnimationPlayer::playStateString(AnimationPlayState playState)
 {
-    switch (playStateInternal()) {
+    switch (playState) {
     case Idle:
         return "idle";
     case Pending:
         return "pending";
     case Running:
         return "running";
     case Paused:
         return "paused";
     case Finished:
         return "finished";
     default:
         ASSERT_NOT_REACHED();
         return "";
     }
 }
 
-AnimationPlayer::AnimationPlayState AnimationPlayer::playStateInternal()
+AnimationPlayer::AnimationPlayState AnimationPlayer::playStateInternal() const
 {
-    if (m_idle)
+    return m_playState;
+}
+
+AnimationPlayer::AnimationPlayState AnimationPlayer::calculatePlayState()
+{
+    if (m_playState == Idle)
         return Idle;
     if (m_currentTimePending || (isNull(m_startTime) && !m_paused && m_playbackRate != 0))
         return Pending;
     if (m_paused)
         return Paused;
     if (finished())
         return Finished;
     return Running;
 }
 
 void AnimationPlayer::pause()
 {
     if (m_paused)
         return;
+
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     if (playing()) {
         setCompositorPending();
         m_currentTimePending = true;
     }
     m_paused = true;
     setCurrentTimeInternal(currentTimeInternal(), TimingUpdateOnDemand);
 }
 
 void AnimationPlayer::unpause()
 {
     if (!m_paused)
         return;
+
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     setCompositorPending();
     m_currentTimePending = true;
     unpauseInternal();
 }
 
 void AnimationPlayer::unpauseInternal()
 {
     if (!m_paused)
         return;
     m_paused = false;
     setCurrentTimeInternal(currentTimeInternal(), TimingUpdateOnDemand);
 }
 
 void AnimationPlayer::play()
 {
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     if (!playing())
         m_startTime = nullValue();
 
     setCompositorPending();
     uncancel();
     unpauseInternal();
     if (!m_content)
         return;
     double currentTime = this->currentTimeInternal();
     if (m_playbackRate > 0 && (currentTime < 0 || currentTime >= sourceEnd()))
         setCurrentTimeInternal(0, TimingUpdateOnDemand);
     else if (m_playbackRate < 0 && (currentTime <= 0 || currentTime > sourceEnd()))
         setCurrentTimeInternal(sourceEnd(), TimingUpdateOnDemand);
-    setFinished(false);
+    m_finished = false;
 }
 
 void AnimationPlayer::reverse()
 {
     if (!m_playbackRate) {
         return;
     }
 
     uncancel();
     setPlaybackRateInternal(-m_playbackRate);
     play();
 }
 
 void AnimationPlayer::finish(ExceptionState& exceptionState)
 {
-    if (!m_playbackRate || m_idle) {
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
+    if (!m_playbackRate || playStateInternal() == Idle) {
         return;
     }
     if (m_playbackRate > 0 && sourceEnd() == std::numeric_limits<double>::infinity()) {
         exceptionState.throwDOMException(InvalidStateError, "AnimationPlayer has source content whose end time is infinity.");
         return;
     }
     if (playing()) {
         setCompositorPending();
     }
 
@@ skipping 19 matching lines @@
     return ActiveDOMObject::executionContext();
 }
 
 bool AnimationPlayer::hasPendingActivity() const
 {
     return m_pendingFinishedEvent || (!m_finished && hasEventListeners(EventTypeNames::finish));
 }
 
 void AnimationPlayer::stop()
 {
-    setFinished(true);
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
+    m_finished = true;
     m_pendingFinishedEvent = nullptr;
 }
 
 bool AnimationPlayer::dispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
 {
     if (m_pendingFinishedEvent == event)
         m_pendingFinishedEvent = nullptr;
     return EventTargetWithInlineData::dispatchEvent(event);
 }
 
 double AnimationPlayer::playbackRate() const
 {
     UseCounter::count(executionContext(), UseCounter::AnimationPlayerGetPlaybackRate);
     return m_playbackRate;
 }
 
 void AnimationPlayer::setPlaybackRate(double playbackRate)
 {
     UseCounter::count(executionContext(), UseCounter::AnimationPlayerSetPlaybackRate);
     if (!std::isfinite(playbackRate))
         return;
     if (playbackRate == m_playbackRate)
         return;
 
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
     setPlaybackRateInternal(playbackRate);
 }
 
 void AnimationPlayer::setPlaybackRateInternal(double playbackRate)
 {
     ASSERT(std::isfinite(playbackRate));
     ASSERT(playbackRate != m_playbackRate);
 
     setCompositorPending();
     if (!finished() && !paused() && hasStartTime())
         m_currentTimePending = true;
 
     double storedCurrentTime = currentTimeInternal();
     if ((m_playbackRate < 0 && playbackRate >= 0) || (m_playbackRate > 0 && playbackRate <= 0))
-        setFinished(false);
+        m_finished = false;
 
     m_playbackRate = playbackRate;
     m_startTime = std::numeric_limits<double>::quiet_NaN();
     setCurrentTimeInternal(storedCurrentTime, TimingUpdateOnDemand);
 }
 
 void AnimationPlayer::setOutdated()
 {
     m_outdated = true;
     if (m_timeline)
@@ skipping 47 matching lines @@
 {
     if (hasActiveAnimationsOnCompositor())
         toAnimation(m_content.get())->cancelAnimationOnCompositor();
 }
 
 bool AnimationPlayer::update(TimingUpdateReason reason)
 {
     if (!m_timeline)
         return false;
 
-    updateCurrentTimingState(reason);
+    PlayStateUpdateScope updateScope(*this, reason);
+
     m_outdated = false;
+    bool idle = playStateInternal() == Idle;
 
     if (m_content) {
-        double inheritedTime = m_idle || isNull(m_timeline->currentTimeInternal()) ? nullValue() : currentTimeInternal();
+        double inheritedTime = idle || isNull(m_timeline->currentTimeInternal()) ? nullValue() : currentTimeInternal();
         // Special case for end-exclusivity when playing backwards.
         if (inheritedTime == 0 && m_playbackRate < 0)
             inheritedTime = -1;
         m_content->updateInheritedTime(inheritedTime, reason);
     }
 
-    if ((m_idle || finished()) && !m_finished) {
-        if (reason == TimingUpdateForAnimationFrame && (m_idle || hasStartTime())) {
+    if ((idle || finished()) && !m_finished) {
+        if (reason == TimingUpdateForAnimationFrame && (idle || hasStartTime())) {
             const AtomicString& eventType = EventTypeNames::finish;
             if (executionContext() && hasEventListeners(eventType)) {
                 double eventCurrentTime = currentTimeInternal() * 1000;
                 m_pendingFinishedEvent = AnimationPlayerEvent::create(eventType, eventCurrentTime, timeline()->currentTime());
                 m_pendingFinishedEvent->setTarget(this);
                 m_pendingFinishedEvent->setCurrentTarget(this);
                 m_timeline->document()->enqueueAnimationFrameEvent(m_pendingFinishedEvent);
             }
-            setFinished(true);
+            m_finished = true;
         }
     }
     ASSERT(!m_outdated);
     return !m_finished;
 }
 
 double AnimationPlayer::timeToEffectChange()
 {
     ASSERT(!m_outdated);
     if (m_held || !hasStartTime())
         return std::numeric_limits<double>::infinity();
     if (!m_content)
         return -currentTimeInternal() / m_playbackRate;
     if (m_playbackRate > 0)
         return m_content->timeToForwardsEffectChange() / m_playbackRate;
     return m_content->timeToReverseEffectChange() / -m_playbackRate;
 }
 
-void AnimationPlayer::setFinished(bool finished)
-{
-    if (m_finished && !finished) {
-        if (m_content) {
-            TRACE_EVENT_ASYNC_BEGIN1("blink", "Animation", this, "Name", TRACE_STR_COPY(m_content->name().utf8().data()));
-        } else {
-            TRACE_EVENT_ASYNC_BEGIN0("blink", "Animation", this);
-        }
-    }
-    if (!m_finished && finished) {
-        TRACE_EVENT_ASYNC_END0("blink", "Animation", this);
-    }
-    m_finished = finished;
-}
-
 void AnimationPlayer::cancel()
 {
-    if (m_idle)
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
+    if (playStateInternal() == Idle)
         return;
 
     m_holdTime = currentTimeInternal();
     m_held = true;
-    m_idle = true;
+    // TODO
+    m_playState = Idle;
     m_startTime = nullValue();
     m_currentTimePending = false;
     setCompositorPending();
 }
 
 void AnimationPlayer::uncancel()
 {
-    if (!m_idle)
+    PlayStateUpdateScope updateScope(*this, TimingUpdateOnDemand);
+
+    if (playStateInternal() != Idle)
         return;
 
-    m_idle = false;
+    // We may not go into the pending state, but setting it to something other
+    // than Idle here will force an update.
+    ASSERT(isNull(m_startTime));
+    m_playState = Pending;
     m_held = true;
     m_holdTime = 0;
-    setFinished(false);
+    m_finished = false;
+}
+
+AnimationPlayer::PlayStateUpdateScope::PlayStateUpdateScope(AnimationPlayer& player, TimingUpdateReason reason)
+    : m_player(player)
+    , m_initial(player.playStateInternal())
+{
+    m_player.updateCurrentTimingState(reason);
+}
+
+AnimationPlayer::PlayStateUpdateScope::~PlayStateUpdateScope()

[shans, 2014/10/15 03:38:00]

can we setCompositorPending in here too?

[dstockwell, 2014/10/15 08:30:04]

Done, this required a few flags as it's not safe to always call it, eg. in
::update we don't want to have to evaluate every frame whether a main-thread
animation could be started on the compositor.

+{
+    AnimationPlayState oldPlayState = m_initial;
+    AnimationPlayState newPlayState = m_player.calculatePlayState();
+    if (oldPlayState != newPlayState) {
+        bool wasActive = oldPlayState == Pending || oldPlayState == Running;
+        bool isActive = newPlayState == Pending || newPlayState == Running;
+        if (!wasActive && isActive) {
+            if (m_player.m_content) {
+                TRACE_EVENT_ASYNC_BEGIN1("blink", "Animation", &m_player, "Name", TRACE_STR_COPY(m_player.m_content->name().utf8().data()));
+            } else {
+                TRACE_EVENT_ASYNC_BEGIN0("blink", "Animation", &m_player);
+            }
+        } else if (wasActive && !isActive) {
+            if (oldPlayState != Idle && oldPlayState != Finished) {
+                TRACE_EVENT_ASYNC_END0("blink", "Animation", &m_player);
+            }
+        }
+        if (isActive) {
+            TRACE_EVENT_ASYNC_STEP_INTO0("blink", "Animation", &m_player, playStateString(newPlayState));
+        }
+    }
+
+    m_player.m_playState = newPlayState;
+
+#if ENABLE(ASSERT)
+    // Verify that current time is up to date.
+    m_player.currentTimeInternal();
+#endif
 }
 
 
 #if !ENABLE(OILPAN)
 bool AnimationPlayer::canFree() const
 {
     ASSERT(m_content);
     return hasOneRef() && m_content->isAnimation() && m_content->hasOneRef();
 }
 #endif
@@ skipping 17 matching lines @@
 
 void AnimationPlayer::trace(Visitor* visitor)
 {
     visitor->trace(m_content);
     visitor->trace(m_timeline);
     visitor->trace(m_pendingFinishedEvent);
     EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace