makeOpportunisticTaskDeferralScopeIfPossible has a wrong early exit l…

…ogic

https://bugs.webkit.org/show_bug.cgi?id=259857

Reviewed by Mark Lam, Yusuke Suzuki and Wenson Hsieh.

We want to defer opportunistic task whenever we have a timer firing in the next 1ms,
not whenever we have a timer firing in 1ms or later. But changing the condition to
that causes ~1% Speedometer 2.1 regression in macOS Sonoma so simply delete
OpportunisticTaskDeferralScope entirely out of DOMTimer. This seems perf neutral on
macOS Sonoma and around ~0.7% Speedometer 2.1 progression in macOS Ventura.

* Source/WebCore/page/DOMTimer.cpp:
(WebCore::DOMTimer::install):
(WebCore::DOMTimer::removeById):
(WebCore::DOMTimer::fired):
(WebCore::DOMTimer::didStop):
(WebCore::DOMTimer::makeOpportunisticTaskDeferralScopeIfPossible): Deleted.
(WebCore::DOMTimer::clearOpportunisticTaskDeferralScopeIfPossible): Deleted.
* Source/WebCore/page/DOMTimer.h:
* Source/WebCore/page/Page.h:

Canonical link: https://commits.webkit.org/266680@main

Source/WebCore/page/DOMTimer.cpp

@@ -189,7 +189,6 @@ int DOMTimer::install(ScriptExecutionContext& context, Function<void(ScriptExecu
 {
     Ref<DOMTimer> timer = adoptRef(*new DOMTimer(context, WTFMove(action), timeout, type));
     timer->suspendIfNeeded();
-    timer->makeOpportunisticTaskDeferralScopeIfPossible(context);
 
     // Keep asking for the next id until we're given one that we don't already have.
     do {
@@ -236,8 +235,7 @@ void DOMTimer::removeById(ScriptExecutionContext& context, int timeoutId)
 
     InspectorInstrumentation::didRemoveTimer(context, timeoutId);
 
-    if (auto timer = context.takeTimeout(timeoutId))
-        timer->clearOpportunisticTaskDeferralScopeIfPossible();
+    context.takeTimeout(timeoutId);
 }
 
 inline bool DOMTimer::isDOMTimersThrottlingEnabled(const Document& document) const
@@ -333,7 +331,6 @@ void DOMTimer::fired()
 
         updateThrottlingStateIfNecessary(fireState);
 
-        clearOpportunisticTaskDeferralScopeIfPossible();
         return;
     }
 
@@ -360,8 +357,6 @@ void DOMTimer::fired()
         }
         nestedTimers->stopTracking();
     }
-
-    clearOpportunisticTaskDeferralScopeIfPossible();
 }
 
 void DOMTimer::didStop()
@@ -370,7 +365,6 @@ void DOMTimer::didStop()
     // because they can form circular references back to the ScriptExecutionContext
     // which will cause a memory leak.
     m_action = nullptr;
-    clearOpportunisticTaskDeferralScopeIfPossible();
 }
 
 void DOMTimer::updateTimerIntervalIfNecessary()
@@ -425,30 +419,6 @@ std::optional<MonotonicTime> DOMTimer::alignedFireTime(MonotonicTime fireTime) c
     return adjustedFireTime - (adjustedFireTime % alignmentInterval) + alignmentInterval + randomizedOffset;
 }
 
-void DOMTimer::makeOpportunisticTaskDeferralScopeIfPossible(ScriptExecutionContext& context)
-{
-    if (!m_oneShot || m_currentTimerInterval <= 1_ms) {
-        // FIXME: This should eventually account for repeating timers and one-shot timers that were
-        // previously scheduled, and are about to fire.
-        return;
-    }
-
-    RefPtr document = dynamicDowncast<Document>(context);
-    if (!document)
-        return;
-
-    auto* page = document->page();
-    if (!page)
-        return;
-
-    m_opportunisticTaskDeferralScope = page->opportunisticTaskScheduler().makeDeferralScope();
-}
-
-void DOMTimer::clearOpportunisticTaskDeferralScopeIfPossible()
-{
-    m_opportunisticTaskDeferralScope = nullptr;
-}
-
 const char* DOMTimer::activeDOMObjectName() const
 {
     return "DOMTimer";

Source/WebCore/page/DOMTimer.h

@@ -38,7 +38,6 @@ namespace WebCore {
 
 class DOMTimerFireState;
 class Document;
-class OpportunisticTaskDeferralScope;
 class ScheduledAction;
 
 class DOMTimer final : public RefCounted<DOMTimer>, public SuspendableTimerBase, public CanMakeWeakPtr<DOMTimer> {
@@ -70,9 +69,6 @@ class DOMTimer final : public RefCounted<DOMTimer>, public SuspendableTimerBase,
 
     WEBCORE_EXPORT Seconds intervalClampedToMinimum() const;
 
-    void makeOpportunisticTaskDeferralScopeIfPossible(ScriptExecutionContext&);
-    void clearOpportunisticTaskDeferralScopeIfPossible();
-
     bool isDOMTimersThrottlingEnabled(const Document&) const;
     void updateThrottlingStateIfNecessary(const DOMTimerFireState&);
 
@@ -98,7 +94,6 @@ class DOMTimer final : public RefCounted<DOMTimer>, public SuspendableTimerBase,
     bool m_oneShot;
     Seconds m_currentTimerInterval;
     RefPtr<UserGestureToken> m_userGestureTokenToForward;
-    std::unique_ptr<OpportunisticTaskDeferralScope> m_opportunisticTaskDeferralScope;
 };
 
 } // namespace WebCore

Source/WebCore/page/Page.h

@@ -141,6 +141,7 @@ class MediaPlaybackTarget;
 class MediaRecorderProvider;
 class MediaSessionCoordinatorPrivate;
 class ModelPlayerProvider;
+class OpportunisticTaskDeferralScope;
 class PageConfiguration;
 class PageConsoleClient;
 class PageDebuggable;