Changeset 185012 in webkit

Timestamp:

May 29, 2015 4:02:36 PM (9 years ago)

Author:

Chris Dumez

Message:

Consider throttling DOM timers in iframes outside the viewport
​https://bugs.webkit.org/show_bug.cgi?id=145465
<rdar://problem/20768957>

Reviewed by Darin Adler.

Source/WebCore:

Throttle DOM timers in iframes that are outside the viewport to decrease
CPU usage, improve performance and reduce power use.

The approach is similar to what we already did for requestAnimationFrame
in r183998.

We already has support for throttling DOM timers at:

• Page level: for backgound pages
• DOM timer level: for timers changing the style of an element outside the viewport or drawing on a canvas outside the viewport.

This patch adds support for throttling DOM timers at Document level so
we can throttle all timers inside a specific iframe / Document. It relies
on the same timerAlignmentInterval that is used for throttling at Page
level with tweaks so that different Documents inside the same Page can
have a different timerAlignmentInterval.

Test: fast/dom/timer-throttling-subframe.html

• dom/Document.cpp:

(WebCore::Document::setTimerThrottlingEnabled):
(WebCore::Document::timerAlignmentInterval):

• dom/Document.h:

(WebCore::Document::isTimerThrottlingEnabled):

• page/DOMTimer.cpp:

(WebCore::DOMTimer::alignedFireTime):
The previous code was not throttling the timer if its fireTime was in
the past. This was causing some aggressive timers on mashable.com to
not be throttled so I got rid of this behavior. I don't see any reason
why we would not throttle a timer simply because it is supposed to have
fired already.

• page/FrameView.cpp:

(WebCore::FrameView::viewportContentsChanged):
(WebCore::FrameView::updateScriptedAnimationsAndTimersThrottlingState):

• page/FrameView.h:

• testing/Internals.cpp:

(WebCore::Internals::areTimersThrottled):

• testing/Internals.h:
• testing/Internals.idl:

Add API to facilitate layout testing of this functionality.

LayoutTests:

Add a layout test to check that DOM timers in iframes outside the
viewport get throttled.

• fast/dom/resources/timer-frame-2.html: Added.
• fast/dom/resources/timer-frame.html: Added.
• fast/dom/timer-throttling-subframe-expected.txt: Added.
• fast/dom/timer-throttling-subframe.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/dom/resources/timer-frame-2.html (added)
• LayoutTests/fast/dom/resources/timer-frame.html (added)
• LayoutTests/fast/dom/timer-throttling-subframe-expected.txt (added)
• LayoutTests/fast/dom/timer-throttling-subframe.html (added)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/dom/Document.cpp (modified) (1 diff)
• Source/WebCore/dom/Document.h (modified) (2 diffs)
• Source/WebCore/page/DOMTimer.cpp (modified) (1 diff)
• Source/WebCore/page/FrameView.cpp (modified) (4 diffs)
• Source/WebCore/page/FrameView.h (modified) (1 diff)
• Source/WebCore/testing/Internals.cpp (modified) (1 diff)
• Source/WebCore/testing/Internals.h (modified) (1 diff)
• Source/WebCore/testing/Internals.idl (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2015-05-29  Chris Dumez  <cdumez@apple.com>
+
+        Consider throttling DOM timers in iframes outside the viewport
+        https://bugs.webkit.org/show_bug.cgi?id=145465
+        <rdar://problem/20768957>
+
+        Reviewed by Darin Adler.
+
+        Add a layout test to check that DOM timers in iframes outside the
+        viewport get throttled.
+
+        * fast/dom/resources/timer-frame-2.html: Added.
+        * fast/dom/resources/timer-frame.html: Added.
+        * fast/dom/timer-throttling-subframe-expected.txt: Added.
+        * fast/dom/timer-throttling-subframe.html: Added.
+
 2015-05-28  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-05-29  Chris Dumez  <cdumez@apple.com>
+
+        Consider throttling DOM timers in iframes outside the viewport
+        https://bugs.webkit.org/show_bug.cgi?id=145465
+        <rdar://problem/20768957>
+
+        Reviewed by Darin Adler.
+
+        Throttle DOM timers in iframes that are outside the viewport to decrease
+        CPU usage, improve performance and reduce power use.
+
+        The approach is similar to what we already did for requestAnimationFrame
+        in r183998.
+
+        We already has support for throttling DOM timers at:
+        - Page level: for backgound pages
+        - DOM timer level: for timers changing the style of an element outside
+          the viewport or drawing on a canvas outside the viewport.
+
+        This patch adds support for throttling DOM timers at Document level so
+        we can throttle all timers inside a specific iframe / Document. It relies
+        on the same timerAlignmentInterval that is used for throttling at Page
+        level with tweaks so that different Documents inside the same Page can
+        have a different timerAlignmentInterval.
+
+        Test: fast/dom/timer-throttling-subframe.html
+
+        * dom/Document.cpp:
+        (WebCore::Document::setTimerThrottlingEnabled):
+        (WebCore::Document::timerAlignmentInterval):
+        * dom/Document.h:
+        (WebCore::Document::isTimerThrottlingEnabled):
+        * page/DOMTimer.cpp:
+        (WebCore::DOMTimer::alignedFireTime):
+        The previous code was not throttling the timer if its fireTime was in
+        the past. This was causing some aggressive timers on mashable.com to
+        not be throttled so I got rid of this behavior. I don't see any reason
+        why we would not throttle a timer simply because it is supposed to have
+        fired already.
+
+        * page/FrameView.cpp:
+        (WebCore::FrameView::viewportContentsChanged):
+        (WebCore::FrameView::updateScriptedAnimationsAndTimersThrottlingState):
+        * page/FrameView.h:
+
+        * testing/Internals.cpp:
+        (WebCore::Internals::areTimersThrottled):
+        * testing/Internals.h:
+        * testing/Internals.idl:
+        Add API to facilitate layout testing of this functionality.
+
 2015-05-29  Brady Eidson  <beidson@apple.com>
 

trunk/Source/WebCore/dom/Document.cpp

@@ -2751 +2751 @@
 }
 
+void Document::setTimerThrottlingEnabled(bool shouldThrottle)
+{
+    if (m_isTimerThrottlingEnabled == shouldThrottle)
+        return;
+
+    double previousInterval = timerAlignmentInterval();
+
+    m_isTimerThrottlingEnabled = shouldThrottle;
+
+    if (previousInterval != timerAlignmentInterval())
+        didChangeTimerAlignmentInterval();
+}
+
 double Document::timerAlignmentInterval() const
 {
+    if (m_isTimerThrottlingEnabled)
+        return DOMTimer::hiddenPageAlignmentInterval();
+
     Page* page = this->page();
     if (!page)

trunk/Source/WebCore/dom/Document.h

@@ -432 +432 @@
     bool hidden() const;
 
+    void setTimerThrottlingEnabled(bool);
+    bool isTimerThrottlingEnabled() const { return m_isTimerThrottlingEnabled; }
+
 #if ENABLE(CSP_NEXT)
     DOMSecurityPolicy& securityPolicy();
@@ -1689 +1692 @@
 
     bool m_hasStyleWithViewportUnits;
+    bool m_isTimerThrottlingEnabled { false };
 
     HashSet<MediaProducer*> m_audioProducers;

trunk/Source/WebCore/page/DOMTimer.cpp

@@ -508 +508 @@
 double DOMTimer::alignedFireTime(double fireTime) const
 {
-    double alignmentInterval = scriptExecutionContext()->timerAlignmentInterval();
-    if (alignmentInterval) {
-        double currentTime = monotonicallyIncreasingTime();
-        if (fireTime <= currentTime)
-            return fireTime;
-
-        double alignedTime = ceil(fireTime / alignmentInterval) * alignmentInterval;
-        return alignedTime;
-    }
+    if (double alignmentInterval = scriptExecutionContext()->timerAlignmentInterval())
+        return ceil(fireTime / alignmentInterval) * alignmentInterval;
 
     return fireTime;

trunk/Source/WebCore/page/FrameView.cpp

@@ -1808 +1808 @@
         frameView.resumeVisibleImageAnimations(visibleRect);
         frameView.updateThrottledDOMTimersState(visibleRect);
-        frameView.updateScriptedAnimationsThrottlingState(visibleRect);
+        frameView.updateScriptedAnimationsAndTimersThrottlingState(visibleRect);
     });
 }
@@ -2169 +2169 @@
 }
 
-void FrameView::updateScriptedAnimationsThrottlingState(const IntRect& visibleRect)
-{
-#if ENABLE(REQUEST_ANIMATION_FRAME)
+void FrameView::updateScriptedAnimationsAndTimersThrottlingState(const IntRect& visibleRect)
+{
     if (frame().isMainFrame())
         return;
@@ -2177 +2176 @@
     auto* document = frame().document();
     if (!document)
-        return;
-
-    auto* scriptedAnimationController = document->scriptedAnimationController();
-    if (!scriptedAnimationController)
         return;
 
@@ -2186 +2181 @@
     // they have a non-null ownerRenderer.
     bool shouldThrottle = !frame().ownerRenderer() || visibleRect.isEmpty();
-    scriptedAnimationController->setThrottled(shouldThrottle);
-#else
-    UNUSED_PARAM(visibleRect);
+
+#if ENABLE(REQUEST_ANIMATION_FRAME)
+    if (auto* scriptedAnimationController = document->scriptedAnimationController())
+        scriptedAnimationController->setThrottled(shouldThrottle);
 #endif
+
+    document->setTimerThrottlingEnabled(shouldThrottle);
 }
 

trunk/Source/WebCore/page/FrameView.h

@@ -607 +607 @@
     void updateThrottledDOMTimersState(const IntRect& visibleRect);
     void resumeVisibleImageAnimations(const IntRect& visibleRect);
-    void updateScriptedAnimationsThrottlingState(const IntRect& visibleRect);
+    void updateScriptedAnimationsAndTimersThrottlingState(const IntRect& visibleRect);
 
     void updateLayerFlushThrottling();

trunk/Source/WebCore/testing/Internals.cpp

@@ -800 +800 @@
 }
 
+bool Internals::areTimersThrottled() const
+{
+    return contextDocument()->isTimerThrottlingEnabled();
+}
+
 String Internals::visiblePlaceholder(Element* element)
 {

trunk/Source/WebCore/testing/Internals.h

@@ -117 +117 @@
     bool isTimerThrottled(int timeoutId, ExceptionCode&);
     bool isRequestAnimationFrameThrottled() const;
+    bool areTimersThrottled() const;
 
     // Spatial Navigation testing.

trunk/Source/WebCore/testing/Internals.idl

@@ -286 +286 @@
 
     boolean isRequestAnimationFrameThrottled();
+    boolean areTimersThrottled();
 
     [RaisesException] void startTrackingStyleRecalcs();