Animation Pipeline: Main Thread to Compositor
Blink28625 Syys 2025

Animation Pipeline: Main Thread to Compositor

The sources provide an extensive architectural overview of the Chromium animation pipeline, detailing the complex process required to accelerate animations by moving them off the main thread onto the compositor thread (cc). The explanation outlines the flow, starting when an animation is initiated in the Blink renderer via classes like Animation and KeyframeEffect, especially if the animation targets compositor-capable properties like transform or opacity. This main thread state is prepared for transfer during the PreCommit phase, where the main thread's AnimationHost creates corresponding compositor objects. The sources then explain the Commit process, where the CommitState structure facilitates the safe synchronization of this animation data to the compositor thread's AnimationHost and ElementAnimations object. Finally, the text describes how animations run on the compositor, ticking every frame and applying values directly to the property trees before sending synchronization events back to Blink regarding start and completion times.

Jaksot(392)

blink::NGPhysicalFragment and friends

blink::NGPhysicalFragment and friends

Layout takes the styled DOM and produces a fragment tree of positioned boxes. In modern Blink this is LayoutNG; the core artifact is NGPhysicalFragment, which stores geometry and is used downstream fo...

10 Loka 202537min

blink::StyleEngine

blink::StyleEngine

style invalidation & resolution (recalc). 
Given DOM/style changes since the last frame, StyleEngine computes updated ComputedStyles, manages active stylesheets/media query state, and marks the right ...

10 Loka 202534min

blink::Document & blink::DocumentLifecycle

blink::Document & blink::DocumentLifecycle

states that gate phases. The document owns the DOM and keeps a DocumentLifecycle state machine that ensures we do things in phase order (style before layout, pre‑paint before paint, etc.). Lifecycle t...

10 Loka 202535min

blink::LocalFrameView

blink::LocalFrameView

orchestrates style → layout → pre‑paint/paint for a frame. This is the workhorse that actually runs lifecycle phases. On a frame tick from WebFrameWidgetImpl, it goes through style recalc, layout (Lay...

9 Loka 202544min

blink::LocalFrame

blink::LocalFrame

the document host and local‑root boundary.
The local frame owns the Document and its LocalFrameView. The local root frame coordinates lifecycle for its subtree (including OOPIF boundaries handled late...

9 Loka 202532min

blink::Page

blink::Page

the page container and animation clock keeper. Page holds frame trees and the PageAnimator that services script‑driven animations on each tick. It’s the top‑level context for the document/view that We...

9 Loka 202534min

blink::WebFrameWidgetImpl

blink::WebFrameWidgetImpl

renderer‑main entry to Blink’s lifecycle. This is where a compositor BeginFrame (coming in via content/public and mojo plumbing) first turns into Blink work on the renderer main thread. It receives th...

9 Loka 202532min

Blink's ComputedStyle: An In-Depth Analysis

Blink's ComputedStyle: An In-Depth Analysis

The collection of sources provides a detailed technical analysis of the ComputedStyle object within Blink, the rendering engine for Chromium. The primary source, an in-depth analysis document, explain...

9 Loka 202545min