B6: RenderProcessHost: Lifecycle and Architecture Management
Blink28628 Marras 2025

B6: RenderProcessHost: Lifecycle and Architecture Management

The provided documents outline the essential functions of the RenderProcessHost (RPH), a crucial component within Chromium's multi-process architecture that resides in the browser process to manage a single associated renderer process. This host object serves as the browser-side anchor for all interactions, primarily by establishing and facilitating Inter-Process Communication (IPC) channels for message transfer and handling. The RPH is responsible for the complete process lifecycle management, overseeing the launch, graceful shutdown, or abrupt termination of the renderer, while also managing crash detection. Furthermore, it enforces critical security and sandboxing policies by filtering sensitive actions like unauthorized URL requests and maintaining site isolation locks to protect the browser. Sophisticated mechanisms for resource management allow the RPH to control process priority, backgrounding processes when hidden, and manage ref counts to keep active workers running. It also tracks the mapping of internal frames and views, ensuring that incoming IPC messages are correctly routed to the appropriate target within the browser process.

Jaksot(417)

cc::PropertyTrees

cc::PropertyTrees

(TransformTree / ClipTree / EffectTree / ScrollTree) with nodes cc::TransformNode / ClipNode / EffectNode / ScrollNode — The impl‑side property‑tree state that positions, clips, blends, and scrolls co...

22 Syys 202534min

cc::LayerTreeHostImpl

cc::LayerTreeHostImpl

The compositor‑thread twin that owns the active/pending trees, runs impl‑side animations/scroll, and prepares draw. Implements cc::InputHandler for threaded scrolling/pinch.

22 Syys 202546min

main —> impl cc::LayerTreeHost

main —> impl cc::LayerTreeHost

Packages updated layers/property trees; kicks a commit to the compositor thread (via the proxy).

22 Syys 202536min

blink::PropertyTreeManager

blink::PropertyTreeManager

Bridges Blink’s paint property trees into cc property trees: creates/updates cc TransformNode, ClipNode, EffectNode, and ScrollNode (including inner/outer viewport scroll nodes).

22 Syys 202539min

blink::PaintArtifactCompositor

blink::PaintArtifactCompositor

Decides what needs to be composited and prepares the main‑thread representation to feed cc (layers if needed, scrollbar compositing, etc.).

22 Syys 202542min

blink::PaintArtifact

blink::PaintArtifact

The immutable package of paint chunks + display items for this frame, used to drive compositing without re‑painting.

21 Syys 202536min

blink::TransformPaintPropertyNode / ClipPaintPropertyNode / EffectPaintPropertyNode / ScrollPaintPropertyNode

blink::TransformPaintPropertyNode / ClipPaintPropertyNode / EffectPaintPropertyNode / ScrollPaintPropertyNode

The paint property trees captured during painting (transform, clip, effect/opacity, scroll offset) that define visual & coordinate‑space state.

21 Syys 202541min

blink::PaintController

blink::PaintController

Records drawing into a DisplayItemList, segmenting it into PaintChunks keyed by property‑tree state. (Output: a PaintArtifact.)

21 Syys 202533min