Use the LibWebView history mirror to preserve traversable session
history across WebContent process swaps. WebContent reports snapshots to
the UI process, and new renderers can be seeded from the mirror.
Browser back and forward now resolve through the UI-owned used history
steps. WebContent still runs the spec traversal path when the current
renderer has enough matching state to do so.
Handle canceled and no-op UI navigations without leaving speculative
history entries or pending WebDriver waits behind. Preserve traversal
precheck state across synchronous IPC shutdown, and avoid overwriting a
restored target entry's persisted scroll state before the document has
adopted that entry.
Add Internals.deleteAllCookies(), backed by an async WebContent to
browser request and ack pair. CookieJar can now clear transient and
persisted cookies. Note that we only delete all cookies associated
with the current URL so that tests are able to run in parallel with
one another without impacting shared cookie state.
Firefox sends the same storage actor mutation requests for Web Storage
that it uses for cookies. Handle addItem, editItem, removeItem, and
removeAll for localStorage and sessionStorage actors.
Apply the changes through the browser-process storage jar and emit the
matching store update packets so the Storage panel stays current after a
DevTools-initiated edit.
Firefox exposes localStorage and sessionStorage through the same
storage actor protocol used by cookies. Add matching resources for the
current tab so the Storage panel can list key/value pairs.
Read the values through WebContent rather than directly from the
browser process. Session storage lives in LibWeb, and using the same
path for both stores keeps the actor independent of the backing store.
Move PropertyNameAndID, custom property data, registered custom
properties, and Typed OM associated property names to Utf16FlyString.
This removes the FlyString storage boundary from CSS property-name
handling and lets CSSStyleProperties keep the name it receives from
CSSOM instead of converting it back to UTF-8.
Collect the style rules that apply to an inspected element and expose
them through the existing DOM node inspection path. This gives Firefox's
Rules panel real rule forms instead of the previous empty getApplied
response.
Extend the existing DOM node inspection request with an options payload
and carry it through the browser process, WebView, IPC, and WebContent.
This lets later DevTools requests forward Firefox's top-level flags
without changing any inspected-node behavior yet.
Use Core::Process::terminate_immediately() when the UI process goes
away or a sync IPC request fails because the client disconnected. This
avoids running exit-time destructors during WebContent shutdown.
Enable -Wexit-time-destructors for the WebContent executable and
service target, then convert the existing warning sites to permanent
process lifetime storage.
Grid and flex inspector payloads are only consumed by DevTools, but
layout currently builds them for every page. Gate that collection on an
active DevTools client so ordinary browsing avoids the extra CPU work
and retained memory.
DevTools may connect after the page has already completed layout, so
force one catch-up layout pass when the first DevTools client attaches.
After that, normal relayouts keep the data fresh until DevTools
disconnects. Inspection requests only flush dirty layout instead of
forcing repeated collection passes.
When DevTools detaches, clear the stored inspection data and overlays.
Firefox can still send highlight requests for node fronts that are
being replaced during navigation. Those node IDs can refer to a
disconnected or inactive document. Active documents may also have dirty
layout by the time the request arrives.
Ignore stale nodes and update layout before reading the layout node.
This keeps late highlight requests from tripping layout freshness
assertions.
Page IDs were allocated independently by each WebContent PageHost,
starting at zero for every process. That made them unsuitable as a
global identity for page-presenting compositor contexts, because the
same numeric page ID could exist in multiple WebContent processes.
Move page ID allocation to WebView::Application and initialize each
WebContent process with its browser-assigned first page ID over IPC.
New view requests now get a browser-assigned page ID before
WebContent creates the PageClient, and PageHost no longer owns a
local page counter.
This gives page-presenting compositor contexts a stable global page
identity, which will allow their context IDs to be derived from page
IDs and simplify compositor context allocation in a follow-up.
Add a debug-menu toggle for caret hit testing at the mouse position.
Paint the insertion rect and log the result so selection bugs can be
inspected without temporary probes.
Request frames and repaint invalidation when the overlay state changes.
Also repaint when the caret rect moves within the same text node.
Picking needs hit testing in the page process, where layout and event
targeting state live. Expose a small page-level query and WebContent IPC
entry point that returns the node id at a viewport position.
This lets DevTools ask WebContent what the picker is pointing at without
duplicating hit-test logic outside LibWeb.
Firefox's grid inspector builds its subgrid tree from two protocol
signals: isSubgrid on each GridActor form, and
Walker.getParentGridNode() for each subgrid container. Teach the walker
to answer the parent grid lookup so Firefox can attach subgrids below
their parent grid in the Layout panel.
Add IPC structures and requests for inspecting grid layout data from
WebContent.
WebView forwards the async replies to LibDevTools and exposes the grid
highlighter hooks used by the protocol layer.
Parse Firefox grid highlighter options in WebContent and store them with
the active grid highlight.
Snapshot DevTools DOM mutation payloads immediately, but defer subtree
serialization until the target document's layout is up to date.
This avoids re-entering layout-backed DOM serialization from style and
layout updates, which could crash WebContent while DevTools was
listening for mutations.
This lays the groundwork to allow shared workers, nested workers (i.e.
workers owned by workers) and service workers to function independently
of WebContent.
Track whether WebContent still needs a beforeunload check and let the
frontends immediately remove a tab or window when no prompt can be
shown. WebContent still receives the close request so pagehide, unload,
and cleanup steps can run.
When the visible view is removed immediately, keep detached ownership of
the WebContent page until it reports that the top-level traversable
closed. If no acknowledgement arrives, release detached ownership and
ask ProcessManager to shut down the unused WebContent process.
Input events can arrive after a page has been removed during browser
teardown. Those events used to be queued anyway, but no page could
request a frame to drain the queue and send the matching input-event
completion response back to LibWebView.
Drop input events whose target page no longer exists and immediately
notify the client with EventResult::Dropped. The mouse-event coalescing
path now uses the page lookup performed before enqueueing, avoiding the
diagnostic for missing pages while keeping valid events on the normal
queue path.
Remove the command-line option that allowed Browser to start
WebContent with the in-process compositor thread instead of the
Compositor helper process. The compositor process is now the default
path, so the opt-out flag and the matching WebContent selector only kept
the old thread mode reachable.
With that option gone, simplify Browser and WebContent startup to wire
each WebContent process to the Compositor process directly. The old
local Browser-to-WebContent compositor IPC setup and its fallback input
and ready-to-paint branches are no longer needed.
Replace the local substring matcher with the adblock-rust engine exposed
through the dedicated content blocker Rust FFI. Keep the previous engine
when a replacement list cannot be parsed.
Pass shared list buffers directly into Rust instead of building a
duplicate C++ vector of lines first. Generate cosmetic CSS through the
Rust matcher, including generic class and id selectors collected from
shadow-including descendants.
Keep a supplemental index for generic cosmetic selector-list rules.
adblock-rust indexes these rules under the first class or id token only,
so also key them by later simple class and id selectors in the list.
Update ContentBlocker coverage for rule options, exceptions, third-party
checks, blob and file URLs, invalid list replacement, filtering toggles,
cosmetic CSS, and generic selector-list cosmetics.
The browser previously treated the out-of-process Compositor as fatal.
Restart the shared Compositor from the browser process, reconnect
process-backed WebContent clients, recreate compositor contexts, restore
viewport state, and ask WebContent to repaint and republish canvas and
media resources. WebContent now marks its compositor connection lost,
returns conservative values for synchronous compositor queries while
reconnecting, and drops outgoing updates until the replacement transport
arrives.
Synchronous input queries through the compositor control connection now
use fallible IPC. If the Compositor exits after the open check or before
the sync reply arrives, scroll and mouse handling report that the
Compositor did not handle the event and let the normal WebContent
fallback run.
Mouse events queued while the Compositor is unavailable now fall back to
direct WebContent dispatch. This keeps input completion in step with the
pending-event queue.
Recovery is capped at three automatic restarts. If the restart limit is
exceeded, if restart, reconnect, or context recreation fails, or if the
replacement Compositor exits during active recovery, the browser crashes
instead of switching process-backed views to a fallback path.
We are moving toward an architecture where the browser owns a single
process that holds the GPU context, so Skia resources can be shared
across every renderer and WebContent processes can be sandboxed away
from direct GPU access. A dedicated Compositor helper process is the
first step. The earlier commits laid the foundation; this one turns the
helper on as a selectable backend, gated behind
--enable-compositor-process so the existing in-process path stays the
shipping default.
Default topology -- one compositor per WebContent, in-process:
+---------+
| Browser |
+---------+
/ | \
v v v
+---+ +---+ +---+ each WebContent runs its own
|WC | |WC | |WC | CompositorThread on a dedicated
|+C+| |+C+| |+C+| thread, with its own GPU context.
+---+ +---+ +---+
Opt-in topology -- one single-threaded Compositor, shared by all WCs:
+---------+ control +-------------------+
| Browser |<----------->| Compositor |
+---------+ | (single thread, |
/ | \ | single GPU ctx, |
v v v data | shared by all |
[WC] [WC] [WC] ---------->| connected WCs) |
+-------------------+
Three IPC channels carry the work in the opt-in topology. The
existing Browser<->WebContent channel gains context allocation.
A new Browser<->Compositor channel carries context lifetime,
viewport, UI input, and presentation acks plus backing-store and
frame upcalls. A new WebContent<->Compositor channel carries
display lists, scroll state, video, compositor surfaces, async
scrolling, presentation, and screenshots, with upcalls for
delegated input and compositor loss.
The compositor is moving into a dedicated helper process. That requires
a process to launch, channels for Browser and WebContent to talk to it
over, and client proxies on each side. Land all of that as an inert
scaffold first, gated behind --enable-compositor-process, so the default
rendering path is unchanged and later commits can fill in the protocol,
the service-side state, and the runtime switch against a stable target.
Add a repeatable blocker-list option that reads local list files in the
browser process. The files are concatenated into one buffer and shared
with WebContent through the content blocker IPC path when view options
are applied.
Parse the buffer in WebContent and reject malformed UTF-8 without
replacing the currently installed rules.
Split cosmetic blocker rules out from network patterns. Expose matching
rules as user CSS through StyleScope.
Invalidate affected user style caches when blocker state changes.
Generated cosmetic CSS now respects disabled content blocking.
Rename the local content blocking implementation and its tests from
ContentFilter to ContentBlocker while keeping the existing substring
matcher backend and behavior.
Update the WebContent IPC method, WebView option names, debug toggle,
and default config file name to use content blocker terminology.
Most of this functionality was already implicitly disallowed for
element-reference pseudo-elements by the fact that we weren't creating
entries in `m_pseudo_element_data` for them, but we need to explicitly
limit it in preparation of creating those entries.
Due to the above this is mostly non-functional apart from a regression
where we no longer support custom properties on element-reference
pseudo-elements. Previously when setting custom properties for an
element-reference pseudo-element we would call `ensure_pseudo_element()`
which created a synthetic pseudo-element entry distinct from the
referenced element which only stored custom property data - this was
clearly wrong and will be implemented properly in a future commit.
LibWeb still exposed the concrete CompositorThread to Page,
Navigable, and EventHandler, so compositor IPC would have leaked the
thread implementation into callers. The old thread APIs also bundled
page presentation callbacks and main-thread wakeups into the same
object, which made it awkward for WebContent to put an actor boundary
in between.
Introduce CompositorHost and context handles as the caller-facing API,
and move shared compositor protocol values out of CompositorThread. Add
WebContentCompositor IPC endpoints and route PageHost through a paired
in-process transport. The actor owns CompositorThread with explicit
main-thread and UI presentation clients, while screenshot completion is
serialized on the WebContent event loop using request IDs.
The intention for introducing IPC here is to prepare for moving the
compositor thread into a separate process.
Load the browser-generated crash page as a synthetic response for the
URL that was active when WebContent exited. This keeps the session
history entry, response URL, and created Document aligned with the same
navigation URL, so reload targets the original page without creating a
local document for an HTTP(S) history entry.
Suppress history metadata updates from the generated page and declare
an inert rel=icon. Fallback favicon loading now follows the HTML
condition that no link with the icon keyword exists, which avoids the
credentialed /favicon.ico request from the crashed origin.
Route mouse events over the compositor IPC path while async scrolling is
enabled, and let the compositor capture viewport scrollbar drags before
the main-thread event path sees them. Dragging mutates the compositor
scroll tree and schedules an async-scroll present, so the viewport thumb
and content can move without a main-thread round trip.
Keep normal main-thread event handling for misses and preserve the wheel
bypass behavior for page events.
The synchronous wheel path treats wheel deltas as CSS-pixel scroll
distances, while the async compositor scroll tree mutates scroll state
stored in device pixels. Passing the same unscaled delta into the
compositor made async scrolling advance too little whenever
device pixels per CSSPixel was greater than 1, so scrolling felt slower
than with async scrolling disabled.
Convert wheel deltas before crossing the compositor boundary and make
the compositor IPC carry only the device-pixel position and delta it
needs. This keeps AsyncScrollTree device-pixel native and makes async
viewport scrolling match the synchronous path across high-DPI displays
and page zoom levels.
Exit WebContent immediately when either browser-side IPC peer
disconnects. Plumb Unix process exit status through LibWebView so the
browser process can tell clean owner-driven shutdown apart from renderer
crashes.
This keeps nonzero exits and signal deaths reported as crashes, while
letting status 0 exits disappear without making test-web report the page
as crashed.
Trace the compositor state transitions that matter once presentation and
async scrolling share one path: page registration, backing-store swaps,
did_paint delivery, ready_to_paint acknowledgements, wheel admission,
and deferred presents waiting for reusable bitmaps.
Keep the logs under COMPOSITOR_DEBUG and use the [Compositor] prefix
consistently. The trace is about ownership and backpressure instead of
dumping every wheel event detail, so stalls can be diagnosed without
reintroducing noisy async-scrolling-only logging.
Send the experimental UI-process wheel bypass to WebContent over the
Compositor IPC connection instead of adding a separate async scrolling
transport. This keeps bypass admission on the channel that owns bitmaps
and ready_to_paint acknowledgements.
If the compositor rejects the wheel, LibWebView falls back to regular
input delivery. If it accepts, mark the queued DOM event as having
already performed its default action so dispatch preserves ordering
without scrolling twice.
Introduce a dedicated Compositor IPC channel between the UI process and
WebContent. Use it for backing-store setup, presented bitmap delivery,
and bitmap-specific ready_to_paint acknowledgements.
This makes CompositorThread the single owner of frame presentation
bookkeeping before async scrolling starts producing frames without the
main thread.
Remove old paint and backing-store messages from WebContentClient and
PageClient so the UI process no longer observes two presentation
protocols.
The Paintable tree and its supplemental painting data structures were
GC allocated because that was the easiest way to manage it and avoid
leaks introduced by ref cycles. This included the Paintable subclasses
themselves plus StackingContext, ChromeWidget, Scrollbar, ResizeHandle,
and scroll-frame state.
We are now trying to reduce GC allocation churn on layout and painting
updates, so keeping this short-lived rendering tree outside the JS heap
is a better fit. Move Paintable to RefCountedTreeNode, make painting
helpers ref-counted or weakly reference Paintables, and update the
layout and event-handler call sites to use RefPtr/WeakPtr ownership.
Previously a fixed-rate paint refresh timer kept queueing rendering
update tasks at the maximum configured frame rate, regardless of whether
anything had actually changed. This wasted CPU on idle pages, which
spend most of their time in a steady state where no style, layout, or
paint work is needed.
Replace the repeating timer with a single-shot frame timer driven by
PageClient::request_frame(). A rendering update is now scheduled only
when something requires one. The configured maximum frame rate is
preserved as a ceiling on how closely consecutive frames can follow each
other.
Previously, `AnonymousBuffer::create_with_size(0)` returned an error
because POSIX `mmap` rejects a zero length with `EINVAL`, and Windows
`CreateFileMapping` rejects a zero maximum size for an anonymous
mapping. This caused a crash when using `--headless=text` with zero
size pages like `about:blank`.
Route BroadcastChannel messages over IPC so matching channels can
receive them across WebContent and WebWorker processes, rather than only
within a single process.
Each channel now serializes its payload, sends it upward over IPC, and
receiving processes deliver it locally after matching by storage key and
channel name.
