The autoplay setting was binary and its default blocked all media,
including muted video, leaving sites that rely on muted autoplay
visibly broken. Replace it with a tri-state user-agent autoplay
policy (allow audio and video, block audio, or block audio and video)
defaulting to allowing only inaudible media to autoplay.
This is enforced through the media element's "allowed to play" check,
so unmuting a muted autoplay or calling `play()` cannot slip audio
past the policy; audible playback is permitted once the document has
been activated by the user. The policy lives in a dedicated
AutoplaySettings consulted from HTMLMediaElement instead of the
Permissions Policy "allowed to use feature" check it was previously
conflated with.
Same-document navigations now commit synchronously in WebContent, while
the UI process mirror learns about them over asynchronous IPC. A stale
UI seed could be accepted back into a live non-initial document and
overwrite its latest entry, making queued traversals target unreachable
entries.
Share descriptor comparison helpers between LibWeb and LibWebView.
Reject stale top-level seeds against the active document latest entry,
and let the UI process adopt WebContent current snapshots when a seed is
rejected. Test-only session history dumps now first send WebContent
current state synchronously, so dumps observe the converged state.
Allow post-load UI seeds to carry UI-owned nested histories that the
freshly loaded top-level document has not reconstructed yet. Add unit
coverage for matching those seeds while still checking top-level state.
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.
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.
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.
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.
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.
This lays the groundwork to allow shared workers, nested workers (i.e.
workers owned by workers) and service workers to function independently
of WebContent.
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.
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.
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.
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.
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.
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.
Registering multiple Mach port names with the bootstrap server at
runtime is not how macOS expects it to be used — the bootstrap server
is meant for static services, and the only reason we used it originally
was so child processes could reach back to the UI process.
Remove bootstrap_transport_over_socket(), which had both sides register
dynamic names with the bootstrap server and exchange them over a socket.
Instead, WebDriver and BrowserProcess connections now go through
MachPortServer instances directly. When a non-child process contacts a
MachPortServer, the server creates a port pair on demand (detected via
sysctl ppid check) and returns the local half immediately. This keeps
bootstrap server usage limited to the one original case: child processes
looking up their parent's MachPortServer.
WebDriver Session now runs its own MachPortServer per session.
--webdriver-content-path becomes --webdriver-mach-server-name on macOS.
Spare WebContent launches are skipped when a WebDriver session is active
to avoid bootstrap races.
Add IPC::TransportHandle as an abstraction for passing IPC
transports through .ipc messages. This replaces IPC::File at
all sites where a transport (not a generic file) is being
transferred between processes.
TransportHandle provides from_transport(),
clone_from_transport(), and create_transport() methods that
encapsulate the fd-to-socket-to-transport conversion in one
place. This is preparatory work for Mach port support on
macOS -- when that lands, only TransportHandle's internals
need to change while all .ipc definitions and call sites
remain untouched.
The set_viewport_size and set_device_pixel_ratio IPC messages were sent
separately, potentially causing a race condition when the DPR changes
(e.g. moving a window between screens): the DPR message would arrive
and use a stale viewport size, computing a temporarily wrong CSS
viewport. Combine both into a single set_viewport IPC that updates the
device viewport size and DPR together.
This will allow the UI to request WebContent to properly close the top
level traversable when closing a tab. For example, this allows the site
to ask if the user is sure they want to leave, closes WebSocket
connections and more.
This patch introduces a cookie cache in the WebContent process to reduce
blocking IPC calls when JS accesses document.cookie. The UI process now
maintains a cookie version counter per-domain in shared memory. When JS
reads document.cookie, we check whether we have a valid cached cookie by
comparing the current shared version to the last used version. If they
match, the cached cookie is returned without IPC.
This optimization is based on Chromium's shared versioning, in which it
was observed that 87% of document.cookie accesses were redundant. See:
https://blog.chromium.org/2024/06/introducing-shared-memory-versioning-to.html
Note that this cache only supports document.cookie, not HTTP Cookie
headers. HTTP cookies are attached to requests with varying URLs and
paths. The cookies that match the document URL might not match the
request URL, which we wouldn't know from WebContent. So attaching the
cached document cookie would be incorrect.
On https://twinings.co.uk, we see approximately 600 document.cookie
requests while the page loads. This patch reduces the time spent in
the document.cookie getter from ~45ms to 2-3ms.
When cookies change or expire, we currently send a list of all changed
cookies to all WebContent processes. We then filter that list in the
WebContent process for cookies that match the page's URL before sending
out cookie change events to JS.
We now perform this filtering in the UI process, so each WebContent
process only receives the cookies it would be interested in, if any.
This serves two purposes:
1. Less IPC chatter.
2. This will let each ViewImplementation know that its cookie value has
actually changed.
(2) is for an upcoming change that will introduce a cookie cache, and
will allow each view to know it should bust that cache.
Note that for this filtering to work, we must iterate ViewImplementation
instances rather than WebContentClient in order to have the view's URL.
We must then associate the IPC with the view's page ID.
No changes to the /cookiestore WPT subtests.
To avoid unnecessary IPC traffic, we now only send network response
bodies when a DevTools client is connected.
This requires tracking DevTools connection state in ViewImplementation
so we can propagate it to new WebContent processes created during
cross-site navigation.
Previously, console messages were sent using an index-based system where
DevTools would be notified of new message indices and then request them
in batches. This created synchronization issues during page navigation
when the WebContent process resets while DevTools still has stale index
state.
This changes to a push-based model where console messages are sent
immediately as resources when they are logged, matching how Firefox
DevTools handles console messages. Each message is pushed through IPC
and forwarded to DevTools as a "console-message" or "error-message"
resource.
This eliminates the need for index tracking in FrameActor and simplifies
the entire console message pipeline from WebContent through to DevTools.
Global Privacy Control aims to be a replacement for Do Not Track. DNT
ended up not being a great solution, as it wasn't enforced by law. This
actually resulted in the DNT header serving as an extra fingerprinting
data point.
GPC is becoming enforced by law in USA states such as California and
Colorado. CA is further working on a bill which requires that browsers
implement such an opt-out preference signal (OOPS):
https://cppa.ca.gov/announcements/2025/20250911.html
This patch replaces DNT with GPC and hooks up the associated settings.
We currently have a single IPC to set clipboard data. We will also need
an IPC to retrieve that data from the UI. This defines system clipboard
data in LibWeb to handle this transfer, and adds the IPC to provide it.
Instead of wrapping all non-movable members of TransportSocket in OwnPtr
to keep it movable, make TransportSocket itself non-movable and wrap it
in OwnPtr.
This commit removes the unused m_heap member from ConnectionFromClient.
This also works around an issue where some cmake version doesn't apply
compiler options from within a subdirectory globally.
When we build internal pages (e.g. about:settings), there is currently
quite a lot of boilerplate needed to communicate between the browser and
the page. This includes creating IDL for the page and the IPC for every
message sent between the processes.
These internal pages are also special in that they have privileged
access to and control over the browser process.
The framework introduced here serves to ease the setup of new internal
pages and to reduce the access that WebContent processes have to the
browser process. WebUI pages can send requests to the browser process
via a `ladybird.sendMessage` API. Responses from the browser are passed
through a WebUIMessage event. So, for example, an internal page may:
ladybird.sendMessage("getDataFor", { id: 123 });
document.addEventListener("WebUIMessage", event => {
if (event.name === "gotData") {
console.assert(event.data.id === 123);
}
});
To handle these messages, we set up a new IPC connection between the
browser and WebContent processes. This connection is torn down when
the user navigates away from the internal page.
