Implements https://github.com/whatwg/html/pull/10007 which basically
moves style, layout and painting from HTML processing task into HTML
task with "rendering" source.
The biggest difference is that now we no longer schedule HTML event loop
processing whenever we might need a repaint, but instead queue a global
rendering task 60 times per second that will check if any documents
need a style/layout/paint update.
That is a great simplification of our repaint scheduling model. Before
we had:
- Optional timer that schedules animation updates 60 hz
- Optional timer that schedules rAF updates
- PaintWhenReady state to schedule a paint if navigable doesn't have a
rendering opportunity on the last event loop iteration
Now all that is gone and replaced with a single timer that drives
repainting at 60 hz and we don't have to worry about excessive repaints.
In the future, hard-coded 60 hz refresh interval could be replaced with
CADisplayLink on macOS and similar API on linux to drive repainting in
synchronization with display's refresh rate.
This also fixes a bug where task IDs were being deallocated from the
wrong IDAllocator. I don't know if it was actually possible to cause any
real trouble with that mistake, nor do I know how to write a test for
it, but this makes the bug go away.
EventSource allows opening a persistent HTTP connection to a server over
which events are continuously streamed.
Unfortunately, our test infrastructure does not allow for automating any
tests of this feature yet. It only works with HTTP connections.
...and use HeapFunction instead of SafeFunction for task steps.
Since there is only one EventLoop per process, it lives as a global
handle in the VM custom data.
This makes it much easier to reason about lifetimes of tasks, task
steps, and random stuff captured by them.
The main missing features are rootMargin, proper nested browsing
context support and content clip/clip-path support.
This makes images appear on some sites, such as YouTube and
howstuffworks.com.
In the merging of an extremely large navigables PR, a task queue source
was added after the unique task source start value that was supposed to
remain last in the enum.
Some elements, like HTMLMediaElement, must have a unique task sources
for every instance of that element that is created. Support this with a
simple wrapper around IDAllocator.
This is a monster patch that turns all EventTargets into GC-allocated
PlatformObjects. Their C++ wrapper classes are removed, and the LibJS
garbage collector is now responsible for their lifetimes.
There's a fair amount of hacks and band-aids in this patch, and we'll
have a lot of cleanup to do after this.
This overrides the JS host hooks to follow the spec for queuing
promises, making/calling job callbacks, unhandled promise rejection
handling and FinalizationRegistry queuing.
This also allows us to drop the on_call_stack_emptied hook in
Document::interpreter().
We now invoke DOM timer callbacks via HTML tasks. This brings callback
sequencing closer to the spec, although there are still many
imperfections in this area.
This patch attaches a HTML::EventLoop to the main thread JS::VM used
for JavaScript bindings in the web engine.
The goal here is to model the various task scheduling mechanisms of the
HTML specification.
