Simply how `ProgressiveWebMetrics` works:
1. Keep only a single struct instead of one in layout and one script
that both implement the `ProgressiveWebMetrics` trait. Since layout
and script are the same thread these can now just be a single
`ProgressiveWebMetrics` struct stored in script.
2. Have the compositor be responsible for informing the Constellation
(which informs the ScripThread) about paint metrics. This makes
communication flow one way and removes one dependency between the
compositor and script (of two).
3. All units tests are moved into the `metrics` crate itself since there
is only one struct there now.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
This is one of the first big steps toward making the compositor work
per-WebView. It moves the collection of pipelines into the per-WebView
data structure in the compositor as well as the pending paint metrics.
This means that more messages need to carry information about the
WebView they apply to. Note that there are still a few places that we
need to map from `PipelineId` to `WebViewId`, so this also includes a
shared mapping which tracks this. The mapping can be removed once event
handling is fully per-WebView.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Delan Azabani <dazabani@igalia.com>
* Use 2024 style edition
Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>
* Reformat all code
Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>
---------
Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>
At some point in the past this message was only sent from the
`Constellation` to `script`, but nowadays this is sent from various
parts of servo to the `ScriptThread`, so this is a better name. In
particular, the current name makes it seeem like this message controls
the `Constellation`, which it does not.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Up until now, Servo was using a very old version of time to get a
cross-process monotonic timestamp (using `time::precise_time_ns()`).
This change replaces the usage of old time with a new serializable
monotonic time called `CrossProcessInstant` and uses it where `u64`
timestamps were stored before. The standard library doesn't provide this
functionality because it isn't something you can do reliably on all
platforms. The idea is that we do our best and then fall back
gracefully.
This is a big change, because Servo was using `u64` timestamps all over
the place some as raw values taken from `time::precise_time_ns()` and
some as relative offsets from the "navigation start," which is a concept
similar to DOM's `timeOrigin` (but not exactly the same). It's very
difficult to fix this situation without fixing it everywhere as the
`Instant` concept is supposed to be opaque. The good thing is that this
change clears up all ambiguity when passing times as a `time::Duration`
is unit agnostic and a `CrossProcessInstant` represents an absolute
moment in time.
The `time` version of `Duration` is used because it can both be negative
and is also serializable.
Good things:
- No need too pass around `time` and `time_precise` any longer.
`CrossProcessInstant` is also precise and monotonic.
- The distinction between a time that is unset or at `0` (at some kind
of timer epoch) is now gone.
There still a lot of work to do to clean up timing, but this is the
first step. In general, I've tried to preserve existing behavior, even
when not spec compliant, as much as possible. I plan to submit followup
PRs fixing some of the issues I've noticed.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
For a long time, `gfx_traits` has held a lot of things unrelated to graphics
and also unrelated to the `gfx` crate (which is mostly about fonts).
This is a cleanup which does a few things:
1. Move non `gfx` crate things out of `gfx_traits`. This is important in
order to prevent dependency cycles with a different integration between
layout, script, and fonts.
2. Rename the `msg` crate to `base`. It didn't really contain anything
to do with messages and instead mostly holds ids, which are used
across many different crates in Servo. This new crate will hold the
*rare* data types that are widely used.
Details:
- All BackgroundHangMonitor-related things from base to a new
`background_hang_monitor_api` crate.
- Moved `TraversalDirection` to `script_traits`
- Moved `Epoch`-related things from `gfx_traits` to `base`.
- Moved `PrintTree` to base. This should be widely useful in Servo.
- Moved `WebrenderApi` from `base` to `webrender_traits` and renamed it
to `WebRenderFontApi`.
* script: Do not run layout in a thread
Instead of spawning a thread for layout that almost always runs
synchronously with script, simply run layout in the script thread.
This is a resurrection of #28708, taking just the bits that remove the
layout thread. It's a complex change and thus is just a first step
toward cleaning up the interface between script and layout. Messages are
still passed from script to layout via a `process()` method and script
proxies some messages to layout from other threads as well.
Big changes:
1. Layout is created in the script thread on Document load, thus every
live document is guaranteed to have a layout. This isn't completely
hidden in the interface, but we can safely `unwrap()` on a Document's
layout.
2. Layout configuration is abstracted away into a LayoutConfig struct
and the LayoutFactory is a struct passed around by the Constellation.
This is to avoid having to monomorphize the entire script thread
for each layout.
3. Instead of having the Constellation block on the layout thread to
figure out the current epoch and whether there are pending web fonts
loading, updates are sent synchronously to the Constellation when
rendering to a screenshot. This practically only used by the WPT.
A couple tests start to fail, which is probably inevitable since removing
the layout thread has introduced timing changes in "exit after load" and
screenshot behavior.
Co-authored-by: Josh Matthews <josh@joshmatthews.net>
* Update test expectations
* Fix some issues found during review
* Clarify some comments
* Address review comments
---------
Co-authored-by: Josh Matthews <josh@joshmatthews.net>
