Instead of creating a type for each `TaskSource` variety have each `TaskSource`
hold the same kind of sender (this was inconsistent before, but each
sender was effectively the same trait object), a pipeline, and a
`TaskSourceName`. This elminates the need to reimplement the same
queuing code for every task source.
In addition, have workers hold their own `TaskManager`. This allows just
exposing the manager on the `GlobalScope`. Currently the `TaskCanceller`
is different, but this will also be eliminated in a followup change.
This is a the first step toward having a shared set of `Sender`s on
`GlobalScope`.
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`.
