canvas: Port CanvasMsg channel to generic channel (#39348)

Additionally also improve the warning message if the routed receiver
disconnects and exit the thread.
If the routed receiver disconnects, we can't receive any canvas messages
anymore, and any control messages can't remedy that, so we might as well
exit.

Testing: Channel changes are covered by existing tests. Exiting the
canvas thread if the routed thread disconnects is not tested, and needs
reviewer attention.
Part of https://github.com/servo/servo/issues/38912

Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
This commit is contained in:
Jonathan Schwender 2025-09-18 08:06:08 +08:00 committed by GitHub
parent 76645e5e26
commit 666b17a9a1
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GPG key ID: B5690EEEBB952194
4 changed files with 23 additions and 18 deletions

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@ -5,14 +5,13 @@
use std::borrow::ToOwned;
use std::{f32, thread};
use base::Epoch;
use base::generic_channel::GenericSender;
use base::{Epoch, generic_channel};
use canvas_traits::ConstellationCanvasMsg;
use canvas_traits::canvas::*;
use compositing_traits::CrossProcessCompositorApi;
use crossbeam_channel::{Sender, select, unbounded};
use euclid::default::{Rect, Size2D, Transform2D};
use ipc_channel::ipc::{self, IpcSender};
use ipc_channel::router::ROUTER;
use log::warn;
use pixels::Snapshot;
use rustc_hash::FxHashMap;
@ -39,9 +38,9 @@ impl CanvasPaintThread {
/// communicate with it.
pub fn start(
compositor_api: CrossProcessCompositorApi,
) -> (Sender<ConstellationCanvasMsg>, IpcSender<CanvasMsg>) {
let (ipc_sender, ipc_receiver) = ipc::channel::<CanvasMsg>().unwrap();
let msg_receiver = ROUTER.route_ipc_receiver_to_new_crossbeam_receiver(ipc_receiver);
) -> (Sender<ConstellationCanvasMsg>, GenericSender<CanvasMsg>) {
let (ipc_sender, ipc_receiver) = generic_channel::channel::<CanvasMsg>().unwrap();
let msg_receiver = ipc_receiver.route_preserving_errors();
let (create_sender, create_receiver) = unbounded();
thread::Builder::new()
.name("Canvas".to_owned())
@ -52,17 +51,21 @@ impl CanvasPaintThread {
select! {
recv(msg_receiver) -> msg => {
match msg {
Ok(CanvasMsg::Canvas2d(message, canvas_id)) => {
Ok(Ok(CanvasMsg::Canvas2d(message, canvas_id))) => {
canvas_paint_thread.process_canvas_2d_message(message, canvas_id);
},
Ok(CanvasMsg::Close(canvas_id)) => {
Ok(Ok(CanvasMsg::Close(canvas_id))) => {
canvas_paint_thread.canvases.remove(&canvas_id);
},
Ok(CanvasMsg::Recreate(size, canvas_id)) => {
Ok(Ok(CanvasMsg::Recreate(size, canvas_id))) => {
canvas_paint_thread.canvas(canvas_id).recreate(size);
},
Err(e) => {
warn!("Error on CanvasPaintThread receive ({})", e);
Ok(Err(e)) => {
warn!("CanvasPaintThread message deserialization error: {e:?}");
}
Err(_disconnected) => {
warn!("CanvasMsg receiver disconnected");
break;
},
}
}