compositor: Create a single cross-process compositor API (#33619)

Instead of exposing many different kinds of messages to the compositor
that are routed through the constellation, expose a single message type
which can be sent across IPC channels. In addition, this IPC channel and
the route to the crossbeam channel with the compositor is created along
with the `CompositorProxy`, simplifying what needs to be passed around
during pipeline initialization.

Previously, some image updates (from video) were sent over IPC with a
special serialization routine and some were sent via crossbeam channels
(canvas). Now all updates go over the IPC channel `IpcSharedMemory` is
used to avoid serialization penalties. This should improve performance
and reduce copies for video, but add a memory copy overhead for canvas.
This will improve in the future when canvas renders directly into a
texture.

All-in-all this is a simplification which opens the path toward having a
standard compositor API and reduces the number of duplicate messages and
proxying that had to happen in libservo.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
This commit is contained in:
Martin Robinson 2024-10-03 16:42:04 +02:00 committed by GitHub
parent 986c3a38a3
commit f2f5614ad6
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GPG key ID: B5690EEEBB952194
28 changed files with 547 additions and 801 deletions

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@ -108,8 +108,7 @@ use canvas_traits::canvas::{CanvasId, CanvasMsg};
use canvas_traits::webgl::WebGLThreads;
use canvas_traits::ConstellationCanvasMsg;
use compositing_traits::{
CompositorMsg, CompositorProxy, ConstellationMsg as FromCompositorMsg,
ForwardedToCompositorMsg, SendableFrameTree,
CompositorMsg, CompositorProxy, ConstellationMsg as FromCompositorMsg, SendableFrameTree,
};
use crossbeam_channel::{after, never, select, unbounded, Receiver, Sender};
use devtools_traits::{
@ -157,7 +156,7 @@ use webgpu::swapchain::WGPUImageMap;
use webgpu::{self, WebGPU, WebGPURequest, WebGPUResponse};
use webrender::{RenderApi, RenderApiSender};
use webrender_api::DocumentId;
use webrender_traits::{WebRenderNetApi, WebRenderScriptApi, WebrenderExternalImageRegistry};
use webrender_traits::WebrenderExternalImageRegistry;
use crate::browsingcontext::{
AllBrowsingContextsIterator, BrowsingContext, FullyActiveBrowsingContextsIterator,
@ -392,14 +391,6 @@ pub struct Constellation<STF, SWF> {
/// Webrender related objects required by WebGPU threads
webrender_wgpu: WebrenderWGPU,
/// A channel for content processes to send messages that will
/// be relayed to the WebRender thread.
webrender_api_ipc_sender: WebRenderScriptApi,
/// A channel for content process image caches to send messages
/// that will be relayed to the WebRender thread.
webrender_image_api_sender: WebRenderNetApi,
/// A map of message-port Id to info.
message_ports: HashMap<MessagePortId, MessagePortInfo>,
@ -506,7 +497,7 @@ pub struct InitialConstellationState {
/// A channel through which messages can be sent to the embedder.
pub embedder_proxy: EmbedderProxy,
/// A channel through which messages can be sent to the compositor.
/// A channel through which messages can be sent to the compositor in-process.
pub compositor_proxy: CompositorProxy,
/// A channel to the developer tools, if applicable.
@ -705,35 +696,6 @@ where
// Zero is reserved for the embedder.
PipelineNamespace::install(PipelineNamespaceId(1));
let (webrender_ipc_sender, webrender_ipc_receiver) =
ipc::channel().expect("ipc channel failure");
let (webrender_image_ipc_sender, webrender_image_ipc_receiver) =
ipc::channel().expect("ipc channel failure");
let compositor_proxy = state.compositor_proxy.clone();
ROUTER.add_route(
webrender_ipc_receiver.to_opaque(),
Box::new(move |message| {
compositor_proxy.send(CompositorMsg::Forwarded(
ForwardedToCompositorMsg::Layout(
message.to().expect("conversion failure"),
),
));
}),
);
let compositor_proxy = state.compositor_proxy.clone();
ROUTER.add_route(
webrender_image_ipc_receiver.to_opaque(),
Box::new(move |message| {
compositor_proxy.send(CompositorMsg::Forwarded(
ForwardedToCompositorMsg::Net(
message.to().expect("conversion failure"),
),
));
}),
);
let webrender_wgpu = WebrenderWGPU {
webrender_api: state.webrender_api_sender.create_api(),
webrender_external_images: state.webrender_external_images,
@ -788,8 +750,6 @@ where
scheduler_receiver,
document_states: HashMap::new(),
webrender_document: state.webrender_document,
webrender_api_ipc_sender: WebRenderScriptApi::new(webrender_ipc_sender),
webrender_image_api_sender: WebRenderNetApi::new(webrender_image_ipc_sender),
webrender_wgpu,
shutting_down: false,
handled_warnings: VecDeque::new(),
@ -1053,8 +1013,6 @@ where
event_loop,
load_data,
prev_throttled: throttled,
webrender_api_sender: self.webrender_api_ipc_sender.clone(),
webrender_image_api_sender: self.webrender_image_api_sender.clone(),
webrender_document: self.webrender_document,
webgl_chan: self
.webgl_threads
@ -1751,18 +1709,6 @@ where
response_sender.send(true).unwrap_or_default();
},
FromScriptMsg::GetClientWindow(response_sender) => {
self.compositor_proxy
.send(CompositorMsg::GetClientWindow(response_sender));
},
FromScriptMsg::GetScreenSize(response_sender) => {
self.compositor_proxy
.send(CompositorMsg::GetScreenSize(response_sender));
},
FromScriptMsg::GetScreenAvailSize(response_sender) => {
self.compositor_proxy
.send(CompositorMsg::GetScreenAvailSize(response_sender));
},
FromScriptMsg::LogEntry(thread_name, entry) => {
self.handle_log_entry(Some(source_top_ctx_id), thread_name, entry);
},