Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-09-30 00:29:14 +01:00
Code Issues Projects Releases Packages Wiki Activity

Add direct script to embedder channel (#39039)

Browse source 
This PR **removes** `ScriptToConstellationMessage::ForwardToEmbedder`,
and replaces it with an explicit `ScriptToEmbedderChannel`. This new
channel is based on `GenericCallback` and in single-process mode will
directly send the message the to the embedder and wake it. In
multi-process mode, the message is routed via the ROUTER, since waking
is only possible from the same process currently. This means in
multi-process mode there are likely no direct perf benefits, since we
still need to hop the message over the ROUTER (instead of over the
constellation).
In single-process mode we can directly send the message to the embedder,
which should provide a noticable latency improvement in all cases where
script is blocked waiting on the embedder to reply.

This does not change the way the embedder receives messages - the
receiving end is unchanged.

## How was sending messages to the embedder working before?

1. Script wraps it's message to the embedder in
`ScriptToConstellationMessage::ForwardToEmbedder` and sends it to
constellation.
2. The [constellation event loop] receives the message in
[handle_request]
3. If deserialization fails, [an error is logged and the message is
ignored]
4. Since our message came from script, it is handle in
[handle_request_from_script]
5. The message is logged with trace log level
6. If the pipeline is closed, [a warning is logged and the message
ignored]
7. The wrapped `EmbedderMsg` [is forwarded to the embedder]. Sending the
message also invokes `wake()` on the embedder eventloop waker.

[constellation event loop]:
2e1b2e7260/components/constellation/constellation.rs (L755)

[handle request]:
2e1b2e7260/components/constellation/constellation.rs (L1182)

[an error is logged and the message is ignored]:
2e1b2e7260/components/constellation/constellation.rs (L1252)

[handle_request_from_script]:
https://github.com/servo/servo/blob/main/components/constellation/constellation.rs#L1590
 
[a warning is logged and the message ignored]:
2e1b2e7260/components/constellation/constellation.rs (L1599)

[is forwarded to the embedder]:
2e1b2e7260/components/constellation/constellation.rs (L1701)

Testing: Communication between Script and Embedder is extensive, so this
should be covered by existing tests.

Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
This commit is contained in:
Jonathan Schwender 2025-09-02 08:33:44 +02:00 • committed by GitHub
parent 97c8c83cbb
commit f4dd2960b8
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
21 changed files with 120 additions and 113 deletions
Download patch file Download diff file Expand all files Collapse all files

71
components/constellation/tracing.rs
View file

@ -110,8 +110,6 @@ mod from_compositor {
}
mod from_script {
use embedder_traits::LoadStatus;
use super::LogTarget;
macro_rules! target {
@ -141,7 +139,6 @@ mod from_script {
target!("RemoveBroadcastChannelNameInRouter")
},
Self::ScheduleBroadcast(..) => target!("ScheduleBroadcast"),
Self::ForwardToEmbedder(msg) => msg.log_target(),
Self::BroadcastStorageEvent(..) => target!("BroadcastStorageEvent"),
Self::ChangeRunningAnimationsState(..) => target!("ChangeRunningAnimationsState"),
Self::CreateCanvasPaintThread(..) => target!("CreateCanvasPaintThread"),
@ -188,72 +185,4 @@ mod from_script {
}
}
}
impl LogTarget for embedder_traits::EmbedderMsg {
fn log_target(&self) -> &'static str {
macro_rules! target_variant {
($name:literal) => {
target!("ForwardToEmbedder(" $name ")")
};
}
match self {
Self::Status(..) => target_variant!("Status"),
Self::ChangePageTitle(..) => target_variant!("ChangePageTitle"),
Self::MoveTo(..) => target_variant!("MoveTo"),
Self::ResizeTo(..) => target_variant!("ResizeTo"),
Self::ShowSimpleDialog(..) => target_variant!("ShowSimpleDialog"),
Self::RequestAuthentication(..) => target_variant!("RequestAuthentication"),
Self::ShowContextMenu(..) => target_variant!("ShowContextMenu"),
Self::AllowNavigationRequest(..) => target_variant!("AllowNavigationRequest"),
Self::AllowOpeningWebView(..) => target_variant!("AllowOpeningWebView"),
Self::WebViewClosed(..) => target_variant!("WebViewClosed"),
Self::WebViewFocused(..) => target_variant!("WebViewFocused"),
Self::WebViewBlurred => target_variant!("WebViewBlurred"),
Self::WebResourceRequested(..) => target_variant!("WebResourceRequested"),
Self::AllowUnload(..) => target_variant!("AllowUnload"),
Self::Keyboard(..) => target_variant!("Keyboard"),
Self::ClearClipboard(..) => target_variant!("ClearClipboard"),
Self::GetClipboardText(..) => target_variant!("GetClipboardText"),
Self::SetClipboardText(..) => target_variant!("SetClipboardText"),
Self::SetCursor(..) => target_variant!("SetCursor"),
Self::NewFavicon(..) => target_variant!("NewFavicon"),
Self::HistoryChanged(..) => target_variant!("HistoryChanged"),
Self::HistoryTraversalComplete(..) => target_variant!("HistoryTraversalComplete"),
Self::GetWindowRect(..) => target_variant!("GetWindowRect"),
Self::GetScreenMetrics(..) => target_variant!("GetScreenMetrics"),
Self::NotifyFullscreenStateChanged(..) => {
target_variant!("NotifyFullscreenStateChanged")
},
Self::NotifyLoadStatusChanged(_, LoadStatus::Started) => {
target_variant!("NotifyLoadStatusChanged(LoadStatus::Started)")
},
Self::NotifyLoadStatusChanged(_, LoadStatus::HeadParsed) => {
target_variant!("NotifyLoadStatusChanged(LoadStatus::HeadParsed)")
},
Self::NotifyLoadStatusChanged(_, LoadStatus::Complete) => {
target_variant!("NotifyLoadStatusChanged(LoadStatus::Complete")
},
Self::Panic(..) => target_variant!("Panic"),
Self::GetSelectedBluetoothDevice(..) => {
target_variant!("GetSelectedBluetoothDevice")
},
Self::SelectFiles(..) => target_variant!("SelectFiles"),
Self::PromptPermission(..) => target_variant!("PromptPermission"),
Self::ShowIME(..) => target_variant!("ShowIME"),
Self::HideIME(..) => target_variant!("HideIME"),
Self::ReportProfile(..) => target_variant!("ReportProfile"),
Self::MediaSessionEvent(..) => target_variant!("MediaSessionEvent"),
Self::OnDevtoolsStarted(..) => target_variant!("OnDevtoolsStarted"),
Self::RequestDevtoolsConnection(..) => target_variant!("RequestDevtoolsConnection"),
Self::PlayGamepadHapticEffect(..) => target_variant!("PlayGamepadHapticEffect"),
Self::StopGamepadHapticEffect(..) => target_variant!("StopGamepadHapticEffect"),
Self::ShutdownComplete => target_variant!("ShutdownComplete"),
Self::ShowNotification(..) => target_variant!("ShowNotification"),
Self::ShowFormControl(..) => target_variant!("ShowFormControl"),
Self::FinishJavaScriptEvaluation(..) => {
target_variant!("FinishJavaScriptEvaluation")
},
}
}
}
}