Add retry for hit tests with expired epoch in result (#37085)

Follow up to [hit_test failed occasionally when the touch event is
sent](https://github.com/servo/servo/issues/35788#top) and
https://github.com/servo/servo/issues/36676#issuecomment-2882917136,
this PR adds a retry for hit tests with expired epoch in result.

Hit tests with outdated epoch mean it is too early to perform the hit
test.

Solution: retry hit test for the event on the next webrender frame.
The retry should guarantee that:

- Keep the correct order of events
- Retry time is not too long

Test cases: `./mach test-wpt --product servodriver -r
tests\wpt\tests\webdriver\tests\classic\element_click\events.py`

cc: @xiaochengh , @yezhizhen

---------

Signed-off-by: batu_hoang <longvatrong111@gmail.com>
This commit is contained in:
batu_hoang 2025-06-04 13:56:20 +08:00 committed by GitHub
parent 7439fa18d3
commit b422a65a00
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 134 additions and 51 deletions

View file

@ -281,6 +281,11 @@ impl PipelineDetails {
}
}
pub enum HitTestError {
EpochMismatch,
Others,
}
impl ServoRenderer {
pub fn shutdown_state(&self) -> ShutdownState {
self.shutdown_state.get()
@ -290,15 +295,19 @@ impl ServoRenderer {
&self,
point: DevicePoint,
details_for_pipeline: impl Fn(PipelineId) -> Option<&'a PipelineDetails>,
) -> Option<CompositorHitTestResult> {
self.hit_test_at_point_with_flags_and_pipeline(
) -> Result<CompositorHitTestResult, HitTestError> {
match self.hit_test_at_point_with_flags_and_pipeline(
point,
HitTestFlags::empty(),
None,
details_for_pipeline,
)
.first()
.cloned()
) {
Ok(hit_test_results) => hit_test_results
.first()
.cloned()
.ok_or(HitTestError::Others),
Err(error) => Err(error),
}
}
// TODO: split this into first half (global) and second half (one for whole compositor, one for webview)
@ -308,14 +317,15 @@ impl ServoRenderer {
flags: HitTestFlags,
pipeline_id: Option<WebRenderPipelineId>,
details_for_pipeline: impl Fn(PipelineId) -> Option<&'a PipelineDetails>,
) -> Vec<CompositorHitTestResult> {
) -> Result<Vec<CompositorHitTestResult>, HitTestError> {
// DevicePoint and WorldPoint are the same for us.
let world_point = WorldPoint::from_untyped(point.to_untyped());
let results =
self.webrender_api
.hit_test(self.webrender_document, pipeline_id, world_point, flags);
results
let mut epoch_mismatch = false;
let results = results
.items
.iter()
.filter_map(|item| {
@ -323,10 +333,16 @@ impl ServoRenderer {
let details = details_for_pipeline(pipeline_id)?;
// If the epoch in the tag does not match the current epoch of the pipeline,
// then the hit test is against an old version of the display list and we
// should ignore this hit test for now.
// then the hit test is against an old version of the display list.
match details.most_recent_display_list_epoch {
Some(epoch) if epoch.as_u16() == item.tag.1 => {},
Some(epoch) => {
if epoch.as_u16() != item.tag.1 {
// It's too early to hit test for now.
// New scene building is in progress.
epoch_mismatch = true;
return None;
}
},
_ => return None,
}
@ -340,7 +356,13 @@ impl ServoRenderer {
scroll_tree_node: info.scroll_tree_node,
})
})
.collect()
.collect();
if epoch_mismatch {
return Err(HitTestError::EpochMismatch);
}
Ok(results)
}
pub(crate) fn send_transaction(&mut self, transaction: Transaction) {
@ -619,7 +641,7 @@ impl IOCompositor {
.global
.borrow()
.hit_test_at_point(point, details_for_pipeline);
if let Some(result) = result {
if let Ok(result) = result {
self.global.borrow_mut().update_cursor(point, &result);
}
}
@ -649,7 +671,7 @@ impl IOCompositor {
};
let dppx = webview_renderer.device_pixels_per_page_pixel();
let point = dppx.transform_point(Point2D::new(x, y));
webview_renderer.dispatch_input_event(
webview_renderer.dispatch_point_input_event(
InputEvent::MouseButton(MouseButtonEvent::new(action, button, point))
.with_webdriver_message_id(Some(message_id)),
);
@ -662,7 +684,7 @@ impl IOCompositor {
};
let dppx = webview_renderer.device_pixels_per_page_pixel();
let point = dppx.transform_point(Point2D::new(x, y));
webview_renderer.dispatch_input_event(
webview_renderer.dispatch_point_input_event(
InputEvent::MouseMove(MouseMoveEvent::new(point))
.with_webdriver_message_id(Some(message_id)),
);
@ -684,7 +706,7 @@ impl IOCompositor {
let scroll_delta =
dppx.transform_vector(Vector2D::new(delta_x as f32, delta_y as f32));
webview_renderer
.dispatch_input_event(InputEvent::Wheel(WheelEvent { delta, point }));
.dispatch_point_input_event(InputEvent::Wheel(WheelEvent { delta, point }));
webview_renderer.on_webdriver_wheel_action(scroll_delta, point);
},
@ -792,6 +814,8 @@ impl IOCompositor {
let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else {
return warn!("Could not find WebView for incoming display list");
};
// WebRender is not ready until we receive "NewWebRenderFrameReady"
webview_renderer.webrender_frame_ready.set(false);
let pipeline_id = display_list_info.pipeline_id;
let details = webview_renderer.ensure_pipeline_details(pipeline_id.into());
@ -841,7 +865,8 @@ impl IOCompositor {
flags,
pipeline,
details_for_pipeline,
);
)
.unwrap_or_default();
let _ = sender.send(result);
},
@ -1629,11 +1654,20 @@ impl IOCompositor {
},
CompositorMsg::NewWebRenderFrameReady(..) => {
found_recomposite_msg = true;
compositor_messages.push(msg)
compositor_messages.push(msg);
},
_ => compositor_messages.push(msg),
}
}
if found_recomposite_msg {
// Process all pending events
self.webview_renderers.iter().for_each(|webview| {
webview.dispatch_pending_point_input_events();
webview.webrender_frame_ready.set(true);
});
}
for msg in compositor_messages {
self.handle_browser_message(msg);