Remove extra webgl message pumping thread.

components/script/dom/bindings/trace.rs

@@ -54,6 +54,7 @@ use canvas_traits::webgl::{WebGLShaderId, WebGLTextureId, WebGLVersion, WebGLVer
 use crossbeam_channel::{Receiver, Sender};
 use cssparser::RGBA;
 use devtools_traits::{CSSError, TimelineMarkerType, WorkerId};
+use embedder_traits::EventLoopWaker;
 use encoding_rs::{Decoder, Encoding};
 use euclid::default::{Point2D, Rect, Rotation3D, Transform2D, Transform3D};
 use euclid::Length as EuclidLength;
@@ -146,7 +147,7 @@ pub unsafe trait JSTraceable {
     unsafe fn trace(&self, trc: *mut JSTracer);
 }
 
-unsafe_no_jsmanaged_fields!(Box<dyn TaskBox>);
+unsafe_no_jsmanaged_fields!(Box<dyn TaskBox>, Box<dyn EventLoopWaker>);
 
 unsafe_no_jsmanaged_fields!(CSSError);
 

components/script/dom/vrdisplay.rs

@@ -32,11 +32,11 @@ use crate::dom::vreyeparameters::VREyeParameters;
 use crate::dom::vrframedata::VRFrameData;
 use crate::dom::vrpose::VRPose;
 use crate::dom::vrstageparameters::VRStageParameters;
-use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use crate::dom::webglrenderingcontext::{WebGLMessageSender, WebGLRenderingContext};
 use crate::script_runtime::CommonScriptMsg;
 use crate::script_runtime::ScriptThreadEventCategory::WebVREvent;
 use crate::task_source::{TaskSource, TaskSourceName};
-use canvas_traits::webgl::{webgl_channel, WebGLMsgSender, WebGLReceiver, WebVRCommand};
+use canvas_traits::webgl::{webgl_channel, WebGLReceiver, WebVRCommand};
 use crossbeam_channel::{unbounded, Sender};
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
@@ -102,7 +102,7 @@ struct VRRAFUpdate {
     depth_near: f64,
     depth_far: f64,
     /// WebGL API sender
-    api_sender: Option<WebGLMsgSender>,
+    api_sender: Option<WebGLMessageSender>,
     /// Number uniquely identifying the WebGL context
     /// so that we may setup/tear down VR compositors as things change
     context_id: usize,
@@ -583,7 +583,7 @@ impl VRDisplay {
             .fire(self.global().upcast::<EventTarget>());
     }
 
-    fn api_sender(&self) -> Option<WebGLMsgSender> {
+    fn api_sender(&self) -> Option<WebGLMessageSender> {
         self.layer_ctx.get().map(|c| c.webgl_sender())
     }
 

components/script/dom/webglrenderingcontext.rs

@@ -54,12 +54,13 @@ use backtrace::Backtrace;
 use canvas_traits::webgl::WebGLError::*;
 use canvas_traits::webgl::{
     webgl_channel, AlphaTreatment, DOMToTextureCommand, GLContextAttributes, GLLimits, GlType,
-    Parameter, TexDataType, TexFormat, TexParameter, WebGLCommand, WebGLCommandBacktrace,
-    WebGLContextShareMode, WebGLError, WebGLFramebufferBindingRequest, WebGLMsg, WebGLMsgSender,
-    WebGLProgramId, WebGLResult, WebGLSLVersion, WebGLSender, WebGLVersion, WebVRCommand,
-    YAxisTreatment,
+    Parameter, TexDataType, TexFormat, TexParameter, WebGLChan, WebGLCommand,
+    WebGLCommandBacktrace, WebGLContextId, WebGLContextShareMode, WebGLError,
+    WebGLFramebufferBindingRequest, WebGLMsg, WebGLMsgSender, WebGLProgramId, WebGLResult,
+    WebGLSLVersion, WebGLSendResult, WebGLSender, WebGLVersion, WebVRCommand, YAxisTreatment,
 };
 use dom_struct::dom_struct;
+use embedder_traits::EventLoopWaker;
 use euclid::default::{Point2D, Rect, Size2D};
 use ipc_channel::ipc::{self, IpcSharedMemory};
 use js::jsapi::{JSContext, JSObject, Type};
@@ -79,6 +80,7 @@ use std::cell::Cell;
 use std::cmp;
 use std::ptr::{self, NonNull};
 use std::rc::Rc;
+use webrender_api::ImageKey;
 
 // From the GLES 2.0.25 spec, page 85:
 //
@@ -135,7 +137,7 @@ bitflags! {
 pub struct WebGLRenderingContext {
     reflector_: Reflector,
     #[ignore_malloc_size_of = "Channels are hard"]
-    webgl_sender: WebGLMsgSender,
+    webgl_sender: WebGLMessageSender,
     #[ignore_malloc_size_of = "Defined in webrender"]
     webrender_image: Cell<Option<webrender_api::ImageKey>>,
     share_mode: WebGLContextShareMode,
@@ -197,7 +199,10 @@ impl WebGLRenderingContext {
             let max_combined_texture_image_units = ctx_data.limits.max_combined_texture_image_units;
             Self {
                 reflector_: Reflector::new(),
-                webgl_sender: ctx_data.sender,
+                webgl_sender: WebGLMessageSender::new(
+                    ctx_data.sender,
+                    window.get_event_loop_waker(),
+                ),
                 webrender_image: Cell::new(None),
                 share_mode: ctx_data.share_mode,
                 webgl_version,
@@ -319,7 +324,7 @@ impl WebGLRenderingContext {
         }
     }
 
-    pub fn webgl_sender(&self) -> WebGLMsgSender {
+    pub(crate) fn webgl_sender(&self) -> WebGLMessageSender {
         self.webgl_sender.clone()
     }
 
@@ -4288,3 +4293,92 @@ impl TexPixels {
         }
     }
 }
+
+#[derive(JSTraceable)]
+pub(crate) struct WebGLCommandSender {
+    sender: WebGLChan,
+    waker: Option<Box<dyn EventLoopWaker>>,
+}
+
+impl WebGLCommandSender {
+    pub fn new(sender: WebGLChan, waker: Option<Box<dyn EventLoopWaker>>) -> WebGLCommandSender {
+        WebGLCommandSender { sender, waker }
+    }
+
+    pub fn send(&self, msg: WebGLMsg) -> WebGLSendResult {
+        let result = self.sender.send(msg);
+        if let Some(ref waker) = self.waker {
+            waker.wake();
+        }
+        result
+    }
+}
+
+#[derive(JSTraceable, MallocSizeOf)]
+pub(crate) struct WebGLMessageSender {
+    sender: WebGLMsgSender,
+    #[ignore_malloc_size_of = "traits are cumbersome"]
+    waker: Option<Box<dyn EventLoopWaker>>,
+}
+
+impl Clone for WebGLMessageSender {
+    fn clone(&self) -> WebGLMessageSender {
+        WebGLMessageSender {
+            sender: self.sender.clone(),
+            waker: self.waker.as_ref().map(|w| (*w).clone_box()),
+        }
+    }
+}
+
+impl WebGLMessageSender {
+    fn wake_after_send<F: FnOnce() -> WebGLSendResult>(&self, f: F) -> WebGLSendResult {
+        let result = f();
+        if let Some(ref waker) = self.waker {
+            waker.wake();
+        }
+        result
+    }
+
+    pub fn new(
+        sender: WebGLMsgSender,
+        waker: Option<Box<dyn EventLoopWaker>>,
+    ) -> WebGLMessageSender {
+        WebGLMessageSender { sender, waker }
+    }
+
+    pub fn context_id(&self) -> WebGLContextId {
+        self.sender.context_id()
+    }
+
+    pub fn send(&self, msg: WebGLCommand, backtrace: WebGLCommandBacktrace) -> WebGLSendResult {
+        self.wake_after_send(|| self.sender.send(msg, backtrace))
+    }
+
+    pub fn send_vr(&self, command: WebVRCommand) -> WebGLSendResult {
+        self.wake_after_send(|| self.sender.send_vr(command))
+    }
+
+    pub fn send_resize(
+        &self,
+        size: Size2D<u32>,
+        sender: WebGLSender<Result<(), String>>,
+    ) -> WebGLSendResult {
+        self.wake_after_send(|| self.sender.send_resize(size, sender))
+    }
+
+    pub fn send_remove(&self) -> WebGLSendResult {
+        self.wake_after_send(|| self.sender.send_remove())
+    }
+
+    pub fn send_update_wr_image(&self, sender: WebGLSender<ImageKey>) -> WebGLSendResult {
+        self.wake_after_send(|| self.sender.send_update_wr_image(sender))
+    }
+
+    pub fn send_dom_to_texture(&self, command: DOMToTextureCommand) -> WebGLSendResult {
+        self.wake_after_send(|| self.sender.send_dom_to_texture(command))
+    }
+
+    pub fn webxr_external_image_api(&self) -> impl webxr_api::WebGLExternalImageApi {
+        self.sender.webxr_external_image_api()
+    }
+}

components/script/dom/window.rs

@@ -50,6 +50,7 @@ use crate::dom::promise::Promise;
 use crate::dom::screen::Screen;
 use crate::dom::storage::Storage;
 use crate::dom::testrunner::TestRunner;
+use crate::dom::webglrenderingcontext::WebGLCommandSender;
 use crate::dom::windowproxy::WindowProxy;
 use crate::dom::worklet::Worklet;
 use crate::dom::workletglobalscope::WorkletGlobalScopeType;
@@ -73,7 +74,7 @@ use crossbeam_channel::{unbounded, Sender, TryRecvError};
 use cssparser::{Parser, ParserInput, SourceLocation};
 use devtools_traits::{ScriptToDevtoolsControlMsg, TimelineMarker, TimelineMarkerType};
 use dom_struct::dom_struct;
-use embedder_traits::EmbedderMsg;
+use embedder_traits::{EmbedderMsg, EventLoopWaker};
 use euclid::default::{Point2D as UntypedPoint2D, Rect as UntypedRect};
 use euclid::{Point2D, Rect, Scale, Size2D, Vector2D};
 use ipc_channel::ipc::{channel, IpcSender};
@@ -326,6 +327,10 @@ pub struct Window {
     /// Window's GL context from application
     #[ignore_malloc_size_of = "defined in script_thread"]
     player_context: WindowGLContext,
+
+    /// A mechanism to force the compositor to process events.
+    #[ignore_malloc_size_of = "traits are cumbersome"]
+    event_loop_waker: Option<Box<dyn EventLoopWaker>>,
 }
 
 impl Window {
@@ -432,8 +437,10 @@ impl Window {
         self.current_viewport.clone().get()
     }
 
-    pub fn webgl_chan(&self) -> Option<WebGLChan> {
-        self.webgl_chan.clone()
+    pub(crate) fn webgl_chan(&self) -> Option<WebGLCommandSender> {
+        self.webgl_chan
+            .as_ref()
+            .map(|chan| WebGLCommandSender::new(chan.clone(), self.get_event_loop_waker()))
     }
 
     pub fn webvr_thread(&self) -> Option<IpcSender<WebVRMsg>> {
@@ -498,6 +505,10 @@ impl Window {
     pub fn get_player_context(&self) -> WindowGLContext {
         self.player_context.clone()
     }
+
+    pub fn get_event_loop_waker(&self) -> Option<Box<dyn EventLoopWaker>> {
+        self.event_loop_waker.as_ref().map(|w| (*w).clone_box())
+    }
 }
 
 // https://html.spec.whatwg.org/multipage/#atob
@@ -2087,6 +2098,7 @@ impl Window {
         replace_surrogates: bool,
         user_agent: Cow<'static, str>,
         player_context: WindowGLContext,
+        event_loop_waker: Option<Box<dyn EventLoopWaker>>,
     ) -> DomRoot<Self> {
         let layout_rpc: Box<dyn LayoutRPC + Send> = {
             let (rpc_send, rpc_recv) = unbounded();
@@ -2169,6 +2181,7 @@ impl Window {
             userscripts_path,
             replace_surrogates,
             player_context,
+            event_loop_waker,
         });
 
         unsafe { WindowBinding::Wrap(JSContext::from_ptr(runtime.cx()), win) }