From 7481ce177f4b124f869d3cf8b8f1c2fbf8b84429 Mon Sep 17 00:00:00 2001
From: Anthony Ramine <n.oxyde@gmail.com>
Date: Wed, 13 Sep 2017 10:34:07 +0200
Subject: [PATCH] Store a Rc<MicrotaskQueue> directly on Window

---
 components/script/dom/globalscope.rs |  8 ++++----
 components/script/dom/window.rs      | 17 +++++++++++++++++
 components/script/script_thread.rs   |  1 +
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/components/script/dom/globalscope.rs b/components/script/dom/globalscope.rs
index 4cd2ac2b8d1..90f5b7a9596 100644
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@@ -479,8 +479,8 @@ impl GlobalScope {
 
     /// Perform a microtask checkpoint.
     pub fn perform_a_microtask_checkpoint(&self) {
-        if self.is::<Window>() {
-            return ScriptThread::invoke_perform_a_microtask_checkpoint();
+        if let Some(window) = self.downcast::<Window>() {
+            return window.perform_a_microtask_checkpoint();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.perform_a_microtask_checkpoint();
@@ -493,8 +493,8 @@ impl GlobalScope {
 
     /// Enqueue a microtask for subsequent execution.
     pub fn enqueue_microtask(&self, job: Microtask) {
-        if self.is::<Window>() {
-            return ScriptThread::enqueue_microtask(job);
+        if let Some(window) = self.downcast::<Window>() {
+            return window.enqueue_microtask(job);
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.enqueue_microtask(job);
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index b606192cb54..56022e66f01 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -59,6 +59,7 @@ use js::jsapi::{JS_GC, JS_GetRuntime};
 use js::jsval::UndefinedValue;
 use js::rust::Runtime;
 use layout_image::fetch_image_for_layout;
+use microtask::{Microtask, MicrotaskQueue};
 use msg::constellation_msg::{FrameType, PipelineId};
 use net_traits::{ResourceThreads, ReferrerPolicy};
 use net_traits::image_cache::{ImageCache, ImageResponder, ImageResponse};
@@ -287,6 +288,10 @@ pub struct Window {
     test_worklet: MutNullableJS<Worklet>,
     /// https://drafts.css-houdini.org/css-paint-api-1/#paint-worklet
     paint_worklet: MutNullableJS<Worklet>,
+
+    /// https://html.spec.whatwg.org/multipage/#microtask-queue
+    #[ignore_heap_size_of = "Rc<T> is hard"]
+    microtask_queue: Rc<MicrotaskQueue>,
 }
 
 impl Window {
@@ -1785,6 +1790,16 @@ impl Window {
             .send(msg)
             .unwrap();
     }
+
+    pub fn enqueue_microtask(&self, job: Microtask) {
+        self.microtask_queue.enqueue(job);
+    }
+
+    pub fn perform_a_microtask_checkpoint(&self) {
+        self.microtask_queue.checkpoint(|_| {
+            Some(Root::from_ref(self.upcast::<GlobalScope>()))
+        });
+    }
 }
 
 impl Window {
@@ -1818,6 +1833,7 @@ impl Window {
         navigation_start_precise: f64,
         webgl_chan: WebGLChan,
         webvr_chan: Option<IpcSender<WebVRMsg>>,
+        microtask_queue: Rc<MicrotaskQueue>,
     ) -> Root<Self> {
         let layout_rpc: Box<LayoutRPC + Send> = {
             let (rpc_send, rpc_recv) = channel();
@@ -1890,6 +1906,7 @@ impl Window {
             unminified_js_dir: Default::default(),
             test_worklet: Default::default(),
             paint_worklet: Default::default(),
+            microtask_queue,
         };
 
         unsafe {
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 597d1dce11c..b2359c3ea94 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -2068,6 +2068,7 @@ impl ScriptThread {
             incomplete.navigation_start_precise,
             self.webgl_chan.channel(),
             self.webvr_chan.clone(),
+            self.microtask_queue.clone(),
         );
 
         // Initialize the browsing context for the window.