Auto merge of #21804 - AgustinCB:unify-task-source-canceller-api, r=gterzian

Unify the task source and task canceller API

To do so, I created a struct `TaskManagement(TaskSource,
TaskCanceller)` and made `*_task_source` return that instead of just
the task source.

Next, I refactored all places in which `task_canceller` by basically
removing them in favour of a previously called `*_task_source`.

I tried to make `task_canceller` a private method in `Window`, with the
hope of enforcing the use of `*_task_source`. However, it's used in
components/script/dom/globalscope.rs:575 in such a way that will make it
harder to avoid. I decided to leave it that way.

It'd be possible to unify `*_task_source` in such a way that we would
have only one method. However, I decided not to do it because one of the
`TaskSource` implementations is special:
`history_traversal_task_source`. Not wanting to over complicate things,
I decided to leave the structure this way.

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #21154 (github issue number if applicable).

- [x] These changes do not require tests because it's refactoring code that should already be tested.

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---
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components/profile/time.rs

@@ -129,6 +129,7 @@ impl Formattable for ProfilerCategory {
             ProfilerCategory::ScriptDomEvent => "Script Dom Event",
             ProfilerCategory::ScriptEvaluate => "Script JS Evaluate",
             ProfilerCategory::ScriptFileRead => "Script File Read",
+            ProfilerCategory::ScriptHistoryEvent => "Script History Event",
             ProfilerCategory::ScriptImageCacheMsg => "Script Image Cache Msg",
             ProfilerCategory::ScriptInputEvent => "Script Input Event",
             ProfilerCategory::ScriptNetworkEvent => "Script Network Event",

components/profile_traits/time.rs

@@ -103,6 +103,7 @@ pub enum ProfilerCategory {
     ScriptWebVREvent = 0x79,
     ScriptWorkletEvent = 0x7a,
     ScriptPerformanceEvent = 0x7b,
+    ScriptHistoryEvent = 0x7c,
     TimeToFirstPaint = 0x80,
     TimeToFirstContentfulPaint = 0x81,
     TimeToInteractive = 0x82,

components/script/dom/analysernode.rs

@@ -17,7 +17,7 @@ use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::reflect_dom_object;
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::window::Window;
-use crate::task_source::{TaskSource, TaskSourceName};
+use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::{self, IpcReceiver};
 use ipc_channel::router::ROUTER;
@@ -97,8 +97,9 @@ impl AnalyserNode {
     ) -> Fallible<DomRoot<AnalyserNode>> {
         let (node, recv) = AnalyserNode::new_inherited(window, context, options)?;
         let object = reflect_dom_object(Box::new(node), window, AnalyserNodeBinding::Wrap);
-        let source = window.dom_manipulation_task_source();
+        let (source, canceller) = window
-        let canceller = window.task_canceller(TaskSourceName::DOMManipulation);
+            .task_manager()
+            .dom_manipulation_task_source_with_canceller();
         let this = Trusted::new(&*object);
 
         ROUTER.add_route(

components/script/dom/audiocontext.rs

@@ -126,7 +126,7 @@ impl AudioContextMethods for AudioContext {
 
         // Steps 4 and 5.
         let window = DomRoot::downcast::<Window>(self.global()).unwrap();
-        let task_source = window.dom_manipulation_task_source();
+        let task_source = window.task_manager().dom_manipulation_task_source();
         let trusted_promise = TrustedPromise::new(promise.clone());
         match self.context.audio_context_impl().suspend() {
             Ok(_) => {
@@ -141,7 +141,7 @@ impl AudioContextMethods for AudioContext {
                     if base_context.State() != AudioContextState::Suspended {
                         base_context.set_state_attribute(AudioContextState::Suspended);
                         let window = DomRoot::downcast::<Window>(context.global()).unwrap();
-                        window.dom_manipulation_task_source().queue_simple_event(
+                        window.task_manager().dom_manipulation_task_source().queue_simple_event(
                             context.upcast(),
                             atom!("statechange"),
                             &window
@@ -188,7 +188,7 @@ impl AudioContextMethods for AudioContext {
 
         // Steps 4 and 5.
         let window = DomRoot::downcast::<Window>(self.global()).unwrap();
-        let task_source = window.dom_manipulation_task_source();
+        let task_source = window.task_manager().dom_manipulation_task_source();
         let trusted_promise = TrustedPromise::new(promise.clone());
         match self.context.audio_context_impl().close() {
             Ok(_) => {
@@ -203,7 +203,7 @@ impl AudioContextMethods for AudioContext {
                     if base_context.State() != AudioContextState::Closed {
                         base_context.set_state_attribute(AudioContextState::Closed);
                         let window = DomRoot::downcast::<Window>(context.global()).unwrap();
-                        window.dom_manipulation_task_source().queue_simple_event(
+                        window.task_manager().dom_manipulation_task_source().queue_simple_event(
                             context.upcast(),
                             atom!("statechange"),
                             &window

components/script/dom/audioscheduledsourcenode.rs

@@ -10,7 +10,7 @@ use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::num::Finite;
 use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::DomObject;
-use crate::task_source::{TaskSource, TaskSourceName};
+use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use servo_media::audio::node::OnEndedCallback;
 use servo_media::audio::node::{AudioNodeInit, AudioNodeMessage, AudioScheduledSourceNodeMessage};
@@ -71,15 +71,16 @@ impl AudioScheduledSourceNodeMethods for AudioScheduledSourceNode {
         let this = Trusted::new(self);
         let global = self.global();
         let window = global.as_window();
-        let task_source = window.dom_manipulation_task_source();
+        let (task_source, canceller) = window
-        let canceller = window.task_canceller(TaskSourceName::DOMManipulation);
+            .task_manager()
+            .dom_manipulation_task_source_with_canceller();
         let callback = OnEndedCallback::new(move || {
             let _ = task_source.queue_with_canceller(
                 task!(ended: move || {
                     let this = this.root();
                     let global = this.global();
                     let window = global.as_window();
-                    window.dom_manipulation_task_source().queue_simple_event(
+                    window.task_manager().dom_manipulation_task_source().queue_simple_event(
                         this.upcast(),
                         atom!("ended"),
                         &window

components/script/dom/baseaudiocontext.rs

@@ -40,7 +40,7 @@ use crate::dom::oscillatornode::OscillatorNode;
 use crate::dom::pannernode::PannerNode;
 use crate::dom::promise::Promise;
 use crate::dom::window::Window;
-use crate::task_source::{TaskSource, TaskSourceName};
+use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use js::rust::CustomAutoRooterGuard;
 use js::typedarray::ArrayBuffer;
@@ -213,7 +213,7 @@ impl BaseAudioContext {
     pub fn resume(&self) {
         let global = self.global();
         let window = global.as_window();
-        let task_source = window.dom_manipulation_task_source();
+        let task_source = window.task_manager().dom_manipulation_task_source();
         let this = Trusted::new(self);
         // Set the rendering thread state to 'running' and start
         // rendering the audio graph.
@@ -227,7 +227,7 @@ impl BaseAudioContext {
                             if this.state.get() != AudioContextState::Running {
                                 this.state.set(AudioContextState::Running);
                                 let window = DomRoot::downcast::<Window>(this.global()).unwrap();
-                                window.dom_manipulation_task_source().queue_simple_event(
+                                window.task_manager().dom_manipulation_task_source().queue_simple_event(
                                     this.upcast(),
                                     atom!("statechange"),
                                     &window
@@ -428,10 +428,12 @@ impl BaseAudioContextMethods for BaseAudioContext {
             let decoded_audio__ = decoded_audio.clone();
             let this = Trusted::new(self);
             let this_ = this.clone();
-            let task_source = window.dom_manipulation_task_source();
+            let (task_source, canceller) = window
-            let task_source_ = window.dom_manipulation_task_source();
+                .task_manager()
-            let canceller = window.task_canceller(TaskSourceName::DOMManipulation);
+                .dom_manipulation_task_source_with_canceller();
-            let canceller_ = window.task_canceller(TaskSourceName::DOMManipulation);
+            let (task_source_, canceller_) = window
+                .task_manager()
+                .dom_manipulation_task_source_with_canceller();
             let callbacks = AudioDecoderCallbacks::new()
                 .ready(move |channel_count| {
                     decoded_audio

components/script/dom/document.rs

@@ -521,6 +521,7 @@ impl Document {
                 if self.ready_state.get() == DocumentReadyState::Complete {
                     let document = Trusted::new(self);
                     self.window
+                        .task_manager()
                         .dom_manipulation_task_source()
                         .queue(
                             task!(fire_pageshow_event: move || {
@@ -1869,6 +1870,7 @@ impl Document {
         debug!("Document loads are complete.");
         let document = Trusted::new(self);
         self.window
+            .task_manager()
             .dom_manipulation_task_source()
             .queue(
                 task!(fire_load_event: move || {
@@ -1922,6 +1924,7 @@ impl Document {
         let document = Trusted::new(self);
         if document.root().browsing_context().is_some() {
             self.window
+                .task_manager()
                 .dom_manipulation_task_source()
                 .queue(
                     task!(fire_pageshow_event: move || {
@@ -2104,13 +2107,16 @@ impl Document {
 
         // Step 4.1.
         let window = self.window();
-        window.dom_manipulation_task_source().queue_event(
+        window
-            self.upcast(),
+            .task_manager()
-            atom!("DOMContentLoaded"),
+            .dom_manipulation_task_source()
-            EventBubbles::Bubbles,
+            .queue_event(
-            EventCancelable::NotCancelable,
+                self.upcast(),
-            window,
+                atom!("DOMContentLoaded"),
-        );
+                EventBubbles::Bubbles,
+                EventCancelable::NotCancelable,
+                window,
+            );
 
         window.reflow(ReflowGoal::Full, ReflowReason::DOMContentLoaded);
         update_with_current_time_ms(&self.dom_content_loaded_event_end);

components/script/dom/globalscope.rs

@@ -476,7 +476,7 @@ impl GlobalScope {
     /// this global scope.
     pub fn networking_task_source(&self) -> NetworkingTaskSource {
         if let Some(window) = self.downcast::<Window>() {
-            return window.networking_task_source();
+            return window.task_manager().networking_task_source();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.networking_task_source();
@@ -488,7 +488,7 @@ impl GlobalScope {
     /// this global scope.
     pub fn remote_event_task_source(&self) -> RemoteEventTaskSource {
         if let Some(window) = self.downcast::<Window>() {
-            return window.remote_event_task_source();
+            return window.task_manager().remote_event_task_source();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.remote_event_task_source();
@@ -500,7 +500,7 @@ impl GlobalScope {
     /// this global scope.
     pub fn websocket_task_source(&self) -> WebsocketTaskSource {
         if let Some(window) = self.downcast::<Window>() {
-            return window.websocket_task_source();
+            return window.task_manager().websocket_task_source();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.websocket_task_source();
@@ -635,7 +635,7 @@ impl GlobalScope {
     /// properly cancelled when the global scope is destroyed.
     pub fn task_canceller(&self, name: TaskSourceName) -> TaskCanceller {
         if let Some(window) = self.downcast::<Window>() {
-            return window.task_canceller(name);
+            return window.task_manager().task_canceller(name);
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             // Note: the "name" is not passed to the worker,
@@ -691,7 +691,7 @@ impl GlobalScope {
 
     pub fn dom_manipulation_task_source(&self) -> DOMManipulationTaskSource {
         if let Some(window) = self.downcast::<Window>() {
-            return window.dom_manipulation_task_source();
+            return window.task_manager().dom_manipulation_task_source();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.dom_manipulation_task_source();
@@ -703,7 +703,7 @@ impl GlobalScope {
     /// this of this global scope.
     pub fn file_reading_task_source(&self) -> FileReadingTaskSource {
         if let Some(window) = self.downcast::<Window>() {
-            return window.file_reading_task_source();
+            return window.task_manager().file_reading_task_source();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.file_reading_task_source();
@@ -756,7 +756,7 @@ impl GlobalScope {
     /// of this global scope.
     pub fn performance_timeline_task_source(&self) -> PerformanceTimelineTaskSource {
         if let Some(window) = self.downcast::<Window>() {
-            return window.performance_timeline_task_source();
+            return window.task_manager().performance_timeline_task_source();
         }
         if let Some(worker) = self.downcast::<WorkerGlobalScope>() {
             return worker.performance_timeline_task_source();

components/script/dom/htmldetailselement.rs

@@ -76,7 +76,7 @@ impl VirtualMethods for HTMLDetailsElement {
             let window = window_from_node(self);
             let this = Trusted::new(self);
             // FIXME(nox): Why are errors silenced here?
-            let _ = window.dom_manipulation_task_source().queue(
+            let _ = window.task_manager().dom_manipulation_task_source().queue(
                 task!(details_notification_task_steps: move || {
                     let this = this.root();
                     if counter == this.toggle_counter.get() {

components/script/dom/htmldialogelement.rs

@@ -90,7 +90,8 @@ impl HTMLDialogElementMethods for HTMLDialogElement {
         // TODO: Step 4 implement pending dialog stack removal
 
         // Step 5
-        win.dom_manipulation_task_source()
+        win.task_manager()
+            .dom_manipulation_task_source()
             .queue_simple_event(target, atom!("close"), &win);
     }
 }

components/script/dom/htmlformelement.rs

@@ -523,6 +523,7 @@ impl HTMLFormElement {
 
         // Step 3.
         target
+            .task_manager()
             .dom_manipulation_task_source()
             .queue(task, target.upcast())
             .unwrap();

components/script/dom/htmliframeelement.rs

@@ -237,7 +237,7 @@ impl HTMLIFrameElement {
             let this = Trusted::new(self);
             let pipeline_id = self.pipeline_id().unwrap();
             // FIXME(nox): Why are errors silenced here?
-            let _ = window.dom_manipulation_task_source().queue(
+            let _ = window.task_manager().dom_manipulation_task_source().queue(
                 task!(iframe_load_event_steps: move || {
                     this.root().iframe_load_event_steps(pipeline_id);
                 }),

components/script/dom/htmlimageelement.rs

@@ -40,7 +40,7 @@ use crate::dom::window::Window;
 use crate::microtask::{Microtask, MicrotaskRunnable};
 use crate::network_listener::{NetworkListener, PreInvoke};
 use crate::script_thread::ScriptThread;
-use crate::task_source::{TaskSource, TaskSourceName};
+use crate::task_source::TaskSource;
 use cssparser::{Parser, ParserInput};
 use dom_struct::dom_struct;
 use euclid::Point2D;
@@ -237,8 +237,9 @@ impl HTMLImageElement {
             let (responder_sender, responder_receiver) = ipc::channel().unwrap();
 
             let window = window_from_node(elem);
-            let task_source = window.networking_task_source();
+            let (task_source, canceller) = window
-            let task_canceller = window.task_canceller(TaskSourceName::Networking);
+                .task_manager()
+                .networking_task_source_with_canceller();
             let generation = elem.generation.get();
             ROUTER.add_route(
                 responder_receiver.to_opaque(),
@@ -257,7 +258,7 @@ impl HTMLImageElement {
                             element.process_image_response(image);
                         }
                     }),
-                        &task_canceller,
+                        &canceller,
                     );
                 }),
             );
@@ -308,10 +309,14 @@ impl HTMLImageElement {
         }));
 
         let (action_sender, action_receiver) = ipc::channel().unwrap();
+        let (task_source, canceller) = document
+            .window()
+            .task_manager()
+            .networking_task_source_with_canceller();
         let listener = NetworkListener {
-            context: context,
+            context,
-            task_source: window.networking_task_source(),
+            task_source,
-            canceller: Some(window.task_canceller(TaskSourceName::Networking)),
+            canceller: Some(canceller),
         };
         ROUTER.add_route(
             action_receiver.to_opaque(),
@@ -780,7 +785,7 @@ impl HTMLImageElement {
     fn update_the_image_data_sync_steps(&self) {
         let document = document_from_node(self);
         let window = document.window();
-        let task_source = window.dom_manipulation_task_source();
+        let task_source = window.task_manager().dom_manipulation_task_source();
         let this = Trusted::new(self);
         let (src, pixel_density) = match self.select_image_source() {
             // Step 8
@@ -938,7 +943,7 @@ impl HTMLImageElement {
                     current_request.current_pixel_density = pixel_density;
                     let this = Trusted::new(self);
                     let src = String::from(src);
-                    let _ = window.dom_manipulation_task_source().queue(
+                    let _ = window.task_manager().dom_manipulation_task_source().queue(
                         task!(image_load_event: move || {
                             let this = this.root();
                             {
@@ -989,8 +994,9 @@ impl HTMLImageElement {
             let (responder_sender, responder_receiver) = ipc::channel().unwrap();
 
             let window = window_from_node(elem);
-            let task_source = window.networking_task_source();
+            let (task_source, canceller) = window
-            let task_canceller = window.task_canceller(TaskSourceName::Networking);
+                .task_manager()
+                .networking_task_source_with_canceller();
             let generation = elem.generation.get();
             ROUTER.add_route(responder_receiver.to_opaque(), Box::new(move |message| {
                 debug!("Got image {:?}", message);
@@ -1008,7 +1014,7 @@ impl HTMLImageElement {
                             DOMString::from_string(selected_source_clone), generation, selected_pixel_density);
                         }
                     }),
-                    &task_canceller,
+                    &canceller,
                 );
             }));
 
@@ -1133,7 +1139,7 @@ impl HTMLImageElement {
         let this = Trusted::new(self);
         let window = window_from_node(self);
         let src = src.to_string();
-        let _ = window.dom_manipulation_task_source().queue(
+        let _ = window.task_manager().dom_manipulation_task_source().queue(
             task!(image_load_event: move || {
                 let this = this.root();
                 let relevant_mutation = this.generation.get() != generation;

components/script/dom/htmlinputelement.rs

@@ -1515,13 +1515,16 @@ impl VirtualMethods for HTMLInputElement {
         {
             if event.IsTrusted() {
                 let window = window_from_node(self);
-                let _ = window.user_interaction_task_source().queue_event(
+                let _ = window
-                    &self.upcast(),
+                    .task_manager()
-                    atom!("input"),
+                    .user_interaction_task_source()
-                    EventBubbles::Bubbles,
+                    .queue_event(
-                    EventCancelable::NotCancelable,
+                        &self.upcast(),
-                    &window,
+                        atom!("input"),
-                );
+                        EventBubbles::Bubbles,
+                        EventCancelable::NotCancelable,
+                        &window,
+                    );
             }
         }
     }

components/script/dom/htmlmediaelement.rs

@@ -36,7 +36,7 @@ use crate::fetch::FetchCanceller;
 use crate::microtask::{Microtask, MicrotaskRunnable};
 use crate::network_listener::{NetworkListener, PreInvoke};
 use crate::script_thread::ScriptThread;
-use crate::task_source::{TaskSource, TaskSourceName};
+use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use headers_core::HeaderMapExt;
 use headers_ext::ContentLength;
@@ -295,7 +295,7 @@ impl HTMLMediaElement {
 
         let window = window_from_node(self);
         // FIXME(nox): Why are errors silenced here?
-        let task_source = window.media_element_task_source();
+        let task_source = window.task_manager().media_element_task_source();
         if self.Paused() {
             // Step 6.1.
             self.paused.set(false);
@@ -373,7 +373,7 @@ impl HTMLMediaElement {
             let window = window_from_node(self);
             let this = Trusted::new(self);
             let generation_id = self.generation_id.get();
-            let _ = window.media_element_task_source().queue(
+            let _ = window.task_manager().media_element_task_source().queue(
                 task!(internal_pause_steps: move || {
                     let this = this.root();
                     if generation_id != this.generation_id.get() {
@@ -415,7 +415,7 @@ impl HTMLMediaElement {
         let this = Trusted::new(self);
         let generation_id = self.generation_id.get();
         // FIXME(nox): Why are errors silenced here?
-        let _ = window.media_element_task_source().queue(
+        let _ = window.task_manager().media_element_task_source().queue(
             task!(notify_about_playing: move || {
                 let this = this.root();
                 if generation_id != this.generation_id.get() {
@@ -449,7 +449,7 @@ impl HTMLMediaElement {
         }
 
         let window = window_from_node(self);
-        let task_source = window.media_element_task_source();
+        let task_source = window.task_manager().media_element_task_source();
 
         // Step 1.
         match (old_ready_state, ready_state) {
@@ -604,11 +604,10 @@ impl HTMLMediaElement {
 
         // Step 8.
         let window = window_from_node(self);
-        window.media_element_task_source().queue_simple_event(
+        window
-            self.upcast(),
+            .task_manager()
-            atom!("loadstart"),
+            .media_element_task_source()
-            &window,
+            .queue_simple_event(self.upcast(), atom!("loadstart"), &window);
-        );
 
         // Step 9.
         match mode {
@@ -710,10 +709,13 @@ impl HTMLMediaElement {
         let context = Arc::new(Mutex::new(HTMLMediaElementContext::new(self)));
         let (action_sender, action_receiver) = ipc::channel().unwrap();
         let window = window_from_node(self);
+        let (task_source, canceller) = window
+            .task_manager()
+            .networking_task_source_with_canceller();
         let listener = NetworkListener {
             context,
-            task_source: window.networking_task_source(),
+            task_source,
-            canceller: Some(window.task_canceller(TaskSourceName::Networking)),
+            canceller: Some(canceller),
         };
         ROUTER.add_route(
             action_receiver.to_opaque(),
@@ -768,15 +770,15 @@ impl HTMLMediaElement {
 
                     // Step 4.remote.1.2.
                     let window = window_from_node(self);
-                    window.media_element_task_source().queue_simple_event(
+                    window
-                        self.upcast(),
+                        .task_manager()
-                        atom!("suspend"),
+                        .media_element_task_source()
-                        &window,
+                        .queue_simple_event(self.upcast(), atom!("suspend"), &window);
-                    );
 
                     // Step 4.remote.1.3.
                     let this = Trusted::new(self);
                     window
+                        .task_manager()
                         .media_element_task_source()
                         .queue(
                             task!(set_media_delay_load_event_flag_to_false: move || {
@@ -817,7 +819,7 @@ impl HTMLMediaElement {
         let generation_id = self.generation_id.get();
         self.take_pending_play_promises(Err(Error::NotSupported));
         // FIXME(nox): Why are errors silenced here?
-        let _ = window.media_element_task_source().queue(
+        let _ = window.task_manager().media_element_task_source().queue(
             task!(dedicated_media_source_failure_steps: move || {
                 let this = this.root();
                 if generation_id != this.generation_id.get() {
@@ -874,7 +876,7 @@ impl HTMLMediaElement {
         }
 
         let window = window_from_node(self);
-        let task_source = window.media_element_task_source();
+        let task_source = window.task_manager().media_element_task_source();
 
         // Step 5.
         let network_state = self.network_state.get();
@@ -1051,7 +1053,7 @@ impl HTMLMediaElement {
 
         // Step 10.
         let window = window_from_node(self);
-        let task_source = window.media_element_task_source();
+        let task_source = window.task_manager().media_element_task_source();
         task_source.queue_simple_event(self.upcast(), atom!("seeking"), &window);
 
         // Step 11.
@@ -1074,7 +1076,7 @@ impl HTMLMediaElement {
 
         // Step 16.
         let window = window_from_node(self);
-        let task_source = window.media_element_task_source();
+        let task_source = window.task_manager().media_element_task_source();
         task_source.queue_simple_event(self.upcast(), atom!("timeupdate"), &window);
 
         // Step 17.
@@ -1090,8 +1092,9 @@ impl HTMLMediaElement {
 
         let trusted_node = Trusted::new(self);
         let window = window_from_node(self);
-        let task_source = window.media_element_task_source();
+        let (task_source, canceller) = window
-        let task_canceller = window.task_canceller(TaskSourceName::DOMManipulation);
+            .task_manager()
+            .dom_manipulation_task_source_with_canceller();
         ROUTER.add_route(
             action_receiver.to_opaque(),
             Box::new(move |message| {
@@ -1102,7 +1105,7 @@ impl HTMLMediaElement {
                         task!(handle_player_event: move || {
                             this.root().handle_player_event(&event);
                         }),
-                        &task_canceller,
+                        &canceller,
                     )
                     .unwrap();
             }),
@@ -1134,7 +1137,7 @@ impl HTMLMediaElement {
                 }
                 if previous_duration != self.duration.get() {
                     let window = window_from_node(self);
-                    let task_source = window.media_element_task_source();
+                    let task_source = window.task_manager().media_element_task_source();
                     task_source.queue_simple_event(self.upcast(), atom!("durationchange"), &window);
                 }
 
@@ -1147,7 +1150,7 @@ impl HTMLMediaElement {
                         video_elem.set_video_width(metadata.width);
                         video_elem.set_video_height(metadata.height);
                         let window = window_from_node(self);
-                        let task_source = window.media_element_task_source();
+                        let task_source = window.task_manager().media_element_task_source();
                         task_source.queue_simple_event(self.upcast(), atom!("resize"), &window);
                     }
                 }
@@ -1515,11 +1518,10 @@ impl FetchResponseListener for HTMLMediaElementContext {
         // => "If mode is remote" step 2
         if time::get_time() > self.next_progress_event {
             let window = window_from_node(&*elem);
-            window.media_element_task_source().queue_simple_event(
+            window
-                elem.upcast(),
+                .task_manager()
-                atom!("progress"),
+                .media_element_task_source()
-                &window,
+                .queue_simple_event(elem.upcast(), atom!("progress"), &window);
-            );
             self.next_progress_event = time::get_time() + Duration::milliseconds(350);
         }
     }

components/script/dom/htmlscriptelement.rs

@@ -25,7 +25,6 @@ use crate::dom::node::{document_from_node, window_from_node};
 use crate::dom::node::{ChildrenMutation, CloneChildrenFlag, Node};
 use crate::dom::virtualmethods::VirtualMethods;
 use crate::network_listener::{NetworkListener, PreInvoke};
-use crate::task_source::TaskSourceName;
 use dom_struct::dom_struct;
 use encoding_rs::Encoding;
 use html5ever::{LocalName, Prefix};
@@ -294,10 +293,14 @@ fn fetch_a_classic_script(
     }));
 
     let (action_sender, action_receiver) = ipc::channel().unwrap();
+    let (task_source, canceller) = doc
+        .window()
+        .task_manager()
+        .networking_task_source_with_canceller();
     let listener = NetworkListener {
-        context: context,
+        context,
-        task_source: doc.window().networking_task_source(),
+        task_source,
-        canceller: Some(doc.window().task_canceller(TaskSourceName::Networking)),
+        canceller: Some(canceller),
     };
 
     ROUTER.add_route(
@@ -623,11 +626,10 @@ impl HTMLScriptElement {
 
     pub fn queue_error_event(&self) {
         let window = window_from_node(self);
-        window.dom_manipulation_task_source().queue_simple_event(
+        window
-            self.upcast(),
+            .task_manager()
-            atom!("error"),
+            .dom_manipulation_task_source()
-            &window,
+            .queue_simple_event(self.upcast(), atom!("error"), &window);
-        );
     }
 
     pub fn dispatch_load_event(&self) {

components/script/dom/htmlstyleelement.rs

@@ -127,11 +127,10 @@ impl HTMLStyleElement {
         // No subresource loads were triggered, queue load event
         if self.pending_loads.get() == 0 {
             let window = window_from_node(self);
-            window.dom_manipulation_task_source().queue_simple_event(
+            window
-                self.upcast(),
+                .task_manager()
-                atom!("load"),
+                .dom_manipulation_task_source()
-                &window,
+                .queue_simple_event(self.upcast(), atom!("load"), &window);
-            );
         }
 
         self.set_stylesheet(sheet);

components/script/dom/htmltextareaelement.rs

@@ -565,13 +565,16 @@ impl VirtualMethods for HTMLTextAreaElement {
         } else if event.type_() == atom!("keypress") && !event.DefaultPrevented() {
             if event.IsTrusted() {
                 let window = window_from_node(self);
-                let _ = window.user_interaction_task_source().queue_event(
+                let _ = window
-                    &self.upcast(),
+                    .task_manager()
-                    atom!("input"),
+                    .user_interaction_task_source()
-                    EventBubbles::Bubbles,
+                    .queue_event(
-                    EventCancelable::NotCancelable,
+                        &self.upcast(),
-                    &window,
+                        atom!("input"),
-                );
+                        EventBubbles::Bubbles,
+                        EventCancelable::NotCancelable,
+                        &window,
+                    );
             }
         }
     }

components/script/dom/offlineaudiocontext.rs

@@ -20,7 +20,7 @@ use crate::dom::event::{Event, EventBubbles, EventCancelable};
 use crate::dom::offlineaudiocompletionevent::OfflineAudioCompletionEvent;
 use crate::dom::promise::Promise;
 use crate::dom::window::Window;
-use crate::task_source::{TaskSource, TaskSourceName};
+use crate::task_source::TaskSource;
 use dom_struct::dom_struct;
 use servo_media::audio::context::OfflineAudioContextOptions as ServoMediaOfflineAudioContextOptions;
 use std::cell::Cell;
@@ -141,8 +141,9 @@ impl OfflineAudioContextMethods for OfflineAudioContext {
         let this = Trusted::new(self);
         let global = self.global();
         let window = global.as_window();
-        let task_source = window.dom_manipulation_task_source();
+        let (task_source, canceller) = window
-        let canceller = window.task_canceller(TaskSourceName::DOMManipulation);
+            .task_manager()
+            .dom_manipulation_task_source_with_canceller();
         Builder::new()
             .name("OfflineAudioContextResolver".to_owned())
             .spawn(move || {

components/script/dom/storage.rs

@@ -209,6 +209,7 @@ impl Storage {
         let this = Trusted::new(self);
         global
             .as_window()
+            .task_manager()
             .dom_manipulation_task_source()
             .queue(
                 task!(send_storage_notification: move || {

components/script/dom/textcontrol.rs

@@ -297,13 +297,16 @@ impl<'a, E: TextControlElement> TextControlSelection<'a, E> {
         // Step 6
         if textinput.selection_state() != original_selection_state {
             let window = window_from_node(self.element);
-            window.user_interaction_task_source().queue_event(
+            window
-                &self.element.upcast::<EventTarget>(),
+                .task_manager()
-                atom!("select"),
+                .user_interaction_task_source()
-                EventBubbles::Bubbles,
+                .queue_event(
-                EventCancelable::NotCancelable,
+                    &self.element.upcast::<EventTarget>(),
-                &window,
+                    atom!("select"),
-            );
+                    EventBubbles::Bubbles,
+                    EventCancelable::NotCancelable,
+                    &window,
+                );
         }
 
         self.element

components/script/dom/window.rs

@@ -64,16 +64,7 @@ use crate::script_runtime::{
 };
 use crate::script_thread::{ImageCacheMsg, MainThreadScriptChan, MainThreadScriptMsg};
 use crate::script_thread::{ScriptThread, SendableMainThreadScriptChan};
-use crate::task::TaskCanceller;
+use crate::task_manager::TaskManager;
-use crate::task_source::dom_manipulation::DOMManipulationTaskSource;
-use crate::task_source::file_reading::FileReadingTaskSource;
-use crate::task_source::history_traversal::HistoryTraversalTaskSource;
-use crate::task_source::media_element::MediaElementTaskSource;
-use crate::task_source::networking::NetworkingTaskSource;
-use crate::task_source::performance_timeline::PerformanceTimelineTaskSource;
-use crate::task_source::remote_event::RemoteEventTaskSource;
-use crate::task_source::user_interaction::UserInteractionTaskSource;
-use crate::task_source::websocket::WebsocketTaskSource;
 use crate::task_source::TaskSourceName;
 use crate::timers::{IsInterval, TimerCallback};
 use crate::webdriver_handlers::jsval_to_webdriver;
@@ -127,7 +118,7 @@ use std::fs;
 use std::io::{stderr, stdout, Write};
 use std::mem;
 use std::rc::Rc;
-use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::atomic::Ordering;
 use std::sync::{Arc, Mutex};
 use style::error_reporting::ParseErrorReporter;
 use style::media_queries;
@@ -180,24 +171,7 @@ pub struct Window {
     globalscope: GlobalScope,
     #[ignore_malloc_size_of = "trait objects are hard"]
     script_chan: MainThreadScriptChan,
-    #[ignore_malloc_size_of = "task sources are hard"]
+    task_manager: TaskManager,
-    dom_manipulation_task_source: DOMManipulationTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    media_element_task_source: MediaElementTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    user_interaction_task_source: UserInteractionTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    networking_task_source: NetworkingTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    history_traversal_task_source: HistoryTraversalTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    file_reading_task_source: FileReadingTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    performance_timeline_task_source: PerformanceTimelineTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    remote_event_task_source: RemoteEventTaskSource,
-    #[ignore_malloc_size_of = "task sources are hard"]
-    websocket_task_source: WebsocketTaskSource,
     navigator: MutNullableDom<Navigator>,
     #[ignore_malloc_size_of = "Arc"]
     image_cache: Arc<ImageCache>,
@@ -273,10 +247,6 @@ pub struct Window {
 
     current_viewport: Cell<Rect<Au>>,
 
-    /// A map of flags to prevent events from a given task source from attempting to interact with this window.
-    #[ignore_malloc_size_of = "defined in std"]
-    ignore_further_async_events: DomRefCell<HashMap<TaskSourceName, Arc<AtomicBool>>>,
-
     error_reporter: CSSErrorReporter,
 
     /// A list of scroll offsets for each scrollable element.
@@ -324,6 +294,10 @@ pub struct Window {
 }
 
 impl Window {
+    pub fn task_manager(&self) -> &TaskManager {
+        &self.task_manager
+    }
+
     pub fn get_exists_mut_observer(&self) -> bool {
         self.exists_mut_observer.get()
     }
@@ -343,7 +317,7 @@ impl Window {
     }
 
     fn ignore_all_events(&self) {
-        let mut ignore_flags = self.ignore_further_async_events.borrow_mut();
+        let mut ignore_flags = self.task_manager.task_cancellers.borrow_mut();
         for task_source_name in TaskSourceName::all() {
             let flag = ignore_flags
                 .entry(task_source_name)
@@ -365,42 +339,6 @@ impl Window {
         self.js_runtime.borrow().as_ref().unwrap().cx()
     }
 
-    pub fn dom_manipulation_task_source(&self) -> DOMManipulationTaskSource {
-        self.dom_manipulation_task_source.clone()
-    }
-
-    pub fn media_element_task_source(&self) -> MediaElementTaskSource {
-        self.media_element_task_source.clone()
-    }
-
-    pub fn user_interaction_task_source(&self) -> UserInteractionTaskSource {
-        self.user_interaction_task_source.clone()
-    }
-
-    pub fn networking_task_source(&self) -> NetworkingTaskSource {
-        self.networking_task_source.clone()
-    }
-
-    pub fn history_traversal_task_source(&self) -> Box<dyn ScriptChan + Send> {
-        self.history_traversal_task_source.clone()
-    }
-
-    pub fn file_reading_task_source(&self) -> FileReadingTaskSource {
-        self.file_reading_task_source.clone()
-    }
-
-    pub fn performance_timeline_task_source(&self) -> PerformanceTimelineTaskSource {
-        self.performance_timeline_task_source.clone()
-    }
-
-    pub fn remote_event_task_source(&self) -> RemoteEventTaskSource {
-        self.remote_event_task_source.clone()
-    }
-
-    pub fn websocket_task_source(&self) -> WebsocketTaskSource {
-        self.websocket_task_source.clone()
-    }
-
     pub fn main_thread_script_chan(&self) -> &Sender<MainThreadScriptMsg> {
         &self.script_chan.0
     }
@@ -1234,14 +1172,6 @@ impl Window {
         self.paint_worklet.or_init(|| self.new_paint_worklet())
     }
 
-    pub fn task_canceller(&self, name: TaskSourceName) -> TaskCanceller {
-        let mut flags = self.ignore_further_async_events.borrow_mut();
-        let cancel_flag = flags.entry(name).or_insert(Default::default());
-        TaskCanceller {
-            cancelled: Some(cancel_flag.clone()),
-        }
-    }
-
     pub fn get_navigation_start(&self) -> u64 {
         self.navigation_start_precise.get()
     }
@@ -1252,10 +1182,10 @@ impl Window {
 
     /// Cancels all the tasks associated with that window.
     ///
-    /// This sets the current `ignore_further_async_events` sentinel value to
+    /// This sets the current `task_manager.task_cancellers` sentinel value to
     /// `true` and replaces it with a brand new one for future tasks.
     pub fn cancel_all_tasks(&self) {
-        let mut ignore_flags = self.ignore_further_async_events.borrow_mut();
+        let mut ignore_flags = self.task_manager.task_cancellers.borrow_mut();
         for task_source_name in TaskSourceName::all() {
             let flag = ignore_flags
                 .entry(task_source_name)
@@ -1269,7 +1199,7 @@ impl Window {
     /// This sets the current sentinel value to
     /// `true` and replaces it with a brand new one for future tasks.
     pub fn cancel_all_tasks_from_source(&self, task_source_name: TaskSourceName) {
-        let mut ignore_flags = self.ignore_further_async_events.borrow_mut();
+        let mut ignore_flags = self.task_manager.task_cancellers.borrow_mut();
         let flag = ignore_flags
             .entry(task_source_name)
             .or_insert(Default::default());
@@ -1830,7 +1760,8 @@ impl Window {
                 let _ = self.script_chan.send(CommonScriptMsg::Task(
                     ScriptThreadEventCategory::DomEvent,
                     Box::new(
-                        self.task_canceller(TaskSourceName::DOMManipulation)
+                        self.task_manager
+                            .task_canceller(TaskSourceName::DOMManipulation)
                             .wrap_task(task),
                     ),
                     self.pipeline_id(),
@@ -2076,15 +2007,7 @@ impl Window {
     pub fn new(
         runtime: Rc<Runtime>,
         script_chan: MainThreadScriptChan,
-        dom_manipulation_task_source: DOMManipulationTaskSource,
+        task_manager: TaskManager,
-        media_element_task_source: MediaElementTaskSource,
-        user_interaction_task_source: UserInteractionTaskSource,
-        networking_task_source: NetworkingTaskSource,
-        history_traversal_task_source: HistoryTraversalTaskSource,
-        file_reading_task_source: FileReadingTaskSource,
-        performance_timeline_task_source: PerformanceTimelineTaskSource,
-        remote_event_task_source: RemoteEventTaskSource,
-        websocket_task_source: WebsocketTaskSource,
         image_cache_chan: Sender<ImageCacheMsg>,
         image_cache: Arc<dyn ImageCache>,
         resource_threads: ResourceThreads,
@@ -2132,15 +2055,7 @@ impl Window {
                 microtask_queue,
             ),
             script_chan,
-            dom_manipulation_task_source,
+            task_manager,
-            media_element_task_source,
-            user_interaction_task_source,
-            networking_task_source,
-            history_traversal_task_source,
-            file_reading_task_source,
-            performance_timeline_task_source,
-            remote_event_task_source,
-            websocket_task_source,
             image_cache_chan,
             image_cache,
             navigator: Default::default(),
@@ -2173,7 +2088,6 @@ impl Window {
             devtools_marker_sender: Default::default(),
             devtools_markers: Default::default(),
             webdriver_script_chan: Default::default(),
-            ignore_further_async_events: Default::default(),
             error_reporter,
             scroll_offsets: Default::default(),
             media_query_lists: DOMTracker::new(),
@@ -2314,7 +2228,8 @@ impl Window {
         let _ = self.script_chan.send(CommonScriptMsg::Task(
             ScriptThreadEventCategory::DomEvent,
             Box::new(
-                self.task_canceller(TaskSourceName::DOMManipulation)
+                self.task_manager
+                    .task_canceller(TaskSourceName::DOMManipulation)
                     .wrap_task(task),
             ),
             self.pipeline_id(),

components/script/layout_image.rs

@@ -10,7 +10,6 @@
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::node::{document_from_node, Node};
 use crate::network_listener::{NetworkListener, PreInvoke};
-use crate::task_source::TaskSourceName;
 use ipc_channel::ipc;
 use ipc_channel::router::ROUTER;
 use net_traits::image_cache::{ImageCache, PendingImageId};
@@ -57,13 +56,16 @@ pub fn fetch_image_for_layout(
     }));
 
     let document = document_from_node(node);
-    let window = document.window();
 
     let (action_sender, action_receiver) = ipc::channel().unwrap();
+    let (task_source, canceller) = document
+        .window()
+        .task_manager()
+        .networking_task_source_with_canceller();
     let listener = NetworkListener {
-        context: context,
+        context,
-        task_source: window.networking_task_source(),
+        task_source,
-        canceller: Some(window.task_canceller(TaskSourceName::Networking)),
+        canceller: Some(canceller),
     };
     ROUTER.add_route(
         action_receiver.to_opaque(),

components/script/lib.rs

@@ -69,6 +69,7 @@ pub mod script_thread;
 mod serviceworker_manager;
 mod serviceworkerjob;
 mod stylesheet_loader;
+mod task_manager;
 mod task_queue;
 mod task_source;
 pub mod test;

components/script/script_runtime.rs

@@ -101,6 +101,7 @@ pub enum ScriptThreadEventCategory {
     DomEvent,
     FileRead,
     FormPlannedNavigation,
+    HistoryEvent,
     ImageCacheMsg,
     InputEvent,
     NetworkEvent,

components/script/script_thread.rs

@@ -70,6 +70,7 @@ use crate::microtask::{Microtask, MicrotaskQueue};
 use crate::script_runtime::{get_reports, new_rt_and_cx, Runtime, ScriptPort};
 use crate::script_runtime::{CommonScriptMsg, ScriptChan, ScriptThreadEventCategory};
 use crate::serviceworkerjob::{Job, JobQueue};
+use crate::task_manager::TaskManager;
 use crate::task_queue::{QueuedTask, QueuedTaskConversion, TaskQueue};
 use crate::task_source::dom_manipulation::DOMManipulationTaskSource;
 use crate::task_source::file_reading::FileReadingTaskSource;
@@ -521,7 +522,7 @@ pub struct ScriptThread {
 
     networking_task_sender: Box<dyn ScriptChan>,
 
-    history_traversal_task_source: HistoryTraversalTaskSource,
+    history_traversal_task_sender: Sender<MainThreadScriptMsg>,
 
     file_reading_task_sender: Box<dyn ScriptChan>,
 
@@ -1042,7 +1043,7 @@ impl ScriptThread {
             performance_timeline_task_sender: boxed_script_sender.clone(),
             remote_event_task_sender: boxed_script_sender.clone(),
 
-            history_traversal_task_source: HistoryTraversalTaskSource(chan),
+            history_traversal_task_sender: chan.clone(),
 
             control_chan: state.control_chan,
             control_port: control_port,
@@ -1409,6 +1410,7 @@ impl ScriptThread {
                 ScriptThreadEventCategory::FormPlannedNavigation => {
                     ProfilerCategory::ScriptPlannedNavigation
                 },
+                ScriptThreadEventCategory::HistoryEvent => ProfilerCategory::ScriptHistoryEvent,
                 ScriptThreadEventCategory::ImageCacheMsg => ProfilerCategory::ScriptImageCacheMsg,
                 ScriptThreadEventCategory::InputEvent => ProfilerCategory::ScriptInputEvent,
                 ScriptThreadEventCategory::NetworkEvent => ProfilerCategory::ScriptNetworkEvent,
@@ -2180,6 +2182,13 @@ impl ScriptThread {
         PerformanceTimelineTaskSource(self.performance_timeline_task_sender.clone(), pipeline_id)
     }
 
+    pub fn history_traversal_task_source(
+        &self,
+        pipeline_id: PipelineId,
+    ) -> HistoryTraversalTaskSource {
+        HistoryTraversalTaskSource(self.history_traversal_task_sender.clone(), pipeline_id)
+    }
+
     pub fn user_interaction_task_source(
         &self,
         pipeline_id: PipelineId,
@@ -2560,7 +2569,6 @@ impl ScriptThread {
         );
 
         let MainThreadScriptChan(ref sender) = self.chan;
-        let HistoryTraversalTaskSource(ref history_sender) = self.history_traversal_task_source;
 
         let (ipc_timer_event_chan, ipc_timer_event_port) = ipc::channel().unwrap();
         route_ipc_receiver_to_new_servo_sender(ipc_timer_event_port, self.timer_event_chan.clone());
@@ -2576,20 +2584,23 @@ impl ScriptThread {
             pipeline_id: incomplete.pipeline_id,
         };
 
+        let task_manager = TaskManager::new(
+            self.dom_manipulation_task_source(incomplete.pipeline_id),
+            self.file_reading_task_source(incomplete.pipeline_id),
+            self.history_traversal_task_source(incomplete.pipeline_id),
+            self.media_element_task_source(incomplete.pipeline_id),
+            self.networking_task_source(incomplete.pipeline_id),
+            self.performance_timeline_task_source(incomplete.pipeline_id)
+                .clone(),
+            self.user_interaction_task_source(incomplete.pipeline_id),
+            self.remote_event_task_source(incomplete.pipeline_id),
+            self.websocket_task_source(incomplete.pipeline_id),
+        );
         // Create the window and document objects.
         let window = Window::new(
             self.js_runtime.clone(),
             MainThreadScriptChan(sender.clone()),
-            self.dom_manipulation_task_source(incomplete.pipeline_id),
+            task_manager,
-            self.media_element_task_source(incomplete.pipeline_id),
-            self.user_interaction_task_source(incomplete.pipeline_id),
-            self.networking_task_source(incomplete.pipeline_id),
-            HistoryTraversalTaskSource(history_sender.clone()),
-            self.file_reading_task_source(incomplete.pipeline_id),
-            self.performance_timeline_task_source(incomplete.pipeline_id)
-                .clone(),
-            self.remote_event_task_source(incomplete.pipeline_id),
-            self.websocket_task_source(incomplete.pipeline_id),
             self.image_cache_channel.clone(),
             self.image_cache.clone(),
             self.resource_threads.clone(),

components/script/stylesheet_loader.rs

@@ -13,7 +13,6 @@ use crate::dom::htmlelement::HTMLElement;
 use crate::dom::htmllinkelement::{HTMLLinkElement, RequestGenerationId};
 use crate::dom::node::{document_from_node, window_from_node};
 use crate::network_listener::{NetworkListener, PreInvoke};
-use crate::task_source::TaskSourceName;
 use cssparser::SourceLocation;
 use encoding_rs::UTF_8;
 use ipc_channel::ipc;
@@ -245,10 +244,14 @@ impl<'a> StylesheetLoader<'a> {
         }));
 
         let (action_sender, action_receiver) = ipc::channel().unwrap();
+        let (task_source, canceller) = document
+            .window()
+            .task_manager()
+            .networking_task_source_with_canceller();
         let listener = NetworkListener {
-            context: context,
+            context,
-            task_source: document.window().networking_task_source(),
+            task_source,
-            canceller: Some(document.window().task_canceller(TaskSourceName::Networking)),
+            canceller: Some(canceller),
         };
         ROUTER.add_route(
             action_receiver.to_opaque(),

components/script/task_manager.rs

@@ -0,0 +1,162 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use crate::dom::bindings::cell::DomRefCell;
+use crate::task::TaskCanceller;
+use crate::task_source::dom_manipulation::DOMManipulationTaskSource;
+use crate::task_source::file_reading::FileReadingTaskSource;
+use crate::task_source::history_traversal::HistoryTraversalTaskSource;
+use crate::task_source::media_element::MediaElementTaskSource;
+use crate::task_source::networking::NetworkingTaskSource;
+use crate::task_source::performance_timeline::PerformanceTimelineTaskSource;
+use crate::task_source::remote_event::RemoteEventTaskSource;
+use crate::task_source::user_interaction::UserInteractionTaskSource;
+use crate::task_source::websocket::WebsocketTaskSource;
+use crate::task_source::TaskSourceName;
+use std::collections::HashMap;
+use std::sync::atomic::AtomicBool;
+use std::sync::Arc;
+
+macro_rules! task_source_functions {
+    ($self:ident,$with_canceller:ident,$task_source:ident,$task_source_type:ident,$task_source_name:ident) => {
+        pub fn $with_canceller(&$self) -> ($task_source_type, TaskCanceller) {
+            ($self.$task_source.clone(), $self.task_canceller(TaskSourceName::$task_source_name))
+        }
+
+        pub fn $task_source(&$self) -> $task_source_type {
+            $self.$task_source.clone()
+        }
+    }
+}
+
+#[derive(JSTraceable, MallocSizeOf)]
+pub struct TaskManager {
+    #[ignore_malloc_size_of = "task sources are hard"]
+    pub task_cancellers: DomRefCell<HashMap<TaskSourceName, Arc<AtomicBool>>>,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    dom_manipulation_task_source: DOMManipulationTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    file_reading_task_source: FileReadingTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    history_traversal_task_source: HistoryTraversalTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    media_element_task_source: MediaElementTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    networking_task_source: NetworkingTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    performance_timeline_task_source: PerformanceTimelineTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    user_interaction_task_source: UserInteractionTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    remote_event_task_source: RemoteEventTaskSource,
+    #[ignore_malloc_size_of = "task sources are hard"]
+    websocket_task_source: WebsocketTaskSource,
+}
+
+impl TaskManager {
+    pub fn new(
+        dom_manipulation_task_source: DOMManipulationTaskSource,
+        file_reading_task_source: FileReadingTaskSource,
+        history_traversal_task_source: HistoryTraversalTaskSource,
+        media_element_task_source: MediaElementTaskSource,
+        networking_task_source: NetworkingTaskSource,
+        performance_timeline_task_source: PerformanceTimelineTaskSource,
+        user_interaction_task_source: UserInteractionTaskSource,
+        remote_event_task_source: RemoteEventTaskSource,
+        websocket_task_source: WebsocketTaskSource,
+    ) -> Self {
+        TaskManager {
+            dom_manipulation_task_source,
+            file_reading_task_source,
+            history_traversal_task_source,
+            media_element_task_source,
+            networking_task_source,
+            performance_timeline_task_source,
+            user_interaction_task_source,
+            remote_event_task_source,
+            websocket_task_source,
+            task_cancellers: Default::default(),
+        }
+    }
+
+    task_source_functions!(
+        self,
+        dom_manipulation_task_source_with_canceller,
+        dom_manipulation_task_source,
+        DOMManipulationTaskSource,
+        DOMManipulation
+    );
+
+    task_source_functions!(
+        self,
+        media_element_task_source_with_canceller,
+        media_element_task_source,
+        MediaElementTaskSource,
+        MediaElement
+    );
+
+    task_source_functions!(
+        self,
+        user_interaction_task_source_with_canceller,
+        user_interaction_task_source,
+        UserInteractionTaskSource,
+        UserInteraction
+    );
+
+    task_source_functions!(
+        self,
+        networking_task_source_with_canceller,
+        networking_task_source,
+        NetworkingTaskSource,
+        Networking
+    );
+
+    task_source_functions!(
+        self,
+        file_reading_task_source_with_canceller,
+        file_reading_task_source,
+        FileReadingTaskSource,
+        FileReading
+    );
+
+    task_source_functions!(
+        self,
+        history_traversal_task_source_with_canceller,
+        history_traversal_task_source,
+        HistoryTraversalTaskSource,
+        HistoryTraversal
+    );
+
+    task_source_functions!(
+        self,
+        performance_timeline_task_source_with_canceller,
+        performance_timeline_task_source,
+        PerformanceTimelineTaskSource,
+        PerformanceTimeline
+    );
+
+    task_source_functions!(
+        self,
+        remote_event_task_source_with_canceller,
+        remote_event_task_source,
+        RemoteEventTaskSource,
+        RemoteEvent
+    );
+
+    task_source_functions!(
+        self,
+        websocket_task_source_with_canceller,
+        websocket_task_source,
+        WebsocketTaskSource,
+        Websocket
+    );
+
+    pub fn task_canceller(&self, name: TaskSourceName) -> TaskCanceller {
+        let mut flags = self.task_cancellers.borrow_mut();
+        let cancel_flag = flags.entry(name).or_insert(Default::default());
+        TaskCanceller {
+            cancelled: Some(cancel_flag.clone()),
+        }
+    }
+}

components/script/task_source/history_traversal.rs

@@ -2,21 +2,29 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use crate::script_runtime::{CommonScriptMsg, ScriptChan};
+use crate::script_runtime::{CommonScriptMsg, ScriptThreadEventCategory};
 use crate::script_thread::MainThreadScriptMsg;
+use crate::task::{TaskCanceller, TaskOnce};
+use crate::task_source::{TaskSource, TaskSourceName};
+use msg::constellation_msg::PipelineId;
 use servo_channel::Sender;
 
-#[derive(JSTraceable)]
+#[derive(Clone, JSTraceable)]
-pub struct HistoryTraversalTaskSource(pub Sender<MainThreadScriptMsg>);
+pub struct HistoryTraversalTaskSource(pub Sender<MainThreadScriptMsg>, pub PipelineId);
 
-impl ScriptChan for HistoryTraversalTaskSource {
+impl TaskSource for HistoryTraversalTaskSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
+    const NAME: TaskSourceName = TaskSourceName::HistoryTraversal;
-        self.0
-            .send(MainThreadScriptMsg::Common(msg))
-            .map_err(|_| ())
-    }
 
-    fn clone(&self) -> Box<dyn ScriptChan + Send> {
+    fn queue_with_canceller<T>(&self, task: T, canceller: &TaskCanceller) -> Result<(), ()>
-        Box::new(HistoryTraversalTaskSource((&self.0).clone()))
+    where
+        T: TaskOnce + 'static,
+    {
+        let msg = MainThreadScriptMsg::Common(CommonScriptMsg::Task(
+            ScriptThreadEventCategory::HistoryEvent,
+            Box::new(canceller.wrap_task(task)),
+            Some(self.1),
+            HistoryTraversalTaskSource::NAME,
+        ));
+        self.0.send(msg).map_err(|_| ())
     }
 }