Add task_source directory

Use DOMManipulationTaskSource whenever possible

17 files changed, 261 insertions, 185 deletions

diff --git a/components/script/dom/bindings/global.rs b/components/script/dom/bindings/global.rs
index c7ba5aaaf6c..dab74fd5850 100644
--- a/components/script/dom/bindings/global.rs
+++ b/components/script/dom/bindings/global.rs
@@ -21,8 +21,10 @@ use js::{JSCLASS_IS_DOMJSCLASS, JSCLASS_IS_GLOBAL};
 use msg::constellation_msg::{ConstellationChan, PipelineId};
 use net_traits::ResourceThread;
 use profile_traits::mem;
-use script_thread::{CommonScriptMsg, ScriptChan, ScriptPort, ScriptThread};
+use script_thread::{CommonScriptMsg, MainThreadScriptChan, ScriptChan, ScriptPort, ScriptThread};
 use script_traits::{MsDuration, ScriptMsg as ConstellationMsg, TimerEventRequest};
+use task_source::TaskSource;
+use task_source::dom_manipulation::DOMManipulationTask;
 use timers::{OneshotTimerCallback, OneshotTimerHandle};
 use url::Url;
 
@@ -142,13 +144,24 @@ impl<'a> GlobalRef<'a> {
 
     /// `ScriptChan` used to send messages to the event loop of this global's
     /// thread.
-    pub fn dom_manipulation_task_source(&self) -> Box<ScriptChan + Send> {
+    pub fn script_chan(&self) -> Box<ScriptChan + Send> {
         match *self {
-            GlobalRef::Window(ref window) => window.dom_manipulation_task_source(),
+            GlobalRef::Window(ref window) => {
+                MainThreadScriptChan(window.main_thread_script_chan().clone()).clone()
+            }
             GlobalRef::Worker(ref worker) => worker.script_chan(),
         }
     }
 
+    /// `TaskSource` used to queue DOM manipulation messages to the event loop of this global's
+    /// thread.
+    pub fn dom_manipulation_task_source(&self) -> Box<TaskSource<DOMManipulationTask> + Send> {
+        match *self {
+            GlobalRef::Window(ref window) => window.dom_manipulation_task_source(),
+            GlobalRef::Worker(_) => unimplemented!(),
+        }
+    }
+
     /// `ScriptChan` used to send messages to the event loop of this global's
     /// thread.
     pub fn user_interaction_task_source(&self) -> Box<ScriptChan + Send> {
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 7d0a3be8b14..e0f4c0c5592 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -89,7 +89,7 @@ use net_traits::CookieSource::NonHTTP;
 use net_traits::response::HttpsState;
 use net_traits::{AsyncResponseTarget, PendingAsyncLoad};
 use num::ToPrimitive;
-use script_thread::{MainThreadScriptMsg, Runnable};
+use script_thread::{MainThreadScriptChan, MainThreadScriptMsg, Runnable, ScriptChan};
 use script_traits::{AnimationState, MouseButton, MouseEventType, MozBrowserEvent};
 use script_traits::{ScriptMsg as ConstellationMsg, ScriptToCompositorMsg};
 use script_traits::{TouchEventType, TouchId};
@@ -108,6 +108,7 @@ use string_cache::{Atom, QualName};
 use style::context::ReflowGoal;
 use style::restyle_hints::ElementSnapshot;
 use style::servo::Stylesheet;
+use task_source::dom_manipulation::DOMManipulationTask;
 use time;
 use url::percent_encoding::percent_decode;
 use url::{Host, Url};
@@ -1406,11 +1407,11 @@ impl Document {
 
         update_with_current_time(&self.dom_content_loaded_event_start);
 
-        let doctarget = self.upcast::<EventTarget>();
-        let _ = doctarget.fire_event("DOMContentLoaded",
-                                     EventBubbles::Bubbles,
-                                     EventCancelable::NotCancelable);
-
+        let chan = MainThreadScriptChan(self.window().main_thread_script_chan().clone()).clone();
+        let doctarget = Trusted::new(self.upcast::<EventTarget>(), chan);
+        let task_source = self.window().dom_manipulation_task_source();
+        let _ = task_source.queue(DOMManipulationTask::FireEvent(
+            atom!("DOMContentLoaded"), doctarget, EventBubbles::Bubbles, EventCancelable::NotCancelable));
         self.window().reflow(ReflowGoal::ForDisplay,
                              ReflowQueryType::NoQuery,
                              ReflowReason::DOMContentLoaded);
@@ -2590,13 +2591,13 @@ fn update_with_current_time(marker: &Cell<u64>) {
 }
 
 pub struct DocumentProgressHandler {
-    addr: Trusted<Document>,
+    addr: Trusted<Document>
 }
 
 impl DocumentProgressHandler {
-    pub fn new(addr: Trusted<Document>) -> DocumentProgressHandler {
+     pub fn new(addr: Trusted<Document>) -> DocumentProgressHandler {
         DocumentProgressHandler {
-            addr: addr,
+            addr: addr
         }
     }
 
diff --git a/components/script/dom/htmldetailselement.rs b/components/script/dom/htmldetailselement.rs
index 8b8735ca0d6..01286dd2265 100644
--- a/components/script/dom/htmldetailselement.rs
+++ b/components/script/dom/htmldetailselement.rs
@@ -14,10 +14,10 @@ use dom::eventtarget::EventTarget;
 use dom::htmlelement::HTMLElement;
 use dom::node::{Node, window_from_node};
 use dom::virtualmethods::VirtualMethods;
-use script_thread::ScriptThreadEventCategory::DomEvent;
-use script_thread::{CommonScriptMsg, Runnable};
+use script_thread::{MainThreadScriptChan, Runnable, ScriptChan};
 use std::cell::Cell;
 use string_cache::Atom;
+use task_source::dom_manipulation::DOMManipulationTask;
 use util::str::DOMString;
 
 #[dom_struct]
@@ -69,7 +69,17 @@ impl VirtualMethods for HTMLDetailsElement {
         if attr.local_name() == &atom!("open") {
             let counter = self.toggle_counter.get() + 1;
             self.toggle_counter.set(counter);
-            ToggleEventRunnable::send(&self, counter);
+
+            let window = window_from_node(self);
+            let window = window.r();
+            let task_source = window.dom_manipulation_task_source();
+            let chan = MainThreadScriptChan(window.main_thread_script_chan().clone()).clone();
+            let details = Trusted::new(self, chan.clone());
+            let runnable = box ToggleEventRunnable {
+                element: details,
+                toggle_number: counter
+            };
+            let _ = task_source.queue(DOMManipulationTask::FireToggleEvent(runnable));
         }
     }
 }
@@ -79,20 +89,6 @@ pub struct ToggleEventRunnable {
     toggle_number: u32
 }
 
-impl ToggleEventRunnable {
-    pub fn send(node: &HTMLDetailsElement, toggle_number: u32) {
-        let window = window_from_node(node);
-        let window = window.r();
-        let chan = window.dom_manipulation_task_source();
-        let handler = Trusted::new(node, chan.clone());
-        let dispatcher = ToggleEventRunnable {
-            element: handler,
-            toggle_number: toggle_number,
-        };
-        let _ = chan.send(CommonScriptMsg::RunnableMsg(DomEvent, box dispatcher));
-    }
-}
-
 impl Runnable for ToggleEventRunnable {
     fn handler(self: Box<ToggleEventRunnable>) {
         let target = self.element.root();
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index 167e1698845..1d84c78f78b 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -37,12 +37,12 @@ use hyper::header::ContentType;
 use hyper::method::Method;
 use hyper::mime;
 use msg::constellation_msg::{LoadData, PipelineId};
-use script_thread::ScriptThreadEventCategory::FormPlannedNavigation;
-use script_thread::{CommonScriptMsg, MainThreadScriptMsg, Runnable, ScriptChan};
+use script_thread::{MainThreadScriptChan, MainThreadScriptMsg, Runnable, ScriptChan};
 use std::borrow::ToOwned;
 use std::cell::Cell;
 use std::sync::mpsc::Sender;
 use string_cache::Atom;
+use task_source::dom_manipulation::DOMManipulationTask;
 use url::form_urlencoded::serialize;
 use util::str::DOMString;
 
@@ -76,6 +76,10 @@ impl HTMLFormElement {
         let element = HTMLFormElement::new_inherited(localName, prefix, document);
         Node::reflect_node(box element, document, HTMLFormElementBinding::Wrap)
     }
+
+    pub fn generation_id(&self) -> GenerationId {
+        self.generation_id.get()
+    }
 }
 
 impl HTMLFormElementMethods for HTMLFormElement {
@@ -322,17 +326,20 @@ impl HTMLFormElement {
         // generation ID is the same as its own generation ID.
         let GenerationId(prev_id) = self.generation_id.get();
         self.generation_id.set(GenerationId(prev_id + 1));
+
         // Step 2
+        let chan = MainThreadScriptChan(window.main_thread_script_chan().clone()).clone();
         let nav = box PlannedNavigation {
             load_data: load_data,
             pipeline_id: window.pipeline(),
             script_chan: window.main_thread_script_chan().clone(),
             generation_id: self.generation_id.get(),
-            form: Trusted::new(self, window.dom_manipulation_task_source())
+            form: Trusted::new(self, chan)
         };
+
         // Step 3
-        window.dom_manipulation_task_source().send(
-            CommonScriptMsg::RunnableMsg(FormPlannedNavigation, nav)).unwrap();
+        window.dom_manipulation_task_source().queue(
+            DOMManipulationTask::PlannedNavigation(nav)).unwrap();
     }
 
     /// Interactively validate the constraints of form elements
diff --git a/components/script/dom/htmlscriptelement.rs b/components/script/dom/htmlscriptelement.rs
index b0e0c9c041e..bbd1884dc4f 100644
--- a/components/script/dom/htmlscriptelement.rs
+++ b/components/script/dom/htmlscriptelement.rs
@@ -19,6 +19,7 @@ use dom::bindings::trace::JSTraceable;
 use dom::document::Document;
 use dom::element::{AttributeMutation, Element, ElementCreator};
 use dom::event::{Event, EventBubbles, EventCancelable};
+use dom::eventtarget::EventTarget;
 use dom::htmlelement::HTMLElement;
 use dom::node::{ChildrenMutation, CloneChildrenFlag, Node};
 use dom::node::{document_from_node, window_from_node};
@@ -34,13 +35,13 @@ use js::jsapi::RootedValue;
 use js::jsval::UndefinedValue;
 use net_traits::{AsyncResponseListener, AsyncResponseTarget, Metadata};
 use network_listener::{NetworkListener, PreInvoke};
-use script_thread::ScriptThreadEventCategory::ScriptEvent;
-use script_thread::{CommonScriptMsg, Runnable, ScriptChan};
+use script_thread::{MainThreadScriptChan, ScriptChan};
 use std::ascii::AsciiExt;
 use std::cell::Cell;
 use std::mem;
 use std::sync::{Arc, Mutex};
 use string_cache::Atom;
+use task_source::dom_manipulation::DOMManipulationTask;
 use url::Url;
 use util::str::{DOMString, HTML_SPACE_CHARACTERS, StaticStringVec};
 
@@ -442,26 +443,20 @@ impl HTMLScriptElement {
         if external {
             self.dispatch_load_event();
         } else {
-            let chan = window.dom_manipulation_task_source();
-            let handler = Trusted::new(self, chan.clone());
-            let dispatcher = box EventDispatcher {
-                element: handler,
-                is_error: false,
-            };
-            chan.send(CommonScriptMsg::RunnableMsg(ScriptEvent, dispatcher)).unwrap();
+            let chan = MainThreadScriptChan(window.main_thread_script_chan().clone()).clone();
+            let script_element = Trusted::new(self.upcast::<EventTarget>(), chan);
+            let task_source = window.dom_manipulation_task_source();
+            task_source.queue(DOMManipulationTask::FireSimpleEvent(atom!("load"), script_element)).unwrap();
         }
     }
 
     pub fn queue_error_event(&self) {
         let window = window_from_node(self);
         let window = window.r();
-        let chan = window.dom_manipulation_task_source();
-        let handler = Trusted::new(self, chan.clone());
-        let dispatcher = box EventDispatcher {
-            element: handler,
-            is_error: true,
-        };
-        chan.send(CommonScriptMsg::RunnableMsg(ScriptEvent, dispatcher)).unwrap();
+        let chan = MainThreadScriptChan(window.main_thread_script_chan().clone()).clone();
+        let task_source = window.dom_manipulation_task_source();
+        let script_element = Trusted::new(self.upcast::<EventTarget>(), chan);
+        task_source.queue(DOMManipulationTask::FireSimpleEvent(atom!("error"), script_element)).unwrap();
     }
 
     pub fn dispatch_before_script_execute_event(&self) -> bool {
@@ -610,19 +605,3 @@ impl HTMLScriptElementMethods for HTMLScriptElement {
         self.upcast::<Node>().SetTextContent(Some(value))
     }
 }
-
-struct EventDispatcher {
-    element: Trusted<HTMLScriptElement>,
-    is_error: bool,
-}
-
-impl Runnable for EventDispatcher {
-    fn handler(self: Box<EventDispatcher>) {
-        let target = self.element.root();
-        if self.is_error {
-            target.dispatch_error_event();
-        } else {
-            target.dispatch_load_event();
-        }
-    }
-}
diff --git a/components/script/dom/storage.rs b/components/script/dom/storage.rs
index c5d79fe7baf..b264580495a 100644
--- a/components/script/dom/storage.rs
+++ b/components/script/dom/storage.rs
@@ -16,7 +16,8 @@ use dom::urlhelper::UrlHelper;
 use ipc_channel::ipc;
 use net_traits::storage_thread::{StorageThread, StorageThreadMsg, StorageType};
 use page::IterablePage;
-use script_thread::{MainThreadRunnable, MainThreadScriptMsg, ScriptThread};
+use script_thread::{MainThreadRunnable, MainThreadScriptChan, ScriptChan, ScriptThread};
+use task_source::dom_manipulation::DOMManipulationTask;
 use url::Url;
 use util::str::DOMString;
 
@@ -153,10 +154,10 @@ impl Storage {
                                      new_value: Option<String>) {
         let global_root = self.global();
         let global_ref = global_root.r();
-        let main_script_chan = global_ref.as_window().main_thread_script_chan();
-        let script_chan = global_ref.dom_manipulation_task_source();
-        let trusted_storage = Trusted::new(self, script_chan);
-        main_script_chan.send(MainThreadScriptMsg::MainThreadRunnableMsg(
+        let task_source = global_ref.as_window().dom_manipulation_task_source();
+        let chan = MainThreadScriptChan(global_ref.as_window().main_thread_script_chan().clone()).clone();
+        let trusted_storage = Trusted::new(self, chan);
+        task_source.queue(DOMManipulationTask::SendStorageNotification(
             box StorageEventRunnable::new(trusted_storage, key, old_value, new_value))).unwrap();
     }
 }
diff --git a/components/script/dom/webidls/Worker.webidl b/components/script/dom/webidls/Worker.webidl
index c80ff3898cc..62cd5c89f92 100644
--- a/components/script/dom/webidls/Worker.webidl
+++ b/components/script/dom/webidls/Worker.webidl
@@ -14,8 +14,8 @@ interface AbstractWorker {
 interface Worker : EventTarget {
   //void terminate();
 
-  [Throws]
-  void postMessage(any message/*, optional sequence<Transferable> transfer*/);
+[Throws]
+void postMessage(any message/*, optional sequence<Transferable> transfer*/);
            attribute EventHandler onmessage;
 };
 Worker implements AbstractWorker;
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index e81efa4a77c..eeb62d833c6 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -53,9 +53,8 @@ use page::Page;
 use profile_traits::mem;
 use reporter::CSSErrorReporter;
 use rustc_serialize::base64::{FromBase64, STANDARD, ToBase64};
-use script_thread::{DOMManipulationTaskSource, UserInteractionTaskSource, NetworkingTaskSource};
-use script_thread::{HistoryTraversalTaskSource, FileReadingTaskSource, SendableMainThreadScriptChan};
-use script_thread::{ScriptChan, ScriptPort, MainThreadScriptChan, MainThreadScriptMsg, RunnableWrapper};
+use script_thread::{MainThreadScriptChan, MainThreadScriptMsg, RunnableWrapper};
+use script_thread::{SendableMainThreadScriptChan, ScriptChan, ScriptPort};
 use script_traits::{ConstellationControlMsg, UntrustedNodeAddress};
 use script_traits::{DocumentState, MsDuration, ScriptToCompositorMsg, TimerEvent, TimerEventId};
 use script_traits::{MozBrowserEvent, ScriptMsg as ConstellationMsg, TimerEventRequest, TimerSource};
@@ -75,6 +74,12 @@ use string_cache::Atom;
 use style::context::ReflowGoal;
 use style::error_reporting::ParseErrorReporter;
 use style::selector_impl::PseudoElement;
+use task_source::TaskSource;
+use task_source::dom_manipulation::{DOMManipulationTaskSource, DOMManipulationTask};
+use task_source::file_reading::FileReadingTaskSource;
+use task_source::history_traversal::HistoryTraversalTaskSource;
+use task_source::networking::NetworkingTaskSource;
+use task_source::user_interaction::UserInteractionTaskSource;
 use time;
 use timers::{IsInterval, OneshotTimerCallback, OneshotTimerHandle, OneshotTimers, TimerCallback};
 use url::Url;
@@ -258,7 +263,7 @@ impl Window {
         self.js_runtime.borrow().as_ref().unwrap().cx()
     }
 
-    pub fn dom_manipulation_task_source(&self) -> Box<ScriptChan + Send> {
+    pub fn dom_manipulation_task_source(&self) -> Box<TaskSource<DOMManipulationTask> + Send> {
         self.dom_manipulation_task_source.clone()
     }
 
@@ -279,8 +284,7 @@ impl Window {
     }
 
     pub fn main_thread_script_chan(&self) -> &Sender<MainThreadScriptMsg> {
-        let MainThreadScriptChan(ref sender) = self.script_chan;
-        sender
+        &self.script_chan.0
     }
 
     pub fn image_cache_chan(&self) -> ImageCacheChan {
diff --git a/components/script/dom/worker.rs b/components/script/dom/worker.rs
index 815100ba32f..dfa8d1363f3 100644
--- a/components/script/dom/worker.rs
+++ b/components/script/dom/worker.rs
@@ -71,7 +71,7 @@ impl Worker {
 
         let (sender, receiver) = channel();
         let worker = Worker::new(global, sender.clone());
-        let worker_ref = Trusted::new(worker.r(), global.dom_manipulation_task_source());
+        let worker_ref = Trusted::new(worker.r(), global.script_chan());
         let worker_id = global.get_next_worker_id();
 
         let (devtools_sender, devtools_receiver) = ipc::channel().unwrap();
@@ -102,7 +102,7 @@ impl Worker {
         };
         DedicatedWorkerGlobalScope::run_worker_scope(
             init, worker_url, global.pipeline(), devtools_receiver, worker_ref,
-            global.dom_manipulation_task_source(), sender, receiver);
+            global.script_chan(), sender, receiver);
 
         Ok(worker)
     }
@@ -138,15 +138,15 @@ impl Worker {
 }
 
 impl WorkerMethods for Worker {
-    // https://html.spec.whatwg.org/multipage/#dom-dedicatedworkerglobalscope-postmessage
+    // https://html.spec.whatwg.org/multipage/#dom-worker-postmessage
     fn PostMessage(&self, cx: *mut JSContext, message: HandleValue) -> ErrorResult {
         let data = try!(StructuredCloneData::write(cx, message));
-        let address = Trusted::new(self, self.global().r().dom_manipulation_task_source());
+        let address = Trusted::new(self, self.global().r().script_chan());
         self.sender.send((address, WorkerScriptMsg::DOMMessage(data))).unwrap();
         Ok(())
     }
 
-    // https://html.spec.whatwg.org/multipage/#handler-dedicatedworkerglobalscope-onmessage
+    // https://html.spec.whatwg.org/multipage/#handler-worker-onmessage
     event_handler!(message, GetOnmessage, SetOnmessage);
 
     // https://html.spec.whatwg.org/multipage/#handler-workerglobalscope-onerror
diff --git a/components/script/lib.rs b/components/script/lib.rs
index bee43944c69..ed7b530d6f6 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -91,6 +91,7 @@ pub mod parse;
 pub mod reporter;
 #[allow(unsafe_code)]
 pub mod script_thread;
+mod task_source;
 pub mod textinput;
 mod timers;
 mod unpremultiplytable;
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index a735603431a..9cfc2627786 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -99,6 +99,12 @@ use std::sync::atomic::{Ordering, AtomicBool};
 use std::sync::mpsc::{Receiver, Select, Sender, channel};
 use std::sync::{Arc, Mutex};
 use style::context::ReflowGoal;
+use task_source::TaskSource;
+use task_source::dom_manipulation::{DOMManipulationTaskSource, DOMManipulationTask};
+use task_source::file_reading::FileReadingTaskSource;
+use task_source::history_traversal::HistoryTraversalTaskSource;
+use task_source::networking::NetworkingTaskSource;
+use task_source::user_interaction::UserInteractionTaskSource;
 use time::{Tm, now};
 use url::Url;
 use util::opts;
@@ -251,11 +257,11 @@ pub enum MainThreadScriptMsg {
     /// Notifies the script that a window associated with a particular pipeline
     /// should be closed (only dispatched to ScriptThread).
     ExitWindow(PipelineId),
-    /// Generic message for running threads in the ScriptThread
-    MainThreadRunnableMsg(Box<MainThreadRunnable + Send>),
     /// Begins a content-initiated load on the specified pipeline (only
     /// dispatched to ScriptThread).
     Navigate(PipelineId, LoadData),
+    /// Tasks that originate from the DOM manipulation task source
+    DOMManipulation(DOMManipulationTask),
 }
 
 /// A cloneable interface for communicating with an event loop.
@@ -357,102 +363,6 @@ impl MainThreadScriptChan {
     }
 }
 
-// FIXME: Use a task source specific message instead of MainThreadScriptMsg
-#[derive(JSTraceable)]
-pub struct DOMManipulationTaskSource(pub Sender<MainThreadScriptMsg>);
-
-impl ScriptChan for DOMManipulationTaskSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
-        let DOMManipulationTaskSource(ref chan) = *self;
-        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
-    }
-
-    fn clone(&self) -> Box<ScriptChan + Send> {
-        let DOMManipulationTaskSource(ref chan) = *self;
-        box DOMManipulationTaskSource((*chan).clone())
-    }
-}
-
-// FIXME: Use a task source specific message instead of MainThreadScriptMsg
-#[derive(JSTraceable)]
-pub struct UserInteractionTaskSource(pub Sender<MainThreadScriptMsg>);
-
-impl ScriptChan for UserInteractionTaskSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
-        let UserInteractionTaskSource(ref chan) = *self;
-        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
-    }
-
-    fn clone(&self) -> Box<ScriptChan + Send> {
-        let UserInteractionTaskSource(ref chan) = *self;
-        box UserInteractionTaskSource((*chan).clone())
-    }
-}
-
-// FIXME: Use a task source specific message instead of MainThreadScriptMsg
-#[derive(JSTraceable)]
-pub struct NetworkingTaskSource(pub Sender<MainThreadScriptMsg>);
-
-impl ScriptChan for NetworkingTaskSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
-        let NetworkingTaskSource(ref chan) = *self;
-        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
-    }
-
-    fn clone(&self) -> Box<ScriptChan + Send> {
-        let NetworkingTaskSource(ref chan) = *self;
-        box NetworkingTaskSource((*chan).clone())
-    }
-}
-
-// FIXME: Use a task source specific message instead of MainThreadScriptMsg
-#[derive(JSTraceable)]
-pub struct HistoryTraversalTaskSource(pub Sender<MainThreadScriptMsg>);
-
-impl ScriptChan for HistoryTraversalTaskSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
-        let HistoryTraversalTaskSource(ref chan) = *self;
-        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
-    }
-
-    fn clone(&self) -> Box<ScriptChan + Send> {
-        let HistoryTraversalTaskSource(ref chan) = *self;
-        box HistoryTraversalTaskSource((*chan).clone())
-    }
-}
-
-// FIXME: Use a task source specific message instead of MainThreadScriptMsg
-#[derive(JSTraceable)]
-pub struct FileReadingTaskSource(pub Sender<MainThreadScriptMsg>);
-
-impl ScriptChan for FileReadingTaskSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
-        let FileReadingTaskSource(ref chan) = *self;
-        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
-    }
-
-    fn clone(&self) -> Box<ScriptChan + Send> {
-        let FileReadingTaskSource(ref chan) = *self;
-        box FileReadingTaskSource((*chan).clone())
-    }
-}
-
-// FIXME: Use a task source specific message instead of MainThreadScriptMsg
-#[derive(JSTraceable)]
-pub struct ProfilerThreadSource(pub Sender<MainThreadScriptMsg>);
-
-impl ScriptChan for ProfilerThreadSource {
-    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
-        let ProfilerThreadSource(ref chan) = *self;
-        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
-    }
-
-    fn clone(&self) -> Box<ScriptChan + Send> {
-        let ProfilerThreadSource(ref chan) = *self;
-        box ProfilerThreadSource((*chan).clone())
-    }
-}
-
 pub struct StackRootTLS<'a>(PhantomData<&'a u32>);
 
 impl<'a> StackRootTLS<'a> {
@@ -494,6 +404,7 @@ pub struct ScriptThread {
     /// A channel to hand out to script thread-based entities that need to be able to enqueue
     /// events in the event queue.
     chan: MainThreadScriptChan,
+
     dom_manipulation_task_source: DOMManipulationTaskSource,
 
     user_interaction_task_source: UserInteractionTaskSource,
@@ -1155,8 +1066,6 @@ impl ScriptThread {
                 self.handle_navigate(id, None, load_data),
             MainThreadScriptMsg::ExitWindow(id) =>
                 self.handle_exit_window_msg(id),
-            MainThreadScriptMsg::MainThreadRunnableMsg(runnable) =>
-                runnable.handler(self),
             MainThreadScriptMsg::DocumentLoadsComplete(id) =>
                 self.handle_loads_complete(id),
             MainThreadScriptMsg::Common(CommonScriptMsg::RunnableMsg(_, runnable)) => {
@@ -1170,6 +1079,8 @@ impl ScriptThread {
                 LiveDOMReferences::cleanup(addr),
             MainThreadScriptMsg::Common(CommonScriptMsg::CollectReports(reports_chan)) =>
                 self.collect_reports(reports_chan),
+            MainThreadScriptMsg::DOMManipulation(msg) =>
+                msg.handle_msg(self),
         }
     }
 
@@ -1366,7 +1277,7 @@ impl ScriptThread {
         // https://html.spec.whatwg.org/multipage/#the-end step 7
         let addr: Trusted<Document> = Trusted::new(doc, self.chan.clone());
         let handler = box DocumentProgressHandler::new(addr.clone());
-        self.chan.send(CommonScriptMsg::RunnableMsg(ScriptThreadEventCategory::DocumentEvent, handler)).unwrap();
+        self.dom_manipulation_task_source.queue(DOMManipulationTask::DocumentProgress(handler)).unwrap();
 
         let ConstellationChan(ref chan) = self.constellation_chan;
         chan.send(ConstellationMsg::LoadComplete(pipeline)).unwrap();
diff --git a/components/script/task_source/dom_manipulation.rs b/components/script/task_source/dom_manipulation.rs
new file mode 100644
index 00000000000..d60ce7de93d
--- /dev/null
+++ b/components/script/task_source/dom_manipulation.rs
@@ -0,0 +1,63 @@
+/* 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 dom::bindings::refcounted::Trusted;
+use dom::event::{EventBubbles, EventCancelable};
+use dom::eventtarget::EventTarget;
+use script_thread::{MainThreadRunnable, MainThreadScriptMsg, Runnable, ScriptThread};
+use std::result::Result;
+use std::sync::mpsc::Sender;
+use string_cache::Atom;
+use task_source::TaskSource;
+
+#[derive(JSTraceable)]
+pub struct DOMManipulationTaskSource(pub Sender<MainThreadScriptMsg>);
+
+impl TaskSource<DOMManipulationTask> for DOMManipulationTaskSource {
+    fn queue(&self, msg: DOMManipulationTask) -> Result<(), ()> {
+        let DOMManipulationTaskSource(ref chan) = *self;
+        chan.send(MainThreadScriptMsg::DOMManipulation(msg)).map_err(|_| ())
+    }
+
+    fn clone(&self) -> Box<TaskSource<DOMManipulationTask> + Send> {
+        let DOMManipulationTaskSource(ref chan) = *self;
+        box DOMManipulationTaskSource((*chan).clone())
+    }
+}
+
+pub enum DOMManipulationTask {
+    // https://html.spec.whatwg.org/multipage/#the-end step 7
+    DocumentProgress(Box<Runnable + Send>),
+    // https://dom.spec.whatwg.org/#concept-event-fire
+    FireEvent(Atom, Trusted<EventTarget>, EventBubbles, EventCancelable),
+    // https://html.spec.whatwg.org/multipage/#fire-a-simple-event
+    FireSimpleEvent(Atom, Trusted<EventTarget>),
+    // https://html.spec.whatwg.org/multipage/#details-notification-task-steps
+    FireToggleEvent(Box<Runnable + Send>),
+    // https://html.spec.whatwg.org/multipage/#planned-navigation
+    PlannedNavigation(Box<Runnable + Send>),
+    // https://html.spec.whatwg.org/multipage/#send-a-storage-notification
+    SendStorageNotification(Box<MainThreadRunnable + Send>)
+}
+
+impl DOMManipulationTask {
+    pub fn handle_msg(self, script_thread: &ScriptThread) {
+        use self::DOMManipulationTask::*;
+
+        match self {
+            DocumentProgress(runnable) => runnable.handler(),
+            FireEvent(name, element, bubbles, cancelable) => {
+                let target = element.root();
+                target.fire_event(&*name, bubbles, cancelable);
+            }
+            FireSimpleEvent(name, element) => {
+                let target = element.root();
+                target.fire_simple_event(&*name);
+            }
+            FireToggleEvent(runnable) => runnable.handler(),
+            PlannedNavigation(runnable) => runnable.handler(),
+            SendStorageNotification(runnable) => runnable.handler(script_thread)
+        }
+    }
+}
diff --git a/components/script/task_source/file_reading.rs b/components/script/task_source/file_reading.rs
new file mode 100644
index 00000000000..e4afad34b4b
--- /dev/null
+++ b/components/script/task_source/file_reading.rs
@@ -0,0 +1,21 @@
+/* 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 script_thread::{CommonScriptMsg, MainThreadScriptMsg, ScriptChan};
+use std::sync::mpsc::Sender;
+
+#[derive(JSTraceable)]
+pub struct FileReadingTaskSource(pub Sender<MainThreadScriptMsg>);
+
+impl ScriptChan for FileReadingTaskSource {
+    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
+        let FileReadingTaskSource(ref chan) = *self;
+        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
+    }
+
+    fn clone(&self) -> Box<ScriptChan + Send> {
+        let FileReadingTaskSource(ref chan) = *self;
+        box FileReadingTaskSource((*chan).clone())
+    }
+}
diff --git a/components/script/task_source/history_traversal.rs b/components/script/task_source/history_traversal.rs
new file mode 100644
index 00000000000..0916c121345
--- /dev/null
+++ b/components/script/task_source/history_traversal.rs
@@ -0,0 +1,21 @@
+/* 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 script_thread::{CommonScriptMsg, MainThreadScriptMsg, ScriptChan};
+use std::sync::mpsc::Sender;
+
+#[derive(JSTraceable)]
+pub struct HistoryTraversalTaskSource(pub Sender<MainThreadScriptMsg>);
+
+impl ScriptChan for HistoryTraversalTaskSource {
+    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
+        let HistoryTraversalTaskSource(ref chan) = *self;
+        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
+    }
+
+    fn clone(&self) -> Box<ScriptChan + Send> {
+        let HistoryTraversalTaskSource(ref chan) = *self;
+        box HistoryTraversalTaskSource((*chan).clone())
+    }
+}
diff --git a/components/script/task_source/mod.rs b/components/script/task_source/mod.rs
new file mode 100644
index 00000000000..74dd7347e9e
--- /dev/null
+++ b/components/script/task_source/mod.rs
@@ -0,0 +1,16 @@
+/* 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/. */
+
+pub mod dom_manipulation;
+pub mod file_reading;
+pub mod history_traversal;
+pub mod networking;
+pub mod user_interaction;
+
+use std::result::Result;
+
+pub trait TaskSource<T> {
+    fn queue(&self, msg: T) -> Result<(), ()>;
+    fn clone(&self) -> Box<TaskSource<T> + Send>;
+}
diff --git a/components/script/task_source/networking.rs b/components/script/task_source/networking.rs
new file mode 100644
index 00000000000..8ebeecdb965
--- /dev/null
+++ b/components/script/task_source/networking.rs
@@ -0,0 +1,21 @@
+/* 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 script_thread::{CommonScriptMsg, MainThreadScriptMsg, ScriptChan};
+use std::sync::mpsc::Sender;
+
+#[derive(JSTraceable)]
+pub struct NetworkingTaskSource(pub Sender<MainThreadScriptMsg>);
+
+impl ScriptChan for NetworkingTaskSource {
+    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
+        let NetworkingTaskSource(ref chan) = *self;
+        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
+    }
+
+    fn clone(&self) -> Box<ScriptChan + Send> {
+        let NetworkingTaskSource(ref chan) = *self;
+        box NetworkingTaskSource((*chan).clone())
+    }
+}
diff --git a/components/script/task_source/user_interaction.rs b/components/script/task_source/user_interaction.rs
new file mode 100644
index 00000000000..7912eac720d
--- /dev/null
+++ b/components/script/task_source/user_interaction.rs
@@ -0,0 +1,21 @@
+/* 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 script_thread::{CommonScriptMsg, MainThreadScriptMsg, ScriptChan};
+use std::sync::mpsc::Sender;
+
+#[derive(JSTraceable)]
+pub struct UserInteractionTaskSource(pub Sender<MainThreadScriptMsg>);
+
+impl ScriptChan for UserInteractionTaskSource {
+    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
+        let UserInteractionTaskSource(ref chan) = *self;
+        chan.send(MainThreadScriptMsg::Common(msg)).map_err(|_| ())
+    }
+
+    fn clone(&self) -> Box<ScriptChan + Send> {
+        let UserInteractionTaskSource(ref chan) = *self;
+        box UserInteractionTaskSource((*chan).clone())
+    }
+}