servo: Merge #3076 - Implement DedicatedWorkerGlobalScope.postMessage; r=Manishearth (from Ms2ger:DWGS-postMessage)

Source-Repo: https://github.com/servo/servo
Source-Revision: 6d2dcc2852c081b6b04c0de6e8b837abed91ebb8

servo/src/components/script/dom/bindings/global.rs

@@ -72,6 +72,8 @@ impl<'a> GlobalRef<'a> {
         }
     }
 
+    /// `ScriptChan` used to send messages to the event loop of this global's
+    /// thread.
     pub fn script_chan<'b>(&'b self) -> &'b ScriptChan {
         match *self {
             Window(ref window) => &window.script_chan,

servo/src/components/script/dom/bindings/js.rs

@@ -48,6 +48,7 @@
 use dom::bindings::utils::{Reflector, Reflectable};
 use dom::node::Node;
 use dom::xmlhttprequest::{XMLHttpRequest, TrustedXHRAddress};
+use dom::worker::{Worker, TrustedWorkerAddress};
 use js::jsapi::JSObject;
 use layout_interface::TrustedNodeAddress;
 use script_task::StackRoots;
@@ -143,6 +144,15 @@ impl JS<XMLHttpRequest> {
     }
 }
 
+impl JS<Worker> {
+    pub unsafe fn from_trusted_worker_address(inner: TrustedWorkerAddress) -> JS<Worker> {
+        let TrustedWorkerAddress(addr) = inner;
+        JS {
+            ptr: addr as *const Worker
+        }
+    }
+}
+
 impl<T: Reflectable> JS<T> {
     /// Create a new JS-owned value wrapped from a raw Rust pointer.
     pub unsafe fn from_raw(raw: *const T) -> JS<T> {

servo/src/components/script/dom/dedicatedworkerglobalscope.rs

@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding;
+use dom::bindings::codegen::Bindings::DedicatedWorkerGlobalScopeBinding::DedicatedWorkerGlobalScopeMethods;
 use dom::bindings::codegen::InheritTypes::DedicatedWorkerGlobalScopeDerived;
 use dom::bindings::codegen::InheritTypes::{EventTargetCast, WorkerGlobalScopeCast};
 use dom::bindings::global::Worker;
@@ -12,13 +13,17 @@ use dom::bindings::utils::{Reflectable, Reflector};
 use dom::eventtarget::EventTarget;
 use dom::eventtarget::WorkerGlobalScopeTypeId;
 use dom::messageevent::MessageEvent;
+use dom::worker::{Worker, TrustedWorkerAddress};
 use dom::workerglobalscope::DedicatedGlobalScope;
 use dom::workerglobalscope::WorkerGlobalScope;
 use dom::xmlhttprequest::XMLHttpRequest;
-use script_task::{ScriptTask, ScriptChan, ScriptMsg, DOMMessage, XHRProgressMsg};
+use script_task::{ScriptTask, ScriptChan};
+use script_task::{ScriptMsg, DOMMessage, XHRProgressMsg, WorkerRelease};
+use script_task::WorkerPostMessage;
 use script_task::StackRootTLS;
 
 use servo_net::resource_task::{ResourceTask, load_whole_resource};
+use servo_util::str::DOMString;
 
 use js::rust::Cx;
 
@@ -31,40 +36,52 @@ use url::Url;
 pub struct DedicatedWorkerGlobalScope {
     workerglobalscope: WorkerGlobalScope,
     receiver: Untraceable<Receiver<ScriptMsg>>,
+    /// Sender to the parent thread.
+    parent_sender: ScriptChan,
+    worker: Untraceable<TrustedWorkerAddress>,
 }
 
 impl DedicatedWorkerGlobalScope {
     pub fn new_inherited(worker_url: Url,
+                         worker: TrustedWorkerAddress,
                          cx: Rc<Cx>,
-                         receiver: Receiver<ScriptMsg>,
                          resource_task: ResourceTask,
-                         script_chan: ScriptChan)
+                         parent_sender: ScriptChan,
+                         own_sender: ScriptChan,
+                         receiver: Receiver<ScriptMsg>)
                          -> DedicatedWorkerGlobalScope {
         DedicatedWorkerGlobalScope {
             workerglobalscope: WorkerGlobalScope::new_inherited(
                 DedicatedGlobalScope, worker_url, cx, resource_task,
-                script_chan),
+                own_sender),
             receiver: Untraceable::new(receiver),
+            parent_sender: parent_sender,
+            worker: Untraceable::new(worker),
         }
     }
 
     pub fn new(worker_url: Url,
+               worker: TrustedWorkerAddress,
                cx: Rc<Cx>,
-               receiver: Receiver<ScriptMsg>,
                resource_task: ResourceTask,
-               script_chan: ScriptChan)
+               parent_sender: ScriptChan,
+               own_sender: ScriptChan,
+               receiver: Receiver<ScriptMsg>)
                -> Temporary<DedicatedWorkerGlobalScope> {
         let scope = box DedicatedWorkerGlobalScope::new_inherited(
-            worker_url, cx.clone(), receiver, resource_task, script_chan);
+            worker_url, worker, cx.clone(), resource_task, parent_sender,
+            own_sender, receiver);
         DedicatedWorkerGlobalScopeBinding::Wrap(cx.ptr, scope)
     }
 }
 
 impl DedicatedWorkerGlobalScope {
     pub fn run_worker_scope(worker_url: Url,
-                            resource_task: ResourceTask) -> ScriptChan {
-        let (receiver, sender) = ScriptChan::new();
-        let sender_clone = sender.clone();
+                            worker: TrustedWorkerAddress,
+                            resource_task: ResourceTask,
+                            parent_sender: ScriptChan,
+                            own_sender: ScriptChan,
+                            receiver: Receiver<ScriptMsg>) {
         TaskBuilder::new()
             .native()
             .named(format!("Web Worker at {}", worker_url.serialize()))
@@ -84,13 +101,14 @@ impl DedicatedWorkerGlobalScope {
 
             let (_js_runtime, js_context) = ScriptTask::new_rt_and_cx();
             let global = DedicatedWorkerGlobalScope::new(
-                worker_url, js_context.clone(), receiver, resource_task,
-                sender).root();
+                worker_url, worker, js_context.clone(), resource_task,
+                parent_sender, own_sender, receiver).root();
             match js_context.evaluate_script(
                 global.reflector().get_jsobject(), source, url.serialize(), 1) {
                 Ok(_) => (),
                 Err(_) => println!("evaluate_script failed")
             }
+            global.delayed_release_worker();
 
             let scope: &JSRef<WorkerGlobalScope> =
                 WorkerGlobalScopeCast::from_ref(&*global);
@@ -99,21 +117,42 @@ impl DedicatedWorkerGlobalScope {
             loop {
                 match global.receiver.recv_opt() {
                     Ok(DOMMessage(message)) => {
-                        MessageEvent::dispatch(target, &Worker(*scope), message)
+                        MessageEvent::dispatch(target, &Worker(*scope), message);
+                        global.delayed_release_worker();
                     },
                     Ok(XHRProgressMsg(addr, progress)) => {
                         XMLHttpRequest::handle_xhr_progress(addr, progress)
                     },
+                    Ok(WorkerPostMessage(addr, message)) => {
+                        Worker::handle_message(addr, message);
+                    },
+                    Ok(WorkerRelease(addr)) => {
+                        Worker::handle_release(addr)
+                    },
                     Ok(_) => fail!("Unexpected message"),
                     Err(_) => break,
                 }
             }
         });
-        return sender_clone;
     }
 }
 
-pub trait DedicatedWorkerGlobalScopeMethods {
+impl<'a> DedicatedWorkerGlobalScopeMethods for JSRef<'a, DedicatedWorkerGlobalScope> {
+    fn PostMessage(&self, message: DOMString) {
+        let ScriptChan(ref sender) = self.parent_sender;
+        sender.send(WorkerPostMessage(*self.worker, message));
+    }
+}
+
+trait PrivateDedicatedWorkerGlobalScopeHelpers {
+    fn delayed_release_worker(&self);
+}
+
+impl<'a> PrivateDedicatedWorkerGlobalScopeHelpers for JSRef<'a, DedicatedWorkerGlobalScope> {
+    fn delayed_release_worker(&self) {
+        let ScriptChan(ref sender) = self.parent_sender;
+        sender.send(WorkerRelease(*self.worker));
+    }
 }
 
 impl Reflectable for DedicatedWorkerGlobalScope {

servo/src/components/script/dom/webidls/DedicatedWorkerGlobalScope.webidl

@@ -6,5 +6,6 @@
 [Global/*=Worker,DedicatedWorker*/]
 /*sealed*/ interface DedicatedWorkerGlobalScope : WorkerGlobalScope {
   //void postMessage(any message, optional sequence<Transferable> transfer);
+  void postMessage(DOMString message);
   //         attribute EventHandler onmessage;
 };

servo/src/components/script/dom/worker.rs

@@ -4,33 +4,48 @@
 
 use dom::bindings::codegen::Bindings::WorkerBinding;
 use dom::bindings::codegen::Bindings::WorkerBinding::WorkerMethods;
+use dom::bindings::codegen::InheritTypes::EventTargetCast;
 use dom::bindings::error::{Fallible, Syntax};
-use dom::bindings::global::GlobalRef;
-use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::global::{GlobalRef, GlobalField};
+use dom::bindings::js::{JS, JSRef, Temporary};
 use dom::bindings::utils::{Reflectable, Reflector, reflect_dom_object};
 use dom::dedicatedworkerglobalscope::DedicatedWorkerGlobalScope;
 use dom::eventtarget::{EventTarget, WorkerTypeId};
+use dom::messageevent::MessageEvent;
 use script_task::{ScriptChan, DOMMessage};
 
 use servo_util::str::DOMString;
+
+use js::jsapi::{JS_AddObjectRoot, JS_RemoveObjectRoot};
 use url::UrlParser;
 
+use libc::c_void;
+use std::cell::Cell;
+
+pub struct TrustedWorkerAddress(pub *const c_void);
+
 #[deriving(Encodable)]
 pub struct Worker {
     eventtarget: EventTarget,
+    refcount: Cell<uint>,
+    global: GlobalField,
+    /// Sender to the Receiver associated with the DedicatedWorkerGlobalScope
+    /// this Worker created.
     sender: ScriptChan,
 }
 
 impl Worker {
-    pub fn new_inherited(sender: ScriptChan) -> Worker {
+    pub fn new_inherited(global: &GlobalRef, sender: ScriptChan) -> Worker {
         Worker {
             eventtarget: EventTarget::new_inherited(WorkerTypeId),
+            refcount: Cell::new(0),
+            global: GlobalField::from_rooted(global),
             sender: sender,
         }
     }
 
     pub fn new(global: &GlobalRef, sender: ScriptChan) -> Temporary<Worker> {
-        reflect_dom_object(box Worker::new_inherited(sender),
+        reflect_dom_object(box Worker::new_inherited(global, sender),
                            global,
                            WorkerBinding::Wrap)
     }
@@ -45,14 +60,62 @@ impl Worker {
         };
 
         let resource_task = global.resource_task();
-        let sender = DedicatedWorkerGlobalScope::run_worker_scope(
-            worker_url, resource_task);
-        Ok(Worker::new(global, sender))
+        let (receiver, sender) = ScriptChan::new();
+
+        let worker = Worker::new(global, sender.clone()).root();
+        let worker_ref = worker.addref();
+
+        DedicatedWorkerGlobalScope::run_worker_scope(
+            worker_url, worker_ref, resource_task, global.script_chan().clone(),
+            sender, receiver);
+
+        Ok(Temporary::from_rooted(&*worker))
+    }
+
+    pub fn handle_message(address: TrustedWorkerAddress, message: DOMString) {
+        let worker = unsafe { JS::from_trusted_worker_address(address).root() };
+
+        let target: &JSRef<EventTarget> = EventTargetCast::from_ref(&*worker);
+        let global = worker.global.root();
+        MessageEvent::dispatch(target, &global.root_ref(), message);
+    }
+}
+
+impl Worker {
+    // Creates a trusted address to the object, and roots it. Always pair this with a release()
+    pub fn addref(&self) -> TrustedWorkerAddress {
+        let refcount = self.refcount.get();
+        if refcount == 0 {
+            let cx = self.global.root().root_ref().get_cx();
+            unsafe {
+                JS_AddObjectRoot(cx, self.reflector().rootable());
+            }
+        }
+        self.refcount.set(refcount + 1);
+        TrustedWorkerAddress(self as *const Worker as *const c_void)
+    }
+
+    pub fn release(&self) {
+        let refcount = self.refcount.get();
+        assert!(refcount > 0)
+        self.refcount.set(refcount - 1);
+        if refcount == 1 {
+            let cx = self.global.root().root_ref().get_cx();
+            unsafe {
+                JS_RemoveObjectRoot(cx, self.reflector().rootable());
+            }
+        }
+    }
+
+    pub fn handle_release(address: TrustedWorkerAddress) {
+        let worker = unsafe { JS::from_trusted_worker_address(address).root() };
+        worker.release();
     }
 }
 
 impl<'a> WorkerMethods for JSRef<'a, Worker> {
     fn PostMessage(&self, message: DOMString) {
+        self.addref();
         let ScriptChan(ref sender) = self.sender;
         sender.send(DOMMessage(message));
     }

servo/src/components/script/script_task.rs

@@ -20,6 +20,7 @@ use dom::eventtarget::{EventTarget, EventTargetHelpers};
 use dom::node;
 use dom::node::{ElementNodeTypeId, Node, NodeHelpers};
 use dom::window::{TimerId, Window, WindowHelpers};
+use dom::worker::{Worker, TrustedWorkerAddress};
 use dom::xmlhttprequest::{TrustedXHRAddress, XMLHttpRequest, XHRProgress};
 use html::hubbub_html_parser::HtmlParserResult;
 use html::hubbub_html_parser::{HtmlDiscoveredStyle, HtmlDiscoveredScript};
@@ -86,6 +87,10 @@ pub enum ScriptMsg {
     /// Message sent through Worker.postMessage (only dispatched to
     /// DedicatedWorkerGlobalScope).
     DOMMessage(DOMString),
+    /// Posts a message to the Worker object (dispatched to all tasks).
+    WorkerPostMessage(TrustedWorkerAddress, DOMString),
+    /// Releases one reference to the Worker object (dispatched to all tasks).
+    WorkerRelease(TrustedWorkerAddress),
 }
 
 /// Encapsulates internal communication within the script task.
@@ -441,6 +446,8 @@ impl ScriptTask {
                 FromConstellation(ResizeMsg(..)) => fail!("should have handled ResizeMsg already"),
                 FromScript(XHRProgressMsg(addr, progress)) => XMLHttpRequest::handle_xhr_progress(addr, progress),
                 FromScript(DOMMessage(..)) => fail!("unexpected message"),
+                FromScript(WorkerPostMessage(addr, message)) => Worker::handle_message(addr, message),
+                FromScript(WorkerRelease(addr)) => Worker::handle_release(addr),
             }
         }