servo: Merge #12910 - Implement postMessage for ServiceWorkers (from creativcoder:swsender); r=jdm

<!-- Please describe your changes on the following line: -->

Fixes #12773
r? @jdm

Changes:
* Implements `postMessage` on `ServiceWorker` object.
* Removes unused channels from sw and their scopes.
* Fixes a crash when calling `scope.script_chan()` in sw-scopes event handling.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #12773

<!-- Either: -->
- [X] There are tests for these changes at `tests/html/service-worker`

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

Source-Repo: https://github.com/servo/servo
Source-Revision: 0ec4ea4ee188f2e5db9d387d182c34a9d97d07cd

servo/components/constellation/constellation.rs

@@ -996,6 +996,13 @@ impl<Message, LTF, STF> Constellation<Message, LTF, STF>
                 debug!("constellation got store registration scope message");
                 self.handle_register_serviceworker(scope_things, scope);
             }
+            FromScriptMsg::ForwardDOMMessage(msg_vec, scope_url) => {
+                if let Some(ref mgr) = self.swmanager_chan {
+                    let _ = mgr.send(ServiceWorkerMsg::ForwardDOMMessage(msg_vec, scope_url));
+                } else {
+                    warn!("Unable to forward DOMMessage for postMessage call");
+                }
+            }
         }
     }
 

servo/components/script/dom/bindings/structuredclone.rs

@@ -12,11 +12,14 @@ use js::jsapi::{JSContext, JS_ReadStructuredClone, JS_STRUCTURED_CLONE_VERSION};
 use js::jsapi::{JS_ClearPendingException, JS_WriteStructuredClone};
 use libc::size_t;
 use std::ptr;
+use std::slice;
 
 /// A buffer for a structured clone.
-pub struct StructuredCloneData {
-    data: *mut u64,
-    nbytes: size_t,
+pub enum StructuredCloneData {
+    /// A non-serializable (default) variant
+    Struct(*mut u64, size_t),
+    /// A variant that can be serialized
+    Vector(Vec<u8>)
 }
 
 impl StructuredCloneData {
@@ -39,26 +42,47 @@ impl StructuredCloneData {
             }
             return Err(Error::DataClone);
         }
-        Ok(StructuredCloneData {
-            data: data,
-            nbytes: nbytes,
-        })
+        Ok(StructuredCloneData::Struct(data, nbytes))
+    }
+
+    /// Converts a StructuredCloneData to Vec<u8> for inter-thread sharing
+    pub fn move_to_arraybuffer(self) -> Vec<u8> {
+        match self {
+            StructuredCloneData::Struct(data, nbytes) => {
+                unsafe {
+                    slice::from_raw_parts(data as *mut u8, nbytes).to_vec()
+                }
+            }
+            StructuredCloneData::Vector(msg) => msg
+        }
     }
 
     /// Reads a structured clone.
     ///
     /// Panics if `JS_ReadStructuredClone` fails.
-    pub fn read(self, global: GlobalRef, rval: MutableHandleValue) {
+    fn read_clone(global: GlobalRef, data: *mut u64, nbytes: size_t, rval: MutableHandleValue) {
         unsafe {
             assert!(JS_ReadStructuredClone(global.get_cx(),
-                                           self.data,
-                                           self.nbytes,
+                                           data,
+                                           nbytes,
                                            JS_STRUCTURED_CLONE_VERSION,
                                            rval,
                                            ptr::null(),
                                            ptr::null_mut()));
         }
     }
+
+    /// Thunk for the actual `read_clone` method. Resolves proper variant for read_clone.
+    pub fn read(self, global: GlobalRef, rval: MutableHandleValue) {
+        match self {
+            StructuredCloneData::Vector(mut vec_msg) => {
+                let nbytes = vec_msg.len();
+                let data = vec_msg.as_mut_ptr() as *mut u64;
+                StructuredCloneData::read_clone(global, data, nbytes, rval);
+            }
+            StructuredCloneData::Struct(data, nbytes) => StructuredCloneData::read_clone(global, data, nbytes, rval)
+        }
+    }
 }
 
 unsafe impl Send for StructuredCloneData {}

servo/components/script/dom/serviceworker.rs

@@ -2,20 +2,23 @@
  * 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::abstractworker::{SimpleWorkerErrorHandler, WorkerScriptMsg};
+use dom::abstractworker::SimpleWorkerErrorHandler;
 use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
 use dom::bindings::codegen::Bindings::ServiceWorkerBinding::{ServiceWorkerMethods, ServiceWorkerState, Wrap};
+use dom::bindings::error::{ErrorResult, Error};
 use dom::bindings::global::GlobalRef;
 use dom::bindings::inheritance::Castable;
 use dom::bindings::js::Root;
 use dom::bindings::refcounted::Trusted;
-use dom::bindings::reflector::reflect_dom_object;
+use dom::bindings::reflector::{Reflectable, reflect_dom_object};
 use dom::bindings::str::USVString;
+use dom::bindings::structuredclone::StructuredCloneData;
 use dom::eventtarget::EventTarget;
+use js::jsapi::{HandleValue, JSContext};
 use script_thread::Runnable;
+use script_traits::{ScriptMsg, DOMMessage};
 use std::cell::Cell;
-use std::sync::mpsc::Sender;
 use url::Url;
 
 pub type TrustedServiceWorkerAddress = Trusted<ServiceWorker>;
@@ -24,28 +27,31 @@ pub type TrustedServiceWorkerAddress = Trusted<ServiceWorker>;
 pub struct ServiceWorker {
     eventtarget: EventTarget,
     script_url: DOMRefCell<String>,
+    scope_url: Url,
     state: Cell<ServiceWorkerState>,
-    #[ignore_heap_size_of = "Defined in std"]
-    sender: Option<Sender<(TrustedServiceWorkerAddress, WorkerScriptMsg)>>,
     skip_waiting: Cell<bool>
 }
 
 impl ServiceWorker {
     fn new_inherited(script_url: &str,
-                     skip_waiting: bool) -> ServiceWorker {
+                     skip_waiting: bool,
+                     scope_url: Url) -> ServiceWorker {
         ServiceWorker {
             eventtarget: EventTarget::new_inherited(),
-            sender: None,
             script_url: DOMRefCell::new(String::from(script_url)),
             state: Cell::new(ServiceWorkerState::Installing),
+            scope_url: scope_url,
             skip_waiting: Cell::new(skip_waiting)
         }
     }
 
-    pub fn new(global: GlobalRef,
-                script_url: &str,
+    pub fn install_serviceworker(global: GlobalRef,
+                script_url: Url,
+                scope_url: Url,
                 skip_waiting: bool) -> Root<ServiceWorker> {
-        reflect_dom_object(box ServiceWorker::new_inherited(script_url, skip_waiting), global, Wrap)
+        reflect_dom_object(box ServiceWorker::new_inherited(script_url.as_str(),
+                                                            skip_waiting,
+                                                            scope_url), global, Wrap)
     }
 
     pub fn dispatch_simple_error(address: TrustedServiceWorkerAddress) {
@@ -61,14 +67,6 @@ impl ServiceWorker {
     pub fn get_script_url(&self) -> Url {
         Url::parse(&self.script_url.borrow().clone()).unwrap()
     }
-
-    pub fn install_serviceworker(global: GlobalRef,
-                                 script_url: Url,
-                                 skip_waiting: bool) -> Root<ServiceWorker> {
-        ServiceWorker::new(global,
-                           script_url.as_str(),
-                           skip_waiting)
-    }
 }
 
 impl ServiceWorkerMethods for ServiceWorker {
@@ -82,6 +80,20 @@ impl ServiceWorkerMethods for ServiceWorker {
         USVString(self.script_url.borrow().clone())
     }
 
+    // https://slightlyoff.github.io/ServiceWorker/spec/service_worker/#service-worker-postmessage
+    fn PostMessage(&self, cx: *mut JSContext, message: HandleValue) -> ErrorResult {
+        // Step 1
+        if let ServiceWorkerState::Redundant = self.state.get() {
+            return Err(Error::InvalidState);
+        }
+        // Step 7
+        let data = try!(StructuredCloneData::write(cx, message));
+        let msg_vec = DOMMessage(data.move_to_arraybuffer());
+        let _ = self.global().r().constellation_chan().send(ScriptMsg::ForwardDOMMessage(msg_vec,
+                                                                                         self.scope_url.clone()));
+        Ok(())
+    }
+
     // https://slightlyoff.github.io/ServiceWorker/spec/service_worker/#service-worker-container-onerror-attribute
     event_handler!(error, GetOnerror, SetOnerror);
 

servo/components/script/dom/serviceworkercontainer.rs

@@ -95,10 +95,9 @@ impl ServiceWorkerContainerMethods for ServiceWorkerContainer {
             return Err(Error::Type("Scope URL contains forbidden characters".to_owned()));
         }
 
-        let scope_str = scope.as_str().to_owned();
         let worker_registration = ServiceWorkerRegistration::new(self.global().r(),
                                                                  script_url,
-                                                                 scope_str.clone(),
+                                                                 scope.clone(),
                                                                  self);
         ScriptThread::set_registration(scope, &*worker_registration, self.global().r().pipeline_id());
         Ok(worker_registration)

servo/components/script/dom/serviceworkerglobalscope.rs

@@ -5,7 +5,6 @@
 use devtools;
 use devtools_traits::DevtoolScriptControlMsg;
 use dom::abstractworker::WorkerScriptMsg;
-use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::EventHandlerBinding::EventHandlerNonNull;
 use dom::bindings::codegen::Bindings::ServiceWorkerGlobalScopeBinding;
 use dom::bindings::codegen::Bindings::ServiceWorkerGlobalScopeBinding::ServiceWorkerGlobalScopeMethods;
@@ -16,7 +15,6 @@ use dom::bindings::reflector::Reflectable;
 use dom::bindings::str::DOMString;
 use dom::eventtarget::EventTarget;
 use dom::messageevent::MessageEvent;
-use dom::serviceworker::TrustedServiceWorkerAddress;
 use dom::workerglobalscope::WorkerGlobalScope;
 use ipc_channel::ipc::{self, IpcSender, IpcReceiver};
 use ipc_channel::router::ROUTER;
@@ -26,13 +24,12 @@ use js::rust::Runtime;
 use msg::constellation_msg::PipelineId;
 use net_traits::{LoadContext, load_whole_resource, IpcSend, CustomResponseMediator};
 use rand::random;
-use script_runtime::{CommonScriptMsg, StackRootTLS, get_reports, new_rt_and_cx};
+use script_runtime::{CommonScriptMsg, StackRootTLS, get_reports, new_rt_and_cx, ScriptChan};
 use script_traits::{TimerEvent, WorkerGlobalScopeInit, ScopeThings, ServiceWorkerMsg};
 use std::sync::mpsc::{Receiver, RecvError, Select, Sender, channel};
 use std::thread;
 use std::time::Duration;
-use style::thread_state;
-use style::thread_state::{IN_WORKER, SCRIPT};
+use style::thread_state::{self, IN_WORKER, SCRIPT};
 use url::Url;
 use util::prefs::PREFS;
 use util::thread::spawn_named;
@@ -48,7 +45,26 @@ pub enum ServiceWorkerScriptMsg {
 pub enum MixedMessage {
     FromServiceWorker(ServiceWorkerScriptMsg),
     FromDevtools(DevtoolScriptControlMsg),
-    FromTimeoutThread(()),
+    FromTimeoutThread(())
+}
+
+#[derive(JSTraceable, Clone)]
+pub struct ServiceWorkerChan {
+    pub sender: Sender<ServiceWorkerScriptMsg>
+}
+
+impl ScriptChan for ServiceWorkerChan {
+    fn send(&self, msg: CommonScriptMsg) -> Result<(), ()> {
+        self.sender
+            .send(ServiceWorkerScriptMsg::CommonWorker(WorkerScriptMsg::Common(msg)))
+            .map_err(|_| ())
+    }
+
+    fn clone(&self) -> Box<ScriptChan + Send> {
+        box ServiceWorkerChan {
+            sender: self.sender.clone(),
+        }
+    }
 }
 
 #[dom_struct]
@@ -61,12 +77,9 @@ pub struct ServiceWorkerGlobalScope {
     own_sender: Sender<ServiceWorkerScriptMsg>,
     #[ignore_heap_size_of = "Defined in std"]
     timer_event_port: Receiver<()>,
-    #[ignore_heap_size_of = "Trusted<T> has unclear ownership like JS<T>"]
-    worker: DOMRefCell<Option<TrustedServiceWorkerAddress>>,
     #[ignore_heap_size_of = "Defined in std"]
     swmanager_sender: IpcSender<ServiceWorkerMsg>,
-    #[ignore_heap_size_of = "Defined in std"]
-    scope_url: Url
+    scope_url: Url,
 }
 
 impl ServiceWorkerGlobalScope {
@@ -93,7 +106,6 @@ impl ServiceWorkerGlobalScope {
             receiver: receiver,
             timer_event_port: timer_event_port,
             own_sender: own_sender,
-            worker: DOMRefCell::new(None),
             swmanager_sender: swmanager_sender,
             scope_url: scope_url
         }
@@ -228,8 +240,7 @@ impl ServiceWorkerGlobalScope {
             CommonWorker(WorkerScriptMsg::DOMMessage(data)) => {
                 let scope = self.upcast::<WorkerGlobalScope>();
                 let target = self.upcast();
-                let _ac = JSAutoCompartment::new(scope.get_cx(),
-                                                 scope.reflector().get_jsobject().get());
+                let _ac = JSAutoCompartment::new(scope.get_cx(), scope.reflector().get_jsobject().get());
                 rooted!(in(scope.get_cx()) let mut message = UndefinedValue());
                 data.read(GlobalRef::Worker(scope), message.handle_mut());
                 MessageEvent::dispatch_jsval(target, GlobalRef::Worker(scope), message.handle());
@@ -292,6 +303,12 @@ impl ServiceWorkerGlobalScope {
     pub fn process_event(&self, msg: CommonScriptMsg) {
         self.handle_script_event(ServiceWorkerScriptMsg::CommonWorker(WorkerScriptMsg::Common(msg)));
     }
+
+    pub fn script_chan(&self) -> Box<ScriptChan + Send> {
+        box ServiceWorkerChan {
+            sender: self.own_sender.clone()
+        }
+    }
 }
 
 #[allow(unsafe_code)]

servo/components/script/dom/serviceworkerregistration.rs

@@ -25,21 +25,21 @@ pub struct ServiceWorkerRegistration {
 }
 
 impl ServiceWorkerRegistration {
-    fn new_inherited(active_sw: &ServiceWorker, scope: String) -> ServiceWorkerRegistration {
+    fn new_inherited(active_sw: &ServiceWorker, scope: Url) -> ServiceWorkerRegistration {
         ServiceWorkerRegistration {
             eventtarget: EventTarget::new_inherited(),
             active: Some(JS::from_ref(active_sw)),
             installing: None,
             waiting: None,
-            scope: scope,
+            scope: scope.as_str().to_owned(),
         }
     }
     #[allow(unrooted_must_root)]
     pub fn new(global: GlobalRef,
                script_url: Url,
-               scope: String,
+               scope: Url,
                container: &Controllable) -> Root<ServiceWorkerRegistration> {
-        let active_worker = ServiceWorker::install_serviceworker(global, script_url.clone(), true);
+        let active_worker = ServiceWorker::install_serviceworker(global, script_url.clone(), scope.clone(), true);
         active_worker.set_transition_state(ServiceWorkerState::Installed);
         container.set_controller(&*active_worker.clone());
         reflect_dom_object(box ServiceWorkerRegistration::new_inherited(&*active_worker, scope), global, Wrap)

servo/components/script/dom/webidls/ServiceWorker.webidl

@@ -7,7 +7,7 @@
 interface ServiceWorker : EventTarget {
   readonly attribute USVString scriptURL;
   readonly attribute ServiceWorkerState state;
-  //[Throws] void postMessage(any message/*, optional sequence<Transferable> transfer*/);
+  [Throws] void postMessage(any message/*, optional sequence<Transferable> transfer*/);
 
   // event
   attribute EventHandler onstatechange;

servo/components/script/dom/workerglobalscope.rs

@@ -397,12 +397,14 @@ impl WorkerGlobalScope {
     }
 
     pub fn script_chan(&self) -> Box<ScriptChan + Send> {
-        let dedicated =
-            self.downcast::<DedicatedWorkerGlobalScope>();
+        let dedicated = self.downcast::<DedicatedWorkerGlobalScope>();
+        let service_worker = self.downcast::<ServiceWorkerGlobalScope>();
         if let Some(dedicated) = dedicated {
             return dedicated.script_chan();
+        } else if let Some(service_worker) = service_worker {
+            return service_worker.script_chan();
         } else {
-            panic!("need to implement a sender for SharedWorker/ServiceWorker")
+            panic!("need to implement a sender for SharedWorker")
         }
     }
 

servo/components/script/script_thread.rs

@@ -1450,7 +1450,7 @@ impl ScriptThread {
             let scope_things = ServiceWorkerRegistration::create_scope_things(global_ref, script_url);
             let _ = self.constellation_chan.send(ConstellationMsg::RegisterServiceWorker(scope_things, scope));
         } else {
-            warn!("Registration failed for {}", pipeline_id);
+            warn!("Registration failed for {}", scope);
         }
     }
 

servo/components/script/serviceworker_manager.rs

@@ -8,12 +8,14 @@
 //! active_workers map
 
 use devtools_traits::{DevtoolsPageInfo, ScriptToDevtoolsControlMsg};
+use dom::abstractworker::WorkerScriptMsg;
+use dom::bindings::structuredclone::StructuredCloneData;
 use dom::serviceworkerglobalscope::{ServiceWorkerGlobalScope, ServiceWorkerScriptMsg};
 use dom::serviceworkerregistration::longest_prefix_match;
 use ipc_channel::ipc::{self, IpcSender};
 use ipc_channel::router::ROUTER;
 use net_traits::{CustomResponseMediator, CoreResourceMsg};
-use script_traits::{ServiceWorkerMsg, ScopeThings, SWManagerMsg, SWManagerSenders};
+use script_traits::{ServiceWorkerMsg, ScopeThings, SWManagerMsg, SWManagerSenders, DOMMessage};
 use std::collections::HashMap;
 use std::sync::mpsc::{channel, Sender, Receiver, RecvError};
 use url::Url;
@@ -29,7 +31,7 @@ pub struct ServiceWorkerManager {
     // map of registered service worker descriptors
     registered_workers: HashMap<Url, ScopeThings>,
     // map of active service worker descriptors
-    active_workers: HashMap<Url, ScopeThings>,
+    active_workers: HashMap<Url, Sender<ServiceWorkerScriptMsg>>,
     // own sender to send messages here
     own_sender: IpcSender<ServiceWorkerMsg>,
     // receiver to receive messages from constellation
@@ -59,56 +61,52 @@ impl ServiceWorkerManager {
         let _ = sw_senders.resource_sender.send(CoreResourceMsg::NetworkMediator(resource_chan));
         let _ = sw_senders.swmanager_sender.send(SWManagerMsg::OwnSender(own_sender.clone()));
         spawn_named("ServiceWorkerManager".to_owned(), move || {
-            ServiceWorkerManager::new(own_sender, from_constellation, resource_port).handle_message();
+            ServiceWorkerManager::new(own_sender,
+                                      from_constellation,
+                                      resource_port).handle_message();
         });
     }
 
-    pub fn prepare_activation(&mut self, load_url: &Url) -> Option<Sender<ServiceWorkerScriptMsg>> {
-        let mut scope_url = None;
+    pub fn get_matching_scope(&self, load_url: &Url) -> Option<Url> {
         for scope in self.registered_workers.keys() {
             if longest_prefix_match(&scope, load_url) {
-                scope_url = Some(scope.clone());
-                break;
-            }
-        }
-
-        if let Some(scope_url) = scope_url {
-            if self.active_workers.contains_key(&scope_url) {
-                // do not run the same worker if already active.
-                warn!("Service worker for {:?} already active", scope_url);
-                return None;
-            }
-            let scope_things = self.registered_workers.get(&scope_url);
-            if let Some(scope_things) = scope_things {
-                let (sender, receiver) = channel();
-                let (devtools_sender, devtools_receiver) = ipc::channel().unwrap();
-                if let Some(ref chan) = scope_things.devtools_chan {
-                    let title = format!("ServiceWorker for {}", scope_things.script_url);
-                    let page_info = DevtoolsPageInfo {
-                        title: title,
-                        url: scope_things.script_url.clone(),
-                    };
-                    let _ = chan.send(ScriptToDevtoolsControlMsg::NewGlobal((scope_things.pipeline_id,
-                                                                             Some(scope_things.worker_id)),
-                                                                             devtools_sender.clone(),
-                                                                             page_info));
-                };
-                ServiceWorkerGlobalScope::run_serviceworker_scope(scope_things.clone(),
-                                                                              sender.clone(),
-                                                                              receiver,
-                                                                              devtools_receiver,
-                                                                              self.own_sender.clone(),
-                                                                              scope_url.clone());
-                // We store the activated worker
-                self.active_workers.insert(scope_url, scope_things.clone());
-                return Some(sender);
-            } else {
-                warn!("Unable to activate service worker");
+                return Some(scope.clone());
             }
         }
         None
     }
 
+    pub fn wakeup_serviceworker(&mut self, scope_url: Url) -> Option<Sender<ServiceWorkerScriptMsg>> {
+        let scope_things = self.registered_workers.get(&scope_url);
+        if let Some(scope_things) = scope_things {
+            let (sender, receiver) = channel();
+            let (devtools_sender, devtools_receiver) = ipc::channel().unwrap();
+            if let Some(ref chan) = scope_things.devtools_chan {
+                let title = format!("ServiceWorker for {}", scope_things.script_url);
+                let page_info = DevtoolsPageInfo {
+                    title: title,
+                    url: scope_things.script_url.clone(),
+                };
+                let _ = chan.send(ScriptToDevtoolsControlMsg::NewGlobal((scope_things.pipeline_id,
+                                                                         Some(scope_things.worker_id)),
+                                                                         devtools_sender,
+                                                                         page_info));
+            };
+            ServiceWorkerGlobalScope::run_serviceworker_scope(scope_things.clone(),
+                                                              sender.clone(),
+                                                              receiver,
+                                                              devtools_receiver,
+                                                              self.own_sender.clone(),
+                                                              scope_url.clone());
+            // We store the activated worker
+            self.active_workers.insert(scope_url, sender.clone());
+            return Some(sender);
+        } else {
+            warn!("Unable to activate service worker");
+            None
+        }
+    }
+
     fn handle_message(&mut self) {
         while let Ok(message) = self.receive_message() {
             let should_continue = match message {
@@ -125,6 +123,12 @@ impl ServiceWorkerManager {
         }
     }
 
+    fn forward_message(&self, msg: DOMMessage, sender: &Sender<ServiceWorkerScriptMsg>) {
+        let DOMMessage(data) = msg;
+        let data = StructuredCloneData::Vector(data);
+        let _ = sender.send(ServiceWorkerScriptMsg::CommonWorker(WorkerScriptMsg::DOMMessage(data)));
+    }
+
     fn handle_message_from_constellation(&mut self, msg: ServiceWorkerMsg) -> bool {
         match msg {
             ServiceWorkerMsg::RegisterServiceWorker(scope_things, scope) => {
@@ -139,7 +143,19 @@ impl ServiceWorkerManager {
                 if self.active_workers.contains_key(&scope) {
                     let _ = self.active_workers.remove(&scope);
                 } else {
-                    warn!("ScopeThings for {:?} is not active", scope);
+                    warn!("ServiceWorker for {:?} is not active", scope);
+                }
+                true
+            },
+            ServiceWorkerMsg::ForwardDOMMessage(msg, scope_url) => {
+                if self.active_workers.contains_key(&scope_url) {
+                    if let Some(ref sender) = self.active_workers.get(&scope_url) {
+                        self.forward_message(msg, &sender);
+                    }
+                } else {
+                    if let Some(ref sender) = self.wakeup_serviceworker(scope_url) {
+                        self.forward_message(msg, &sender);
+                    }
                 }
                 true
             }
@@ -147,12 +163,20 @@ impl ServiceWorkerManager {
         }
     }
 
-    #[inline]
     fn handle_message_from_resource(&mut self, mediator: CustomResponseMediator) -> bool {
         if serviceworker_enabled() {
-            let worker_sender = self.prepare_activation(&mediator.load_url);
-            if let Some(ref sender) = worker_sender {
-                let _ = sender.send(ServiceWorkerScriptMsg::Response(mediator));
+            if let Some(scope) = self.get_matching_scope(&mediator.load_url) {
+                if self.active_workers.contains_key(&scope) {
+                    if let Some(sender) = self.active_workers.get(&scope) {
+                        let _ = sender.send(ServiceWorkerScriptMsg::Response(mediator));
+                    }
+                } else {
+                    if let Some(sender) = self.wakeup_serviceworker(scope) {
+                        let _ = sender.send(ServiceWorkerScriptMsg::Response(mediator));
+                    }
+                }
+            } else {
+                let  _ = mediator.response_chan.send(None);
             }
         } else {
             let _ = mediator.response_chan.send(None);

servo/components/script_traits/lib.rs

@@ -71,7 +71,7 @@ use util::ipc::OptionalOpaqueIpcSender;
 use webdriver_msg::{LoadStatus, WebDriverScriptCommand};
 
 pub use script_msg::{LayoutMsg, ScriptMsg, EventResult, LogEntry};
-pub use script_msg::{ServiceWorkerMsg, ScopeThings, SWManagerMsg, SWManagerSenders};
+pub use script_msg::{ServiceWorkerMsg, ScopeThings, SWManagerMsg, SWManagerSenders, DOMMessage};
 
 /// The address of a node. Layout sends these back. They must be validated via
 /// `from_untrusted_node_address` before they can be used, because we do not trust layout.
@@ -212,7 +212,7 @@ pub enum ConstellationControlMsg {
     /// Report an error from a CSS parser for the given pipeline
     ReportCSSError(PipelineId, String, usize, usize, String),
     /// Reload the given page.
-    Reload(PipelineId),
+    Reload(PipelineId)
 }
 
 impl fmt::Debug for ConstellationControlMsg {
@@ -241,7 +241,7 @@ impl fmt::Debug for ConstellationControlMsg {
             DispatchFrameLoadEvent { .. } => "DispatchFrameLoadEvent",
             FramedContentChanged(..) => "FramedContentChanged",
             ReportCSSError(..) => "ReportCSSError",
-            Reload(..) => "Reload",
+            Reload(..) => "Reload"
         })
     }
 }

servo/components/script_traits/script_msg.rs

@@ -136,6 +136,9 @@ pub enum ScriptMsg {
     LogEntry(Option<PipelineId>, Option<String>, LogEntry),
     /// Notifies the constellation that this pipeline has exited.
     PipelineExited(PipelineId),
+    /// Send messages from postMessage calls from serviceworker
+    /// to constellation for storing in service worker manager
+    ForwardDOMMessage(DOMMessage, Url),
     /// Store the data required to activate a service worker for the given scope
     RegisterServiceWorker(ScopeThings, Url),
     /// Requests that the compositor shut down.
@@ -159,6 +162,10 @@ pub struct ScopeThings {
     pub worker_id: WorkerId,
 }
 
+/// Message that gets passed to service worker scope on postMessage
+#[derive(Deserialize, Serialize, Debug, Clone)]
+pub struct DOMMessage(pub Vec<u8>);
+
 /// Channels to allow service worker manager to communicate with constellation and resource thread
 pub struct SWManagerSenders {
     /// sender for communicating with constellation
@@ -174,6 +181,8 @@ pub enum ServiceWorkerMsg {
     RegisterServiceWorker(ScopeThings, Url),
     /// Timeout message sent by active service workers
     Timeout(Url),
+    /// Message sent by constellation to forward to a running service worker
+    ForwardDOMMessage(DOMMessage, Url),
     /// Exit the service worker manager
     Exit,
 }
@@ -182,5 +191,6 @@ pub enum ServiceWorkerMsg {
 #[derive(Deserialize, Serialize)]
 pub enum SWManagerMsg {
     /// Provide the constellation with a means of communicating with the Service Worker Manager
-    OwnSender(IpcSender<ServiceWorkerMsg>),
+    OwnSender(IpcSender<ServiceWorkerMsg>)
+
 }

servo/tests/html/service-worker/demo_iframe.html

@@ -8,6 +8,5 @@
 <div>
 <a href="http://github.com/servo/servo">Servo Project</a>
 </div>
-
 </body>
 </html>

servo/tests/html/service-worker/dummy.js

@@ -0,0 +1,3 @@
+function test_importScripts() {
+	console.log('Hi from dummy.js');
+}

servo/tests/html/service-worker/iframe_sw.js

@@ -1,7 +1,11 @@
 self.addEventListener('activate', function(e) {
-	console.log("iframe service worker active");
+    console.log("iframe service worker active");
 });
 
 self.addEventListener('fetch', function(e) {
-	console.log("A fetch event detected by /iframe service worker");
-});
+    console.log("A fetch event detected by /iframe service worker");
+});
+
+self.addEventListener('message', function(e) {
+    console.log(e.data.payload.msg + ' from '+ e.data.payload.worker_id);
+})

servo/tests/html/service-worker/index.html

@@ -16,36 +16,56 @@
     <button onclick="register_zero()">Register for Root (/)</button>
     <button onclick="register_one()">Register for Dashboard (/dashboard)</button>
     <button onclick="register_two()">Register for Profile (/profile)</button>
+    <button onclick="post_message_root()">Msg to Root service worker</button>
 </div>
-
     <script>
+
     var reg = navigator.serviceWorker.register('iframe_sw.js', { 'scope': '/demo_iframe.html' });
     console.log("From client worker registered: ", navigator.serviceWorker.controller);
     console.log("Registered script source: "+ navigator.serviceWorker.controller.scriptURL);
     document.getElementById('iframe_sw').src = 'demo_iframe.html';
+    post_message('/demo_iframe');
 
     function register_zero() {
-        var reg = navigator.serviceWorker.register('sw.js', { 'scope': './' });
+        var reg = navigator.serviceWorker.register('sw.js', { 'scope': './*' });
         console.log("From client worker registered: ", navigator.serviceWorker.controller);
         console.log("Registered script source: "+ navigator.serviceWorker.controller.scriptURL);
     }
 
+    function post_message_root() {
+        // Testing repeated calls of postMessage
+        for(var i=0;i<100;i++){
+            navigator.serviceWorker.controller.postMessage({num:'Dummy message count: '+i});
+        }
+    }
+
     function register_one() {
         var reg = navigator.serviceWorker.register('sw_dashboard.js', { 'scope': '/dashboard' });
         console.log("From client worker registered: ", navigator.serviceWorker.controller);
         console.log("Registered script source: "+ navigator.serviceWorker.controller.scriptURL);
+        post_message('/dashboard');
     }
 
     function register_two() {
         var reg = navigator.serviceWorker.register('sw_profile.js', { 'scope': '/profile' });
         console.log("From client worker registered: ", navigator.serviceWorker.controller);
         console.log("Registered script source: "+ navigator.serviceWorker.controller.scriptURL);
+        post_message('/profile');
     }
 
     navigator.serviceWorker.addEventListener('controllerchange', function(e) {
-        console.log("active Service Worker changed");
+        console.log("navigator.serviceWorker.controller changed");
     });
 
+    function post_message(worker_id) {
+        navigator.serviceWorker.controller.postMessage({
+        payload:{
+            msg:'Hi there! This is a dummy message for testing of postMessage calls from Service Workers',
+            worker_id:worker_id
+            }
+        });
+    }
+
     </script>
 </body>
 </html>

servo/tests/html/service-worker/sw.js

@@ -0,0 +1,11 @@
+self.addEventListener('activate', function(e) {
+    console.log('Root service worker active');
+});
+
+self.addEventListener('fetch', function(e) {
+    console.log("A fetch event detected by / service worker");
+});
+
+self.addEventListener('message', function(e) {
+    console.log(e.data.num);
+})

servo/tests/html/service-worker/sw_dashboard.js

@@ -1,9 +1,11 @@
-importScripts('dashboard_helper.js');
-
 self.addEventListener('activate', function(e) {
-	status_from_dashboard();
+    console.log('Dashboard service worker active');
 });
 
 self.addEventListener('fetch', function(e) {
-	console.log("A fetch event detected by /dashboard service worker");
-});
+    console.log("A fetch event detected by /dashboard service worker");
+});
+
+self.addEventListener('message', function(e) {
+    console.log(e.data.payload.msg + ' from '+ e.data.payload.worker_id);
+})

servo/tests/html/service-worker/sw_profile.js

@@ -1,8 +1,12 @@
 
 self.addEventListener('activate', function(e) {
-	console.log("profile service worker active");
+    console.log("profile service worker active");
 });
 
 self.addEventListener('fetch', function(e) {
-	console.log("A fetch event detected by /profile service worker");
-});
+    console.log("A fetch event detected by /profile service worker");
+});
+
+self.addEventListener('message', function(e) {
+    console.log(e.data.payload.msg + ' from '+ e.data.payload.worker_id);
+})