Auto merge of #12501 - mephisto41:worker-close-impl, r=KiChjang

Implement DedicatedWorkerGlobalScope.close

<!-- Please describe your changes on the following line: -->
Implement DedicatedWorkerGlobalScope.close().
---
<!-- 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 #12466 (github issue number if applicable).

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- [X] There are tests for these changes

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4 files changed, 29 insertions, 5 deletions

diff --git a/components/script/dom/dedicatedworkerglobalscope.rs b/components/script/dom/dedicatedworkerglobalscope.rs
index b65fd72ab62..80c70c45911 100644
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@@ -370,6 +370,12 @@ impl DedicatedWorkerGlobalScopeMethods for DedicatedWorkerGlobalScope {
         Ok(())
     }
 
+    // https://html.spec.whatwg.org/multipage/#dom-dedicatedworkerglobalscope-close
+    fn Close(&self) {
+        // Step 2
+        self.upcast::<WorkerGlobalScope>().close();
+    }
+
     // https://html.spec.whatwg.org/multipage/#handler-dedicatedworkerglobalscope-onmessage
     event_handler!(message, GetOnmessage, SetOnmessage);
 }
diff --git a/components/script/dom/webidls/DedicatedWorkerGlobalScope.webidl b/components/script/dom/webidls/DedicatedWorkerGlobalScope.webidl
index cd0d393e22e..53996ee3965 100644
--- a/components/script/dom/webidls/DedicatedWorkerGlobalScope.webidl
+++ b/components/script/dom/webidls/DedicatedWorkerGlobalScope.webidl
@@ -8,4 +8,6 @@
   [Throws]
   void postMessage(any message/*, optional sequence<Transferable> transfer*/);
            attribute EventHandler onmessage;
+
+  void close();
 };
diff --git a/components/script/dom/worker.rs b/components/script/dom/worker.rs
index c318672fb7a..c1ad7cf5a96 100644
--- a/components/script/dom/worker.rs
+++ b/components/script/dom/worker.rs
@@ -27,6 +27,7 @@ use js::jsapi::{HandleValue, JSContext, JSAutoCompartment};
 use js::jsval::UndefinedValue;
 use script_thread::Runnable;
 use script_traits::WorkerScriptLoadOrigin;
+use std::cell::Cell;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::mpsc::{Sender, channel};
 use std::sync::{Arc, Mutex};
@@ -43,7 +44,8 @@ pub struct Worker {
     sender: Sender<(TrustedWorkerAddress, WorkerScriptMsg)>,
     closing: Arc<AtomicBool>,
     #[ignore_heap_size_of = "Defined in rust-mozjs"]
-    runtime: Arc<Mutex<Option<SharedRt>>>
+    runtime: Arc<Mutex<Option<SharedRt>>>,
+    terminated: Cell<bool>,
 }
 
 impl Worker {
@@ -53,7 +55,8 @@ impl Worker {
             eventtarget: EventTarget::new_inherited(),
             sender: sender,
             closing: closing,
-            runtime: Arc::new(Mutex::new(None))
+            runtime: Arc::new(Mutex::new(None)),
+            terminated: Cell::new(false),
         }
     }
 
@@ -112,11 +115,15 @@ impl Worker {
         self.closing.load(Ordering::SeqCst)
     }
 
+    pub fn is_terminated(&self) -> bool {
+        self.terminated.get()
+    }
+
     pub fn handle_message(address: TrustedWorkerAddress,
                           data: StructuredCloneData) {
         let worker = address.root();
 
-        if worker.is_closing() {
+        if worker.is_terminated() {
             return;
         }
 
@@ -137,7 +144,7 @@ impl Worker {
                                 filename: DOMString, lineno: u32, colno: u32) {
         let worker = address.root();
 
-        if worker.is_closing() {
+        if worker.is_terminated() {
             return;
         }
 
@@ -169,7 +176,10 @@ impl WorkerMethods for Worker {
             return;
         }
 
-        // Step 4
+        // Step 2
+        self.terminated.set(true);
+
+        // Step 3
         if let Some(runtime) = *self.runtime.lock().unwrap() {
             runtime.request_interrupt();
         }
diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index 154705fe145..16388d54d73 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -444,4 +444,10 @@ impl WorkerGlobalScope {
     pub fn set_devtools_wants_updates(&self, value: bool) {
         self.devtools_wants_updates.set(value);
     }
+
+    pub fn close(&self) {
+        if let Some(ref closing) = self.closing {
+            closing.store(true, Ordering::SeqCst);
+        }
+    }
 }