Make RunnableWrapper store an Option<Arc<AtomicBool>>

This makes WorkerGlobalScope::get_runnable_wrapper not panic anymore
when the worker is a ServiceWorkerGlobalScope.

3 files changed, 7 insertions, 5 deletions

diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 4365ba44999..5f5b0bda04a 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -868,7 +868,7 @@ impl WindowMethods for Window {
 impl Window {
     pub fn get_runnable_wrapper(&self) -> RunnableWrapper {
         RunnableWrapper {
-            cancelled: self.ignore_further_async_events.clone()
+            cancelled: Some(self.ignore_further_async_events.clone()),
         }
     }
 
diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index 49b1d4e3257..f1f2229c823 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -155,7 +155,7 @@ impl WorkerGlobalScope {
 
     pub fn get_runnable_wrapper(&self) -> RunnableWrapper {
         RunnableWrapper {
-            cancelled: self.closing.clone().unwrap(),
+            cancelled: self.closing.clone(),
         }
     }
 
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 0d3f605fac1..bbdc766cea4 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -170,7 +170,7 @@ impl InProgressLoad {
 
 /// Encapsulated state required to create cancellable runnables from non-script threads.
 pub struct RunnableWrapper {
-    pub cancelled: Arc<AtomicBool>,
+    pub cancelled: Option<Arc<AtomicBool>>,
 }
 
 impl RunnableWrapper {
@@ -184,7 +184,7 @@ impl RunnableWrapper {
 
 /// A runnable that can be discarded by toggling a shared flag.
 pub struct CancellableRunnable<T: Runnable + Send> {
-    cancelled: Arc<AtomicBool>,
+    cancelled: Option<Arc<AtomicBool>>,
     inner: Box<T>,
 }
 
@@ -192,7 +192,9 @@ impl<T: Runnable + Send> Runnable for CancellableRunnable<T> {
     fn name(&self) -> &'static str { self.inner.name() }
 
     fn is_cancelled(&self) -> bool {
-        self.cancelled.load(Ordering::SeqCst)
+        self.cancelled.as_ref()
+            .map(|cancelled| cancelled.load(Ordering::SeqCst))
+            .unwrap_or(false)
     }
 
     fn main_thread_handler(self: Box<CancellableRunnable<T>>, script_thread: &ScriptThread) {