Bug 927740 (part 3) - Make workers respond to "child-cc-request" notifications. r=khuey.

--HG--
extra : rebase_source : 34a15c4bf15bb0fd1601675e7e7cc4b5117ed433

dom/workers/RuntimeService.cpp

@@ -101,6 +101,7 @@ static_assert(MAX_WORKERS_PER_DOMAIN >= 1,
 #define PREF_MAX_SCRIPT_RUN_TIME_CHROME "dom.max_chrome_script_run_time"
 
 #define GC_REQUEST_OBSERVER_TOPIC "child-gc-request"
+#define CC_REQUEST_OBSERVER_TOPIC "child-cc-request"
 #define MEMORY_PRESSURE_OBSERVER_TOPIC "memory-pressure"
 
 #define BROADCAST_ALL_WORKERS(_func, ...)                                      \
@@ -1579,6 +1580,10 @@ RuntimeService::Init()
     NS_WARNING("Failed to register for GC request notifications!");
   }
 
+  if (NS_FAILED(obs->AddObserver(this, CC_REQUEST_OBSERVER_TOPIC, false))) {
+    NS_WARNING("Failed to register for CC request notifications!");
+  }
+
   if (NS_FAILED(obs->AddObserver(this, MEMORY_PRESSURE_OBSERVER_TOPIC,
                                  false))) {
     NS_WARNING("Failed to register for memory pressure notifications!");
@@ -1827,6 +1832,10 @@ RuntimeService::Cleanup()
         NS_WARNING("Failed to unregister for GC request notifications!");
       }
 
+      if (NS_FAILED(obs->RemoveObserver(this, CC_REQUEST_OBSERVER_TOPIC))) {
+        NS_WARNING("Failed to unregister for CC request notifications!");
+      }
+
       if (NS_FAILED(obs->RemoveObserver(this,
                                         MEMORY_PRESSURE_OBSERVER_TOPIC))) {
         NS_WARNING("Failed to unregister for memory pressure notifications!");
@@ -2203,6 +2212,12 @@ RuntimeService::GarbageCollectAllWorkers(bool aShrinking)
   BROADCAST_ALL_WORKERS(GarbageCollect, aShrinking);
 }
 
+void
+RuntimeService::CycleCollectAllWorkers()
+{
+  BROADCAST_ALL_WORKERS(CycleCollect, /* dummy = */ false);
+}
+
 // nsISupports
 NS_IMPL_ISUPPORTS1(RuntimeService, nsIObserver)
 
@@ -2222,11 +2237,15 @@ RuntimeService::Observe(nsISupports* aSubject, const char* aTopic,
     return NS_OK;
   }
   if (!strcmp(aTopic, GC_REQUEST_OBSERVER_TOPIC)) {
-    GarbageCollectAllWorkers(false);
+    GarbageCollectAllWorkers(/* shrinking = */ false);
+    return NS_OK;
+  }
+  if (!strcmp(aTopic, CC_REQUEST_OBSERVER_TOPIC)) {
+    CycleCollectAllWorkers();
     return NS_OK;
   }
   if (!strcmp(aTopic, MEMORY_PRESSURE_OBSERVER_TOPIC)) {
-    GarbageCollectAllWorkers(true);
+    GarbageCollectAllWorkers(/* shrinking = */ true);
     return NS_OK;
   }
 

dom/workers/RuntimeService.h

@@ -252,6 +252,9 @@ public:
   void
   GarbageCollectAllWorkers(bool aShrinking);
 
+  void
+  CycleCollectAllWorkers();
+
 private:
   RuntimeService();
   ~RuntimeService();

dom/workers/WorkerPrivate.cpp

@@ -1573,7 +1573,7 @@ public:
 
   void
   PostDispatch(JSContext* aCx, WorkerPrivate* aWorkerPrivate,
-                bool aDispatchResult)
+               bool aDispatchResult)
   {
     // Silence bad assertions, this can be dispatched from either the main
     // thread or the timer thread..
@@ -1587,6 +1587,41 @@ public:
   }
 };
 
+class CycleCollectRunnable : public WorkerControlRunnable
+{
+protected:
+  bool mCollectChildren;
+
+public:
+  CycleCollectRunnable(WorkerPrivate* aWorkerPrivate, bool aCollectChildren)
+  : WorkerControlRunnable(aWorkerPrivate, WorkerThread, UnchangedBusyCount),
+    mCollectChildren(aCollectChildren)
+  { }
+
+  bool
+  PreDispatch(JSContext* aCx, WorkerPrivate* aWorkerPrivate)
+  {
+    // Silence bad assertions, this can be dispatched from either the main
+    // thread or the timer thread..
+    return true;
+  }
+
+  void
+  PostDispatch(JSContext* aCx, WorkerPrivate* aWorkerPrivate,
+               bool aDispatchResult)
+  {
+    // Silence bad assertions, this can be dispatched from either the main
+    // thread or the timer thread..
+  }
+
+  bool
+  WorkerRun(JSContext* aCx, WorkerPrivate* aWorkerPrivate)
+  {
+    aWorkerPrivate->CycleCollectInternal(aCx, mCollectChildren);
+    return true;
+  }
+};
+
 class WorkerJSRuntimeStats : public JS::RuntimeStats
 {
   const nsACString& mRtPath;
@@ -2892,9 +2927,25 @@ WorkerPrivateParent<Derived>::GarbageCollect(JSContext* aCx, bool aShrinking)
   AssertIsOnParentThread();
 
   nsRefPtr<GarbageCollectRunnable> runnable =
-    new GarbageCollectRunnable(ParentAsWorkerPrivate(), aShrinking, true);
+    new GarbageCollectRunnable(ParentAsWorkerPrivate(), aShrinking,
+                               /* collectChildren = */ true);
   if (!runnable->Dispatch(aCx)) {
-    NS_WARNING("Failed to update worker heap size!");
+    NS_WARNING("Failed to GC worker!");
+    JS_ClearPendingException(aCx);
+  }
+}
+
+template <class Derived>
+void
+WorkerPrivateParent<Derived>::CycleCollect(JSContext* aCx, bool aDummy)
+{
+  AssertIsOnParentThread();
+
+  nsRefPtr<CycleCollectRunnable> runnable =
+    new CycleCollectRunnable(ParentAsWorkerPrivate(),
+                             /* collectChildren = */ true);
+  if (!runnable->Dispatch(aCx)) {
+    NS_WARNING("Failed to CC worker!");
     JS_ClearPendingException(aCx);
   }
 }
@@ -5218,6 +5269,20 @@ WorkerPrivate::GarbageCollectInternal(JSContext* aCx, bool aShrinking,
   }
 }
 
+void
+WorkerPrivate::CycleCollectInternal(JSContext* aCx, bool aCollectChildren)
+{
+  AssertIsOnWorkerThread();
+
+  nsCycleCollector_collect(nullptr);
+
+  if (aCollectChildren) {
+    for (uint32_t index = 0; index < mChildWorkers.Length(); index++) {
+      mChildWorkers[index]->CycleCollect(aCx, /* dummy = */ false);
+    }
+  }
+}
+
 
 template <class Derived>
 void

dom/workers/WorkerPrivate.h

@@ -494,6 +494,9 @@ public:
   void
   GarbageCollect(JSContext* aCx, bool aShrinking);
 
+  void
+  CycleCollect(JSContext* aCx, bool aDummy);
+
   bool
   RegisterSharedWorker(JSContext* aCx, SharedWorker* aSharedWorker);
 
@@ -1006,6 +1009,9 @@ public:
   GarbageCollectInternal(JSContext* aCx, bool aShrinking,
                          bool aCollectChildren);
 
+  void
+  CycleCollectInternal(JSContext* aCx, bool aCollectChildren);
+
   JSContext*
   GetJSContext() const
   {