Bug 882162: Part 7 - Move tracing of gray roots into mozilla::CycleCollectedJSRuntime. r=mccr8

js/xpconnect/src/XPCJSRuntime.cpp

@@ -439,46 +439,8 @@ void XPCJSRuntime::TraceBlackJS(JSTracer* trc, void* data)
                       nsXPConnect::XPConnect()->IsShuttingDown());
 }
 
-// static
+void XPCJSRuntime::TraceAdditionalNativeRoots(JSTracer *trc)
-void XPCJSRuntime::TraceGrayJS(JSTracer* trc, void* data)
 {
-    XPCJSRuntime* self = (XPCJSRuntime*)data;
-
-    // Mark these roots as gray so the CC can walk them later.
-    self->TraceXPConnectRoots(trc);
-}
-
-struct JsGcTracer : public TraceCallbacks
-{
-    virtual void Trace(JS::Heap<JS::Value> *p, const char *name, void *closure) const MOZ_OVERRIDE {
-        JS_CallHeapValueTracer(static_cast<JSTracer*>(closure), p, name);
-    }
-    virtual void Trace(JS::Heap<jsid> *p, const char *name, void *closure) const MOZ_OVERRIDE {
-        JS_CallHeapIdTracer(static_cast<JSTracer*>(closure), p, name);
-    }
-    virtual void Trace(JS::Heap<JSObject *> *p, const char *name, void *closure) const MOZ_OVERRIDE {
-        JS_CallHeapObjectTracer(static_cast<JSTracer*>(closure), p, name);
-    }
-    virtual void Trace(JS::Heap<JSString *> *p, const char *name, void *closure) const MOZ_OVERRIDE {
-        JS_CallHeapStringTracer(static_cast<JSTracer*>(closure), p, name);
-    }
-    virtual void Trace(JS::Heap<JSScript *> *p, const char *name, void *closure) const MOZ_OVERRIDE {
-        JS_CallHeapScriptTracer(static_cast<JSTracer*>(closure), p, name);
-    }
-};
-
-static PLDHashOperator
-TraceJSHolder(void *holder, nsScriptObjectTracer *&tracer, void *arg)
-{
-    tracer->Trace(holder, JsGcTracer(), arg);
-
-    return PL_DHASH_NEXT;
-}
-
-void XPCJSRuntime::TraceXPConnectRoots(JSTracer *trc)
-{
-    MaybeTraceGlobals(trc);
-
     XPCAutoLock lock(mMapLock);
 
     XPCWrappedNativeScope::TraceWrappedNativesInAllScopes(trc, this);
@@ -488,8 +450,6 @@ void XPCJSRuntime::TraceXPConnectRoots(JSTracer *trc)
 
     for (XPCRootSetElem *e = mWrappedJSRoots; e ; e = e->GetNextRoot())
         static_cast<nsXPCWrappedJS*>(e)->TraceJS(trc);
-
-    mJSHolders.Enumerate(TraceJSHolder, trc);
 }
 
 // static
@@ -2750,7 +2710,6 @@ XPCJSRuntime::XPCJSRuntime(nsXPConnect* aXPConnect)
     mPrevGCSliceCallback = JS::SetGCSliceCallback(runtime, GCSliceCallback);
     JS_SetFinalizeCallback(runtime, FinalizeCallback);
     JS_SetExtraGCRootsTracer(runtime, TraceBlackJS, this);
-    JS_SetGrayGCRootsTracer(runtime, TraceGrayJS, this);
     JS_SetWrapObjectCallbacks(runtime,
                               xpc::WrapperFactory::Rewrap,
                               xpc::WrapperFactory::WrapForSameCompartment,

js/xpconnect/src/xpcprivate.h

@@ -765,9 +765,9 @@ public:
     }
 
     static void TraceBlackJS(JSTracer* trc, void* data);
-    static void TraceGrayJS(JSTracer* trc, void* data);
     void TraceXPConnectRoots(JSTracer *trc);
     void TraverseAdditionalNativeRoots(nsCycleCollectionNoteRootCallback& cb);
+    void TraceAdditionalNativeRoots(JSTracer* aTracer);
     void UnmarkSkippableJSHolders();
 
     static void GCCallback(JSRuntime *rt, JSGCStatus status);

xpcom/base/CycleCollectedJSRuntime.cpp

@@ -418,6 +418,8 @@ CycleCollectedJSRuntime::CycleCollectedJSRuntime(uint32_t aMaxbytes,
     MOZ_CRASH();
   }
 
+  JS_SetGrayGCRootsTracer(mJSRuntime, TraceGrayJS, this);
+
   mJSHolders.Init(512);
 }
 
@@ -654,6 +656,54 @@ CycleCollectedJSRuntime::TraverseNativeRoots(nsCycleCollectionNoteRootCallback&
   mJSHolders.Enumerate(NoteJSHolder, &closure);
 }
 
+/* static */ void
+CycleCollectedJSRuntime::TraceGrayJS(JSTracer* aTracer, void* aData)
+{
+  CycleCollectedJSRuntime* self = static_cast<CycleCollectedJSRuntime*>(aData);
+
+  // Mark these roots as gray so the CC can walk them later.
+  self->TraceNativeRoots(aTracer);
+}
+
+struct JsGcTracer : public TraceCallbacks
+{
+  virtual void Trace(JS::Heap<JS::Value> *p, const char *name, void *closure) const MOZ_OVERRIDE {
+    JS_CallHeapValueTracer(static_cast<JSTracer*>(closure), p, name);
+  }
+  virtual void Trace(JS::Heap<jsid> *p, const char *name, void *closure) const MOZ_OVERRIDE {
+    JS_CallHeapIdTracer(static_cast<JSTracer*>(closure), p, name);
+  }
+  virtual void Trace(JS::Heap<JSObject *> *p, const char *name, void *closure) const MOZ_OVERRIDE {
+    JS_CallHeapObjectTracer(static_cast<JSTracer*>(closure), p, name);
+  }
+  virtual void Trace(JS::Heap<JSString *> *p, const char *name, void *closure) const MOZ_OVERRIDE {
+    JS_CallHeapStringTracer(static_cast<JSTracer*>(closure), p, name);
+  }
+  virtual void Trace(JS::Heap<JSScript *> *p, const char *name, void *closure) const MOZ_OVERRIDE {
+    JS_CallHeapScriptTracer(static_cast<JSTracer*>(closure), p, name);
+  }
+};
+
+static PLDHashOperator
+TraceJSHolder(void* aHolder, nsScriptObjectTracer*& aTracer, void* aArg)
+{
+  aTracer->Trace(aHolder, JsGcTracer(), aArg);
+
+  return PL_DHASH_NEXT;
+}
+
+void
+CycleCollectedJSRuntime::TraceNativeRoots(JSTracer* aTracer)
+{
+  MaybeTraceGlobals(aTracer);
+
+  // NB: This is here just to preserve the existing XPConnect order. I doubt it
+  // would hurt to do this after the JS holders.
+  TraceAdditionalNativeRoots(aTracer);
+
+  mJSHolders.Enumerate(TraceJSHolder, aTracer);
+}
+
 void
 CycleCollectedJSRuntime::AddJSHolder(void* aHolder, nsScriptObjectTracer* aTracer)
 {

xpcom/base/CycleCollectedJSRuntime.h

@@ -88,8 +88,9 @@ protected:
     return mJSRuntime;
   }
 
-  void MaybeTraceGlobals(JSTracer* aTracer) const;
   virtual void TraverseAdditionalNativeRoots(nsCycleCollectionNoteRootCallback& aCb) = 0;
+  virtual void TraceAdditionalNativeRoots(JSTracer* aTracer) = 0;
+
 private:
 
   void
@@ -133,6 +134,12 @@ private:
 
   void TraverseNativeRoots(nsCycleCollectionNoteRootCallback& aCb);
 
+  void MaybeTraceGlobals(JSTracer* aTracer) const;
+
+  static void TraceGrayJS(JSTracer* aTracer, void* aData);
+
+  void TraceNativeRoots(JSTracer* aTracer);
+
 public:
   void AddJSHolder(void* aHolder, nsScriptObjectTracer* aTracer);
   void RemoveJSHolder(void* aHolder);