Bug 785493, part 2 - mark XUL protos of live docs black during GC. r=smaug

content/base/src/nsCCUncollectableMarker.cpp

@@ -10,6 +10,7 @@
 #include "nsServiceManagerUtils.h"
 #include "nsIContentViewer.h"
 #include "nsIDocument.h"
+#include "nsXULDocument.h"
 #include "nsIWindowMediator.h"
 #include "nsPIDOMWindow.h"
 #include "nsIWebNavigation.h"
@@ -394,30 +395,48 @@ nsCCUncollectableMarker::Observe(nsISupports* aSubject, const char* aTopic,
   return NS_OK;
 }
 
+struct TraceClosure
+{
+  TraceClosure(JSTracer* aTrc, uint32_t aGCNumber)
+    : mTrc(aTrc), mGCNumber(aGCNumber)
+  {}
+  JSTracer* mTrc;
+  uint32_t mGCNumber;
+};
+
 static PLDHashOperator
 TraceActiveWindowGlobal(const uint64_t& aId, nsGlobalWindow*& aWindow, void* aClosure)
 {
   if (aWindow->GetDocShell() && aWindow->IsOuterWindow()) {
+    TraceClosure* closure = static_cast<TraceClosure*>(aClosure);
     if (JSObject* global = aWindow->FastGetGlobalJSObject()) {
-      JSTracer* trc = static_cast<JSTracer *>(aClosure);
-      JS_CALL_OBJECT_TRACER(trc, global, "active window global");
+      JS_CALL_OBJECT_TRACER(closure->mTrc, global, "active window global");
     }
+#ifdef MOZ_XUL
+    nsIDocument* doc = aWindow->GetExtantDoc();
+    if (doc && doc->IsXUL()) {
+      nsXULDocument* xulDoc = static_cast<nsXULDocument*>(doc);
+      xulDoc->TraceProtos(closure->mTrc, closure->mGCNumber);
+    }
+#endif
   }
   return PL_DHASH_NEXT;
 }
 
 void
-mozilla::dom::TraceBlackJS(JSTracer* aTrc)
+mozilla::dom::TraceBlackJS(JSTracer* aTrc, uint32_t aGCNumber)
 {
   if (!nsCCUncollectableMarker::sGeneration) {
     return;
   }
 
+  TraceClosure closure(aTrc, aGCNumber);
+
   // Mark globals of active windows black.
   nsGlobalWindow::WindowByIdTable* windowsById =
     nsGlobalWindow::GetWindowsTable();
   if (windowsById) {
-    windowsById->Enumerate(TraceActiveWindowGlobal, aTrc);
+    windowsById->Enumerate(TraceActiveWindowGlobal, &closure);
   }
 
   // Mark the safe context black

content/base/src/nsCCUncollectableMarker.h

@@ -45,7 +45,7 @@ private:
 
 namespace mozilla {
 namespace dom {
-void TraceBlackJS(JSTracer* aTrc);
+void TraceBlackJS(JSTracer* aTrc, uint32_t aGCNumber);
 }
 }
 

content/xul/content/src/nsXULElement.cpp

@@ -2231,6 +2231,22 @@ nsXULPrototypeElement::Unlink()
     mAttributes = nullptr;
 }
 
+void
+nsXULPrototypeElement::TraceAllScripts(JSTracer* aTrc)
+{
+    for (uint32_t i = 0; i < mChildren.Length(); ++i) {
+        nsXULPrototypeNode* child = mChildren[i];
+        if (child->mType == nsXULPrototypeNode::eType_Element) {
+            static_cast<nsXULPrototypeElement*>(child)->TraceAllScripts(aTrc);
+        } else if (child->mType == nsXULPrototypeNode::eType_Script) {
+            JSScript* script = static_cast<nsXULPrototypeScript*>(child)->GetScriptObject();
+            if (script) {
+                JS_CALL_SCRIPT_TRACER(aTrc, script, "active window XUL prototype script");
+            }
+        }
+    }
+}
+
 //----------------------------------------------------------------------
 //
 // nsXULPrototypeScript

content/xul/content/src/nsXULElement.h

@@ -186,6 +186,9 @@ public:
 
     void Unlink();
 
+    // Trace all scripts held by this element and its children.
+    void TraceAllScripts(JSTracer* aTrc);
+
     nsPrototypeArray         mChildren;
 
     nsCOMPtr<nsINodeInfo>    mNodeInfo;           // [OWNER]

content/xul/document/src/nsXULDocument.cpp

@@ -2221,6 +2221,15 @@ nsXULDocument::ApplyPersistentAttributesToElements(nsIRDFResource* aResource,
     return NS_OK;
 }
 
+void
+nsXULDocument::TraceProtos(JSTracer* aTrc, uint32_t aGCNumber)
+{
+    uint32_t i, count = mPrototypes.Length();
+    for (i = 0; i < count; ++i) {
+        mPrototypes[i]->TraceProtos(aTrc, aGCNumber);
+    }
+}
+
 //----------------------------------------------------------------------
 //
 // nsXULDocument::ContextStack

content/xul/document/src/nsXULDocument.h

@@ -40,8 +40,9 @@ class nsIXULPrototypeScript;
 #endif
 #include "nsURIHashKey.h"
 #include "nsInterfaceHashtable.h"
- 
+
 struct JSObject;
+struct JSTracer;
 struct PRLogModuleInfo;
 
 class nsRefMapEntry : public nsStringHashKey
@@ -178,6 +179,9 @@ public:
     NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsXULDocument, nsXMLDocument)
 
     virtual nsXPCClassInfo* GetClassInfo();
+
+    void TraceProtos(JSTracer* aTrc, uint32_t aGCNumber);
+
 protected:
     // Implementation methods
     friend nsresult

content/xul/document/src/nsXULPrototypeDocument.cpp

@@ -127,7 +127,8 @@ JSClass nsXULPDGlobalObject::gSharedGlobalClass = {
 nsXULPrototypeDocument::nsXULPrototypeDocument()
     : mRoot(nullptr),
       mLoaded(false),
-      mCCGeneration(0)
+      mCCGeneration(0),
+      mGCNumber(0)
 {
     ++gRefCnt;
 }
@@ -678,6 +679,18 @@ nsXULPrototypeDocument::NotifyLoadDone()
     return rv;
 }
 
+void
+nsXULPrototypeDocument::TraceProtos(JSTracer* aTrc, uint32_t aGCNumber)
+{
+  // Only trace the protos once per GC.
+  if (mGCNumber == aGCNumber) {
+    return;
+  }
+
+  mGCNumber = aGCNumber;
+  mRoot->TraceAllScripts(aTrc);
+}
+
 //----------------------------------------------------------------------
 //
 // nsIScriptGlobalObjectOwner methods

content/xul/document/src/nsXULPrototypeDocument.h

@@ -22,6 +22,7 @@ class nsXULDocument;
 class nsXULPrototypeElement;
 class nsXULPrototypePI;
 class nsXULPDGlobalObject;
+struct JSTracer;
 
 /**
  * A "prototype" document that stores shared document information
@@ -118,6 +119,8 @@ public:
     NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsXULPrototypeDocument,
                                              nsIScriptGlobalObjectOwner)
 
+    void TraceProtos(JSTracer* aTrc, uint32_t aGCNumber);
+
 protected:
     nsCOMPtr<nsIURI> mURI;
     nsRefPtr<nsXULPrototypeElement> mRoot;
@@ -132,6 +135,7 @@ protected:
     nsRefPtr<nsNodeInfoManager> mNodeInfoManager;
 
     uint32_t mCCGeneration;
+    uint32_t mGCNumber;
 
     nsXULPrototypeDocument();
     virtual ~nsXULPrototypeDocument();

js/xpconnect/src/XPCJSRuntime.cpp

@@ -322,8 +322,7 @@ void XPCJSRuntime::TraceBlackJS(JSTracer* trc, void* data)
             static_cast<XPCJSObjectHolder*>(e)->TraceJS(trc);
     }
 
-    dom::TraceBlackJS(trc);
-
+    dom::TraceBlackJS(trc, JS_GetGCParameter(self->GetJSRuntime(), JSGC_NUMBER));
 }
 
 // static