When doing ExplainLiveExpectedGarbage, suspect all nsXPCWrappedJS so that we get more objects in the graph. b=387224 r=graydon a=brendan

js/src/xpconnect/src/nsXPConnect.cpp

@@ -634,6 +634,27 @@ nsXPConnect::PrintAllReferencesTo(void *p)
                 0x7fffffff, nsnull);
 #endif
 }
+
+JS_STATIC_DLL_CALLBACK(JSDHashOperator)
+SuspectWrappedJS(JSDHashTable *table, JSDHashEntryHdr *hdr,
+                 uint32 number, void *arg)
+{
+    for (nsXPCWrappedJS* wrapper = ((JSObject2WrappedJSMap::Entry*)hdr)->value;
+         wrapper; wrapper = wrapper->GetNextWrapper())
+        if (wrapper->IsValid() && !wrapper->IsSubjectToFinalization())
+            nsCycleCollector_suspectCurrent(
+                NS_CYCLE_COLLECTION_CLASSNAME(nsXPCWrappedJS)::Upcast(wrapper));
+    return JS_DHASH_NEXT;
+}
+
+void
+nsXPConnect::SuspectExtraPointers()
+{
+    // FIXME: We should really just call suspectCurrent on all the roots
+    // in the runtime, or even all the objects in the runtime, except we
+    // can't call suspectCurrent on JS objects.
+    GetRuntime(this)->GetWrappedJSMap()->Enumerate(SuspectWrappedJS, nsnull);
+}
 #endif
 
 NS_IMETHODIMP

js/src/xpconnect/src/xpcprivate.h

@@ -494,6 +494,7 @@ public:
     virtual nsCycleCollectionParticipant *ToParticipant(void *p);
 #ifdef DEBUG_CC
     virtual void PrintAllReferencesTo(void *p);
+    virtual void SuspectExtraPointers();
 #endif
 
     JSObjectRefcounts* GetJSObjectRefcounts() {return mObjRefcounts;}

xpcom/base/nsCycleCollector.cpp

@@ -829,6 +829,7 @@ struct nsCycleCollectionXPCOMRuntime :
 
 #ifdef DEBUG_CC
     virtual void PrintAllReferencesTo(void *p) {}
+    virtual void SuspectExtraPointers() {}
 #endif
 };
 
@@ -2253,8 +2254,10 @@ nsCycleCollector::ExplainLiveExpectedGarbage()
     mBuf.Empty();
 
     for (PRUint32 i = 0; i <= nsIProgrammingLanguage::MAX; ++i) {
-        if (mRuntimes[i])
+        if (mRuntimes[i]) {
             mRuntimes[i]->BeginCycleCollection();
+            mRuntimes[i]->SuspectExtraPointers();
+        }
     }
 
     mCollectionInProgress = PR_TRUE;

xpcom/base/nsCycleCollector.h

@@ -55,6 +55,10 @@ struct nsCycleCollectionLanguageRuntime
     virtual nsCycleCollectionParticipant *ToParticipant(void *p) = 0;
 #ifdef DEBUG_CC
     virtual void PrintAllReferencesTo(void *p) = 0;
+
+    // Call suspectCurrent on any extra pointers that will help build a
+    // larger object graph for debugging.
+    virtual void SuspectExtraPointers() = 0;
 #endif
 };