Bug 713778 - nsICycleCollectorListener should not enable trace_all by default, r=mccr8

xpcom/base/nsCycleCollector.cpp

@@ -1373,7 +1373,7 @@ GraphWalker<Visitor>::DoWalk(nsDeque &aQueue)
 class nsCycleCollectorLogger : public nsICycleCollectorListener
 {
 public:
-    nsCycleCollectorLogger() : mStream(nsnull)
+    nsCycleCollectorLogger() : mStream(nsnull), mWantAllTraces(false)
     {
     }
     ~nsCycleCollectorLogger()
@@ -1384,6 +1384,19 @@ public:
     }
     NS_DECL_ISUPPORTS
 
+    NS_IMETHOD AllTraces(nsICycleCollectorListener** aListener)
+    {
+      mWantAllTraces = true;
+      NS_ADDREF(*aListener = this);
+      return NS_OK;
+    }
+
+    NS_IMETHOD GetWantAllTraces(bool* aAllTraces)
+    {
+      *aAllTraces = mWantAllTraces;
+      return NS_OK;
+    }
+
     NS_IMETHOD Begin()
     {
         char name[255];
@@ -1442,6 +1455,7 @@ public:
 
 private:
     FILE *mStream;
+    bool mWantAllTraces;
 
     static PRUint32 gLogCounter;
 };
@@ -1570,17 +1584,24 @@ GCGraphBuilder::GCGraphBuilder(GCGraph &aGraph,
     if (!PL_DHashTableInit(&mPtrToNodeMap, &PtrNodeOps, nsnull,
                            sizeof(PtrToNodeEntry), 32768))
         mPtrToNodeMap.ops = nsnull;
-    // We want all edges and all info if DEBUG_CC is set or if we have a
-    // listener. Do we want them all the time?
-#ifndef DEBUG_CC
-    if (mListener)
-#endif
-    {
-        mFlags |= nsCycleCollectionTraversalCallback::WANT_DEBUG_INFO |
+
+    PRUint32 flags = 0;
+#ifdef DEBUG_CC
+    flags = nsCycleCollectionTraversalCallback::WANT_DEBUG_INFO |
             nsCycleCollectionTraversalCallback::WANT_ALL_TRACES;
+#endif
+    if (!flags && mListener) {
+        flags = nsCycleCollectionTraversalCallback::WANT_DEBUG_INFO;
+        bool all = false;
+        mListener->GetWantAllTraces(&all);
+        if (all) {
+            flags |= nsCycleCollectionTraversalCallback::WANT_ALL_TRACES;
         }
     }
 
+    mFlags |= flags;
+}
+
 GCGraphBuilder::~GCGraphBuilder()
 {
     if (mPtrToNodeMap.ops)

xpcom/base/nsICycleCollectorListener.idl

@@ -49,9 +49,13 @@
  * a call to end().  If begin() returns an error none of the other
  * functions will be called.
  */
-[scriptable, uuid(3f3901bb-6a1c-4998-b32e-6f10a51db470)]
+[scriptable, uuid(35a3a9b0-a120-4bf7-9739-46027fe96212)]
 interface nsICycleCollectorListener : nsISupports
 {
+    nsICycleCollectorListener allTraces();
+    // false if allTraces() has not been called.
+    readonly attribute boolean wantAllTraces;
+
     void begin();
     void noteRefCountedObject (in unsigned long long aAddress,
 			       in unsigned long aRefCount,