Merge SetObjectNames extra pass into the main pass.

src/profile-generator.cc

Index: src/profile-generator.cc
diff --git a/src/profile-generator.cc b/src/profile-generator.cc
index c78bf28394dd00495ba6382191da2e07d06e3edd..3f4e935b04b6df12c987259b4c2dc1e071be1d73 100644
--- a/src/profile-generator.cc
+++ b/src/profile-generator.cc
@@ -1675,7 +1675,15 @@ HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object) {
                     HeapEntry::kRegExp,
                     collection_->names()->GetName(re->Pattern()));
   } else if (object->IsJSObject()) {
-    return AddEntry(object, HeapEntry::kObject, "");
+    const char* name = collection_->names()->GetName(
+        GetConstructorName(JSObject::cast(object)));
+    if (object->IsJSGlobalObject()) {
+      const char* tag = objects_tags_.GetTag(object);

[yurys, 2012/05/10 12:13:52]

How can we be sure that the object has already been tagged at this point?

[mnaganov (inactive), 2012/05/10 12:15:56]

Global objects tagging is always done before snapshot taking, because it can
modify the heap state. Perhaps, add a comment about this?

[yurys, 2012/05/10 12:23:31]

I think a comment would be helpful here. Also what about non-global objects, do
we care about their tags?

[alexeif, 2012/05/10 13:40:24]

Yep, looks like non-global objects, i.e. arrays those names are setup near line
1713 may miss their tags. This happens if the array is processed before its
retainer. It needs to be fixed. Btw it is not related to this patch, which is
about setting JSGlobalObject tags only.

+      if (tag != NULL) {
+        name = collection_->names()->GetFormatted("%s / %s", name, tag);
+      }
+    }
+    return AddEntry(object, HeapEntry::kObject, name);
   } else if (object->IsString()) {
     return AddEntry(object,
                     HeapEntry::kString,
@@ -2396,32 +2404,6 @@ bool V8HeapExplorer::IterateAndExtractReferences(
 }
 
 
-bool V8HeapExplorer::IterateAndSetObjectNames(SnapshotFillerInterface* filler) {
-  HeapIterator iterator(HeapIterator::kFilterUnreachable);
-  filler_ = filler;
-  for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
-    SetObjectName(obj);
-  }
-  return true;
-}
-
-
-void V8HeapExplorer::SetObjectName(HeapObject* object) {
-  if (!object->IsJSObject() || object->IsJSRegExp() || object->IsJSFunction()) {
-    return;
-  }
-  const char* name = collection_->names()->GetName(
-      GetConstructorName(JSObject::cast(object)));
-  if (object->IsJSGlobalObject()) {
-    const char* tag = objects_tags_.GetTag(object);
-    if (tag != NULL) {
-      name = collection_->names()->GetFormatted("%s / %s", name, tag);
-    }
-  }
-  GetEntry(object)->set_name(name);
-}
-
-
 bool V8HeapExplorer::IsEssentialObject(Object* object) {
   // We have to use raw_unchecked_* versions because checked versions
   // would fail during iteration over object properties.
@@ -3149,15 +3131,8 @@ void HeapSnapshotGenerator::SetProgressTotal(int iterations_count) {
 bool HeapSnapshotGenerator::FillReferences() {
   SnapshotFiller filler(snapshot_, &entries_);
   v8_heap_explorer_.AddRootEntries(&filler);
-  // IterateAndExtractReferences cannot set object names because
-  // it makes call to JSObject::LocalLookupRealNamedProperty which
-  // in turn may relocate objects in property maps thus changing the heap
-  // layout and affecting retainer counts. This is not acceptable because
-  // number of retainers must not change between count and fill passes.
-  // To avoid this there's a separate postpass that set object names.
   return v8_heap_explorer_.IterateAndExtractReferences(&filler)
-      && dom_explorer_.IterateAndExtractReferences(&filler)
-      && v8_heap_explorer_.IterateAndSetObjectNames(&filler);
+      && dom_explorer_.IterateAndExtractReferences(&filler);
 }