HeapProfiler: very slow ~4min "take snapshot time" for 80MB gmail heap.

test/cctest/test-heap-profiler.cc

Index: test/cctest/test-heap-profiler.cc
diff --git a/test/cctest/test-heap-profiler.cc b/test/cctest/test-heap-profiler.cc
index 04f6e0fa130b996bc32b1bc4347b215111628558..0cf9cdaedf58d51c14ce094d1592f3f03dce00c3 100644
--- a/test/cctest/test-heap-profiler.cc
+++ b/test/cctest/test-heap-profiler.cc
@@ -404,12 +404,57 @@ TEST(HeapSnapshotSlicedString) {
   const v8::HeapGraphNode* child_string =
       GetProperty(global, v8::HeapGraphEdge::kProperty, "child_string");
   CHECK_NE(NULL, child_string);
+  CHECK_EQ(v8::HeapGraphNode::kSlicedString, child_string->GetType());
   const v8::HeapGraphNode* parent =
       GetProperty(child_string, v8::HeapGraphEdge::kInternal, "parent");
   CHECK_EQ(parent_string, parent);
+  heap_profiler->DeleteAllHeapSnapshots();
 }
 
 
+TEST(HeapSnapshotConsString) {
+  v8::Isolate* isolate = v8::Isolate::GetCurrent();
+  v8::HandleScope scope(isolate);
+  v8::Local<v8::ObjectTemplate> global_template = v8::ObjectTemplate::New();
+  global_template->SetInternalFieldCount(1);
+  LocalContext env(NULL, global_template);
+  v8::Handle<v8::Object> global_proxy = env->Global();
+  v8::Handle<v8::Object> global = global_proxy->GetPrototype().As<v8::Object>();
+  CHECK_EQ(1, global->InternalFieldCount());
+
+  i::Factory* factory = i::Isolate::Current()->factory();
+  i::Handle<i::String> first =
+      factory->NewStringFromAscii(i::CStrVector("0123456789"));
+  i::Handle<i::String> second =
+      factory->NewStringFromAscii(i::CStrVector("0123456789"));
+  i::Handle<i::String> cons_string = factory->NewConsString(first, second);
+
+  global->SetInternalField(0, v8::ToApiHandle<v8::String>(cons_string));
+
+  v8::HeapProfiler* heap_profiler = isolate->GetHeapProfiler();
+  const v8::HeapSnapshot* snapshot =
+      heap_profiler->TakeHeapSnapshot(v8_str("cons_strings"));
+  CHECK(ValidateSnapshot(snapshot));
+  const v8::HeapGraphNode* global_node = GetGlobalObject(snapshot);
+
+  const v8::HeapGraphNode* string_node =
+      GetProperty(global_node, v8::HeapGraphEdge::kInternal, "0");
+  CHECK_NE(NULL, string_node);
+  CHECK_EQ(v8::HeapGraphNode::kConsString, string_node->GetType());
+
+  const v8::HeapGraphNode* first_node =
+      GetProperty(string_node, v8::HeapGraphEdge::kInternal, "first");
+  CHECK_EQ(v8::HeapGraphNode::kString, first_node->GetType());
+
+  const v8::HeapGraphNode* second_node =
+      GetProperty(string_node, v8::HeapGraphEdge::kInternal, "second");
+  CHECK_EQ(v8::HeapGraphNode::kString, second_node->GetType());
+
+  heap_profiler->DeleteAllHeapSnapshots();
+}
+
+
+
 TEST(HeapSnapshotInternalReferences) {
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   v8::HandleScope scope(isolate);