diff --git a/src/check_jni.cc b/src/check_jni.cc
index 93d3b31..eb829a0 100644
--- a/src/check_jni.cc
+++ b/src/check_jni.cc
@@ -23,6 +23,7 @@
 #include "logging.h"
 #include "scoped_jni_thread_state.h"
 #include "thread.h"
+#include "runtime.h"
 
 namespace art {
 
diff --git a/src/class_linker.cc b/src/class_linker.cc
index 9bbcb0c..89b425f 100644
--- a/src/class_linker.cc
+++ b/src/class_linker.cc
@@ -7,6 +7,7 @@
 
 #include "UniquePtr.h"
 #include "casts.h"
+#include "class_loader.h"
 #include "dex_cache.h"
 #include "dex_file.h"
 #include "dex_verifier.h"
@@ -14,6 +15,7 @@
 #include "logging.h"
 #include "monitor.h"
 #include "object.h"
+#include "runtime.h"
 #include "space.h"
 #include "thread.h"
 #include "utils.h"
@@ -242,14 +244,44 @@
   SetClassRoot(kFloatArrayClass, FindSystemClass("[F"));
   SetClassRoot(kLongArrayClass, FindSystemClass("[J"));
   SetClassRoot(kShortArrayClass, FindSystemClass("[S"));
-  SetClassRoot(kJavaLangStackTraceElement, FindSystemClass("Ljava/lang/StackTraceElement;"));
-  SetClassRoot(kJavaLangStackTraceElementArrayClass, FindSystemClass("[Ljava/lang/StackTraceElement;"));
   BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass));
   ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass));
   DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass));
   FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass));
   LongArray::SetArrayClass(GetClassRoot(kLongArrayClass));
   ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass));
+
+  // java.lang.ref classes need to be specially flagged, but otherwise are normal classes
+  Class* java_lang_ref_FinalizerReference = FindSystemClass("Ljava/lang/ref/FinalizerReference;");
+  Class* java_lang_ref_PhantomReference = FindSystemClass("Ljava/lang/ref/PhantomReference;");
+  Class* java_lang_ref_SoftReference = FindSystemClass("Ljava/lang/ref/SoftReference;");
+  Class* java_lang_ref_WeakReference = FindSystemClass("Ljava/lang/ref/WeakReference;");
+  java_lang_ref_FinalizerReference->access_flags_ |= kAccClassIsReference | kAccClassIsFinalizerReference;
+  java_lang_ref_PhantomReference->access_flags_ |= kAccClassIsReference | kAccClassIsPhantomReference;
+  java_lang_ref_SoftReference->access_flags_ |= kAccClassIsReference;
+  java_lang_ref_WeakReference->access_flags_ |= kAccClassIsReference | kAccClassIsWeakReference;
+
+  // Let the heap know some key offsets into java.lang.ref instances
+  Class* java_lang_ref_Reference = FindSystemClass("Ljava/lang/ref/Reference;");
+  Field* referent = java_lang_ref_Reference->FindDeclaredInstanceField(
+      "referent", "Ljava/lang/Object;");
+  Field* queue = java_lang_ref_Reference->FindDeclaredInstanceField(
+      "queue", "Ljava/lang/ref/ReferenceQueue;");
+  Field* queueNext = java_lang_ref_Reference->FindDeclaredInstanceField(
+      "queueNext", "Ljava/lang/ref/Reference;");
+  Field* pendingNext = java_lang_ref_Reference->FindDeclaredInstanceField(
+      "pendingNext", "Ljava/lang/ref/Reference;");
+  Field* zombie = java_lang_ref_FinalizerReference->FindDeclaredInstanceField(
+      "zombie", "Ljava/lang/Object;");
+  Heap::SetReferenceOffsets(referent->GetOffset(),
+                            queue->GetOffset(),
+                            queueNext->GetOffset(),
+                            pendingNext->GetOffset(),
+                            zombie->GetOffset());
+
+  // Optimization for quick stack trace allocation
+  SetClassRoot(kJavaLangStackTraceElement, FindSystemClass("Ljava/lang/StackTraceElement;"));
+  SetClassRoot(kJavaLangStackTraceElementArrayClass, FindSystemClass("[Ljava/lang/StackTraceElement;"));
   StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement));
 
   FinishInit();
@@ -455,11 +487,11 @@
 }
 
 Field* ClassLinker::AllocField() {
-  return down_cast<Field*>(GetClassRoot(kJavaLangReflectField)->NewInstance());
+  return down_cast<Field*>(GetClassRoot(kJavaLangReflectField)->AllocObject());
 }
 
 Method* ClassLinker::AllocMethod() {
-  return down_cast<Method*>(GetClassRoot(kJavaLangReflectMethod)->NewInstance());
+  return down_cast<Method*>(GetClassRoot(kJavaLangReflectMethod)->AllocObject());
 }
 
 ObjectArray<StackTraceElement>* ClassLinker::AllocStackTraceElementArray(size_t length) {
@@ -649,6 +681,9 @@
   klass->primitive_type_ = Class::kPrimNot;
   klass->status_ = Class::kStatusIdx;
 
+  // Make sure the aren't any "bonus" flags set, since we use them for runtime state.
+  CHECK_EQ(klass->access_flags_ & ~kAccClassFlagsMask, 0U);
+
   klass->super_class_ = NULL;
   klass->super_class_type_idx_ = dex_class_def.superclass_idx_;
 
@@ -701,7 +736,7 @@
       dex_file.dexReadClassDataMethod(&class_data, &dex_method, &last_idx);
       Method* meth = AllocMethod();
       klass->SetDirectMethod(i, meth);
-      LoadMethod(dex_file, dex_method, klass, meth, true);
+      LoadMethod(dex_file, dex_method, klass, meth);
       // TODO: register maps
     }
   }
@@ -717,7 +752,7 @@
       dex_file.dexReadClassDataMethod(&class_data, &dex_method, &last_idx);
       Method* meth = AllocMethod();
       klass->SetVirtualMethod(i, meth);
-      LoadMethod(dex_file, dex_method, klass, meth, false);
+      LoadMethod(dex_file, dex_method, klass, meth);
       // TODO: register maps
     }
   }
@@ -754,8 +789,7 @@
 void ClassLinker::LoadMethod(const DexFile& dex_file,
                              const DexFile::Method& src,
                              Class* klass,
-                             Method* dst,
-                             bool is_direct) {
+                             Method* dst) {
   const DexFile::MethodId& method_id = dex_file.GetMethodId(src.method_idx_);
   dst->declaring_class_ = klass;
   dst->name_ = ResolveString(dex_file, method_id.name_idx_, klass->GetDexCache());
@@ -776,8 +810,6 @@
   dst->dex_cache_code_and_direct_methods_ = klass->dex_cache_->GetCodeAndDirectMethods();
   dst->dex_cache_initialized_static_storage_ = klass->dex_cache_->GetInitializedStaticStorage();
 
-  dst->is_direct_ = is_direct;
-
   // TODO: check for finalize method
 
   const DexFile::CodeItem* code_item = dex_file.GetCodeItem(src);
diff --git a/src/class_linker.h b/src/class_linker.h
index 6e13aa7..1f233b0 100644
--- a/src/class_linker.h
+++ b/src/class_linker.h
@@ -18,6 +18,8 @@
 
 #include "gtest/gtest.h"
 
+class ClassLoader;
+
 namespace art {
 
 class ClassLinker {
@@ -192,8 +194,7 @@
   void LoadMethod(const DexFile& dex_file,
                   const DexFile::Method& dex_method,
                   Class* klass,
-                  Method* dst,
-                  bool is_direct);
+                  Method* dst);
 
   Class* LookupClass(const StringPiece& descriptor, const ClassLoader* class_loader);
 
diff --git a/src/class_linker_test.cc b/src/class_linker_test.cc
index e207fd9..c403065 100644
--- a/src/class_linker_test.cc
+++ b/src/class_linker_test.cc
@@ -7,7 +7,6 @@
 #include "dex_cache.h"
 #include "dex_file.h"
 #include "heap.h"
-#include "gtest/gtest.h"
 
 namespace art {
 
diff --git a/src/class_loader.cc b/src/class_loader.cc
new file mode 100644
index 0000000..9769136
--- /dev/null
+++ b/src/class_loader.cc
@@ -0,0 +1,37 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+
+#include "class_loader.h"
+
+#include "class_linker.h"
+#include "runtime.h"
+
+namespace art {
+
+const std::vector<const DexFile*>& ClassLoader::GetClassPath(const ClassLoader* class_loader) {
+  if (class_loader == NULL) {
+    return Runtime::Current()->GetClassLinker()->GetBootClassPath();
+  }
+  return class_loader->class_path_;
+}
+
+// TODO: get global references for these
+Class* PathClassLoader::dalvik_system_PathClassLoader_ = NULL;
+
+const PathClassLoader* PathClassLoader::Alloc(std::vector<const DexFile*> dex_files) {
+  PathClassLoader* p = down_cast<PathClassLoader*>(dalvik_system_PathClassLoader_->AllocObject());
+  p->SetClassPath(dex_files);
+  return p;
+}
+
+void PathClassLoader::SetClass(Class* dalvik_system_PathClassLoader) {
+  CHECK(dalvik_system_PathClassLoader_ == NULL);
+  CHECK(dalvik_system_PathClassLoader != NULL);
+  dalvik_system_PathClassLoader_ = dalvik_system_PathClassLoader;
+}
+
+void PathClassLoader::ResetClass() {
+  CHECK(dalvik_system_PathClassLoader_ != NULL);
+  dalvik_system_PathClassLoader_ = NULL;
+}
+
+}  // namespace art
diff --git a/src/class_loader.h b/src/class_loader.h
new file mode 100644
index 0000000..da19539
--- /dev/null
+++ b/src/class_loader.h
@@ -0,0 +1,54 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+
+#ifndef ART_SRC_CLASS_LOADER_H_
+#define ART_SRC_CLASS_LOADER_H_
+
+#include <vector>
+
+#include "dex_file.h"
+#include "object.h"
+
+namespace art {
+
+// ClassLoader objects.
+class ClassLoader : public Object {
+ public:
+  static const std::vector<const DexFile*>& GetClassPath(const ClassLoader* class_loader);
+
+  void SetClassPath(std::vector<const DexFile*>& class_path) {
+    DCHECK_EQ(0U, class_path_.size());
+    class_path_ = class_path;
+  }
+
+ private:
+  // Field order required by test "ValidateFieldOrderOfJavaCppUnionClasses".
+  Object* packages_;
+  ClassLoader* parent_;
+
+  // TODO: remove once we can create a real PathClassLoader
+  std::vector<const DexFile*> class_path_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ClassLoader);
+};
+
+class BaseDexClassLoader : public ClassLoader {
+ private:
+  // Field order required by test "ValidateFieldOrderOfJavaCppUnionClasses".
+  String* original_path_;
+  Object* path_list_;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(BaseDexClassLoader);
+};
+
+class PathClassLoader : public BaseDexClassLoader {
+ public:
+  static const PathClassLoader* Alloc(std::vector<const DexFile*> dex_files);
+  static void SetClass(Class* dalvik_system_PathClassLoader);
+  static void ResetClass();
+ private:
+  static Class* dalvik_system_PathClassLoader_;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(PathClassLoader);
+};
+
+}  // namespace art
+
+#endif  // ART_SRC_OBJECT_H_
diff --git a/src/common_test.h b/src/common_test.h
index bb9b93c..c79cea6 100644
--- a/src/common_test.h
+++ b/src/common_test.h
@@ -8,9 +8,11 @@
 #include "UniquePtr.h"
 #include "base64.h"
 #include "class_linker.h"
+#include "class_loader.h"
 #include "dex_file.h"
-#include "heap.h"
 #include "gtest/gtest.h"
+#include "heap.h"
+#include "runtime.h"
 #include "stringprintf.h"
 #include "thread.h"
 #include "unicode/uclean.h"
diff --git a/src/compiler.cc b/src/compiler.cc
index 37f8298..8396bdf 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -4,8 +4,10 @@
 
 #include "assembler.h"
 #include "class_linker.h"
+#include "class_loader.h"
 #include "dex_cache.h"
 #include "jni_compiler.h"
+#include "runtime.h"
 
 extern bool oatCompileMethod(art::Method*, art::InstructionSet);
 
diff --git a/src/compiler/Frontend.cc b/src/compiler/Frontend.cc
index 6c31cfe..9ef2b4f 100644
--- a/src/compiler/Frontend.cc
+++ b/src/compiler/Frontend.cc
@@ -18,6 +18,7 @@
 #include "CompilerInternals.h"
 #include "Dataflow.h"
 #include "constants.h"
+#include "runtime.h"
 
 static inline bool contentIsInsn(const u2* codePtr) {
     u2 instr = *codePtr;
diff --git a/src/compiler/codegen/arm/Thumb2/Gen.cc b/src/compiler/codegen/arm/Thumb2/Gen.cc
index 699a561..3da5aaa 100644
--- a/src/compiler/codegen/arm/Thumb2/Gen.cc
+++ b/src/compiler/codegen/arm/Thumb2/Gen.cc
@@ -535,7 +535,7 @@
 {
     oatFlushAllRegs(cUnit);    /* Everything to home location */
     loadWordDisp(cUnit, rSELF,
-                 OFFSETOF_MEMBER(Thread, pNewInstanceFromCode), rLR);
+                 OFFSETOF_MEMBER(Thread, pAllocObjectFromCode), rLR);
     loadCurrMethodDirect(cUnit, r1);              // arg1 <= Method*
     loadConstant(cUnit, r0, mir->dalvikInsn.vB);  // arg0 <- type_id
     opReg(cUnit, kOpBlx, rLR);
diff --git a/src/dex_cache_test.cc b/src/dex_cache_test.cc
index 843466d..a01647a 100644
--- a/src/dex_cache_test.cc
+++ b/src/dex_cache_test.cc
@@ -7,7 +7,6 @@
 #include "object.h"
 
 #include <stdio.h>
-#include "gtest/gtest.h"
 
 namespace art {
 
diff --git a/src/dex_file.cc b/src/dex_file.cc
index fde6f01..4b56435 100644
--- a/src/dex_file.cc
+++ b/src/dex_file.cc
@@ -3,6 +3,7 @@
 #include "dex_file.h"
 
 #include <fcntl.h>
+#include <limits.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/file.h>
diff --git a/src/dex_verifier.cc b/src/dex_verifier.cc
index e0702b7..0e62b25 100644
--- a/src/dex_verifier.cc
+++ b/src/dex_verifier.cc
@@ -1,14 +1,15 @@
 // Copyright 2011 Google Inc. All Rights Reserved.
 
-#include "class_linker.h"
-#include "dex_file.h"
-#include "dex_instruction.h"
-#include "dex_instruction_visitor.h"
 #include "dex_verifier.h"
 
 #include <iostream>
 
+#include "class_linker.h"
+#include "dex_file.h"
+#include "dex_instruction.h"
+#include "dex_instruction_visitor.h"
 #include "logging.h"
+#include "runtime.h"
 #include "stringpiece.h"
 
 namespace art {
diff --git a/src/file_test.cc b/src/file_test.cc
index 0019c1d..99e4b41 100644
--- a/src/file_test.cc
+++ b/src/file_test.cc
@@ -4,7 +4,6 @@
 
 #include "UniquePtr.h"
 #include "common_test.h"
-#include "gtest/gtest.h"
 #include "os.h"
 
 namespace art {
diff --git a/src/heap.cc b/src/heap.cc
index 286d706..bffd19d 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -31,6 +31,12 @@
 
 HeapBitmap* Heap::live_bitmap_ = NULL;
 
+size_t Heap::reference_referent_offset_ = 0;  // TODO
+size_t Heap::reference_queue_offset_ = 0;  // TODO
+size_t Heap::reference_queueNext_offset_ = 0;  // TODO
+size_t Heap::reference_pendingNext_offset_ = 0;  // TODO
+size_t Heap::finalizer_reference_zombie_offset_ = 0;  // TODO
+
 bool Heap::Init(size_t initial_size, size_t maximum_size, const char* boot_image_file_name) {
   Space* boot_space;
   byte* requested_base;
diff --git a/src/heap.h b/src/heap.h
index bbd05db..d4d43e7 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -67,6 +67,48 @@
     return mark_bitmap_;
   }
 
+  static void SetReferenceOffsets(size_t reference_referent_offset,
+                                  size_t reference_queue_offset,
+                                  size_t reference_queueNext_offset,
+                                  size_t reference_pendingNext_offset,
+                                  size_t finalizer_reference_zombie_offset) {
+    CHECK_NE(reference_referent_offset, 0U);
+    CHECK_NE(reference_queue_offset, 0U);
+    CHECK_NE(reference_queueNext_offset, 0U);
+    CHECK_NE(reference_pendingNext_offset, 0U);
+    CHECK_NE(finalizer_reference_zombie_offset, 0U);
+    reference_referent_offset_ = reference_referent_offset;
+    reference_queue_offset_ = reference_queue_offset;
+    reference_queueNext_offset_ = reference_queueNext_offset;
+    reference_pendingNext_offset_ = reference_pendingNext_offset;
+    finalizer_reference_zombie_offset_ = finalizer_reference_zombie_offset;
+  }
+
+  static size_t GetReferenceReferentOffset() {
+    DCHECK_NE(reference_referent_offset_, 0U);
+    return reference_referent_offset_;
+  }
+
+  static size_t GetReferenceQueueOffset() {
+    DCHECK_NE(reference_queue_offset_, 0U);
+    return reference_queue_offset_;
+  }
+
+  static size_t GetReferenceQueueNextOffset() {
+    DCHECK_NE(reference_queueNext_offset_, 0U);
+    return reference_queueNext_offset_;
+  }
+
+  static size_t GetReferencePendingNextOffset() {
+    DCHECK_NE(reference_pendingNext_offset_, 0U);
+    return reference_pendingNext_offset_;
+  }
+
+  static size_t GetFinalizerReferenceZombieOffset() {
+    DCHECK_NE(finalizer_reference_zombie_offset_, 0U);
+    return finalizer_reference_zombie_offset_;
+  }
+
  private:
   // Allocates uninitialized storage.
   static Object* Allocate(size_t num_bytes);
@@ -108,6 +150,21 @@
   // free.
   static size_t num_objects_allocated_;
 
+  // offset of java.lang.ref.Reference.referent
+  static size_t reference_referent_offset_;
+
+  // offset of java.lang.ref.Reference.queue
+  static size_t reference_queue_offset_;
+
+  // offset of java.lang.ref.Reference.queueNext
+  static size_t reference_queueNext_offset_;
+
+  // offset of java.lang.ref.Reference.pendingNext
+  static size_t reference_pendingNext_offset_;
+
+  // offset of java.lang.ref.FinalizerReference.zombie
+  static size_t finalizer_reference_zombie_offset_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(Heap);
 };
 
diff --git a/src/heap_test.cc b/src/heap_test.cc
new file mode 100644
index 0000000..568ddd2
--- /dev/null
+++ b/src/heap_test.cc
@@ -0,0 +1,14 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+
+#include "common_test.h"
+
+namespace art {
+
+class HeapTest : public CommonTest {};
+
+TEST_F(HeapTest, GarbageCollectClassLinkerInit) {
+  // garbage is created during ClassLinker::Init
+  Heap::CollectGarbage();
+}
+
+} // namespace art
diff --git a/src/image_test.cc b/src/image_test.cc
index 34e243d..b03cbe3 100644
--- a/src/image_test.cc
+++ b/src/image_test.cc
@@ -7,8 +7,6 @@
 #include "space.h"
 #include "utils.h"
 
-#include "gtest/gtest.h"
-
 namespace art {
 
 class ImageTest : public CommonTest {};
diff --git a/src/image_writer.cc b/src/image_writer.cc
index 0a66664..fd3ec4d 100644
--- a/src/image_writer.cc
+++ b/src/image_writer.cc
@@ -8,6 +8,7 @@
 
 #include "UniquePtr.h"
 #include "class_linker.h"
+#include "class_loader.h"
 #include "dex_cache.h"
 #include "file.h"
 #include "globals.h"
@@ -16,6 +17,7 @@
 #include "intern_table.h"
 #include "logging.h"
 #include "object.h"
+#include "runtime.h"
 #include "space.h"
 #include "utils.h"
 
diff --git a/src/image_writer.h b/src/image_writer.h
index 4299373..80012bc 100644
--- a/src/image_writer.h
+++ b/src/image_writer.h
@@ -11,6 +11,7 @@
 #include "mem_map.h"
 #include "object.h"
 #include "os.h"
+#include "space.h"
 
 namespace art {
 
diff --git a/src/indirect_reference_table_test.cc b/src/indirect_reference_table_test.cc
index 352ebd5..cea4afd 100644
--- a/src/indirect_reference_table_test.cc
+++ b/src/indirect_reference_table_test.cc
@@ -18,8 +18,6 @@
 
 #include "indirect_reference_table.h"
 
-#include "gtest/gtest.h"
-
 namespace art {
 
 class IndirectReferenceTableTest : public CommonTest {
@@ -32,13 +30,13 @@
 
   Class* c = class_linker_->FindSystemClass("Ljava/lang/Object;");
   ASSERT_TRUE(c != NULL);
-  Object* obj0 = c->NewInstance();
+  Object* obj0 = c->AllocObject();
   ASSERT_TRUE(obj0 != NULL);
-  Object* obj1 = c->NewInstance();
+  Object* obj1 = c->AllocObject();
   ASSERT_TRUE(obj1 != NULL);
-  Object* obj2 = c->NewInstance();
+  Object* obj2 = c->AllocObject();
   ASSERT_TRUE(obj2 != NULL);
-  Object* obj3 = c->NewInstance();
+  Object* obj3 = c->AllocObject();
   ASSERT_TRUE(obj3 != NULL);
 
   const uint32_t cookie = IRT_FIRST_SEGMENT;
diff --git a/src/intern_table_test.cc b/src/intern_table_test.cc
index 662a8b6..a01c6dd 100644
--- a/src/intern_table_test.cc
+++ b/src/intern_table_test.cc
@@ -5,8 +5,6 @@
 #include "common_test.h"
 #include "object.h"
 
-#include "gtest/gtest.h"
-
 namespace art {
 
 class InternTableTest : public CommonTest {};
diff --git a/src/jni_internal.cc b/src/jni_internal.cc
index 9213056..5acb155 100644
--- a/src/jni_internal.cc
+++ b/src/jni_internal.cc
@@ -14,6 +14,7 @@
 #include "UniquePtr.h"
 #include "assembler.h"
 #include "class_linker.h"
+#include "class_loader.h"
 #include "jni.h"
 #include "logging.h"
 #include "object.h"
@@ -904,7 +905,7 @@
     if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(c)) {
       return NULL;
     }
-    return AddLocalReference<jobject>(ts, c->NewInstance());
+    return AddLocalReference<jobject>(ts, c->AllocObject());
   }
 
   static jobject NewObject(JNIEnv* env, jclass clazz, jmethodID mid, ...) {
@@ -922,7 +923,7 @@
     if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(c)) {
       return NULL;
     }
-    Object* result = c->NewInstance();
+    Object* result = c->AllocObject();
     jobject local_result = AddLocalReference<jobject>(ts, result);
     CallNonvirtualVoidMethodV(env, local_result, java_class, mid, args);
     return local_result;
@@ -934,7 +935,7 @@
     if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(c)) {
       return NULL;
     }
-    Object* result = c->NewInstance();
+    Object* result = c->AllocObject();
     jobject local_result = AddLocalReference<jobjectArray>(ts, result);
     CallNonvirtualVoidMethodA(env, local_result, java_class, mid, args);
     return local_result;
diff --git a/src/jni_internal_test.cc b/src/jni_internal_test.cc
index 1d0f35f..42ab158 100644
--- a/src/jni_internal_test.cc
+++ b/src/jni_internal_test.cc
@@ -6,7 +6,6 @@
 #include <sys/mman.h>
 
 #include "common_test.h"
-#include "gtest/gtest.h"
 
 namespace art {
 
diff --git a/src/mark_sweep.cc b/src/mark_sweep.cc
index eb81cf6..b803c48 100644
--- a/src/mark_sweep.cc
+++ b/src/mark_sweep.cc
@@ -10,17 +10,13 @@
 #include "macros.h"
 #include "mark_stack.h"
 #include "object.h"
+#include "class_loader.h"
+#include "runtime.h"
 #include "space.h"
 #include "thread.h"
 
 namespace art {
 
-size_t MarkSweep::reference_referent_offset_ = 0;  // TODO
-size_t MarkSweep::reference_queue_offset_ = 0;  // TODO
-size_t MarkSweep::reference_queueNext_offset_ = 0;  // TODO
-size_t MarkSweep::reference_pendingNext_offset_ = 0;  // TODO
-size_t MarkSweep::finalizer_reference_zombie_offset_ = 0;  // TODO
-
 bool MarkSweep::Init() {
   mark_stack_ = MarkStack::Create();
   if (mark_stack_ == NULL) {
@@ -65,9 +61,16 @@
   }
 }
 
+void MarkSweep::MarkObjectVisitor(Object* root, void* arg) {
+  DCHECK(root != NULL);
+  DCHECK(arg != NULL);
+  MarkSweep* mark_sweep = reinterpret_cast<MarkSweep*>(arg);
+  mark_sweep->MarkObject0(root, true);
+}
+
 // Marks all objects in the root set.
 void MarkSweep::MarkRoots() {
-  UNIMPLEMENTED(FATAL);
+  Runtime::Current()->VisitRoots(MarkObjectVisitor, this);
 }
 
 void MarkSweep::ScanBitmapCallback(Object* obj, void* finger, void* arg) {
@@ -79,13 +82,21 @@
 // Populates the mark stack based on the set of marked objects and
 // recursively marks until the mark stack is emptied.
 void MarkSweep::RecursiveMark() {
+
+  // RecursiveMark will build the lists of known instances of the Reference classes.
+  // See DelayReferenceReferent for details.
+  CHECK(soft_reference_list_ == NULL);
+  CHECK(weak_reference_list_ == NULL);
+  CHECK(finalizer_reference_list_ == NULL);
+  CHECK(phantom_reference_list_ == NULL);
+  CHECK(cleared_reference_list_ == NULL);
+
   void* arg = reinterpret_cast<void*>(this);
   const std::vector<Space*>& spaces = Heap::GetSpaces();
   for (size_t i = 0; i < spaces.size(); ++i) {
     if (spaces[i]->IsCondemned()) {
       uintptr_t base = reinterpret_cast<uintptr_t>(spaces[i]->GetBase());
-      uintptr_t limit = reinterpret_cast<uintptr_t>(spaces[i]->GetLimit());
-      mark_bitmap_->ScanWalk(base, limit, &MarkSweep::ScanBitmapCallback, arg);
+      mark_bitmap_->ScanWalk(base, &MarkSweep::ScanBitmapCallback, arg);
     }
   }
   finger_ = reinterpret_cast<Object*>(~0);
@@ -224,7 +235,7 @@
 void MarkSweep::EnqueuePendingReference(Object* ref, Object** list) {
   DCHECK(ref != NULL);
   DCHECK(list != NULL);
-  size_t offset = reference_pendingNext_offset_;
+  size_t offset = Heap::GetReferencePendingNextOffset();
   if (*list == NULL) {
     ref->SetFieldObject(offset, ref);
     *list = ref;
@@ -238,7 +249,7 @@
 Object* MarkSweep::DequeuePendingReference(Object** list) {
   DCHECK(list != NULL);
   DCHECK(*list != NULL);
-  size_t offset = reference_pendingNext_offset_;
+  size_t offset = Heap::GetReferencePendingNextOffset();
   Object* head = (*list)->GetFieldObject(offset);
   Object* ref;
   if (*list == head) {
@@ -258,19 +269,20 @@
 // the gcHeap for later processing.
 void MarkSweep::DelayReferenceReferent(Object* obj) {
   DCHECK(obj != NULL);
-  DCHECK(obj->GetClass() != NULL);
-  DCHECK(obj->IsReference());
-  Object* pending = obj->GetFieldObject(reference_pendingNext_offset_);
-  Object* referent = obj->GetFieldObject(reference_referent_offset_);
+  Class* klass = obj->GetClass();
+  DCHECK(klass != NULL);
+  DCHECK(klass->IsReference());
+  Object* pending = obj->GetFieldObject(Heap::GetReferencePendingNextOffset());
+  Object* referent = obj->GetFieldObject(Heap::GetReferenceReferentOffset());
   if (pending == NULL && referent != NULL && !IsMarked(referent)) {
     Object** list = NULL;
-    if (obj->IsSoftReference()) {
+    if (klass->IsSoftReference()) {
       list = &soft_reference_list_;
-    } else if (obj->IsWeakReference()) {
+    } else if (klass->IsWeakReference()) {
       list = &weak_reference_list_;
-    } else if (obj->IsFinalizerReference()) {
+    } else if (klass->IsFinalizerReference()) {
       list = &finalizer_reference_list_;
-    } else if (obj->IsPhantomReference()) {
+    } else if (klass->IsPhantomReference()) {
       list = &phantom_reference_list_;
     }
     DCHECK(list != NULL);
@@ -283,10 +295,11 @@
 // processing
 void MarkSweep::ScanOther(const Object* obj) {
   DCHECK(obj != NULL);
-  DCHECK(obj->GetClass() != NULL);
-  MarkObject(obj->GetClass());
+  Class* klass = obj->GetClass();
+  DCHECK(klass != NULL);
+  MarkObject(klass);
   ScanInstanceFields(obj);
-  if (obj->IsReference()) {
+  if (klass->IsReference()) {
     DelayReferenceReferent(const_cast<Object*>(obj));
   }
 }
@@ -321,20 +334,20 @@
 
 void MarkSweep::ClearReference(Object* ref) {
   DCHECK(ref != NULL);
-  ref->SetFieldObject(reference_referent_offset_, NULL);
+  ref->SetFieldObject(Heap::GetReferenceReferentOffset(), NULL);
 }
 
 bool MarkSweep::IsEnqueuable(const Object* ref) {
   DCHECK(ref != NULL);
-  const Object* queue = ref->GetFieldObject(reference_queue_offset_);
-  const Object* queue_next = ref->GetFieldObject(reference_queueNext_offset_);
+  const Object* queue = ref->GetFieldObject(Heap::GetReferenceQueueOffset());
+  const Object* queue_next = ref->GetFieldObject(Heap::GetReferenceQueueNextOffset());
   return (queue != NULL) && (queue_next == NULL);
 }
 
 void MarkSweep::EnqueueReference(Object* ref) {
   DCHECK(ref != NULL);
-  CHECK(ref->GetFieldObject(reference_queue_offset_) != NULL);
-  CHECK(ref->GetFieldObject(reference_queueNext_offset_) == NULL);
+  CHECK(ref->GetFieldObject(Heap::GetReferenceQueueOffset()) != NULL);
+  CHECK(ref->GetFieldObject(Heap::GetReferenceQueueNextOffset()) == NULL);
   EnqueuePendingReference(ref, &cleared_reference_list_);
 }
 
@@ -348,7 +361,7 @@
   size_t counter = 0;
   while (*list != NULL) {
     Object* ref = DequeuePendingReference(list);
-    Object* referent = ref->GetFieldObject(reference_referent_offset_);
+    Object* referent = ref->GetFieldObject(Heap::GetReferenceReferentOffset());
     if (referent == NULL) {
       // Referent was cleared by the user during marking.
       continue;
@@ -375,7 +388,7 @@
 // scheduled for appending by the heap worker thread.
 void MarkSweep::ClearWhiteReferences(Object** list) {
   DCHECK(list != NULL);
-  size_t offset = reference_referent_offset_;
+  size_t offset = Heap::GetReferenceReferentOffset();
   while (*list != NULL) {
     Object* ref = DequeuePendingReference(list);
     Object* referent = ref->GetFieldObject(offset);
@@ -395,8 +408,8 @@
 // referent field is cleared.
 void MarkSweep::EnqueueFinalizerReferences(Object** list) {
   DCHECK(list != NULL);
-  size_t referent_offset = reference_referent_offset_;
-  size_t zombie_offset = finalizer_reference_zombie_offset_;
+  size_t referent_offset = Heap::GetReferenceReferentOffset();
+  size_t zombie_offset = Heap::GetFinalizerReferenceZombieOffset();
   bool has_enqueued = false;
   while (*list != NULL) {
     Object* ref = DequeuePendingReference(list);
diff --git a/src/mark_sweep.h b/src/mark_sweep.h
index 5f374ae..00bfc4c 100644
--- a/src/mark_sweep.h
+++ b/src/mark_sweep.h
@@ -15,7 +15,13 @@
 class MarkSweep {
  public:
   MarkSweep() :
-      finger_(NULL), condemned_(NULL) {
+      finger_(NULL),
+      condemned_(NULL),
+      soft_reference_list_(NULL),
+      weak_reference_list_(NULL),
+      finalizer_reference_list_(NULL),
+      phantom_reference_list_(NULL),
+      cleared_reference_list_(NULL) {
   }
 
   ~MarkSweep();
@@ -48,6 +54,8 @@
     return mark_bitmap_->Test(object);
   }
 
+  static void MarkObjectVisitor(Object* root, void* arg);
+
   // Marks an object.
   void MarkObject(const Object* obj);
 
@@ -140,16 +148,6 @@
 
   Object* cleared_reference_list_;
 
-  static size_t reference_referent_offset_;
-
-  static size_t reference_queue_offset_;
-
-  static size_t reference_queueNext_offset_;
-
-  static size_t reference_pendingNext_offset_;
-
-  static size_t finalizer_reference_zombie_offset_;
-
   DISALLOW_COPY_AND_ASSIGN(MarkSweep);
 };
 
diff --git a/src/object.cc b/src/object.cc
index 66ea03f..e0544df 100644
--- a/src/object.cc
+++ b/src/object.cc
@@ -6,21 +6,16 @@
 #include <algorithm>
 
 #include "class_linker.h"
+#include "class_loader.h"
 #include "globals.h"
 #include "heap.h"
 #include "logging.h"
 #include "dex_cache.h"
 #include "dex_file.h"
+#include "runtime.h"
 
 namespace art {
 
-const std::vector<const DexFile*>& ClassLoader::GetClassPath(const ClassLoader* class_loader) {
-  if (class_loader == NULL) {
-    return Runtime::Current()->GetClassLinker()->GetBootClassPath();
-  }
-  return class_loader->class_path_;
-}
-
 Array* Array::Alloc(Class* array_class, int32_t component_count, size_t component_size) {
   DCHECK_GE(component_count, 0);
   DCHECK(array_class->IsArrayClass());
@@ -50,7 +45,7 @@
   return Array::Alloc(klass, component_count);
 }
 
-Object* Class::NewInstanceFromCode(uint32_t type_idx, Method* method) {
+Object* Class::AllocObjectFromCode(uint32_t type_idx, Method* method) {
   Class* klass = method->dex_cache_resolved_types_->Get(type_idx);
   if (klass == NULL) {
     klass = Runtime::Current()->GetClassLinker()->ResolveType(type_idx, method);
@@ -59,7 +54,12 @@
       return NULL;
     }
   }
-  return klass->NewInstance();
+  return klass->AllocObject();
+}
+
+Object* Class::AllocObject() {
+  DCHECK(!IsAbstract());
+  return Heap::AllocObject(this, this->object_size_);
 }
 
 bool Class::Implements(const Class* klass) const {
@@ -675,26 +675,6 @@
   java_lang_String_ = NULL;
 }
 
-// TODO: get global references for these
-Class* PathClassLoader::dalvik_system_PathClassLoader_ = NULL;
-
-const PathClassLoader* PathClassLoader::Alloc(std::vector<const DexFile*> dex_files) {
-  PathClassLoader* p = down_cast<PathClassLoader*>(dalvik_system_PathClassLoader_->NewInstance());
-  p->SetClassPath(dex_files);
-  return p;
-}
-
-void PathClassLoader::SetClass(Class* dalvik_system_PathClassLoader) {
-  CHECK(dalvik_system_PathClassLoader_ == NULL);
-  CHECK(dalvik_system_PathClassLoader != NULL);
-  dalvik_system_PathClassLoader_ = dalvik_system_PathClassLoader;
-}
-
-void PathClassLoader::ResetClass() {
-  CHECK(dalvik_system_PathClassLoader_ != NULL);
-  dalvik_system_PathClassLoader_ = NULL;
-}
-
 Class* StackTraceElement::java_lang_StackTraceElement_ = NULL;
 
 void StackTraceElement::SetClass(Class* java_lang_StackTraceElement) {
diff --git a/src/object.h b/src/object.h
index 438b587..1db3e83 100644
--- a/src/object.h
+++ b/src/object.h
@@ -3,22 +3,26 @@
 #ifndef ART_SRC_OBJECT_H_
 #define ART_SRC_OBJECT_H_
 
+#include <vector>
+
 #include "UniquePtr.h"
 #include "casts.h"
 #include "constants.h"
 #include "globals.h"
-#include "heap.h"
 #include "logging.h"
 #include "macros.h"
 #include "monitor.h"
+#include "monitor.h"
 #include "offsets.h"
 #include "stringpiece.h"
+#include "thread.h"
 #include "utf.h"
 
 namespace art {
 
 class Array;
 class Class;
+class ClassLoader;
 class CodeAndDirectMethods;
 class DexCache;
 class Field;
@@ -77,6 +81,52 @@
 static const uint32_t kAccConstructor = 0x00010000;  // method (Dalvik only)
 static const uint32_t kAccDeclaredSynchronized = 0x00020000;  // method (Dalvik only)
 
+static const uint32_t kAccClassFlagsMask = (kAccPublic
+                                            | kAccFinal
+                                            | kAccInterface
+                                            | kAccAbstract
+                                            | kAccSynthetic
+                                            | kAccAnnotation
+                                            | kAccEnum);
+static const uint32_t kAccInnerClassFlagsMask = (kAccClassFlagsMask
+                                                 | kAccPrivate
+                                                 | kAccProtected
+                                                 | kAccStatic);
+static const uint32_t kAccFieldFlagsMask = (kAccPublic
+                                            | kAccPrivate
+                                            | kAccProtected
+                                            | kAccStatic
+                                            | kAccFinal
+                                            | kAccVolatile
+                                            | kAccTransient
+                                            | kAccSynthetic
+                                            | kAccEnum);
+static const uint32_t kAccMethodFlagsMask = (kAccPublic
+                                             | kAccPrivate
+                                             | kAccProtected
+                                             | kAccStatic
+                                             | kAccFinal
+                                             | kAccSynchronized
+                                             | kAccBridge
+                                             | kAccVarargs
+                                             | kAccNative
+                                             | kAccAbstract
+                                             | kAccStrict
+                                             | kAccSynthetic
+                                             | kAccConstructor
+                                             | kAccDeclaredSynchronized);
+
+// if only kAccClassIsReference is set, we have a soft reference
+static const uint32_t kAccClassIsReference          = 0x8000000;  // class is a soft/weak/phantom ref
+static const uint32_t kAccClassIsWeakReference      = 0x4000000;  // class is a weak reference
+static const uint32_t kAccClassIsFinalizerReference = 0x2000000;  // class is a finalizer reference
+static const uint32_t kAccClassIsPhantomReference   = 0x1000000;  // class is a phantom reference
+
+static const uint32_t kAccReferenceFlagsMask = (kAccClassIsReference
+                                                | kAccClassIsWeakReference
+                                                | kAccClassIsFinalizerReference
+                                                | kAccClassIsPhantomReference);
+
 /*
  * Definitions for packing refOffsets in Class.
  */
@@ -221,31 +271,6 @@
     return down_cast<const ObjectArray<T>*>(this);
   }
 
-  bool IsReference() const {
-    UNIMPLEMENTED(FATAL);
-    return true;
-  }
-
-  bool IsWeakReference() const {
-    UNIMPLEMENTED(FATAL);
-    return true;
-  }
-
-  bool IsSoftReference() const {
-    UNIMPLEMENTED(FATAL);
-    return true;
-  }
-
-  bool IsFinalizerReference() const {
-    UNIMPLEMENTED(FATAL);
-    return true;
-  }
-
-  bool IsPhantomReference() const {
-    UNIMPLEMENTED(FATAL);
-    return true;
-  }
-
   bool IsArrayInstance() const;
 
   Array* AsArray() {
@@ -465,6 +490,16 @@
     return (access_flags_ & kAccStatic) != 0;
   }
 
+  // Returns true if the method is a constructor.
+  bool IsConstructor() const {
+    return (access_flags_ & kAccConstructor) != 0;
+  }
+
+  // Returns true if the method is static, private, or a constructor.
+  bool IsDirect() const {
+    return IsStatic() || IsPrivate() || IsConstructor();
+  }
+
   // Returns true if the method is declared synchronized.
   bool IsSynchronized() const {
     uint32_t synchonized = kAccSynchronized | kAccDeclaredSynchronized;
@@ -552,10 +587,6 @@
     return shorty_[0] == 'V';
   }
 
-  bool IsDirect() const {
-    return is_direct_;
-  }
-
   // "Args" may refer to any of the 3 levels of "Args."
   // To avoid confusion, our code will denote which "Args" clearly:
   //  1. UserArgs: Args that a user see.
@@ -736,8 +767,6 @@
   CodeAndDirectMethods* dex_cache_code_and_direct_methods_;
   ObjectArray<StaticStorageBase>* dex_cache_initialized_static_storage_;
 
-  bool is_direct_;
-
  private:
   // Compiled code associated with this method
   UniquePtr<MemMap> code_area_;
@@ -870,45 +899,6 @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(ObjectArray);
 };
 
-// ClassLoader objects.
-class ClassLoader : public Object {
- public:
-  static const std::vector<const DexFile*>& GetClassPath(const ClassLoader* class_loader);
-
-  void SetClassPath(std::vector<const DexFile*>& class_path) {
-    DCHECK_EQ(0U, class_path_.size());
-    class_path_ = class_path;
-  }
-
- private:
-  // Field order required by test "ValidateFieldOrderOfJavaCppUnionClasses".
-  Object* packages_;
-  ClassLoader* parent_;
-
-  // TODO: remove once we can create a real PathClassLoader
-  std::vector<const DexFile*> class_path_;
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ClassLoader);
-};
-
-class BaseDexClassLoader : public ClassLoader {
- private:
-  // Field order required by test "ValidateFieldOrderOfJavaCppUnionClasses".
-  String* original_path_;
-  Object* path_list_;
-  DISALLOW_IMPLICIT_CONSTRUCTORS(BaseDexClassLoader);
-};
-
-class PathClassLoader : public BaseDexClassLoader {
- public:
-  static const PathClassLoader* Alloc(std::vector<const DexFile*> dex_files);
-  static void SetClass(Class* dalvik_system_PathClassLoader);
-  static void ResetClass();
- private:
-  static Class* dalvik_system_PathClassLoader_;
-  DISALLOW_IMPLICIT_CONSTRUCTORS(PathClassLoader);
-};
-
 // Type for the InitializedStaticStorage table. Currently the Class
 // provides the static storage. However, this might change to improve
 // image sharing, so we use this type to avoid assumptions on the
@@ -962,12 +952,10 @@
   // Given the context of a calling Method, use its DexCache to
   // resolve a type to a Class. If it cannot be resolved, throw an
   // error. If it can, use it to create an instance.
-  static Object* NewInstanceFromCode(uint32_t type_idx, Method* method);
+  static Object* AllocObjectFromCode(uint32_t type_idx, Method* method);
 
-  Object* NewInstance() {
-    DCHECK(!IsAbstract());
-    return Heap::AllocObject(this, this->object_size_);
-  }
+  // Creates a raw object instance but does not invoke the default constructor.
+  Object* AllocObject();
 
   Class* GetSuperClass() const {
     return super_class_;
@@ -1101,6 +1089,26 @@
     return (access_flags_ & kAccSynthetic) != 0;
   }
 
+  bool IsReference() const {
+    return (access_flags_ & kAccClassIsReference) != 0;
+  }
+
+  bool IsWeakReference() const {
+    return (access_flags_ & kAccClassIsWeakReference) != 0;
+  }
+
+  bool IsSoftReference() const {
+    return (access_flags_ & ~kAccReferenceFlagsMask) == kAccClassIsReference;
+  }
+
+  bool IsFinalizerReference() const {
+    return (access_flags_ & kAccClassIsFinalizerReference) != 0;
+  }
+
+  bool IsPhantomReference() const {
+    return (access_flags_ & kAccClassIsPhantomReference) != 0;
+  }
+
   // Returns true if this class can access that class.
   bool CanAccess(const Class* that) const {
     return that->IsPublic() || this->IsInSamePackage(that);
@@ -1188,6 +1196,7 @@
   Field* FindInstanceField(const StringPiece& name,
       const StringPiece& descriptor);
 
+  // Finds the given instance field in this class.
   Field* FindDeclaredInstanceField(const StringPiece& name,
       const StringPiece& descriptor);
 
@@ -1195,6 +1204,7 @@
   Field* FindStaticField(const StringPiece& name,
       const StringPiece& descriptor);
 
+  // Finds the given static field in this class.
   Field* FindDeclaredStaticField(const StringPiece& name,
       const StringPiece& descriptor);
 
@@ -1616,7 +1626,7 @@
   }
 
   static String* Alloc(Class* java_lang_String, CharArray* array) {
-    String* string = down_cast<String*>(java_lang_String->NewInstance());
+    String* string = down_cast<String*>(java_lang_String->AllocObject());
     string->array_ = array;
     string->count_ = array->GetLength();
     return string;
@@ -1730,7 +1740,7 @@
 
   static StackTraceElement* Alloc(const String* declaring_class, const String* method_name,
                                   const String* file_name, int32_t line_number) {
-    StackTraceElement* trace = down_cast<StackTraceElement*>(GetStackTraceElement()->NewInstance());
+    StackTraceElement* trace = down_cast<StackTraceElement*>(GetStackTraceElement()->AllocObject());
     trace->declaring_class_ = declaring_class;
     trace->method_name_ = method_name;
     trace->file_name_ = file_name;
diff --git a/src/object_bitmap.cc b/src/object_bitmap.cc
index ae67ee5..4b4c5ee 100644
--- a/src/object_bitmap.cc
+++ b/src/object_bitmap.cc
@@ -31,7 +31,7 @@
 }
 
 // Initialize a HeapBitmap so that it points to a bitmap large enough
-// to cover a heap at <base> of <maxSize> bytes, where objects are
+// to cover a heap at <base> of <max_size> bytes, where objects are
 // guaranteed to be kAlignment-aligned.
 bool HeapBitmap::Init(const byte* base, size_t max_size) {
   CHECK(base != NULL);
@@ -107,14 +107,11 @@
 // address will be visited by the traversal.  If the callback sets a
 // bit for an address below the finger, this address will not be
 // visited.
-void HeapBitmap::ScanWalk(uintptr_t base, uintptr_t max,
-                          ScanCallback* callback, void* arg) {
+void HeapBitmap::ScanWalk(uintptr_t base, ScanCallback* callback, void* arg) {
   CHECK(words_ != NULL);
   CHECK(callback != NULL);
-  CHECK(base <= max);
   CHECK(base >= base_);
-  CHECK(max <= max_);
-  uintptr_t end = HB_OFFSET_TO_INDEX(max - base);
+  uintptr_t end = HB_OFFSET_TO_INDEX(max_ - base);
   for (uintptr_t i = 0; i <= end; ++i) {
     unsigned long word = words_[i];
     if (word != 0) {
@@ -148,7 +145,7 @@
   CHECK(callback != NULL);
   CHECK(base <= max);
   CHECK(base >= live_bitmap.base_);
-  CHECK(max <= live_bitmap.max_);
+  max = std::min(max-1, live_bitmap.max_);
   if (live_bitmap.max_ < live_bitmap.base_) {
     // Easy case; both are obviously empty.
     // TODO: this should never happen
diff --git a/src/object_bitmap.h b/src/object_bitmap.h
index fc9a3a8..dd23d15 100644
--- a/src/object_bitmap.h
+++ b/src/object_bitmap.h
@@ -85,8 +85,7 @@
 
   void Walk(Callback* callback, void* arg);
 
-  void ScanWalk(uintptr_t base, uintptr_t max,
-                ScanCallback* thunk, void* arg);
+  void ScanWalk(uintptr_t base, ScanCallback* thunk, void* arg);
 
   static void SweepWalk(const HeapBitmap& live,
                         const HeapBitmap& mark,
@@ -131,7 +130,7 @@
 
   // The highest pointer value ever returned by an allocation from
   // this heap.  I.e., the highest address that may correspond to a
-  // set bit.  If there are no bits set, (max < base).
+  // set bit.  If there are no bits set, (max_ < base_).
   uintptr_t max_;
 
   const char* name_;
diff --git a/src/object_test.cc b/src/object_test.cc
index 99567e8..f397b2e 100644
--- a/src/object_test.cc
+++ b/src/object_test.cc
@@ -10,7 +10,6 @@
 #include "common_test.h"
 #include "dex_file.h"
 #include "heap.h"
-#include "gtest/gtest.h"
 
 namespace art {
 
@@ -185,7 +184,7 @@
   Class* java_lang_Object = class_linker_->FindSystemClass("Ljava/lang/Object;");
   Method* toString = java_lang_Object->FindVirtualMethod("toString", "()Ljava/lang/String;");
   uint32_t type_idx = FindTypeIdxByDescriptor(*java_lang_dex_file_.get(), "Ljava/lang/String;");
-  Object* string = Class::NewInstanceFromCode(type_idx, toString);
+  Object* string = Class::AllocObjectFromCode(type_idx, toString);
   EXPECT_TRUE(string->IsString());
 }
 
@@ -334,8 +333,8 @@
   EXPECT_FALSE(Object::InstanceOf(NULL, X));
   EXPECT_FALSE(Object::InstanceOf(NULL, Y));
 
-  Object* x = X->NewInstance();
-  Object* y = Y->NewInstance();
+  Object* x = X->AllocObject();
+  Object* y = Y->AllocObject();
   ASSERT_TRUE(x != NULL);
   ASSERT_TRUE(y != NULL);
 
diff --git a/src/reference_table_test.cc b/src/reference_table_test.cc
index 1f065e6..73ec87b 100644
--- a/src/reference_table_test.cc
+++ b/src/reference_table_test.cc
@@ -4,8 +4,6 @@
 
 #include "reference_table.h"
 
-#include "gtest/gtest.h"
-
 namespace art {
 
 class ReferenceTableTest : public CommonTest {
diff --git a/src/runtime.cc b/src/runtime.cc
index 50f25fe..1ac45f4 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -383,4 +383,9 @@
   return true;
 }
 
+void Runtime::VisitRoots(Heap::RootVistor* root_visitor, void* arg) const {
+  GetClassLinker()->VisitRoots(root_visitor, arg);
+  UNIMPLEMENTED(WARNING) << "mark other roots including per thread state and thread stacks";
+}
+
 }  // namespace art
diff --git a/src/runtime.h b/src/runtime.h
index 8694b3c..40db814 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -12,6 +12,7 @@
 
 #include <jni.h>
 
+#include "heap.h"
 #include "globals.h"
 #include "macros.h"
 #include "stringpiece.h"
@@ -93,6 +94,8 @@
     return java_vm_;
   }
 
+  void VisitRoots(Heap::RootVistor* root_visitor, void* arg) const;
+
  private:
   static void PlatformAbort(const char*, int);
 
diff --git a/src/signal_catcher.cc b/src/signal_catcher.cc
index e6e423d..b83e71d 100644
--- a/src/signal_catcher.cc
+++ b/src/signal_catcher.cc
@@ -23,6 +23,7 @@
 #include <unistd.h>
 
 #include "heap.h"
+#include "runtime.h"
 #include "thread.h"
 #include "utils.h"
 
diff --git a/src/thread.cc b/src/thread.cc
index 9d2862d..062550d 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -62,7 +62,7 @@
   pLmul = __aeabi_lmul;
 #endif
   pAllocFromCode = Array::AllocFromCode;
-  pNewInstanceFromCode = Class::NewInstanceFromCode;
+  pAllocObjectFromCode = Class::AllocObjectFromCode;
   pMemcpy = memcpy;
   pArtHandleFillArrayDataNoThrow = artHandleFillArrayDataNoThrow;
   pGet32Static = Field::Get32StaticFromCode;
diff --git a/src/thread.h b/src/thread.h
index 82cca6d..41bb0da 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -6,21 +6,20 @@
 #include <pthread.h>
 #include <list>
 
+#include "dex_file.h"
 #include "globals.h"
 #include "jni_internal.h"
 #include "logging.h"
 #include "macros.h"
 #include "mem_map.h"
 #include "offsets.h"
-#include "runtime.h"
-
 
 namespace art {
 
 class Array;
 class Class;
+class ClassLinker;
 class ClassLoader;
-class JNIEnvExt;
 class Method;
 class Object;
 class Runtime;
@@ -202,7 +201,7 @@
   long long (*pLmul)(long long, long long);
   long long (*pLdivmod)(long long, long long);
   Array* (*pAllocFromCode)(uint32_t, Method*, int32_t);
-  Object* (*pNewInstanceFromCode)(uint32_t, Method*);
+  Object* (*pAllocObjectFromCode)(uint32_t, Method*);
   uint32_t (*pGet32Static)(uint32_t, const Method*);
   void (*pSet32Static)(uint32_t, const Method*, uint32_t);
   uint64_t (*pGet64Static)(uint32_t, const Method*);
diff --git a/src/utils_test.cc b/src/utils_test.cc
index 3d53c35..21167d6 100644
--- a/src/utils_test.cc
+++ b/src/utils_test.cc
@@ -4,8 +4,6 @@
 #include "common_test.h"
 #include "utils.h"
 
-#include "gtest/gtest.h"
-
 namespace art {
 
 class UtilsTest : public CommonTest {
diff --git a/src/zip_archive_test.cc b/src/zip_archive_test.cc
index e6b4002..051f096 100644
--- a/src/zip_archive_test.cc
+++ b/src/zip_archive_test.cc
@@ -8,7 +8,6 @@
 
 #include "UniquePtr.h"
 #include "common_test.h"
-#include "gtest/gtest.h"
 #include "os.h"
 
 namespace art {