diff --git a/runtime/openjdkjvmti/ti_redefine.h b/runtime/openjdkjvmti/ti_redefine.h
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+/* Copyright (C) 2016 The Android Open Source Project
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This file implements interfaces from the file jvmti.h. This implementation
+ * is licensed under the same terms as the file jvmti.h.  The
+ * copyright and license information for the file jvmti.h follows.
+ *
+ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef ART_RUNTIME_OPENJDKJVMTI_TI_REDEFINE_H_
+#define ART_RUNTIME_OPENJDKJVMTI_TI_REDEFINE_H_
+
+#include <string>
+
+#include <jni.h>
+
+#include "art_jvmti.h"
+#include "art_method.h"
+#include "class_linker.h"
+#include "dex_file.h"
+#include "gc_root-inl.h"
+#include "globals.h"
+#include "jni_env_ext-inl.h"
+#include "jvmti.h"
+#include "linear_alloc.h"
+#include "mem_map.h"
+#include "mirror/array-inl.h"
+#include "mirror/array.h"
+#include "mirror/class-inl.h"
+#include "mirror/class.h"
+#include "mirror/class_loader-inl.h"
+#include "mirror/string-inl.h"
+#include "oat_file.h"
+#include "obj_ptr.h"
+#include "scoped_thread_state_change-inl.h"
+#include "stack.h"
+#include "thread_list.h"
+#include "transform.h"
+#include "utf.h"
+#include "utils/dex_cache_arrays_layout-inl.h"
+
+namespace openjdkjvmti {
+
+// Class that can redefine a single class's methods.
+class Redefiner {
+ public:
+  // Redefine the given class with the given dex data. Note this function does not take ownership of
+  // the dex_data pointer. It is not used after this call however and may be freed if desired.
+  // The caller is responsible for freeing it. The runtime makes it's own copy of the data.
+  static jvmtiError RedefineClass(ArtJvmTiEnv* env,
+                                  art::Runtime* runtime,
+                                  art::Thread* self,
+                                  jclass klass,
+                                  const std::string& original_dex_location,
+                                  jint data_len,
+                                  unsigned char* dex_data,
+                                  std::string* error_msg);
+
+ private:
+  jvmtiError result_;
+  art::Runtime* runtime_;
+  art::Thread* self_;
+  // Kept as a jclass since we have weird run-state changes that make keeping it around as a
+  // mirror::Class difficult and confusing.
+  jclass klass_;
+  std::unique_ptr<const art::DexFile> dex_file_;
+  std::string* error_msg_;
+  char* class_sig_;
+
+  // TODO Maybe change jclass to a mirror::Class
+  Redefiner(art::Runtime* runtime,
+            art::Thread* self,
+            jclass klass,
+            char* class_sig,
+            std::unique_ptr<const art::DexFile>& redefined_dex_file,
+            std::string* error_msg)
+      : result_(ERR(INTERNAL)),
+        runtime_(runtime),
+        self_(self),
+        klass_(klass),
+        dex_file_(std::move(redefined_dex_file)),
+        error_msg_(error_msg),
+        class_sig_(class_sig) { }
+
+  static std::unique_ptr<art::MemMap> MoveDataToMemMap(const std::string& original_location,
+                                                       jint data_len,
+                                                       unsigned char* dex_data,
+                                                       std::string* error_msg);
+
+  // TODO Put on all the lock qualifiers.
+  jvmtiError Run() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  bool FinishRemainingAllocations(
+        /*out*/art::MutableHandle<art::mirror::ClassLoader>* source_class_loader,
+        /*out*/art::MutableHandle<art::mirror::Object>* source_dex_file_obj,
+        /*out*/art::MutableHandle<art::mirror::LongArray>* new_dex_file_cookie,
+        /*out*/art::MutableHandle<art::mirror::DexCache>* new_dex_cache)
+      REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  // Preallocates all needed allocations in klass so that we can pause execution safely.
+  // TODO We should be able to free the arrays if they end up not being used. Investigate doing this
+  // in the future. For now we will just take the memory hit.
+  bool EnsureClassAllocationsFinished() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  art::mirror::ClassLoader* GetClassLoader() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  // This finds the java.lang.DexFile we will add the native DexFile to as part of the classpath.
+  // TODO Make sure the DexFile object returned is the one that the klass_ actually comes from.
+  art::mirror::Object* FindSourceDexFileObject(art::Handle<art::mirror::ClassLoader> loader)
+      REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  art::mirror::Class* GetMirrorClass() REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  // Allocates and fills the new DexFileCookie
+  art::mirror::LongArray* AllocateDexFileCookie(art::Handle<art::mirror::Object> java_dex_file_obj)
+      REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  art::mirror::DexCache* CreateNewDexCache(art::Handle<art::mirror::ClassLoader> loader)
+      REQUIRES_SHARED(art::Locks::mutator_lock_);
+
+  void RecordFailure(jvmtiError result, const std::string& error_msg);
+
+  // TODO Actually write this.
+  // This will check that no constraints are violated (more than 1 class in dex file, any changes in
+  // number/declaration of methods & fields, changes in access flags, etc.)
+  bool EnsureRedefinitionIsValid() {
+    return true;
+  }
+
+  bool UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
+                         art::ObjPtr<art::mirror::LongArray> new_cookie,
+                         /*out*/art::ObjPtr<art::mirror::LongArray>* original_cookie)
+      REQUIRES(art::Locks::mutator_lock_);
+
+  void RestoreJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file,
+                          art::ObjPtr<art::mirror::LongArray> original_cookie)
+      REQUIRES(art::Locks::mutator_lock_);
+
+  bool UpdateClass(art::ObjPtr<art::mirror::Class> mclass,
+                   art::ObjPtr<art::mirror::DexCache> new_dex_cache)
+      REQUIRES(art::Locks::mutator_lock_);
+};
+
+}  // namespace openjdkjvmti
+
+#endif  // ART_RUNTIME_OPENJDKJVMTI_TI_REDEFINE_H_