--- /dev/null	2014-12-01 09:12:12.387027487 +0100
+++ new/src/share/vm/memory/strongRootsScope.cpp	2015-04-01 12:39:51.611913544 +0200
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2015, 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.
+ *
+ * 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/stringTable.hpp"
+#include "code/nmethod.hpp"
+#include "memory/strongRootsScope.hpp"
+#include "runtime/thread.hpp"
+
+MarkScope::MarkScope(bool activate)
+  : _active(activate) {
+  if (_active) {
+    nmethod::oops_do_marking_prologue();
+  }
+}
+
+MarkScope::~MarkScope() {
+  if (_active) {
+    nmethod::oops_do_marking_epilogue();
+  }
+}
+
+StrongRootsScope::StrongRootsScope(bool activate)
+  : MarkScope(activate) {
+  if (_active) {
+    Threads::change_thread_claim_parity();
+    // Zero the claimed high water mark in the StringTable
+    StringTable::clear_parallel_claimed_index();
+  }
+}
+
+StrongRootsScope::~StrongRootsScope() {
+  Threads::assert_all_threads_claimed();
+}