--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zResurrection.cpp	Tue Jun 12 17:40:28 2018 +0200
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2016, 2018, 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 "gc/z/zResurrection.hpp"
+#include "runtime/orderAccess.hpp"
+#include "runtime/safepoint.hpp"
+#include "utilities/debug.hpp"
+
+volatile bool ZResurrection::_blocked = false;
+
+void ZResurrection::block() {
+  assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
+  _blocked = true;
+}
+
+void ZResurrection::unblock() {
+  // We use a storestore barrier to make sure all healed
+  // oops are visible before we unblock resurrection.
+  OrderAccess::storestore();
+  _blocked = false;
+}