diff -r e45861098f5a -r fec48bf5a827 hotspot/src/share/vm/gc/shared/gcId.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/shared/gcId.hpp	Wed May 13 15:16:06 2015 +0200
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ */
+
+#ifndef SHARE_VM_GC_SHARED_GCID_HPP
+#define SHARE_VM_GC_SHARED_GCID_HPP
+
+#include "memory/allocation.hpp"
+
+class GCId VALUE_OBJ_CLASS_SPEC {
+ private:
+  uint _id;
+  GCId(uint id) : _id(id) {}
+  GCId() { } // Unused
+
+  static uint _next_id;
+  static const uint UNDEFINED = (uint)-1;
+
+ public:
+  uint id() const {
+    assert(_id != UNDEFINED, "Using undefined GC ID");
+    return _id;
+  }
+  bool is_undefined() const;
+
+  static const GCId create();
+  static const GCId peek();
+  static const GCId undefined();
+};
+
+#endif // SHARE_VM_GC_SHARED_GCID_HPP