--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/services/threadIdTable.hpp	Wed Sep 25 11:10:05 2019 -0700
@@ -0,0 +1,62 @@
+
+/*
+* Copyright (c) 2019, 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_SERVICES_THREADIDTABLE_HPP
+#define SHARE_SERVICES_THREADIDTABLE_HPP
+
+#include "memory/allocation.hpp"
+
+class JavaThread;
+class ThreadsList;
+class ThreadIdTableConfig;
+
+class ThreadIdTable : public AllStatic {
+  friend class ThreadIdTableConfig;
+
+  static volatile bool _is_initialized;
+
+public:
+  // Initialization
+  static void lazy_initialize(const ThreadsList* threads);
+  static bool is_initialized() { return _is_initialized; }
+
+  // Lookup and list management
+  static JavaThread* find_thread_by_tid(jlong tid);
+  static JavaThread* add_thread(jlong tid, JavaThread* thread);
+  static bool remove_thread(jlong tid);
+
+private:
+  static void create_table(size_t size);
+
+  static size_t table_size();
+  static double get_load_factor();
+  static void grow_if_required();
+  static void grow(JavaThread* jt);
+
+  static void item_added();
+  static void item_removed();
+};
+
+#endif // SHARE_SERVICES_THREADIDTABLE_HPP