1 /* 2 * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_RUNTIME_THREADIDENTIFIER_HPP 26 #define SHARE_RUNTIME_THREADIDENTIFIER_HPP 27 28 #include "memory/allStatic.hpp" 29 30 /* 31 * Provides unique monotonic identifiers for threads. 32 * 33 * Java uses unsafe to initialize the tid field for Thread and VirtualThread on construction. 34 * JFR uses next() for a non-reusable id for non-java threads. 35 */ 36 class ThreadIdentifier : AllStatic { 37 public: 38 static int64_t next(); 39 static int64_t current(); 40 static int64_t unsafe_offset(); 41 DEBUG_ONLY(static int64_t initial();) 42 }; 43 44 #endif // SHARE_RUNTIME_THREADIDENTIFIER_HPP