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 #include "precompiled.hpp"
26 #include "runtime/atomic.hpp"
27 #include "runtime/threadIdentifier.hpp"
28
29 static volatile int64_t next_thread_id = 2; // starting at 2, excluding the primordial thread id
30
31 int64_t ThreadIdentifier::unsafe_offset() {
32 return reinterpret_cast<int64_t>(&next_thread_id);
33 }
34
35 int64_t ThreadIdentifier::next() {
36 int64_t next_tid;
37 do {
38 next_tid = Atomic::load(&next_thread_id);
39 } while (Atomic::cmpxchg(&next_thread_id, next_tid, next_tid + 1) != next_tid);
40 return next_tid;
41 }
--- EOF ---