| /* |
| * Copyright (c) 2016, 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. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp" |
| #include "runtime/safepoint.hpp" |
| |
| // Alternating epochs on each rotation allow for concurrent tagging. |
| // The epoch shift happens only during a safepoint. |
| bool JfrTraceIdEpoch::_epoch_state = false; |
| bool volatile JfrTraceIdEpoch::_tag_state = false; |
| |
| void JfrTraceIdEpoch::shift_epoch() { |
| assert(SafepointSynchronize::is_at_safepoint(), "invariant"); |
| _epoch_state = !_epoch_state; |
| } |
