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/*
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* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp"
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#include "runtime/safepoint.hpp"
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// Alternating epochs on each rotation allow for concurrent tagging.
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// The epoch shift happens only during a safepoint.
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bool JfrTraceIdEpoch::_epoch_state = false;
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bool volatile JfrTraceIdEpoch::_tag_state = false;
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void JfrTraceIdEpoch::shift_epoch() {
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assert(SafepointSynchronize::is_at_safepoint(), "invariant");
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_epoch_state = !_epoch_state;
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}
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