jdk-24/hotspot/src/share/vm/services/memPtr.cpp

/*
 * Copyright (c) 2012, 2013, 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
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 */

#include "precompiled.hpp"
#include "runtime/atomic.inline.hpp"
#include "services/memPtr.hpp"
#include "services/memTracker.hpp"

volatile jint SequenceGenerator::_seq_number = 1;
volatile unsigned long SequenceGenerator::_generation = 1;
NOT_PRODUCT(jint SequenceGenerator::_max_seq_number = 1;)

jint SequenceGenerator::next() {
  jint seq = Atomic::add(1, &_seq_number);
  if (seq < 0) {
    MemTracker::shutdown(MemTracker::NMT_sequence_overflow);
  } else {
    NOT_PRODUCT(_max_seq_number = (seq > _max_seq_number) ? seq : _max_seq_number;)
  }
  return seq;
}