1 /* 2 * Copyright (c) 2012, 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 "services/memPtr.hpp" 27 #include "services/memTracker.hpp" 28 29 volatile jint SequenceGenerator::_seq_number = 1; 30 volatile unsigned long SequenceGenerator::_generation = 1; 31 NOT_PRODUCT(jint SequenceGenerator::_max_seq_number = 1;) 32 33 jint SequenceGenerator::next() { 34 jint seq = Atomic::add(1, &_seq_number); 35 if (seq < 0) { 36 MemTracker::shutdown(MemTracker::NMT_sequence_overflow); 37 } 38 assert(seq > 0, "counter overflow"); 39 NOT_PRODUCT(_max_seq_number = (seq > _max_seq_number) ? seq : _max_seq_number;) 40 return seq; 41 } 42