001/*
002 * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.nodes.virtual;
024
025import java.util.*;
026
027import com.oracle.graal.nodes.java.*;
028
029/**
030 * The class implements a simple linked list of MonitorIdNodes, which can be used to describe the
031 * current lock state of an object.
032 */
033public final class LockState {
034
035    public final MonitorIdNode monitorId;
036    public final LockState next;
037
038    public LockState(MonitorIdNode monitorId, LockState next) {
039        this.monitorId = monitorId;
040        this.next = next;
041    }
042
043    @Override
044    public String toString() {
045        return monitorId.getLockDepth() + (next == null ? "" : "," + next);
046    }
047
048    public static List<MonitorIdNode> asList(LockState state) {
049        if (state == null) {
050            return Collections.emptyList();
051        } else {
052            ArrayList<MonitorIdNode> result = new ArrayList<>();
053            LockState a = state;
054            do {
055                result.add(a.monitorId);
056                a = a.next;
057            } while (a != null);
058            return result;
059        }
060    }
061}