1 /*
2  * Copyright (c) 2011, 2018, 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 package org.graalvm.compiler.nodes.virtual;
26 
27 import java.util.ArrayList;
28 import java.util.Collections;
29 import java.util.List;
30 
31 import org.graalvm.compiler.nodes.java.MonitorIdNode;
32 
33 /**
34  * The class implements a simple linked list of MonitorIdNodes, which can be used to describe the
35  * current lock state of an object.
36  */
37 public final class LockState {
38 
39     public final MonitorIdNode monitorId;
40     public final LockState next;
41 
LockState(MonitorIdNode monitorId, LockState next)42     public LockState(MonitorIdNode monitorId, LockState next) {
43         this.monitorId = monitorId;
44         this.next = next;
45     }
46 
47     @Override
toString()48     public String toString() {
49         return monitorId.getLockDepth() + (next == null ? "" : "," + next);
50     }
51 
asList(LockState state)52     public static List<MonitorIdNode> asList(LockState state) {
53         if (state == null) {
54             return Collections.emptyList();
55         } else {
56             ArrayList<MonitorIdNode> result = new ArrayList<>();
57             LockState a = state;
58             do {
59                 result.add(a.monitorId);
60                 a = a.next;
61             } while (a != null);
62             return result;
63         }
64     }
65 }
66