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1   /*
2    * Copyright (c) 2000, 2009, 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 sun.jvm.hotspot.runtime;
26  
27  import java.io.*;
28  import sun.jvm.hotspot.debugger.*;
29  import sun.jvm.hotspot.utilities.*;
30  
31  public class StackValue {
32    private int       type;
33    private OopHandle handleValue;
34    private long      integerValue;
35  
36    public StackValue() {
37      type = BasicType.getTConflict();
38    }
39  
40    public StackValue(OopHandle h, long scalar_replaced) {
41      handleValue = h;
42      type = BasicType.getTObject();
43      integerValue = scalar_replaced;
44      Assert.that(integerValue == 0 || handleValue == null, "not null object should not be marked as scalar replaced");
45    }
46  
47    public StackValue(long i) {
48      integerValue = i;
49      type = BasicType.getTInt();
50    }
51  
52    /** This returns one of the "enum" values in BasicType.java */
53    public int getType() {
54      return type;
55    }
56  
57    public OopHandle getObject() {
58      if (Assert.ASSERTS_ENABLED) {
59        Assert.that(type == BasicType.getTObject(), "type check");
60      }
61      return handleValue;
62    }
63  
64    boolean objIsScalarReplaced() {
65      if (Assert.ASSERTS_ENABLED) {
66        Assert.that(type == BasicType.getTObject(), "type check");
67      }
68      return integerValue != 0;
69    }
70  
71    public long getInteger() {
72      if (Assert.ASSERTS_ENABLED) {
73        Assert.that(type == BasicType.getTInt(), "type check");
74      }
75      return integerValue;
76    }
77  
78    public boolean equals(Object arg) {
79      if (arg == null) {
80        return false;
81      }
82  
83      if (!arg.getClass().equals(getClass())) {
84        return false;
85      }
86  
87      StackValue sv = (StackValue) arg;
88      if (type != sv.type) {
89        return false;
90      }
91      if (type == BasicType.getTObject()) {
92        return handleValue.equals(sv.handleValue);
93      } else if (type == BasicType.getTInt()) {
94        return (integerValue == sv.integerValue);
95      } else {
96        // Conflict type (not yet used)
97        return true;
98      }
99    }
100 
101   public int hashCode() {
102     if (type == BasicType.getTObject()) {
103       return handleValue != null ? handleValue.hashCode() : 5;
104     } else {
105       // Returns 0 for conflict type
106       return (int) integerValue;
107     }
108   }
109 
110   public void print() {
111     printOn(System.out);
112   }
113 
114   public void printOn(PrintStream tty) {
115     if (type == BasicType.getTInt()) {
116       tty.print(integerValue + " (long) " + (int) integerValue + " (int)");
117     } else if (type == BasicType.getTObject()) {
118       tty.print("<" + handleValue + ">");
119     } else if (type == BasicType.getTConflict()) {
120       tty.print("conflict");
121     } else {
122       throw new RuntimeException("should not reach here");
123     }
124   }
125 }