1 /*
   2  * Copyright (c) 2011, 2019, 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 package jdk.vm.ci.code;
  24 
  25 /**
  26  * Represents a compiled instance of a method. It may have been invalidated or removed in the
  27  * meantime.
  28  */
  29 public class InstalledCode {
  30 
  31     /**
  32      * Raw address address of entity representing this installed code.
  33      */
  34     protected long address;
  35 
  36     /**
  37      * Raw address of entryPoint of this installed code.
  38      */
  39     protected long entryPoint;
  40 
  41     /**
  42      * Counts how often the address field was reassigned.
  43      */
  44     protected long version;
  45 
  46     protected final String name;
  47 
  48     public InstalledCode(String name) {
  49         this.name = name;
  50     }
  51 
  52     /**
  53      * @return the address of entity representing this installed code.
  54      */
  55     public long getAddress() {
  56         return address;
  57     }
  58 
  59     /**
  60      * @return the address of the normal entry point of the installed code.
  61      */
  62     public long getEntryPoint() {
  63         return entryPoint;
  64     }
  65 
  66     /**
  67      * @return the version number of this installed code
  68      */
  69     public final long getVersion() {
  70         return version;
  71     }
  72 
  73     /**
  74      * Returns the name of this installed code.
  75      */
  76     public String getName() {
  77         return name;
  78     }
  79 
  80     /**
  81      * Returns the start address of this installed code if it is {@linkplain #isValid() valid}, 0
  82      * otherwise.
  83      */
  84     public long getStart() {
  85         return 0;
  86     }
  87 
  88     /**
  89      * @return true if the code represented by this object is still valid for invocation, false
  90      *         otherwise (may happen due to deopt, etc.)
  91      */
  92     public boolean isValid() {
  93         return entryPoint != 0;
  94     }
  95 
  96     /**
  97      * @return true if the code represented by this object still exists and might have live
  98      *         activations, false otherwise (may happen due to deopt, etc.)
  99      */
 100     public boolean isAlive() {
 101         return address != 0;
 102     }
 103 
 104     /**
 105      * Returns a copy of this installed code if it is {@linkplain #isValid() valid}, null otherwise.
 106      */
 107     public byte[] getCode() {
 108         return null;
 109     }
 110 
 111     /**
 112      * Invalidates this installed code such that any subsequent
 113      * {@linkplain #executeVarargs(Object...) invocation} will throw an
 114      * {@link InvalidInstalledCodeException} and all existing invocations will be deoptimized.
 115      */
 116     public void invalidate() {
 117         throw new UnsupportedOperationException();
 118     }
 119 
 120     /**
 121      * Executes the installed code with a variable number of arguments.
 122      *
 123      * @param args the array of object arguments
 124      * @return the value returned by the executed code
 125      */
 126     @SuppressWarnings("unused")
 127     public Object executeVarargs(Object... args) throws InvalidInstalledCodeException {
 128         throw new UnsupportedOperationException();
 129     }
 130 }