1 /*
   2  * Copyright (c) 2014, 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.stack;
  24 
  25 import jdk.vm.ci.meta.ResolvedJavaMethod;
  26 
  27 /**
  28  * Access to the object variables in a stack frame.
  29  */
  30 public interface InspectedFrame {
  31 
  32     /**
  33      * Returns the value of the object local at {@code index}. This value is a copy iff
  34      * {@link #isVirtual(int)} is true.
  35      */
  36     Object getLocal(int index);
  37 
  38     /**
  39      * Returns whether the local at {@code index} is a virtual object, and therefore the object
  40      * returned by {@link #getLocal(int)} is a copy.
  41      */
  42     boolean isVirtual(int index);
  43 
  44     /**
  45      * Returns true if the stack frame is a compiled stack frame and there are virtual objects
  46      * anywhere in the current state of the compiled method. This can return true even if
  47      * {@link #isVirtual(int)} return false for all locals.
  48      */
  49     boolean hasVirtualObjects();
  50 
  51     /**
  52      * This method will materialize all virtual objects, deoptimize the stack frame and make sure
  53      * that subsequent execution of the deoptimized frame uses the materialized values.
  54      */
  55     void materializeVirtualObjects(boolean invalidateCode);
  56 
  57     /**
  58      * @return the current bytecode index
  59      */
  60     int getBytecodeIndex();
  61 
  62     /**
  63      * @return the current method
  64      */
  65     ResolvedJavaMethod getMethod();
  66 
  67     /**
  68      * Checks if the current method is equal to the given method. This is semantically equivalent to
  69      * {@code method.equals(getMethod())}, but can be implemented more efficiently.
  70      */
  71     boolean isMethod(ResolvedJavaMethod method);
  72 }