1 /*
   2  * Copyright (c) 2013, 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.memory;
  26 
  27 /**
  28  * Encapsulates properties of a node describing how it accesses the heap.
  29  */
  30 public interface HeapAccess {
  31 
  32     /**
  33      * The types of (write/read) barriers attached to stores.
  34      */
  35     enum BarrierType {
  36         /**
  37          * Primitive access which do not necessitate barriers.
  38          */
  39         NONE,
  40         /**
  41          * Array object access.
  42          */
  43         ARRAY,
  44         /**
  45          * Field object access.
  46          */
  47         FIELD,
  48         /**
  49          * Unknown (aka field or array) object access.
  50          */
  51         UNKNOWN,
  52         /**
  53          * Weak field access (e.g. Hotspot's Reference.referent field).
  54          */
  55         WEAK_FIELD
  56     }
  57 
  58     /**
  59      * Gets the write barrier type for that particular access.
  60      */
  61     BarrierType getBarrierType();
  62 }