1 /*
   2  * Copyright (c) 2000, 2015, 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.
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  23  */
  24 
  25 #ifndef SHARE_VM_GC_SHARED_WATERMARK_HPP
  26 #define SHARE_VM_GC_SHARED_WATERMARK_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "utilities/globalDefinitions.hpp"
  30 
  31 // A water mark points into a space and is used during GC to keep track of
  32 // progress.
  33 
  34 class Space;
  35 
  36 class WaterMark VALUE_OBJ_CLASS_SPEC {
  37   friend class VMStructs;
  38  private:
  39   HeapWord* _point;
  40   Space*    _space;
  41  public:
  42   // Accessors
  43   Space* space() const        { return _space;  }
  44   void set_space(Space* s)    { _space = s;     }
  45   HeapWord* point() const     { return _point;  }
  46   void set_point(HeapWord* p) { _point = p;     }
  47 
  48   // Constructors
  49   WaterMark(Space* s, HeapWord* p) : _space(s), _point(p) {};
  50   WaterMark() : _space(NULL), _point(NULL) {};
  51 };
  52 
  53 inline bool operator==(const WaterMark& x, const WaterMark& y) {
  54   return (x.point() == y.point()) && (x.space() == y.space());
  55 }
  56 
  57 inline bool operator!=(const WaterMark& x, const WaterMark& y) {
  58   return !(x == y);
  59 }
  60 
  61 #endif // SHARE_VM_GC_SHARED_WATERMARK_HPP