1 #ifdef USE_PRAGMA_IDENT_HDR
   2 #pragma ident "@(#)immutableSpace.hpp   1.14 07/05/05 17:05:33 JVM"
   3 #endif
   4 /*
   5  * Copyright 2001-2006 Sun Microsystems, Inc.  All Rights Reserved.
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This code is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 only, as
  10  * published by the Free Software Foundation.
  11  *
  12  * This code is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * version 2 for more details (a copy is included in the LICENSE file that
  16  * accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License version
  19  * 2 along with this work; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *  
  26  */
  27 
  28 // An ImmutableSpace is a viewport into a contiguous range
  29 // (or subrange) of previously allocated objects.
  30 
  31 // Invariant: bottom() and end() are on page_size boundaries and
  32 // bottom() <= end() 
  33 
  34 class ImmutableSpace: public CHeapObj {
  35   friend class VMStructs;
  36  protected:
  37   HeapWord* _bottom;
  38   HeapWord* _end;
  39 
  40  public:
  41   ImmutableSpace()                   { _bottom = NULL; _end = NULL;  }
  42   HeapWord* bottom() const           { return _bottom;               }
  43   HeapWord* end() const              { return _end;                  }
  44 
  45   MemRegion region() const { return MemRegion(bottom(), end()); }
  46 
  47   // Initialization
  48   void initialize(MemRegion mr);
  49 
  50   bool contains(const void* p) const { return _bottom <= p && p < _end; }
  51 
  52   // Size computations.  Sizes are in bytes.
  53   size_t capacity_in_bytes() const            { return capacity_in_words() * HeapWordSize; }
  54 
  55   // Size computations.  Sizes are in heapwords.
  56   size_t capacity_in_words() const            { return pointer_delta(end(), bottom()); }
  57 
  58   // Iteration.
  59   virtual void oop_iterate(OopClosure* cl);
  60   virtual void object_iterate(ObjectClosure* cl);
  61 
  62   // Debugging
  63   virtual void print() const            PRODUCT_RETURN;
  64   virtual void print_short() const      PRODUCT_RETURN;
  65   virtual void verify(bool allow_dirty) const;
  66 };