1 /*

     2  * Copyright 2001-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 // An ImmutableSpace is a viewport into a contiguous range

    26 // (or subrange) of previously allocated objects.

    27 

    28 // Invariant: bottom() and end() are on page_size boundaries and

    29 // bottom() <= end()

    30 

    31 class ImmutableSpace: public CHeapObj {

    32   friend class VMStructs;

    33  protected:

    34   HeapWord* _bottom;

    35   HeapWord* _end;

    36 

    37  public:

    38   ImmutableSpace()                   { _bottom = NULL; _end = NULL;  }

    39   HeapWord* bottom() const           { return _bottom;               }

    40   HeapWord* end() const              { return _end;                  }

    41 

    42   MemRegion region() const { return MemRegion(bottom(), end()); }

    43 

    44   // Initialization

    45   void initialize(MemRegion mr);

    46 

    47   bool contains(const void* p) const { return _bottom <= p && p < _end; }

    48 

    49   // Size computations.  Sizes are in bytes.

    50   size_t capacity_in_bytes() const            { return capacity_in_words() * HeapWordSize; }

    51 

    52   // Size computations.  Sizes are in heapwords.

    53   size_t capacity_in_words() const            { return pointer_delta(end(), bottom()); }

    54 

    55   // Iteration.

    56   virtual void oop_iterate(OopClosure* cl);

    57   virtual void object_iterate(ObjectClosure* cl);

    58 

    59   // Debugging

    60   virtual void print() const            PRODUCT_RETURN;

    61   virtual void print_short() const      PRODUCT_RETURN;

    62   virtual void verify(bool allow_dirty) const;

    63 };