1 /*

     2  * Copyright (c) 2001, 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

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    24 

    25 #ifndef SHARE_VM_GC_PARALLEL_IMMUTABLESPACE_HPP

    26 #define SHARE_VM_GC_PARALLEL_IMMUTABLESPACE_HPP

    27 

    28 #include "memory/iterator.hpp"

    29 

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

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

    32 

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

    34 // bottom() <= end()

    35 

    36 class ImmutableSpace: public CHeapObj<mtGC> {

    37   friend class VMStructs;

    38  protected:

    39   HeapWord* _bottom;

    40   HeapWord* _end;

    41 

    42  public:

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

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

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

    46 

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

    48 

    49   // Initialization

    50   void initialize(MemRegion mr);

    51 

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

    53 

    54   // Size computations.  Sizes are in bytes.

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

    56 

    57   // Size computations.  Sizes are in heapwords.

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

    59   virtual size_t capacity_in_words(Thread*) const { return capacity_in_words(); }

    60 

    61   // Iteration.

    62   virtual void oop_iterate(ExtendedOopClosure* cl);

    63   virtual void object_iterate(ObjectClosure* cl);

    64 

    65   // Debugging

    66   virtual void print() const            PRODUCT_RETURN;

    67   virtual void print_short() const      PRODUCT_RETURN;

    68   virtual void verify();

    69 };

    70 

    71 #endif // SHARE_VM_GC_PARALLEL_IMMUTABLESPACE_HPP