1 /*

     2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  * 1. Redistributions of source code must retain the above copyright

     8  *    notice, this list of conditions and the following disclaimer.

     9  * 2. Redistributions in binary form must reproduce the above copyright

    10  *    notice, this list of conditions and the following disclaimer in the

    11  *    documentation and/or other materials provided with the distribution.

    12  *

    13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY

    14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR

    17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

    18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

    19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

    20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

    21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

    23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

    24  */

    25 

    26 #include "config.h"

    27 #include "Collector.h"

    28 

    29 #ifndef CollectorHeapIterator_h

    30 #define CollectorHeapIterator_h

    31 

    32 namespace JSC {

    33 

    34     template <HeapType heapType> class CollectorHeapIterator {

    35     public:

    36         CollectorHeapIterator(CollectorBlock** block, CollectorBlock** endBlock);

    37 

    38         bool operator!=(const CollectorHeapIterator<heapType>& other) { return m_block != other.m_block || m_cell != other.m_cell; }

    39         CollectorHeapIterator<heapType>& operator++();

    40         JSCell* operator*() const;

    41     

    42     private:

    43         typedef typename HeapConstants<heapType>::Block Block;

    44         typedef typename HeapConstants<heapType>::Cell Cell;

    45 

    46         Block** m_block;

    47         Block** m_endBlock;

    48         Cell* m_cell;

    49         Cell* m_endCell;

    50     };

    51 

    52     template <HeapType heapType> 

    53     CollectorHeapIterator<heapType>::CollectorHeapIterator(CollectorBlock** block, CollectorBlock** endBlock)

    54         : m_block(reinterpret_cast<Block**>(block))

    55         , m_endBlock(reinterpret_cast<Block**>(endBlock))

    56         , m_cell(m_block == m_endBlock ? 0 : (*m_block)->cells)

    57         , m_endCell(m_block == m_endBlock ? 0 : (*m_block)->cells + HeapConstants<heapType>::cellsPerBlock)

    58     {

    59         if (m_cell && m_cell->u.freeCell.zeroIfFree == 0)

    60             ++*this;

    61     }

    62 

    63     template <HeapType heapType> 

    64     CollectorHeapIterator<heapType>& CollectorHeapIterator<heapType>::operator++()

    65     {

    66         do {

    67             for (++m_cell; m_cell != m_endCell; ++m_cell)

    68                 if (m_cell->u.freeCell.zeroIfFree != 0) {

    69                     return *this;

    70                 }

    71 

    72             if (++m_block != m_endBlock) {

    73                 m_cell = (*m_block)->cells;

    74                 m_endCell = (*m_block)->cells + HeapConstants<heapType>::cellsPerBlock;

    75             }

    76         } while(m_block != m_endBlock);

    77 

    78         m_cell = 0;

    79         return *this;

    80     }

    81 

    82     template <HeapType heapType> 

    83     JSCell* CollectorHeapIterator<heapType>::operator*() const

    84     {

    85         return reinterpret_cast<JSCell*>(m_cell);

    86     }

    87 

    88 } // namespace JSC

    89 

    90 #endif // CollectorHeapIterator_h