1/*
2 * Copyright (C) 2011 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. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "MarkedBlock.h"
28
29#include "JSCell.h"
30#include "JSObject.h"
31#include "JSZombie.h"
32#include "ScopeChain.h"
33
34namespace JSC {
35
36MarkedBlock* MarkedBlock::create(JSGlobalData* globalData, size_t cellSize)
37{
38    PageAllocationAligned allocation = PageAllocationAligned::allocate(blockSize, blockSize, OSAllocator::JSGCHeapPages);
39    if (!static_cast<bool>(allocation))
40        CRASH();
41    return new (allocation.base()) MarkedBlock(allocation, globalData, cellSize);
42}
43
44void MarkedBlock::destroy(MarkedBlock* block)
45{
46    for (size_t i = block->firstAtom(); i < block->m_endAtom; i += block->m_atomsPerCell)
47        reinterpret_cast<JSCell*>(&block->atoms()[i])->~JSCell();
48    block->m_allocation.deallocate();
49}
50
51MarkedBlock::MarkedBlock(const PageAllocationAligned& allocation, JSGlobalData* globalData, size_t cellSize)
52    : m_nextAtom(firstAtom())
53    , m_allocation(allocation)
54    , m_heap(&globalData->heap)
55    , m_prev(0)
56    , m_next(0)
57{
58    m_atomsPerCell = (cellSize + atomSize - 1) / atomSize;
59    m_endAtom = atomsPerBlock - m_atomsPerCell + 1;
60
61    Structure* dummyMarkableCellStructure = globalData->dummyMarkableCellStructure.get();
62    for (size_t i = firstAtom(); i < m_endAtom; i += m_atomsPerCell)
63        new (&atoms()[i]) JSCell(*globalData, dummyMarkableCellStructure);
64}
65
66void MarkedBlock::sweep()
67{
68    Structure* dummyMarkableCellStructure = m_heap->globalData()->dummyMarkableCellStructure.get();
69
70    for (size_t i = firstAtom(); i < m_endAtom; i += m_atomsPerCell) {
71        if (m_marks.get(i))
72            continue;
73
74        JSCell* cell = reinterpret_cast<JSCell*>(&atoms()[i]);
75#if ENABLE(JSC_ZOMBIES)
76        if (cell->structure() && cell->structure() != dummyMarkableCellStructure && !cell->isZombie()) {
77            const ClassInfo* info = cell->classInfo();
78            cell->~JSCell();
79            new (cell) JSZombie(*m_heap->globalData(), info, m_heap->globalData()->zombieStructure.get());
80            m_marks.set(i);
81        }
82#else
83        cell->~JSCell();
84        new (cell) JSCell(*m_heap->globalData(), dummyMarkableCellStructure);
85#endif
86    }
87}
88
89} // namespace JSC
90