heap/WeakSet.cpp

   1 /*
   2  * Copyright (C) 2012 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 "WeakSet.h"
  28
  29 #include "Heap.h"
  30 #include "VM.h"
  31
  32 namespace JSC {
  33
  34 WeakSet::~WeakSet()
  35 {
  36     WeakBlock* next = 0;
  37     for (WeakBlock* block = m_blocks.head(); block; block = next) {
  38         next = block->next();
  39         heap()->blockAllocator().deallocate(WeakBlock::destroy(block));
  40     }
  41     m_blocks.clear();
  42 }
  43
  44 void WeakSet::sweep()
  45 {
  46     for (WeakBlock* block = m_blocks.head(); block; block = block->next())
  47         block->sweep();
  48
  49     resetAllocator();
  50 }
  51
  52 WeakBlock::FreeCell* WeakSet::findAllocator()
  53 {
  54     if (WeakBlock::FreeCell* allocator = tryFindAllocator())
  55         return allocator;
  56
  57     return addAllocator();
  58 }
  59
  60 WeakBlock::FreeCell* WeakSet::tryFindAllocator()
  61 {
  62     while (m_nextAllocator) {
  63         WeakBlock* block = m_nextAllocator;
  64         m_nextAllocator = m_nextAllocator->next();
  65
  66         WeakBlock::SweepResult sweepResult = block->takeSweepResult();
  67         if (sweepResult.freeList)
  68             return sweepResult.freeList;
  69     }
  70
  71     return 0;
  72 }
  73
  74 WeakBlock::FreeCell* WeakSet::addAllocator()
  75 {
  76     WeakBlock* block = WeakBlock::create(heap()->blockAllocator().allocate<WeakBlock>());
  77     heap()->didAllocate(WeakBlock::blockSize);
  78     m_blocks.append(block);
  79     WeakBlock::SweepResult sweepResult = block->takeSweepResult();
  80     ASSERT(!sweepResult.isNull() && sweepResult.freeList);
  81     return sweepResult.freeList;
  82 }
  83
  84 void WeakSet::removeAllocator(WeakBlock* block)
  85 {
  86     m_blocks.remove(block);
  87     heap()->blockAllocator().deallocate(WeakBlock::destroy(block));
  88 }
  89
  90 } // namespace JSC