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