heap/WeakSet.h

   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 #ifndef WeakSet_h
  27 #define WeakSet_h
  28
  29 #include "WeakBlock.h"
  30
  31 namespace JSC {
  32
  33 class Heap;
  34 class WeakImpl;
  35
  36 class WeakSet {
  37 public:
  38     WeakSet(Heap*);
  39     void finalizeAll();
  40     ~WeakSet();
  41
  42     static WeakImpl* allocate(JSValue, WeakHandleOwner* = 0, void* context = 0);
  43     static void deallocate(WeakImpl*);
  44
  45     void visitLiveWeakImpls(HeapRootVisitor&);
  46     void visitDeadWeakImpls(HeapRootVisitor&);
  47
  48     void sweep();
  49     void resetAllocator();
  50
  51     void shrink();
  52
  53 private:
  54     JS_EXPORT_PRIVATE WeakBlock::FreeCell* findAllocator();
  55     WeakBlock::FreeCell* tryFindAllocator();
  56     WeakBlock::FreeCell* addAllocator();
  57     void removeAllocator(WeakBlock*);
  58
  59     WeakBlock::FreeCell* m_allocator;
  60     WeakBlock* m_nextAllocator;
  61     DoublyLinkedList<WeakBlock> m_blocks;
  62     Heap* m_heap;
  63 };
  64
  65 inline WeakSet::WeakSet(Heap* heap)
  66     : m_allocator(0)
  67     , m_nextAllocator(0)
  68     , m_heap(heap)
  69 {
  70 }
  71
  72 inline void WeakSet::deallocate(WeakImpl* weakImpl)
  73 {
  74     weakImpl->setState(WeakImpl::Deallocated);
  75 }
  76
  77 } // namespace JSC
  78
  79 #endif // WeakSet_h