heap/HeapBlock.h

   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. ``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 #ifndef HeapBlock_h
  27 #define HeapBlock_h
  28
  29 #include <wtf/DoublyLinkedList.h>
  30 #include <wtf/StdLibExtras.h>
  31
  32 namespace JSC {
  33
  34 enum AllocationEffort { AllocationCanFail, AllocationMustSucceed };
  35
  36 class Region;
  37
  38 #if COMPILER(GCC)
  39 #define CLASS_IF_GCC class
  40 #else
  41 #define CLASS_IF_GCC
  42 #endif
  43
  44 template<typename T>
  45 class HeapBlock : public DoublyLinkedListNode<T> {
  46     friend CLASS_IF_GCC DoublyLinkedListNode<T>;
  47 public:
  48     static HeapBlock* destroy(HeapBlock* block) WARN_UNUSED_RETURN
  49     {
  50         static_cast<T*>(block)->~T();
  51         return block;
  52     }
  53
  54     HeapBlock(Region* region)
  55         : DoublyLinkedListNode<T>()
  56         , m_region(region)
  57         , m_prev(0)
  58         , m_next(0)
  59     {
  60         ASSERT(m_region);
  61     }
  62
  63     Region* region() const { return m_region; }
  64
  65 private:
  66     Region* m_region;
  67     T* m_prev;
  68     T* m_next;
  69 };
  70
  71 } // namespace JSC
  72
  73 #endif