runtime/StorageBarrier.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. 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 StorageBarrier_h
  27 #define StorageBarrier_h
  28
  29 #include "JSGlobalData.h"
  30 #include "WriteBarrier.h"
  31
  32 namespace JSC {
  33
  34 typedef WriteBarrierBase<Unknown>* PropertyStorage;
  35 typedef const WriteBarrierBase<Unknown>* ConstPropertyStorage;
  36
  37 class StorageBarrier {
  38 public:
  39     enum UncheckedTag { Unchecked };
  40     StorageBarrier(JSGlobalData& globalData, JSCell* owner, PropertyStorage storage)
  41     {
  42         set(globalData, owner, storage);
  43     }
  44
  45     StorageBarrier(PropertyStorage storage, UncheckedTag)
  46     {
  47         set(storage, Unchecked);
  48     }
  49
  50     void set(JSGlobalData&, JSCell*, PropertyStorage newStorage)
  51     {
  52         m_storage = newStorage;
  53     }
  54
  55     void set(PropertyStorage newStorage, UncheckedTag)
  56     {
  57         m_storage = newStorage;
  58     }
  59
  60     WriteBarrierBase<Unknown>* operator->() const { return m_storage; }
  61     WriteBarrierBase<Unknown>* operator->() { return m_storage; }
  62     WriteBarrierBase<Unknown> operator*() const { return *m_storage; }
  63     WriteBarrierBase<Unknown> operator*() { return *m_storage; }
  64     const WriteBarrierBase<Unknown>& operator[](size_t i) const { return m_storage[i]; }
  65     WriteBarrierBase<Unknown>& operator[](size_t i) { return m_storage[i]; }
  66
  67     ConstPropertyStorage get() const { return m_storage; }
  68     PropertyStorage get() { return m_storage; }
  69
  70 private:
  71     PropertyStorage m_storage;
  72 };
  73
  74 }
  75
  76 #endif