heap/RecursiveAllocationScope.h

   1 /*
   2  * Copyright (C) 2013 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 RecursiveAllocationScope_h
  27 #define RecursiveAllocationScope_h
  28
  29 #include "Heap.h"
  30 #include "VM.h"
  31
  32 namespace JSC {
  33
  34 class RecursiveAllocationScope {
  35 public:
  36     RecursiveAllocationScope(Heap& heap)
  37         : m_heap(heap)
  38 #ifndef NDEBUG
  39         , m_savedObjectClass(heap.vm()->m_initializingObjectClass)
  40 #endif
  41     {
  42 #ifndef NDEBUG
  43         m_heap.vm()->m_initializingObjectClass = nullptr;
  44 #endif
  45         m_heap.m_deferralDepth++; // Make sure that we don't GC.
  46     }
  47
  48     ~RecursiveAllocationScope()
  49     {
  50         m_heap.m_deferralDepth--; // Decrement deferal manually so we don't GC when we do so since we are already GCing!.
  51 #ifndef NDEBUG
  52         m_heap.vm()->m_initializingObjectClass = m_savedObjectClass;
  53 #endif
  54     }
  55
  56 private:
  57     Heap& m_heap;
  58 #ifndef NDEBUG
  59     const ClassInfo* m_savedObjectClass;
  60 #endif
  61 };
  62
  63 }
  64
  65 #endif // RecursiveAllocationScope_h