heap/HeapRootVisitor.h

   1 /*
   2  * Copyright (C) 2009, 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 HeapRootVisitor_h
  27 #define HeapRootVisitor_h
  28
  29 #include "SlotVisitor.h"
  30 #include "SlotVisitorInlines.h"
  31
  32 namespace JSC {
  33
  34     // Privileged class for marking JSValues directly. It is only safe to use
  35     // this class to mark direct heap roots that are marked during every GC pass.
  36     // All other references should be wrapped in WriteBarriers.
  37     class HeapRootVisitor {
  38     private:
  39         friend class Heap;
  40         HeapRootVisitor(SlotVisitor&);
  41
  42     public:
  43         void visit(JSValue*);
  44         void visit(JSValue*, size_t);
  45         void visit(JSString**);
  46         void visit(JSCell**);
  47
  48         SlotVisitor& visitor();
  49
  50     private:
  51         SlotVisitor& m_visitor;
  52     };
  53
  54     inline HeapRootVisitor::HeapRootVisitor(SlotVisitor& visitor)
  55         : m_visitor(visitor)
  56     {
  57     }
  58
  59     inline void HeapRootVisitor::visit(JSValue* slot)
  60     {
  61         m_visitor.append(slot);
  62     }
  63
  64     inline void HeapRootVisitor::visit(JSValue* slot, size_t count)
  65     {
  66         m_visitor.append(slot, count);
  67     }
  68
  69     inline void HeapRootVisitor::visit(JSString** slot)
  70     {
  71         m_visitor.append(reinterpret_cast<JSCell**>(slot));
  72     }
  73
  74     inline void HeapRootVisitor::visit(JSCell** slot)
  75     {
  76         m_visitor.append(slot);
  77     }
  78
  79     inline SlotVisitor& HeapRootVisitor::visitor()
  80     {
  81         return m_visitor;
  82     }
  83
  84 } // namespace JSC
  85
  86 #endif // HeapRootVisitor_h