runtime/ArgList.cpp

   1 /*
   2  *  Copyright (C) 2003, 2004, 2005, 2006, 2007, 2009 Apple Inc. All rights reserved.
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  *  This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU Library General Public License
  15  *  along with this library; see the file COPYING.LIB.  If not, write to
  16  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  *  Boston, MA 02110-1301, USA.
  18  *
  19  */
  20
  21 #include "config.h"
  22 #include "ArgList.h"
  23
  24 #include "JSValue.h"
  25 #include "JSCell.h"
  26
  27 using std::min;
  28
  29 namespace JSC {
  30
  31 void ArgList::getSlice(int startIndex, ArgList& result) const
  32 {
  33     if (startIndex <= 0 || static_cast<unsigned>(startIndex) >= m_argCount) {
  34         result = ArgList(m_args, 0);
  35         return;
  36     }
  37     result = ArgList(m_args + startIndex, m_argCount - startIndex);
  38 }
  39
  40 void MarkedArgumentBuffer::markLists(MarkStack& markStack, ListSet& markSet)
  41 {
  42     ListSet::iterator end = markSet.end();
  43     for (ListSet::iterator it = markSet.begin(); it != end; ++it) {
  44         MarkedArgumentBuffer* list = *it;
  45         markStack.appendValues(reinterpret_cast<JSValue*>(list->m_buffer), list->m_size);
  46     }
  47 }
  48
  49 void MarkedArgumentBuffer::slowAppend(JSValue v)
  50 {
  51     // As long as our size stays within our Vector's inline
  52     // capacity, all our values are allocated on the stack, and
  53     // therefore don't need explicit marking. Once our size exceeds
  54     // our Vector's inline capacity, though, our values move to the
  55     // heap, where they do need explicit marking.
  56     if (!m_markSet) {
  57         // We can only register for explicit marking once we know which heap
  58         // is the current one, i.e., when a non-immediate value is appended.
  59         if (Heap* heap = Heap::heap(v)) {
  60             ListSet& markSet = heap->markListSet();
  61             markSet.add(this);
  62             m_markSet = &markSet;
  63         }
  64     }
  65
  66     if (m_vector.size() < m_vector.capacity()) {
  67         m_vector.uncheckedAppend(v);
  68         return;
  69     }
  70
  71     // 4x growth would be excessive for a normal vector, but it's OK for Lists
  72     // because they're short-lived.
  73     m_vector.reserveCapacity(m_vector.capacity() * 4);
  74
  75     m_vector.uncheckedAppend(v);
  76     m_buffer = m_vector.data();
  77 }
  78
  79 } // namespace JSC