runtime/ArgList.cpp

   1 /*
   2  *  Copyright (C) 2003, 2004, 2005, 2006, 2007 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(ListSet& markSet)
  41 {
  42     ListSet::iterator end = markSet.end();
  43     for (ListSet::iterator it = markSet.begin(); it != end; ++it) {
  44         MarkedArgumentBuffer* list = *it;
  45
  46         iterator end2 = list->end();
  47         for (iterator it2 = list->begin(); it2 != end2; ++it2)
  48             if (!(*it2).marked())
  49                 (*it2).mark();
  50     }
  51 }
  52
  53 void MarkedArgumentBuffer::slowAppend(JSValue v)
  54 {
  55     // As long as our size stays within our Vector's inline
  56     // capacity, all our values are allocated on the stack, and
  57     // therefore don't need explicit marking. Once our size exceeds
  58     // our Vector's inline capacity, though, our values move to the
  59     // heap, where they do need explicit marking.
  60     if (!m_markSet) {
  61         // We can only register for explicit marking once we know which heap
  62         // is the current one, i.e., when a non-immediate value is appended.
  63         if (Heap* heap = Heap::heap(v)) {
  64             ListSet& markSet = heap->markListSet();
  65             markSet.add(this);
  66             m_markSet = &markSet;
  67         }
  68     }
  69
  70     if (m_vector.size() < m_vector.capacity()) {
  71         m_vector.uncheckedAppend(v);
  72         return;
  73     }
  74
  75     // 4x growth would be excessive for a normal vector, but it's OK for Lists
  76     // because they're short-lived.
  77     m_vector.reserveCapacity(m_vector.capacity() * 4);
  78
  79     m_vector.uncheckedAppend(v);
  80     m_buffer = m_vector.data();
  81 }
  82
  83 } // namespace JSC