heap/WriteBarrierBuffer.cpp

   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 #include "config.h"
  27 #include "WriteBarrierBuffer.h"
  28
  29 #include "GCAssertions.h"
  30 #include "Heap.h"
  31 #include "JSCell.h"
  32 #include "JSCInlines.h"
  33 #include "Structure.h"
  34
  35 namespace JSC {
  36
  37 WriteBarrierBuffer::WriteBarrierBuffer(unsigned capacity)
  38     : m_currentIndex(0)
  39     , m_capacity(capacity)
  40     , m_buffer(static_cast<JSCell**>(fastMalloc(sizeof(JSCell*) * capacity)))
  41 {
  42 }
  43
  44 WriteBarrierBuffer::~WriteBarrierBuffer()
  45 {
  46     fastFree(m_buffer);
  47     m_buffer = 0;
  48 }
  49
  50 void WriteBarrierBuffer::flush(Heap& heap)
  51 {
  52     ASSERT(m_currentIndex <= m_capacity);
  53     for (size_t i = 0; i < m_currentIndex; ++i)
  54         heap.writeBarrier(m_buffer[i]);
  55     m_currentIndex = 0;
  56 }
  57
  58 void WriteBarrierBuffer::reset()
  59 {
  60     m_currentIndex = 0;
  61 }
  62
  63 void WriteBarrierBuffer::add(JSCell* cell)
  64 {
  65     ASSERT_GC_OBJECT_LOOKS_VALID(cell);
  66     ASSERT(m_currentIndex < m_capacity);
  67     m_buffer[m_currentIndex++] = cell;
  68 }
  69
  70 } // namespace JSC