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      1 /*
      2  * Copyright (C) 2009, 2010 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 #include "config.h"
     27 #include "ParserArena.h"
     28 
     29 #include "Nodes.h"
     30 #include <wtf/PassOwnPtr.h>
     31 
     32 namespace JSC {
     33 
     34 ParserArena::ParserArena()
     35     : m_freeableMemory(0)
     36     , m_freeablePoolEnd(0)
     37     , m_identifierArena(adoptPtr(new IdentifierArena))
     38 {
     39 }
     40 
     41 inline void* ParserArena::freeablePool()
     42 {
     43     ASSERT(m_freeablePoolEnd);
     44     return m_freeablePoolEnd - freeablePoolSize;
     45 }
     46 
     47 inline void ParserArena::deallocateObjects()
     48 {
     49     if (m_freeablePoolEnd)
     50         fastFree(freeablePool());
     51 
     52     size_t size = m_freeablePools.size();
     53     for (size_t i = 0; i < size; ++i)
     54         fastFree(m_freeablePools[i]);
     55 
     56     size = m_deletableObjects.size();
     57     for (size_t i = 0; i < size; ++i) {
     58         ParserArenaDeletable* object = m_deletableObjects[i];
     59         object->~ParserArenaDeletable();
     60         fastFree(object);
     61     }
     62 }
     63 
     64 ParserArena::~ParserArena()
     65 {
     66     deallocateObjects();
     67 }
     68 
     69 bool ParserArena::contains(ParserArenaRefCounted* object) const
     70 {
     71     return m_refCountedObjects.find(object) != notFound;
     72 }
     73 
     74 ParserArenaRefCounted* ParserArena::last() const
     75 {
     76     return m_refCountedObjects.last().get();
     77 }
     78 
     79 void ParserArena::removeLast()
     80 {
     81     m_refCountedObjects.removeLast();
     82 }
     83 
     84 void ParserArena::reset()
     85 {
     86     // Since this code path is used only when parsing fails, it's not bothering to reuse
     87     // any of the memory the arena allocated. We could improve that later if we want to
     88     // efficiently reuse the same arena.
     89 
     90     deallocateObjects();
     91 
     92     m_freeableMemory = 0;
     93     m_freeablePoolEnd = 0;
     94     m_identifierArena->clear();
     95     m_freeablePools.clear();
     96     m_deletableObjects.clear();
     97     m_refCountedObjects.clear();
     98 }
     99 
    100 void ParserArena::allocateFreeablePool()
    101 {
    102     if (m_freeablePoolEnd)
    103         m_freeablePools.append(freeablePool());
    104 
    105     char* pool = static_cast<char*>(fastMalloc(freeablePoolSize));
    106     m_freeableMemory = pool;
    107     m_freeablePoolEnd = pool + freeablePoolSize;
    108     ASSERT(freeablePool() == pool);
    109 }
    110 
    111 bool ParserArena::isEmpty() const
    112 {
    113     return !m_freeablePoolEnd
    114         && m_identifierArena->isEmpty()
    115         && m_freeablePools.isEmpty()
    116         && m_deletableObjects.isEmpty()
    117         && m_refCountedObjects.isEmpty();
    118 }
    119 
    120 void ParserArena::derefWithArena(PassRefPtr<ParserArenaRefCounted> object)
    121 {
    122     m_refCountedObjects.append(object);
    123 }
    124 
    125 }
    126