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