parser/ParserArena.cpp

   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 }