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1 /*
2  * Copyright (C) 2003 Apple Computer, Inc.
3  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
4  *
5  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
20  *
21  * Alternatively, the contents of this file may be used under the terms
22  * of either the Mozilla Public License Version 1.1, found at
23  * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public
24  * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html
25  * (the "GPL"), in which case the provisions of the MPL or the GPL are
26  * applicable instead of those above.  If you wish to allow use of your
27  * version of this file only under the terms of one of those two
28  * licenses (the MPL or the GPL) and not to allow others to use your
29  * version of this file under the LGPL, indicate your decision by
30  * deletingthe provisions above and replace them with the notice and
31  * other provisions required by the MPL or the GPL, as the case may be.
32  * If you do not delete the provisions above, a recipient may use your
33  * version of this file under any of the LGPL, the MPL or the GPL.
34  */
35 
36 #include "config.h"
37 #include "RenderArena.h"
38 
39 #include <stdlib.h>
40 #include <string.h>
41 #include <wtf/Assertions.h>
42 
43 #define ROUNDUP(x, y) ((((x)+((y)-1))/(y))*(y))
44 
45 namespace WebCore {
46 
47 #ifndef NDEBUG
48 
49 const int signature = 0xDBA00AEA;
50 const int signatureDead = 0xDBA00AED;
51 
52 typedef struct {
53     RenderArena* arena;
54     size_t size;
55     int signature;
56 } RenderArenaDebugHeader;
57 
58 static const size_t debugHeaderSize = ARENA_ALIGN(sizeof(RenderArenaDebugHeader));
59 
60 #endif
61 
RenderArena(unsigned arenaSize)62 RenderArena::RenderArena(unsigned arenaSize)
63 {
64     // Initialize the arena pool
65     INIT_ARENA_POOL(&m_pool, "RenderArena", arenaSize);
66 
67     // Zero out the recyclers array
68     memset(m_recyclers, 0, sizeof(m_recyclers));
69 }
70 
~RenderArena()71 RenderArena::~RenderArena()
72 {
73     FinishArenaPool(&m_pool);
74 }
75 
allocate(size_t size)76 void* RenderArena::allocate(size_t size)
77 {
78 #ifndef NDEBUG
79     // Use standard malloc so that memory debugging tools work.
80     ASSERT(this);
81     void* block = ::malloc(debugHeaderSize + size);
82     RenderArenaDebugHeader* header = static_cast<RenderArenaDebugHeader*>(block);
83     header->arena = this;
84     header->size = size;
85     header->signature = signature;
86     return static_cast<char*>(block) + debugHeaderSize;
87 #else
88     void* result = 0;
89 
90     // Ensure we have correct alignment for pointers.  Important for Tru64
91     size = ROUNDUP(size, sizeof(void*));
92 
93     // Check recyclers first
94     if (size < gMaxRecycledSize) {
95         const int index = size >> 2;
96 
97         result = m_recyclers[index];
98         if (result) {
99             // Need to move to the next object
100             void* next = *((void**)result);
101             m_recyclers[index] = next;
102         }
103     }
104 
105     if (!result) {
106         // Allocate a new chunk from the arena
107         ARENA_ALLOCATE(result, &m_pool, size);
108     }
109 
110     return result;
111 #endif
112 }
113 
free(size_t size,void * ptr)114 void RenderArena::free(size_t size, void* ptr)
115 {
116 #ifndef NDEBUG
117     // Use standard free so that memory debugging tools work.
118     void* block = static_cast<char*>(ptr) - debugHeaderSize;
119     RenderArenaDebugHeader* header = static_cast<RenderArenaDebugHeader*>(block);
120     ASSERT(header->signature == signature);
121     ASSERT_UNUSED(size, header->size == size);
122     ASSERT(header->arena == this);
123     header->signature = signatureDead;
124     ::free(block);
125 #else
126     // Ensure we have correct alignment for pointers.  Important for Tru64
127     size = ROUNDUP(size, sizeof(void*));
128 
129     // See if it's a size that we recycle
130     if (size < gMaxRecycledSize) {
131         const int index = size >> 2;
132         void* currentTop = m_recyclers[index];
133         m_recyclers[index] = ptr;
134         *((void**)ptr) = currentTop;
135     }
136 #endif
137 }
138 
139 #ifdef ANDROID_INSTRUMENT
reportPoolSize() const140 size_t RenderArena::reportPoolSize() const
141 {
142     return ReportPoolSize(&m_pool);
143 }
144 #endif
145 
146 } // namespace WebCore
147