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 #ifndef ConservativeRoots_h
27 #define ConservativeRoots_h
28
29 #include "Heap.h"
30 #include <wtf/OSAllocator.h>
31 #include <wtf/Vector.h>
32
33 namespace JSC {
34
35 class JSCell;
36 class Heap;
37
38 // May contain duplicates.
39
40 class ConservativeRoots {
41 public:
42 ConservativeRoots(Heap*);
43 ~ConservativeRoots();
44
45 void add(void*);
46 void add(void* begin, void* end);
47
48 size_t size();
49 JSCell** roots();
50
51 private:
52 static const size_t inlineCapacity = 128;
53 static const size_t nonInlineCapacity = 8192 / sizeof(JSCell*);
54
55 void grow();
56
57 Heap* m_heap;
58 JSCell** m_roots;
59 size_t m_size;
60 size_t m_capacity;
61 JSCell* m_inlineRoots[inlineCapacity];
62 };
63
ConservativeRoots(Heap * heap)64 inline ConservativeRoots::ConservativeRoots(Heap* heap)
65 : m_heap(heap)
66 , m_roots(m_inlineRoots)
67 , m_size(0)
68 , m_capacity(inlineCapacity)
69 {
70 }
71
~ConservativeRoots()72 inline ConservativeRoots::~ConservativeRoots()
73 {
74 if (m_roots != m_inlineRoots)
75 OSAllocator::decommitAndRelease(m_roots, m_capacity * sizeof(JSCell*));
76 }
77
add(void * p)78 inline void ConservativeRoots::add(void* p)
79 {
80 if (!m_heap->contains(p))
81 return;
82
83 if (m_size == m_capacity)
84 grow();
85
86 m_roots[m_size++] = reinterpret_cast<JSCell*>(p);
87 }
88
size()89 inline size_t ConservativeRoots::size()
90 {
91 return m_size;
92 }
93
roots()94 inline JSCell** ConservativeRoots::roots()
95 {
96 return m_roots;
97 }
98
99 } // namespace JSC
100
101 #endif // ConservativeRoots_h
102