1/*
2 * Copyright (C) 2016-2018 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 "LargeMap.h"
27#include <utility>
28
29namespace bmalloc {
30
31LargeRange LargeMap::remove(size_t alignment, size_t size)
32{
33 size_t alignmentMask = alignment - 1;
34
35 LargeRange* candidate = m_free.end();
36 for (LargeRange* it = m_free.begin(); it != m_free.end(); ++it) {
37 if (!it->isEligibile())
38 continue;
39
40 if (it->size() < size)
41 continue;
42
43 if (candidate != m_free.end() && candidate->begin() < it->begin())
44 continue;
45
46 if (test(it->begin(), alignmentMask)) {
47 char* aligned = roundUpToMultipleOf(alignment, it->begin());
48 if (aligned < it->begin()) // Check for overflow.
49 continue;
50
51 char* alignedEnd = aligned + size;
52 if (alignedEnd < aligned) // Check for overflow.
53 continue;
54
55 if (alignedEnd > it->end())
56 continue;
57 }
58
59 candidate = it;
60 }
61
62 if (candidate == m_free.end())
63 return LargeRange();
64
65 return m_free.pop(candidate);
66}
67
68void LargeMap::add(const LargeRange& range)
69{
70 LargeRange merged = range;
71
72 for (size_t i = 0; i < m_free.size(); ++i) {
73 if (!canMerge(merged, m_free[i]))
74 continue;
75
76 merged = merge(merged, m_free.pop(i--));
77 }
78
79 merged.setUsedSinceLastScavenge();
80 m_free.push(merged);
81}
82
83void LargeMap::markAllAsEligibile()
84{
85 for (LargeRange& range : m_free)
86 range.setEligible(true);
87}
88
89} // namespace bmalloc
90