1/*
2 * Copyright (C) 2014 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 BumpAllocator_h
27#define BumpAllocator_h
28
29#include "BAssert.h"
30#include "BumpRange.h"
31#include "ObjectType.h"
32
33namespace bmalloc {
34
35// Helper object for allocating small objects.
36
37class BumpAllocator {
38public:
39 BumpAllocator();
40 void init(size_t);
41
42 size_t size() { return m_size; }
43
44 bool isNull() { return !m_ptr; }
45 void clear();
46
47 bool canAllocate() { return !!m_remaining; }
48 void* allocate();
49
50 void refill(const BumpRange&);
51
52private:
53 char* m_ptr;
54 unsigned m_size;
55 unsigned m_remaining;
56};
57
58inline BumpAllocator::BumpAllocator()
59 : m_ptr()
60 , m_size()
61 , m_remaining()
62{
63}
64
65inline void BumpAllocator::init(size_t size)
66{
67 m_ptr = nullptr;
68 m_size = size;
69 m_remaining = 0;
70}
71
72inline void* BumpAllocator::allocate()
73{
74 BASSERT(m_remaining);
75
76 --m_remaining;
77 char* result = m_ptr;
78 m_ptr += m_size;
79 return result;
80}
81
82inline void BumpAllocator::refill(const BumpRange& bumpRange)
83{
84 BASSERT(!canAllocate());
85 m_ptr = bumpRange.begin;
86 m_remaining = bumpRange.objectCount;
87 BASSERT(canAllocate());
88}
89
90inline void BumpAllocator::clear()
91{
92 m_ptr = nullptr;
93 m_remaining = 0;
94}
95
96} // namespace bmalloc
97
98#endif // BumpAllocator_h
99