1/*
2 * Copyright (C) 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#pragma once
27
28#include "VMAllocate.h"
29#include <vector>
30
31namespace bmalloc {
32
33class BulkDecommit {
34 using Data = std::vector<std::pair<char*, size_t>>;
35
36public:
37 void addEager(void* ptr, size_t size)
38 {
39 add(m_eager, ptr, size);
40 }
41 void addLazy(void* ptr, size_t size)
42 {
43 add(m_lazy, ptr, size);
44 }
45 void processEager()
46 {
47 process(m_eager);
48 }
49 void processLazy()
50 {
51 process(m_lazy);
52 }
53
54private:
55 void add(Data& data, void* ptr, size_t size)
56 {
57 char* begin = roundUpToMultipleOf(vmPageSizePhysical(), static_cast<char*>(ptr));
58 char* end = roundDownToMultipleOf(vmPageSizePhysical(), static_cast<char*>(ptr) + size);
59 if (begin >= end)
60 return;
61 data.push_back({begin, end - begin});
62 }
63
64 void process(BulkDecommit::Data& decommits)
65 {
66 std::sort(
67 decommits.begin(), decommits.end(),
68 [&] (const auto& a, const auto& b) -> bool {
69 return a.first < b.first;
70 });
71
72 char* run = nullptr;
73 size_t runSize = 0;
74 for (unsigned i = 0; i < decommits.size(); ++i) {
75 auto& pair = decommits[i];
76 if (run + runSize != pair.first) {
77 if (run)
78 vmDeallocatePhysicalPages(run, runSize);
79 run = pair.first;
80 runSize = pair.second;
81 } else {
82 BASSERT(run);
83 runSize += pair.second;
84 }
85 }
86
87 if (run)
88 vmDeallocatePhysicalPages(run, runSize);
89 }
90
91 Data m_eager;
92 Data m_lazy;
93};
94
95} // namespace bmalloc
96