1/*
2 * Copyright (C) 2017 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 "BInline.h"
29#include "IsoDeallocator.h"
30#include "IsoPage.h"
31#include "IsoSharedPage.h"
32#include "Mutex.h"
33#include <mutex>
34
35namespace bmalloc {
36
37template<typename Config>
38IsoDeallocator<Config>::IsoDeallocator(Mutex& lock)
39 : m_lock(&lock)
40{
41}
42
43template<typename Config>
44IsoDeallocator<Config>::~IsoDeallocator()
45{
46}
47
48template<typename Config>
49template<typename Type>
50void IsoDeallocator<Config>::deallocate(api::IsoHeap<Type>& handle, void* ptr)
51{
52 static constexpr bool verbose = false;
53 if (verbose)
54 fprintf(stderr, "%p: deallocating %p of size %u\n", &IsoPage<Config>::pageFor(ptr)->heap(), ptr, Config::objectSize);
55
56 // For allocation from shared pages, we deallocate immediately rather than batching deallocations with object log.
57 // The batching delays the reclamation of the shared cells, which can make allocator mistakenly think that "we exhaust shared
58 // cells because this is allocated a lot". Since the number of shared cells are limited, this immediate deallocation path
59 // should be rarely taken. If we see frequent malloc-and-free pattern, we tier up the allocator from shared mode to fast mode.
60 IsoPageBase* page = IsoPageBase::pageFor(ptr);
61 if (page->isShared()) {
62 std::lock_guard<Mutex> locker(*m_lock);
63 static_cast<IsoSharedPage*>(page)->free<Config>(locker, handle, ptr);
64 return;
65 }
66
67 if (m_objectLog.size() == m_objectLog.capacity())
68 scavenge();
69
70 m_objectLog.push(ptr);
71}
72
73template<typename Config>
74BNO_INLINE void IsoDeallocator<Config>::scavenge()
75{
76 std::lock_guard<Mutex> locker(*m_lock);
77
78 for (void* ptr : m_objectLog)
79 IsoPage<Config>::pageFor(ptr)->free(ptr);
80 m_objectLog.clear();
81}
82
83} // namespace bmalloc
84
85