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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <Kernel/VM/MemoryManager.h>
28#include <Kernel/VM/PhysicalPage.h>
29#include <Kernel/VM/PurgeableVMObject.h>
30
31namespace Kernel {
32
33NonnullRefPtr<PurgeableVMObject> PurgeableVMObject::create_with_size(size_t size)
34{
35 return adopt(*new PurgeableVMObject(size));
36}
37
38PurgeableVMObject::PurgeableVMObject(size_t size)
39 : AnonymousVMObject(size)
40{
41}
42
43PurgeableVMObject::PurgeableVMObject(const PurgeableVMObject& other)
44 : AnonymousVMObject(other)
45{
46}
47
48PurgeableVMObject::~PurgeableVMObject()
49{
50}
51
52NonnullRefPtr<VMObject> PurgeableVMObject::clone()
53{
54 return adopt(*new PurgeableVMObject(*this));
55}
56
57int PurgeableVMObject::purge()
58{
59 LOCKER(m_paging_lock);
60 return purge_impl();
61}
62
63int PurgeableVMObject::purge_with_interrupts_disabled(Badge<MemoryManager>)
64{
65 ASSERT_INTERRUPTS_DISABLED();
66 if (m_paging_lock.is_locked())
67 return 0;
68 return purge_impl();
69}
70
71int PurgeableVMObject::purge_impl()
72{
73 if (!m_volatile)
74 return 0;
75 int purged_page_count = 0;
76 for (size_t i = 0; i < m_physical_pages.size(); ++i) {
77 if (m_physical_pages[i])
78 ++purged_page_count;
79 m_physical_pages[i] = MM.shared_zero_page();
80 }
81 m_was_purged = true;
82
83 for_each_region([&](auto& region) {
84 region.remap();
85 });
86
87 return purged_page_count;
88}
89
90}