1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* Copyright (C) 2008 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#ifndef BUILDING_ON_TIGER
#include "PurgeableBuffer.h"
#include <mach/mach.h>
#include <wtf/Assertions.h>
namespace WebCore {
static const size_t minPurgeableBufferSize = 4096; // one page
PurgeableBuffer::PurgeableBuffer(char* data, size_t size)
: m_data(data)
, m_size(size)
, m_purgePriority(PurgeDefault)
, m_state(NonVolatile)
{
}
PurgeableBuffer::~PurgeableBuffer()
{
vm_deallocate(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), m_size);
}
PurgeableBuffer* PurgeableBuffer::create(const char* data, size_t size)
{
if (size < minPurgeableBufferSize)
return 0;
vm_address_t buffer = 0;
kern_return_t ret = vm_allocate(mach_task_self(), &buffer, size, VM_FLAGS_PURGABLE | VM_FLAGS_ANYWHERE);
ASSERT(ret == KERN_SUCCESS);
if (ret != KERN_SUCCESS)
return 0;
ret = vm_copy(mach_task_self(), reinterpret_cast<vm_address_t>(data), size, buffer);
ASSERT(ret == KERN_SUCCESS);
if (ret != KERN_SUCCESS) {
vm_deallocate(mach_task_self(), buffer, size);
return 0;
}
return new PurgeableBuffer(reinterpret_cast<char*>(buffer), size);
}
bool PurgeableBuffer::makePurgeable(bool purgeable)
{
if (purgeable) {
if (m_state != NonVolatile)
return true;
int volatileGroup;
if (m_purgePriority == PurgeFirst)
volatileGroup = VM_VOLATILE_GROUP_0;
else if (m_purgePriority == PurgeMiddle)
volatileGroup = VM_VOLATILE_GROUP_4;
else
volatileGroup = VM_VOLATILE_GROUP_7;
int state = VM_PURGABLE_VOLATILE | volatileGroup;
// So apparently "purgeable" is the correct spelling and the API here is misspelled.
kern_return_t ret = vm_purgable_control(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), VM_PURGABLE_SET_STATE, &state);
if (ret != KERN_SUCCESS) {
// If that failed we have no clue what state we are in so assume purged.
m_state = Purged;
return true;
}
m_state = Volatile;
return true;
}
if (m_state == NonVolatile)
return true;
if (m_state == Purged)
return false;
int state = VM_PURGABLE_NONVOLATILE;
kern_return_t ret = vm_purgable_control(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), VM_PURGABLE_SET_STATE, &state);
if (ret != KERN_SUCCESS) {
// If that failed we have no clue what state we are in so assume purged.
m_state = Purged;
return false;
}
m_state = state & VM_PURGABLE_EMPTY ? Purged : NonVolatile;
return m_state == NonVolatile;
}
bool PurgeableBuffer::wasPurged() const
{
if (m_state == NonVolatile)
return false;
if (m_state == Purged)
return true;
int state;
kern_return_t ret = vm_purgable_control(mach_task_self(), reinterpret_cast<vm_address_t>(m_data), VM_PURGABLE_GET_STATE, &state);
if (ret != KERN_SUCCESS) {
// If that failed we have no clue what state we are in so assume purged.
m_state = Purged;
return true;
}
if (state & VM_PURGABLE_EMPTY) {
m_state = Purged;
return true;
}
return false;
}
void PurgeableBuffer::setPurgePriority(PurgePriority priority)
{
if (priority == m_purgePriority)
return;
m_purgePriority = priority;
if (m_state != Volatile)
return;
m_state = NonVolatile;
makePurgeable(true);
}
const char* PurgeableBuffer::data() const
{
ASSERT(m_state == NonVolatile);
return m_data;
}
}
#endif // BUILDING_ON_TIGER
|
