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
|
/* libs/corecg/SkChunkAlloc.cpp
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include "SkChunkAlloc.h"
struct SkChunkAlloc::Block {
Block* fNext;
size_t fFreeSize;
char* fFreePtr;
// data[] follows
char* startOfData() {
return reinterpret_cast<char*>(this + 1);
}
void freeChain() { // this can be null
Block* block = this;
while (block) {
Block* next = block->fNext;
sk_free(block);
block = next;
}
};
Block* tail() {
Block* block = this;
if (block) {
for (;;) {
Block* next = block->fNext;
if (NULL == next) {
break;
}
block = next;
}
}
return block;
}
bool contains(const void* addr) const {
const char* ptr = reinterpret_cast<const char*>(addr);
return ptr >= (const char*)(this + 1) && ptr < fFreePtr;
}
};
SkChunkAlloc::SkChunkAlloc(size_t minSize)
: fBlock(NULL), fMinSize(SkAlign4(minSize)), fPool(NULL), fTotalCapacity(0)
{
}
SkChunkAlloc::~SkChunkAlloc() {
this->reset();
}
void SkChunkAlloc::reset() {
fBlock->freeChain();
fBlock = NULL;
fPool->freeChain();
fPool = NULL;
fTotalCapacity = 0;
}
void SkChunkAlloc::reuse() {
if (fPool && fBlock) {
fPool->tail()->fNext = fBlock;
}
fPool = fBlock;
fBlock = NULL;
fTotalCapacity = 0;
}
SkChunkAlloc::Block* SkChunkAlloc::newBlock(size_t bytes, AllocFailType ftype) {
Block* block = fPool;
if (block && bytes <= block->fFreeSize) {
fPool = block->fNext;
return block;
}
size_t size = bytes;
if (size < fMinSize)
size = fMinSize;
block = (Block*)sk_malloc_flags(sizeof(Block) + size,
ftype == kThrow_AllocFailType ? SK_MALLOC_THROW : 0);
if (block) {
// block->fNext = fBlock;
block->fFreeSize = size;
block->fFreePtr = block->startOfData();
fTotalCapacity += size;
}
return block;
}
void* SkChunkAlloc::alloc(size_t bytes, AllocFailType ftype) {
bytes = SkAlign4(bytes);
Block* block = fBlock;
if (block == NULL || bytes > block->fFreeSize) {
block = this->newBlock(bytes, ftype);
if (NULL == block) {
return NULL;
}
block->fNext = fBlock;
fBlock = block;
}
SkASSERT(block && bytes <= block->fFreeSize);
void* ptr = block->fFreePtr;
block->fFreeSize -= bytes;
block->fFreePtr += bytes;
return ptr;
}
size_t SkChunkAlloc::unalloc(void* ptr) {
size_t bytes = 0;
Block* block = fBlock;
if (block) {
char* cPtr = reinterpret_cast<char*>(ptr);
char* start = block->startOfData();
if (start <= cPtr && cPtr < block->fFreePtr) {
bytes = block->fFreePtr - cPtr;
block->fFreeSize += bytes;
block->fFreePtr = cPtr;
}
}
return bytes;
}
bool SkChunkAlloc::contains(const void* addr) const {
const Block* block = fBlock;
while (block) {
if (block->contains(addr)) {
return true;
}
block = block->fNext;
}
return false;
}
|
