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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
|
#include "Heap.class.h"
#ifdef THIS_IS_MELON_KERNEL
#include <MemoryManager/PageDirectory.class.h>
#define ALLOC(x) m_pagedir->allocFrame(x, m_user, m_rw)
#define FREE(x) m_pagedir->freeFrame(x)
#else
#define ALLOC(x) m_process.allocPage(x)
#define FREE(x) m_process.freePage(x)
#endif
#ifdef THIS_IS_MELON_KERNEL
Heap::Heap() : m_mutex(MUTEX_FALSE) {
#else
Heap::Heap() : m_mutex(MUTEX_FALSE), m_process(Process::get()) {
#endif
m_usable = false;
m_index.data = 0;
m_index.size = 0;
}
Heap::~Heap() {
//TODO (optionnal) : free pages.
}
#ifdef THIS_IS_MELON_KERNEL
void Heap::create(u32int start, u32int size, u32int idxsize, PageDirectory* pagedir, bool user, bool rw) {
#else
void Heap::create(u32int start, u32int size, u32int idxsize) {
#endif
if (m_usable) return;
if (start & 0x0FFF) start = (start & 0xFFFFF000) + 0x1000;
if (size & 0x0FFF) size = (size & 0xFFFFF000) + 0x1000;
m_start = start + idxsize; //m_start is start of real data, start is start of index.
m_end = start + size;
#ifdef THIS_IS_MELON_KERNEL
m_pagedir = pagedir;
m_user = user;
m_rw = rw;
#endif
//Allocate frames for heap
for (u32int i = start ; i < m_end; i += 0x1000) {
ALLOC(i);
}
#ifdef THIS_IS_MELON_KERNEL
m_pagedir->switchTo();
#endif
m_index.data = (heap_header_t **)start; //Set index start. start == start of all heap
m_index.size = 0;
heap_header_t *hole = (heap_header_t*) m_start; //m_start == start of data
hole->size = (m_end - m_start);
hole->magic = HEAP_MAGIC;
hole->is_hole = true;
heap_footer_t *hole_footer = (heap_footer_t*) (m_end - sizeof(heap_footer_t));
hole_footer->header = hole;
hole_footer->magic = HEAP_MAGIC;
insertIntoIndex(hole);
m_usable = true;
m_free = (m_end - m_start);
m_mutex.unlock();
}
void Heap::expand(u32int quantity) {
if (quantity & 0x00000FFF)
quantity = (quantity & 0xFFFFF000) + 0x1000;
u32int newEnd = m_end + quantity;
for (u32int i = m_end; i < newEnd; i++) {
ALLOC(i);
}
heap_footer_t *last_footer = (heap_footer_t*) (m_end - sizeof(heap_footer_t));
heap_header_t *last_header = last_footer->header;
if (last_header->is_hole) { //Last block of heap is a hole, update its size
removeFromIndex(last_header);
last_header->size += quantity;
last_footer = (heap_footer_t*) (newEnd - sizeof(heap_footer_t));
last_footer->magic = HEAP_MAGIC;
last_footer->header = last_header;
insertIntoIndex(last_header);
} else { //Last block is not a hole. Just add a new hole at the end
last_header = (heap_header_t*)m_end;
last_footer = (heap_footer_t*) (newEnd - sizeof(heap_footer_t));
last_header->is_hole = true;
last_header->magic = HEAP_MAGIC;
last_header->size = quantity;
last_footer->magic = HEAP_MAGIC;
last_footer->header = last_header;
insertIntoIndex(last_header);
}
m_end = newEnd;
m_free += quantity;
}
void Heap::contract() { //Automatically work out how much we can contract
heap_footer_t *last_footer = (heap_footer_t*) (m_end - sizeof(heap_footer_t));
heap_header_t *last_header = last_footer->header;
if (last_header->is_hole == false) return; //We need a hole at end of heap
u32int quantity = 0;
while ((m_end - m_start) - quantity > HEAP_MIN_SIZE and
(last_header->size - quantity) > 0x1000) //Always keep at least 0x1000 free at end
quantity += 0x1000;
if (quantity == 0) return;
u32int newEnd = m_end - quantity;
m_free -= quantity;
removeFromIndex(last_header);
last_header->size -= quantity;
last_footer = (heap_footer_t*)((u32int)last_footer - quantity);
last_footer->magic = HEAP_MAGIC;
last_footer->header = last_header;
insertIntoIndex(last_header);
for (u32int i = newEnd; i < m_end; i += 0x1000) {
FREE(i);
}
m_end = newEnd;
}
void *Heap::alloc(u32int sz, bool no_expand) {
m_mutex.waitLock();
u32int newsize = sz + sizeof(heap_header_t) + sizeof(heap_footer_t);
u32int iterator = 0;
while (iterator < m_index.size) {
if (m_index.data[iterator]->size >= newsize) break;
iterator++;
}
if (iterator == m_index.size) { //No hole is big enough
if (no_expand) {
m_mutex.unlock();
return 0;
}
expand((sz & 0xFFFFF000) + 0x1000);
m_mutex.unlock();
return alloc(sz, true); //Recurse call
}
heap_header_t *loc = m_index.data[iterator];
heap_footer_t *footer = (heap_footer_t*)((u32int)loc + loc->size - sizeof(heap_footer_t));
loc->is_hole = false; //Update current header
removeFromIndex(loc);
//Here we create a new hole after currently allocated block, but only if we have enough space. If we don't, we simply allocate a bigger block so that we don't loose space
if (loc->size > (newsize + sizeof(heap_header_t) + sizeof(heap_footer_t))) {
loc->size = newsize; //Update header for return block
heap_footer_t *newfooter = (heap_footer_t*)((u32int)loc + newsize - sizeof(heap_footer_t)); //Write footer for return block
newfooter->header = loc;
newfooter->magic = HEAP_MAGIC;
heap_header_t *nextloc = (heap_header_t*)((u32int)loc + newsize); //Write header for new hole
nextloc->is_hole = true;
nextloc->magic = HEAP_MAGIC;
nextloc->size = ((u32int)footer - (u32int)nextloc + sizeof(heap_footer_t));
footer->header = nextloc; //Write footer for new hole
footer->magic = HEAP_MAGIC;
insertIntoIndex(nextloc);
}
m_free -= loc->size;
m_mutex.unlock();
return (void*)((u32int)loc + sizeof(heap_header_t));
}
void Heap::free(void *ptr) {
if (ptr == 0) return;
heap_header_t *header = (heap_header_t*) ((u32int)ptr - sizeof(heap_header_t));
heap_footer_t *footer = (heap_footer_t*)((u32int)header + header->size - sizeof(heap_footer_t));
if (header->magic != HEAP_MAGIC or footer->magic != HEAP_MAGIC) return;
m_mutex.waitLock();
m_free += header->size;
//Unify left
heap_footer_t *prev_footer = (heap_footer_t*)((u32int)header - sizeof(heap_footer_t));
if (prev_footer->magic == HEAP_MAGIC && prev_footer->header->is_hole) {
header = prev_footer->header;
removeFromIndex(header);
footer->header = header;
header->size = ((u32int)footer - (u32int)header + sizeof(heap_footer_t));
}
//Unify right
heap_header_t *next_header = (heap_header_t*)((u32int)footer + sizeof(heap_footer_t));
if (next_header->magic == HEAP_MAGIC && next_header->is_hole) {
removeFromIndex(next_header);
footer = (heap_footer_t*)((u32int)footer + next_header->size);
footer->header = header;
header->size = ((u32int)footer - (u32int)header + sizeof(heap_footer_t));
}
header->is_hole = true;
insertIntoIndex(header);
if ((u32int)footer == (m_end - sizeof(heap_footer_t)) and
header->size >= 0x2000 and (m_end - m_start > HEAP_MIN_SIZE)) {
contract();
}
m_mutex.unlock();
}
|
