blob: 22216165e799b64e8d2e60cc2ccb956e0e9da78c (
plain) (
blame)
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
|
#include "arena.h"
struct block {
size_t size;
size_t used;
struct block *next;
char data_start[];
};
static const size_t min_block_room = 16 * 1024 - sizeof(struct block);
static void add_block(struct arena* a, size_t room_wanted)
{
if (room_wanted < min_block_room) {
room_wanted = min_block_room;
}
struct block *new_block = malloc(sizeof(struct block) + room_wanted);
new_block->size = room_wanted;
new_block->used = 0;
new_block->next = a->cur_block;
a->cur_block = new_block;
}
void arena_init(struct arena *a)
{
a->cur_block = NULL;
}
void* arena_malloc(struct arena *a, size_t amount)
{
struct block* b = a->cur_block;
if (b == NULL || b->size - b->used < amount) {
add_block(a, amount);
b = a->cur_block;
}
void* result = &b->data_start[b->used];
b->used += amount;
return result;
}
void arena_free(struct arena *a)
{
struct block* b = a->cur_block;
while (b != NULL) {
struct block* next = b->next;
free(b);
b = next;
}
a->cur_block = NULL;
}
|
