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
|
package common
import "core:mem"
import "core:runtime"
Scratch_Allocator :: struct {
data: []byte,
curr_offset: int,
prev_allocation: rawptr,
backup_allocator: mem.Allocator,
leaked_allocations: [dynamic][]byte,
}
scratch_allocator_init :: proc(
s: ^Scratch_Allocator,
size: int,
backup_allocator := context.allocator,
) {
s.data, _ = mem.make_aligned(
[]byte,
size,
2 * align_of(rawptr),
backup_allocator,
)
s.curr_offset = 0
s.prev_allocation = nil
s.backup_allocator = backup_allocator
s.leaked_allocations.allocator = backup_allocator
}
scratch_allocator_destroy :: proc(s: ^Scratch_Allocator) {
if s == nil {
return
}
for ptr in s.leaked_allocations {
mem.free_bytes(ptr, s.backup_allocator)
}
delete(s.leaked_allocations)
delete(s.data, s.backup_allocator)
s^ = {}
}
scratch_allocator_proc :: proc(
allocator_data: rawptr,
mode: mem.Allocator_Mode,
size, alignment: int,
old_memory: rawptr,
old_size: int,
loc := #caller_location,
) -> (
[]byte,
mem.Allocator_Error,
) {
s := (^Scratch_Allocator)(allocator_data)
if s.data == nil {
DEFAULT_BACKING_SIZE :: 1 << 22
if !(context.allocator.procedure != scratch_allocator_proc &&
context.allocator.data != allocator_data) {
panic("cyclic initialization of the scratch allocator with itself")
}
scratch_allocator_init(s, DEFAULT_BACKING_SIZE)
}
size := size
switch mode {
case .Alloc, .Alloc_Non_Zeroed:
size = mem.align_forward_int(size, alignment)
switch {
case s.curr_offset + size <= len(s.data):
start := uintptr(raw_data(s.data))
ptr := start + uintptr(s.curr_offset)
ptr = mem.align_forward_uintptr(ptr, uintptr(alignment))
mem.zero(rawptr(ptr), size)
s.prev_allocation = rawptr(ptr)
offset := int(ptr - start)
s.curr_offset = offset + size
return mem.byte_slice(rawptr(ptr), size), nil
}
a := s.backup_allocator
if a.procedure == nil {
a = context.allocator
s.backup_allocator = a
}
ptr, err := mem.alloc_bytes(size, alignment, a, loc)
if err != nil {
return ptr, err
}
if s.leaked_allocations == nil {
s.leaked_allocations = make([dynamic][]byte, a)
}
append(&s.leaked_allocations, ptr)
if logger := context.logger; logger.lowest_level <= .Warning {
if logger.procedure != nil {
logger.procedure(
logger.data,
.Warning,
"mem.Scratch_Allocator resorted to backup_allocator",
logger.options,
loc,
)
}
}
return ptr, err
case .Free:
case .Free_All:
s.curr_offset = 0
s.prev_allocation = nil
for ptr in s.leaked_allocations {
mem.free_bytes(ptr, s.backup_allocator)
}
clear(&s.leaked_allocations)
case .Resize, .Resize_Non_Zeroed:
begin := uintptr(raw_data(s.data))
end := begin + uintptr(len(s.data))
old_ptr := uintptr(old_memory)
data, err := scratch_allocator_proc(
allocator_data,
.Alloc,
size,
alignment,
old_memory,
old_size,
loc,
)
if err != nil {
return data, err
}
runtime.copy(data, mem.byte_slice(old_memory, old_size))
_, err = scratch_allocator_proc(
allocator_data,
.Free,
0,
alignment,
old_memory,
old_size,
loc,
)
return data, err
case .Query_Features:
set := (^mem.Allocator_Mode_Set)(old_memory)
if set != nil {
set^ = {.Alloc, .Free, .Free_All, .Resize, .Query_Features}
}
return nil, nil
case .Query_Info:
return nil, nil
}
return nil, nil
}
scratch_allocator :: proc(allocator: ^Scratch_Allocator) -> mem.Allocator {
return mem.Allocator{procedure = scratch_allocator_proc, data = allocator}
}
|
