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
|
#ifndef UNIVERSAL_SERVICE_H
#define UNIVERSAL_SERVICE_H
/* Copyright (C) 2024 Peter McGoron
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include <stddef.h>
#if !defined(UNS_WORD) && __STDC_VERSION__ >= 199101L
# include <stdint.h>
# include <limits.h>
# define UNS_WORD uintptr_t
# define UNS_SIGNED_WORD intptr_t
# define UNS_WORD_MAX UINTPTR_MAX
# define UNS_SWORD_MAX INTPTR_MAX
# define UNS_SWORD_MIN INTPTR_MIN
#elif !defined(UNS_WORD)
# include <limits.h>
# define UNS_WORD unsigned long
# define UNS_WORD_MAX ULONG_MAX
# define UNS_SIGNED_WORD long
# define UNS_SWORD_MAX LONG_MAX
# define UNS_SWORD_MIN LONG_MIN
#endif
typedef UNS_WORD uns_word;
typedef UNS_SIGNED_WORD uns_sword;
/** Doubly linked list used to
*
* 1) Store roots of the GC,
* 2) Store GC pointers used in C and possibly not pointed-to anywhere
* else in GC space,
* 3) Preserve the location of a pointer after it moves.
*
* A root that is not a part of any GC MUST have ``prev`` and ``next``
* set to NULL.
*/
struct uns_ctr {
struct uns_ctr *prev;
void *p;
struct uns_ctr *next;
};
struct uns_gc {
void *ctx;
/* The collector only changes the pointer values of "p".
*
* * The collector never adds or removes roots.
* * The collector never rearranges the order of the container structures.
*
* The roots list can have repeated values.
*/
struct uns_ctr *roots;
size_t next_alloc;
void (*oom)(struct uns_gc *);
void (*after_gc)(struct uns_gc *);
size_t before_collection;
size_t after_collection;
long collection_number;
void (*deinit)(struct uns_gc *);
/* These functions, and only these functions, may invalidate
* pointers by either moving them or freeing them.
*/
int (*collect)(struct uns_gc *);
void *(*alloc)(struct uns_gc *, size_t);
void *(*alloc_record)(struct uns_gc *, size_t);
/* These functions MUST NOT cause collections. */
/* This function is optional. It is only provided if the GC can
* calculate the length of the pointer quickly.
*/
size_t (*len)(void *);
void (*record_set_ptr)(void *, size_t, void *);
void *(*record_get_ptr)(void *, size_t);
};
/** Add a root to the GC. The root must point to valid memory, or NULL. */
void uns_root_add(struct uns_gc *gc, struct uns_ctr *root);
/** Remove a root from the GC. It is OK to remove a root that is not a
* part of any GC using this function (the call will have no effect).
*/
void uns_root_remove(struct uns_gc *gc, struct uns_ctr *root);
#endif
|
