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author | Bad Diode <bd@badd10de.dev> | 2021-10-15 17:58:05 +0200 |
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committer | Bad Diode <bd@badd10de.dev> | 2021-10-15 17:58:05 +0200 |
commit | 87b1a0d4a833dd0b2164481be45f7d1c59375040 (patch) | |
tree | 87828c2149c7db2880b22a306b2c5d3511185cae /src/bootstrap/gc.c | |
parent | 14814ecbf53760654aab34e0613abf347a54113f (diff) | |
download | bdl-87b1a0d4a833dd0b2164481be45f7d1c59375040.tar.gz bdl-87b1a0d4a833dd0b2164481be45f7d1c59375040.zip |
Add boilerplate for GC allocator
Diffstat (limited to 'src/bootstrap/gc.c')
-rw-r--r-- | src/bootstrap/gc.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/src/bootstrap/gc.c b/src/bootstrap/gc.c new file mode 100644 index 0000000..fff4201 --- /dev/null +++ b/src/bootstrap/gc.c | |||
@@ -0,0 +1,48 @@ | |||
1 | typedef struct GC { | ||
2 | Object *obj_list; | ||
3 | // Free list keeps track of the offset numbers from the obj_list | ||
4 | size_t *free_list; | ||
5 | size_t obj_size; | ||
6 | size_t obj_cap; | ||
7 | size_t fl_pos; | ||
8 | size_t available_slots; | ||
9 | } GC; | ||
10 | |||
11 | // FIXME: small value for testing purposes | ||
12 | #define GC_INITIAL_HEAP 100000 | ||
13 | |||
14 | static GC gc; | ||
15 | |||
16 | void | ||
17 | init_gc(void) { | ||
18 | gc = (GC){ | ||
19 | .obj_cap = GC_INITIAL_HEAP, | ||
20 | .available_slots = GC_INITIAL_HEAP, | ||
21 | }; | ||
22 | gc.free_list = malloc(GC_INITIAL_HEAP * sizeof(size_t *)); | ||
23 | gc.obj_list = malloc(GC_INITIAL_HEAP * sizeof(Object *)); | ||
24 | |||
25 | // The free list stores the offset from the initial position for all | ||
26 | // available slots. | ||
27 | for (size_t i = 0; i < gc.obj_cap; i++) { | ||
28 | gc.free_list[i] = i; | ||
29 | } | ||
30 | } | ||
31 | |||
32 | Object * | ||
33 | alloc_object(ObjectType type) { | ||
34 | if (gc.available_slots == 0) { | ||
35 | // TODO: trigger garbage collection. | ||
36 | if (gc.available_slots == 0) { | ||
37 | // TODO: grow heap tables. | ||
38 | // NOTE: When growing the tables, we might lose the pointer | ||
39 | // references! Should we work with offsets all the way? That is for | ||
40 | // cdr and car? Should we have a utility function? | ||
41 | } | ||
42 | } | ||
43 | size_t slot = gc.free_list[gc.fl_pos++]; | ||
44 | gc.available_slots--; | ||
45 | Object *obj = gc.obj_list + slot; | ||
46 | obj->type = type; | ||
47 | return obj; | ||
48 | } | ||