diff options
Diffstat (limited to 'src/runtime/gc.c')
| -rw-r--r-- | src/runtime/gc.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/src/runtime/gc.c b/src/runtime/gc.c new file mode 100644 index 0000000..fcb5f89 --- /dev/null +++ b/src/runtime/gc.c @@ -0,0 +1,100 @@ +#include <lcq/pit/runtime/gc.h> + +static i64 gc_copy(pit_runtime *rt, pit_value_heavy *h) { + if (h->hsort == PIT_VALUE_HEAVY_SORT_FORWARDING_POINTER) { + return h->in.forwarding_pointer; + } else { + i64 ret = rt->backbuffer->next; + pit_value_heavy *g = pit_arena_alloc(rt->backbuffer); + *g = *h; + h->hsort = PIT_VALUE_HEAVY_SORT_FORWARDING_POINTER; + h->in.forwarding_pointer = ret; + return ret; + } +} +static pit_value gc_copy_value(pit_runtime *rt, pit_value v) { + if (pit_value_sort(v) == PIT_VALUE_SORT_REF) { + pit_ref r = pit_value_as_ref(rt, v); + pit_value_heavy *h = pit_value_ref_deref(rt, r); + i64 new = gc_copy(rt, h); + pit_annotated_ref *ann = pit_annotation_get(rt, r); + if (ann != NULL) { + pit_annotated_ref newann = *ann; + newann.ref = new; + if (pit_vec_push(pit_annotated_ref)(rt->backtrace, newann) < 0) + pit_error(rt, "annotation overflow"); + } + return pit_value_ref_new(rt, new); + } else { + return v; + } +} +void pit_gc(pit_runtime *rt) { + rt->frozen_values = 0; + rt->frozen_symtab = 0; + pit_arena *fromspace = rt->heap; + pit_arena *tospace = rt->backbuffer; + pit_vec(pit_annotated_ref) *fromspace_ann = rt->annotations; + pit_vec(pit_annotated_ref) *tospace_ann = rt->backtrace; + pit_arena_reset(tospace); + pit_vec_reset(pit_annotated_ref)(tospace_ann); + /* populate tospace with immediately reachable values */ + for (i64 i = 0; i < rt->symtab->next; ++i) { + pit_symtab_entry *ent = pit_vec_get(pit_symtab_entry)(rt->symtab, i); + if (ent == NULL) continue; /* TODO warn on failure here? */ + ent->name = gc_copy_value(rt, ent->name); + ent->value = gc_copy_value(rt, ent->value); + ent->function = gc_copy_value(rt, ent->function); + } + for (i64 i = 0; i < rt->saved_bindings->next; ++i) { + pit_value *v = pit_vec_get(pit_value)(rt->saved_bindings, i); + if (v != NULL) *v = gc_copy_value(rt, *v); /* TODO warn on failure here? */ + } + for (i64 scan = 0; scan < tospace->next; ++scan) { + pit_value_heavy *h = pit_arena_get(tospace, scan); + switch (h->hsort) { + case PIT_VALUE_HEAVY_SORT_CELL: + h->in.cell = gc_copy_value(rt, h->in.cell); + break; + case PIT_VALUE_HEAVY_SORT_CONS: + h->in.cons.car = gc_copy_value(rt, h->in.cons.car); + h->in.cons.cdr = gc_copy_value(rt, h->in.cons.cdr); + break; + case PIT_VALUE_HEAVY_SORT_ARRAY: { + i64 byte_len = 0; pit_mul(&byte_len, sizeof(pit_value), h->in.array.len); + pit_value *data = pit_arena_alloc_back(tospace, byte_len); + for (i64 i = 0; i < h->in.array.len; ++i) { + data[i] = gc_copy_value(rt, h->in.array.data[i]); + } + h->in.array.data = data; + break; + } + case PIT_VALUE_HEAVY_SORT_BYTES: { + u8 *data = pit_arena_alloc_back(tospace, h->in.bytes.len); + for (i64 i = 0; i < h->in.bytes.len; ++i) { + data[i] = h->in.bytes.data[i]; + } + h->in.bytes.data = data; + break; + } + case PIT_VALUE_HEAVY_SORT_FUNC: + h->in.func.env = gc_copy_value(rt, h->in.func.env); + h->in.func.args = gc_copy_value(rt, h->in.func.args); + h->in.func.arg_rest_nm = gc_copy_value(rt, h->in.func.arg_rest_nm); + h->in.func.body = gc_copy_value(rt, h->in.func.body); + break; + case PIT_VALUE_HEAVY_SORT_NATIVEFUNC: break; + case PIT_VALUE_HEAVY_SORT_NATIVEDATA: + h->in.nativedata.tag = gc_copy_value(rt, h->in.nativedata.tag); + break; + case PIT_VALUE_HEAVY_SORT_FORWARDING_POINTER: + pit_error(rt, "garbage collection broken! encountered forwarding pointer in to-space"); + break; + } + } + rt->heap = tospace; + rt->backbuffer = fromspace; + rt->annotations = tospace_ann; + rt->backtrace = fromspace_ann; + pit_vec_reset(pit_annotated_ref)(rt->backtrace); +} |