MIRROR: javascript for 🐜's, a tiny runtime with big ambitions
optimize garbage collection, reduce stalls
+16
-25
-3
include/gc.h
-3
include/gc.h
···
2
2
#define GC_H
3
3
4
4
#include <types.h>
5
-
#include <stddef.h>
6
5
#include <stdbool.h>
7
6
8
7
#define ROPE_FLAG (1ULL << 63)
···
21
20
#define GC_FWD_LOAD_FACTOR 70
22
21
#define GC_ROOTS_INITIAL_CAP 32
23
22
#define GC_CB(ret, name, arg) ret (*name)(void *ctx, arg old)
24
-
25
-
size_t js_gc_compact(ant_t *js);
26
23
27
24
#define GC_CTX void *ctx
28
25
#define GC_FWD_OFF GC_CB(jsoff_t, fwd_off, jsoff_t)
+16
-22
src/gc.c
+16
-22
src/gc.c
···
675
675
}
676
676
}
677
677
678
-
size_t js_gc_compact(ant_t *js) {
679
-
if (!js || js->brk == 0) return 0;
680
-
if (js->brk < 2 * 1024 * 1024) return 0;
678
+
static void gc_compact(ant_t *js) {
679
+
js->needs_gc = false;
680
+
681
+
if (!js || js->brk == 0) return;
682
+
if (js->brk < 2 * 1024 * 1024) return;
681
683
682
684
if (!js->gc_safe) {
683
-
js->needs_gc = true;
684
-
return 0;
685
+
js->needs_gc = true; return;
685
686
}
686
687
687
688
mco_coro *running = mco_running();
688
689
int in_coroutine = (running != NULL && running->stack_base != NULL);
689
690
690
691
if (in_coroutine) {
691
-
js->needs_gc = true;
692
-
return 0;
692
+
js->needs_gc = true; return;
693
693
}
694
694
695
695
time_t now = time(NULL);
···
705
705
if (elapsed >= 0.0
706
706
&& elapsed < cooldown
707
707
&& js->gc_alloc_since < js->brk / 4
708
-
) return 0;
708
+
) return;
709
709
}
710
+
710
711
if (now != (time_t)-1) gc_last_run_time = now;
711
-
712
-
size_t old_brk = js->brk;
713
712
size_t new_size = js->size;
714
713
715
714
if (new_size > gc_scratch_size) {
···
718
717
gc_scratch_size = gc_scratch_buf ? new_size : 0;
719
718
}
720
719
721
-
if (!gc_scratch_buf) return 0;
720
+
if (!gc_scratch_buf) return;
722
721
uint8_t *new_mem = gc_scratch_buf;
723
722
724
723
size_t bitmap_size = (js->brk / 8 + 7) / 8 + 1;
725
724
uint8_t *mark_bits = (uint8_t *)calloc(1, bitmap_size);
726
-
if (!mark_bits) return 0;
725
+
if (!mark_bits) return;
727
726
728
727
size_t estimated_objs = js->brk / 64;
729
728
if (estimated_objs < 256) estimated_objs = 256;
···
736
735
ctx.mark_bits = mark_bits;
737
736
738
737
if (!fwd_init(&ctx.fwd, estimated_objs)) {
739
-
free(mark_bits);
740
-
return 0;
738
+
free(mark_bits); return;
741
739
}
742
740
743
741
if (!work_init(&ctx.work, estimated_objs / 4 < 64 ? 64 : estimated_objs / 4)) {
744
742
fwd_free(&ctx.fwd);
745
-
free(mark_bits);
746
-
return 0;
743
+
free(mark_bits); return;
747
744
}
748
745
749
746
ctx.failed = false;
···
765
762
if (ctx.failed) {
766
763
free(mark_bits);
767
764
work_free(&ctx.work);
768
-
fwd_free(&ctx.fwd);
769
-
return 0;
765
+
fwd_free(&ctx.fwd); return;
770
766
}
771
767
772
768
js_gc_update_roots(js,
···
795
791
if (target < ARENA_GROW_INCREMENT) target = ARENA_GROW_INCREMENT;
796
792
if (target < old_size) { ant_arena_decommit(js->mem, old_size, target); js->size = (jsoff_t)target; }
797
793
}
798
-
799
-
return (old_brk > new_brk ? old_brk - new_brk : 0);
800
794
}
801
795
802
796
void js_gc_maybe(ant_t *js) {
···
814
808
if (thresh > max_thresh) thresh = max_thresh;
815
809
816
810
if (js->gc_alloc_since > thresh || js->needs_gc) {
817
-
js->needs_gc = false;
818
-
if (js_gc_compact(js) > 0) js->gc_alloc_since = 0;
811
+
gc_compact(js);
812
+
js->gc_alloc_since = 0;
819
813
}
820
814
}