Files
mruby-mruby/include/mruby/gc.h
T
Yukihiro "Matz" Matsumoto 31fea1709f gc.c: replace gcnext gray linked list with fixed-size gray stack
remove per-object gcnext pointer from MRB_OBJECT_HEADER, saving one
word (8 bytes on 64-bit) per object slot. the gray list for tri-color
marking is replaced by a fixed-size stack (MRB_GRAY_STACK_SIZE=1024)
in mrb_gc. when the stack overflows, a linear heap rescan recovers
gray objects.

object slot size: 48 -> 40 bytes (16.7% reduction on 64-bit).
benchmarks show up to 12% RSS reduction on object-heavy workloads
with neutral performance impact.

Co-authored-by: Claude <noreply@anthropic.com>
2026-02-12 13:38:21 +09:00

78 lines
2.4 KiB
C

/**
** @file mruby/gc.h - garbage collector for mruby
**
** See Copyright Notice in mruby.h
*/
#ifndef MRUBY_GC_H
#define MRUBY_GC_H
#include "common.h"
/**
* Uncommon memory management stuffs.
*/
MRB_BEGIN_DECL
struct mrb_state;
#define MRB_EACH_OBJ_OK 0
#define MRB_EACH_OBJ_BREAK 1
typedef int (mrb_each_object_callback)(struct mrb_state *mrb, struct RBasic *obj, void *data);
void mrb_objspace_each_objects(struct mrb_state *mrb, mrb_each_object_callback *callback, void *data);
size_t mrb_objspace_page_slot_size(void);
MRB_API void mrb_free_context(struct mrb_state *mrb, struct mrb_context *c);
#ifndef MRB_GC_ARENA_SIZE
#define MRB_GC_ARENA_SIZE 100
#endif
#ifndef MRB_GRAY_STACK_SIZE
#define MRB_GRAY_STACK_SIZE 1024
#endif
typedef enum {
MRB_GC_STATE_ROOT = 0,
MRB_GC_STATE_MARK,
MRB_GC_STATE_SWEEP
} mrb_gc_state;
typedef struct mrb_gc {
struct mrb_heap_page *heaps; /* all heaps pages */
struct mrb_heap_page *free_heaps;/* heaps for allocation */
struct mrb_heap_page *sweeps; /* page where sweep starts */
struct RBasic *gray_stack[MRB_GRAY_STACK_SIZE]; /* stack of gray objects */
size_t gray_stack_top; /* top index of gray stack */
mrb_bool gray_overflow:1; /* gray stack overflowed; needs heap rescan */
size_t live; /* count of live objects */
size_t live_after_mark; /* old generation objects */
size_t threshold; /* threshold to start GC */
size_t oldgen_threshold; /* threshold to kick major GC */
mrb_gc_state state; /* current state of gc */
int interval_ratio;
int step_ratio;
int current_white_part :2; /* make white object by white_part */
mrb_bool iterating :1; /* currently iterating over objects */
mrb_bool disabled :1; /* GC disabled */
mrb_bool generational :1; /* generational GC mode */
mrb_bool full :1; /* major GC mode */
mrb_bool out_of_memory :1; /* out-of-memory error occurred */
#ifdef MRB_GC_FIXED_ARENA
struct RBasic *arena[MRB_GC_ARENA_SIZE]; /* GC protection array */
#else
struct RBasic **arena; /* GC protection array */
int arena_capa; /* size of protection array */
#endif
int arena_idx;
} mrb_gc;
MRB_API mrb_bool mrb_object_dead_p(struct mrb_state *mrb, struct RBasic *object);
#define MRB_GC_RED 7
MRB_END_DECL
#endif /* MRUBY_GC_H */