From e58814d150b0652f5e11958b36b85d977fdd0426 Mon Sep 17 00:00:00 2001 From: Aaron Patterson Date: Wed, 6 Nov 2019 15:12:28 -0800 Subject: Revert "Use a monotonically increasing number for object_id" This reverts commit bd2b314a05ae9192b3143e1e678a37c370d8a9ce. --- gc.c | 138 ++++++++++++++++++++++++++++++++++--------------------------------- 1 file changed, 70 insertions(+), 68 deletions(-) (limited to 'gc.c') diff --git a/gc.c b/gc.c index a92a875c99..5a4f72d9ff 100644 --- a/gc.c +++ b/gc.c @@ -700,7 +700,6 @@ typedef struct rb_objspace { rb_event_flag_t hook_events; size_t total_allocated_objects; - VALUE next_object_id; rb_heap_t eden_heap; rb_heap_t tomb_heap; /* heap for zombies and ghosts */ @@ -748,6 +747,7 @@ typedef struct rb_objspace { #if USE_RGENGC size_t minor_gc_count; size_t major_gc_count; + size_t object_id_collisions; #if RGENGC_PROFILE > 0 size_t total_generated_normal_object_count; size_t total_generated_shady_object_count; @@ -2846,41 +2846,12 @@ obj_free(rb_objspace_t *objspace, VALUE obj) } } - -#define OBJ_ID_INCREMENT (sizeof(RVALUE) / 2) -#define OBJ_ID_INITIAL (OBJ_ID_INCREMENT * 2) - -static int -object_id_cmp(st_data_t x, st_data_t y) -{ - if (RB_TYPE_P(x, T_BIGNUM)) { - return !rb_big_eql(x, y); - } else { - return x != y; - } -} - -static st_index_t -object_id_hash(st_data_t n) -{ - if (RB_TYPE_P(n, T_BIGNUM)) { - return FIX2LONG(rb_big_hash(n)); - } else { - return st_numhash(n); - } -} -static const struct st_hash_type object_id_hash_type = { - object_id_cmp, - object_id_hash, -}; - void Init_heap(void) { rb_objspace_t *objspace = &rb_objspace; - objspace->next_object_id = INT2FIX(OBJ_ID_INITIAL); - objspace->id_to_obj_tbl = st_init_table(&object_id_hash_type); + objspace->id_to_obj_tbl = st_init_numtable(); objspace->obj_to_id_tbl = st_init_numtable(); #if RGENGC_ESTIMATE_OLDMALLOC @@ -3605,33 +3576,37 @@ id2ref(VALUE obj, VALUE objid) VALUE orig; void *p0; - if (FIXNUM_P(objid) || rb_big_size(objid) <= SIZEOF_VOIDP) { - ptr = NUM2PTR(objid); - if (ptr == Qtrue) return Qtrue; - if (ptr == Qfalse) return Qfalse; - if (ptr == Qnil) return Qnil; - if (FIXNUM_P(ptr)) return (VALUE)ptr; - if (FLONUM_P(ptr)) return (VALUE)ptr; - - ptr = obj_id_to_ref(objid); - if ((ptr % sizeof(RVALUE)) == (4 << 2)) { - ID symid = ptr / sizeof(RVALUE); - p0 = (void *)ptr; - if (rb_id2str(symid) == 0) - rb_raise(rb_eRangeError, "%p is not symbol id value", p0); - return ID2SYM(symid); - } - } + ptr = NUM2PTR(objid); + p0 = (void *)ptr; + + if (ptr == Qtrue) return Qtrue; + if (ptr == Qfalse) return Qfalse; + if (ptr == Qnil) return Qnil; + if (FIXNUM_P(ptr)) return (VALUE)ptr; + if (FLONUM_P(ptr)) return (VALUE)ptr; + ptr = obj_id_to_ref(objid); - if (st_lookup(objspace->id_to_obj_tbl, objid, &orig)) { + if (st_lookup(objspace->id_to_obj_tbl, ptr, &orig)) { return orig; } - if (rb_int_ge(objid, objspace->next_object_id)) { - rb_raise(rb_eRangeError, "%+"PRIsVALUE" is not id value", rb_int2str(objid, 10)); - } else { - rb_raise(rb_eRangeError, "%+"PRIsVALUE" is recycled object", rb_int2str(objid, 10)); + if ((ptr % sizeof(RVALUE)) == (4 << 2)) { + ID symid = ptr / sizeof(RVALUE); + if (rb_id2str(symid) == 0) + rb_raise(rb_eRangeError, "%p is not symbol id value", p0); + return ID2SYM(symid); + } + + if (!is_id_value(objspace, ptr)) { + rb_raise(rb_eRangeError, "%p is not id value", p0); + } + if (!is_live_object(objspace, ptr)) { + rb_raise(rb_eRangeError, "%p is recycled object", p0); + } + if (RBASIC(ptr)->klass == 0) { + rb_raise(rb_eRangeError, "%p is internal object", p0); } + return (VALUE)ptr; } static VALUE @@ -3662,20 +3637,27 @@ cached_object_id(VALUE obj) if (st_lookup(objspace->obj_to_id_tbl, (st_data_t)obj, &id)) { GC_ASSERT(FL_TEST(obj, FL_SEEN_OBJ_ID)); - return id; + return nonspecial_obj_id(id); } else { GC_ASSERT(!FL_TEST(obj, FL_SEEN_OBJ_ID)); + id = obj; - id = objspace->next_object_id; - objspace->next_object_id = rb_int_plus(id, INT2FIX(OBJ_ID_INCREMENT)); - - st_insert(objspace->obj_to_id_tbl, (st_data_t)obj, (st_data_t)id); - st_insert(objspace->id_to_obj_tbl, (st_data_t)id, (st_data_t)obj); - FL_SET(obj, FL_SEEN_OBJ_ID); - - return id; + while (1) { + /* id is the object id */ + if (st_is_member(objspace->id_to_obj_tbl, (st_data_t)id)) { + objspace->profile.object_id_collisions++; + id += sizeof(VALUE); + } + else { + st_insert(objspace->obj_to_id_tbl, (st_data_t)obj, (st_data_t)id); + st_insert(objspace->id_to_obj_tbl, (st_data_t)id, (st_data_t)obj); + FL_SET(obj, FL_SEEN_OBJ_ID); + return nonspecial_obj_id(id); + } + } } + return nonspecial_obj_id(obj); } static VALUE @@ -5584,10 +5566,6 @@ gc_mark_roots(rb_objspace_t *objspace, const char **categoryp) MARK_CHECKPOINT("global_tbl"); rb_gc_mark_global_tbl(); - MARK_CHECKPOINT("object_id"); - rb_gc_mark(objspace->next_object_id); - mark_tbl_no_pin(objspace, objspace->obj_to_id_tbl); /* Only mark ids */ - if (stress_to_class) rb_gc_mark(stress_to_class); MARK_CHECKPOINT("finish"); @@ -7573,6 +7551,18 @@ gc_is_moveable_obj(rb_objspace_t *objspace, VALUE obj) return FALSE; } +static int +update_id_to_obj(st_data_t *key, st_data_t *value, st_data_t arg, int exists) +{ + if (exists) { + *value = arg; + return ST_CONTINUE; + } + else { + return ST_STOP; + } +} + static VALUE gc_move(rb_objspace_t *objspace, VALUE scan, VALUE free, VALUE moved_list) { @@ -7606,6 +7596,17 @@ gc_move(rb_objspace_t *objspace, VALUE scan, VALUE free, VALUE moved_list) rb_mv_generic_ivar((VALUE)src, (VALUE)dest); } + VALUE id; + + /* If the source object's object_id has been seen, we need to update + * the object to object id mapping. */ + if (st_lookup(objspace->obj_to_id_tbl, (VALUE)src, &id)) { + gc_report(4, objspace, "Moving object with seen id: %p -> %p\n", (void *)src, (void *)dest); + st_delete(objspace->obj_to_id_tbl, (st_data_t *)&src, 0); + st_insert(objspace->obj_to_id_tbl, (VALUE)dest, id); + st_update(objspace->id_to_obj_tbl, (st_data_t)id, update_id_to_obj, (st_data_t)dest); + } + /* Move the object */ memcpy(dest, src, sizeof(RVALUE)); memset(src, 0, sizeof(RVALUE)); @@ -8427,8 +8428,6 @@ gc_update_references(rb_objspace_t * objspace) rb_transient_heap_update_references(); global_symbols.ids = rb_gc_location(global_symbols.ids); global_symbols.dsymbol_fstr_hash = rb_gc_location(global_symbols.dsymbol_fstr_hash); - gc_update_table_refs(objspace, objspace->obj_to_id_tbl); - gc_update_table_refs(objspace, objspace->id_to_obj_tbl); gc_update_table_refs(objspace, global_symbols.str_sym); gc_update_table_refs(objspace, finalizer_table); } @@ -8886,6 +8885,7 @@ enum gc_stat_sym { #if USE_RGENGC gc_stat_sym_minor_gc_count, gc_stat_sym_major_gc_count, + gc_stat_sym_object_id_collisions, gc_stat_sym_remembered_wb_unprotected_objects, gc_stat_sym_remembered_wb_unprotected_objects_limit, gc_stat_sym_old_objects, @@ -8961,6 +8961,7 @@ setup_gc_stat_symbols(void) S(malloc_increase_bytes_limit); #if USE_RGENGC S(minor_gc_count); + S(object_id_collisions); S(major_gc_count); S(remembered_wb_unprotected_objects); S(remembered_wb_unprotected_objects_limit); @@ -9133,6 +9134,7 @@ gc_stat_internal(VALUE hash_or_sym) SET(malloc_increase_bytes_limit, malloc_limit); #if USE_RGENGC SET(minor_gc_count, objspace->profile.minor_gc_count); + SET(object_id_collisions, objspace->profile.object_id_collisions); SET(major_gc_count, objspace->profile.major_gc_count); SET(remembered_wb_unprotected_objects, objspace->rgengc.uncollectible_wb_unprotected_objects); SET(remembered_wb_unprotected_objects_limit, objspace->rgengc.uncollectible_wb_unprotected_objects_limit); 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