Add generic ivar reference updating step

Previously, generic ivars worked differently than the other global tables
during compaction. The other global tables had their references updated
through iteration during rb_gc_update_vm_references. Generic ivars updated
the keys when the object moved and updated the values while reference
updating the object. This is inefficient as this required one lookup for
every moved object and one lookup for every object with generic ivars.

Instead, this commit changes it to iterate over the generic ivar table to
update both the keys and values.

1 files changed, 26 insertions, 17 deletions

diff --git a/variable.c b/variable.c
index 66b960cabe..9def7645ae 100644
--- a/variable.c
+++ b/variable.c
@@ -1136,31 +1136,40 @@ rb_mark_generic_ivar(VALUE obj)
     }
 }
 
-void
-rb_ref_update_generic_ivar(VALUE obj)
+static int
+rb_generic_ivar_update_references_i(st_data_t key, st_data_t val, st_data_t _data)
 {
-    struct gen_ivtbl *ivtbl;
+    VALUE orig_obj = (VALUE)key;
+    VALUE obj = rb_gc_location(orig_obj);
+    struct gen_ivtbl *ivtbl = (struct gen_ivtbl *)val;
 
-    if (rb_gen_ivtbl_get(obj, 0, &ivtbl)) {
-        if (rb_shape_obj_too_complex(obj)) {
-            rb_gc_ref_update_table_values_only(ivtbl->as.complex.table);
-        }
-        else {
-            for (uint32_t i = 0; i < ivtbl->as.shape.numiv; i++) {
-                ivtbl->as.shape.ivptr[i] = rb_gc_location(ivtbl->as.shape.ivptr[i]);
-            }
+    if (rb_shape_obj_too_complex(obj)) {
+        rb_gc_ref_update_table_values_only(ivtbl->as.complex.table);
+    }
+    else {
+        for (uint32_t i = 0; i < ivtbl->as.shape.numiv; i++) {
+            ivtbl->as.shape.ivptr[i] = rb_gc_location(ivtbl->as.shape.ivptr[i]);
         }
     }
+
+    if (obj != orig_obj) {
+        st_insert(generic_iv_tbl_, (st_data_t)obj, (st_data_t)ivtbl);
+
+        return ST_DELETE;
+    }
+    else {
+        return ST_CONTINUE;
+    }
 }
 
 void
-rb_mv_generic_ivar(VALUE rsrc, VALUE dst)
+rb_generic_ivar_update_references(void)
 {
-    st_data_t key = (st_data_t)rsrc;
-    st_data_t ivtbl;
-
-    if (st_delete(generic_ivtbl_no_ractor_check(rsrc), &key, &ivtbl))
-        st_insert(generic_ivtbl_no_ractor_check(dst), (st_data_t)dst, ivtbl);
+    DURING_GC_COULD_MALLOC_REGION_START();
+    {
+        st_foreach(generic_iv_tbl_, rb_generic_ivar_update_references_i, (st_data_t)0);
+    }
+    DURING_GC_COULD_MALLOC_REGION_END();
 }
 
 void