sync RClass::ext::iv_index_tbl

iv_index_tbl manages instance variable indexes (ID -> index).
This data structure should be synchronized with other ractors
so introduce some VM locks.

This patch also introduced atomic ivar cache used by
set/getinlinecache instructions. To make updating ivar cache (IVC),
we changed iv_index_tbl data structure to manage (ID -> entry)
and an entry points serial and index. IVC points to this entry so
that cache update becomes atomically.

1 files changed, 7 insertions, 1 deletions

diff --git a/internal/class.h b/internal/class.h
index bb12825162..eade920ff0 100644
--- a/internal/class.h
+++ b/internal/class.h
@@ -25,8 +25,14 @@ struct rb_subclass_entry {
     struct rb_subclass_entry *next;
 };
 
+struct rb_iv_index_tbl_entry {
+    uint32_t index;
+    rb_serial_t class_serial;
+    VALUE class_value;
+};
+
 struct rb_classext_struct {
-    struct st_table *iv_index_tbl;
+    struct st_table *iv_index_tbl; // ID -> struct rb_iv_index_tbl_entry
     struct st_table *iv_tbl;
 #if SIZEOF_SERIAL_T == SIZEOF_VALUE /* otherwise m_tbl is in struct RClass */
     struct rb_id_table *m_tbl;