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, 1 insertions, 2 deletions

diff --git a/vm_core.h b/vm_core.h
index e62d43d4aa..73b6be52f6 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -225,8 +225,7 @@ struct iseq_inline_cache_entry {
 };
 
 struct iseq_inline_iv_cache_entry {
-    rb_serial_t ic_serial;
-    size_t index;
+    struct rb_iv_index_tbl_entry *entry;
 };
 
 union iseq_inline_storage_entry {