add SET_SHAREABLE macros

* `RB_OBJ_SET_SHAREABLE(obj)` makes obj shareable.
  All of reachable objects from `obj` should be shareable.
* `RB_OBJ_SET_FROZEN_SHAREABLE(obj)` same as above
  but freeze `obj` before making it shareable.

Also `rb_gc_verify_shareable(obj)` is introduced to check
the `obj` does not violate shareable rule (an shareable object
only refers shareable objects) strictly.

The rule has some exceptions (some shareable objects can refer to
unshareable objects, such as a Ractor object (which is a shareable
object) can refer to the Ractor local objects.
To handle such case, `check_shareable` flag is also introduced.

`STRICT_VERIFY_SHAREABLE` macro is also introduced to verify
the strict shareable rule at `SET_SHAREABLE`.

1 files changed, 14 insertions, 0 deletions

diff --git a/include/ruby/ractor.h b/include/ruby/ractor.h
index 7811616f6d..85222bbe11 100644
--- a/include/ruby/ractor.h
+++ b/include/ruby/ractor.h
@@ -261,4 +261,18 @@ rb_ractor_shareable_p(VALUE obj)
     }
 }
 
+// TODO: optimize on interpreter core
+#ifndef RB_OBJ_SET_SHAREABLE
+VALUE rb_obj_set_shareable(VALUE obj); // ractor.c
+#define RB_OBJ_SET_SHAREABLE(obj) rb_obj_set_shareable(obj)
+#endif
+
+static inline VALUE
+RB_OBJ_SET_FROZEN_SHAREABLE(VALUE obj)
+{
+    RB_OBJ_FREEZE(obj);
+    RB_OBJ_SET_SHAREABLE(obj);
+    return obj;
+}
+
 #endif /* RUBY_RACTOR_H */