fix shared array terminology.

Shared arrays created by Array#dup and so on points
a shared_root object to manage lifetime of Array buffer.
However, sometimes shared_root is called only shared so
it is confusing. So I fixed these wording "shared" to "shared_root".

* RArray::heap::aux::shared -> RArray::heap::aux::shared_root
* ARY_SHARED() -> ARY_SHARED_ROOT()
* ARY_SHARED_NUM() -> ARY_SHARED_ROOT_REFCNT()

Also, add some debug_counters to count shared array objects.

* ary_shared_create: shared ary by Array#dup and so on.
* ary_shared: finished in shard.
* ary_shared_root_occupied: shared_root but has only 1 refcnt.
  The number (ary_shared - ary_shared_root_occupied) is meaningful.

1 files changed, 3 insertions, 3 deletions

diff --git a/gc.c b/gc.c
index f1e9ecf47c..060e1ed48b 100644
--- a/gc.c
+++ b/gc.c
@@ -5083,7 +5083,7 @@ gc_mark_children(rb_objspace_t *objspace, VALUE obj)
 
       case T_ARRAY:
         if (FL_TEST(obj, ELTS_SHARED)) {
-            VALUE root = any->as.array.as.heap.aux.shared;
+            VALUE root = any->as.array.as.heap.aux.shared_root;
             gc_mark(objspace, root);
 	}
 	else {
@@ -8007,7 +8007,7 @@ gc_update_object_references(rb_objspace_t *objspace, VALUE obj)
 
       case T_ARRAY:
         if (FL_TEST(obj, ELTS_SHARED)) {
-            UPDATE_IF_MOVED(objspace, any->as.array.as.heap.aux.shared);
+            UPDATE_IF_MOVED(objspace, any->as.array.as.heap.aux.shared_root);
         }
         else {
             gc_ref_update_array(objspace, obj);
@@ -11219,7 +11219,7 @@ rb_raw_obj_info(char *buff, const int buff_size, VALUE obj)
 	  case T_ARRAY:
             if (FL_TEST(obj, ELTS_SHARED)) {
                 APPENDF((BUFF_ARGS, "shared -> %s",
-                         rb_obj_info(RARRAY(obj)->as.heap.aux.shared)));
+                         rb_obj_info(RARRAY(obj)->as.heap.aux.shared_root)));
             }
             else if (FL_TEST(obj, RARRAY_EMBED_FLAG)) {
                 APPENDF((BUFF_ARGS, "[%s%s] len: %d (embed)",