merge revision(s) e626da82eae3d437b84d4f9ead0164d436b08e1a, f3af5ae7e6c1c096bbfe46d69de825a02b1696cf: [Backport #20311]

	Don't pin named structs defined in Ruby

	[Bug #20311]

	`rb_define_class_under` assumes it's called from C and that the
	reference might be held in a C global variable, so it adds the
	class to the VM root.

	In the case of `Struct.new('Name')` it's wasteful and make
	the struct immortal.

	Make Struct memory leak test faster

	[Bug #20311]

	It times out on some platform, so we can reduce iterations.
	On my machine it completes in 250ms and RSS grows 8X.

1 files changed, 9 insertions, 4 deletions

diff --git a/struct.c b/struct.c
index f68c496728..8b7fea7f95 100644
--- a/struct.c
+++ b/struct.c
@@ -274,7 +274,7 @@ new_struct(VALUE name, VALUE super)
         rb_warn("redefining constant %"PRIsVALUE"::%"PRIsVALUE, super, name);
         rb_mod_remove_const(super, ID2SYM(id));
     }
-    return rb_define_class_id_under(super, id, super);
+    return rb_define_class_id_under_no_pin(super, id, super);
 }
 
 NORETURN(static void invalid_struct_pos(VALUE s, VALUE idx));
@@ -495,8 +495,13 @@ rb_struct_define(const char *name, ...)
     ary = struct_make_members_list(ar);
     va_end(ar);
 
-    if (!name) st = anonymous_struct(rb_cStruct);
-    else st = new_struct(rb_str_new2(name), rb_cStruct);
+    if (!name) {
+        st = anonymous_struct(rb_cStruct);
+    }
+    else {
+        st = new_struct(rb_str_new2(name), rb_cStruct);
+        rb_vm_add_root_module(st);
+    }
     return setup_struct(st, ary);
 }
 
@@ -510,7 +515,7 @@ rb_struct_define_under(VALUE outer, const char *name, ...)
     ary = struct_make_members_list(ar);
     va_end(ar);
 
-    return setup_struct(rb_define_class_under(outer, name, rb_cStruct), ary);
+    return setup_struct(rb_define_class_id_under(outer, rb_intern(name), rb_cStruct), ary);
 }
 
 /*