commit addd0615bfbc956ca0b9b7328955d0198218e2e7
author Aaron Patterson <tenderlove@ruby-lang.org> Wed Mar 10 13:54:04 2021 -0800
committer Aaron Patterson <tenderlove@ruby-lang.org> Wed Mar 10 13:54:04 2021 -0800
tree fbf82ddcb97d52c35d53b8cd268eab47636d9d6c
parent 43aca5761385db72e1e8d04997195a262314378a

Register mark objects so Protobuf is compaction friendly

This commit removes an unused reference and registers globals with the
GC so that they will never die.  Ruby is getting a compacting GC, and it
means that these references can move.  Registering them with
`rb_gc_register_mark_object` will ensure the constants don't move and
will not be collected.

ruby/ext/google/protobuf_c/protobuf.c

diff --git a/ruby/ext/google/protobuf_c/protobuf.c b/ruby/ext/google/protobuf_c/protobuf.c
index c27f30a..c9eecee 100644
--- a/ruby/ext/google/protobuf_c/protobuf.c
+++ b/ruby/ext/google/protobuf_c/protobuf.c
@@ -37,7 +37,7 @@
 #include "message.h"
 #include "repeated_field.h"
 
-VALUE cError;
+VALUE cParseError;
 VALUE cTypeError;
 
 const upb_fielddef* map_field_key(const upb_fielddef* field) {
@@ -368,8 +368,10 @@
   Map_register(protobuf);
   Message_register(protobuf);
 
-  cError = rb_const_get(protobuf, rb_intern("Error"));
+  cParseError = rb_const_get(protobuf, rb_intern("ParseError"));
+  rb_gc_register_mark_object(cParseError);
   cTypeError = rb_const_get(protobuf, rb_intern("TypeError"));
+  rb_gc_register_mark_object(cTypeError);
 
   rb_define_singleton_method(protobuf, "discard_unknown",
                              Google_Protobuf_discard_unknown, 1);