Fix object movement bugs (#638)

* Move objects around to check for movement bugs * Pin objects saved to C globals in init routines
ohler55 · Jan 23, 2021 · 6786984 · 6786984
1 parent 7ee1236
commit 6786984
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diff --git a/ext/oj/mimic_json.c b/ext/oj/mimic_json.c
@@ -841,6 +841,7 @@ oj_mimic_json_methods(VALUE json) {
     }
     // Pull in the JSON::State mimic file.
     state_class = rb_const_get_at(generator, rb_intern("State"));
+    rb_gc_register_mark_object(state_class);
 
     symbolize_names_sym = ID2SYM(rb_intern("symbolize_names"));	rb_gc_register_address(&symbolize_names_sym);
 }

diff --git a/ext/oj/oj.c b/ext/oj/oj.c
@@ -1649,13 +1649,21 @@ Init_oj() {
     rb_require("oj/schandler");
 
     oj_bag_class = rb_const_get_at(Oj, rb_intern("Bag"));
+    rb_gc_register_mark_object(oj_bag_class);
     oj_bigdecimal_class = rb_const_get(rb_cObject, rb_intern("BigDecimal"));
+    rb_gc_register_mark_object(oj_bigdecimal_class);
     oj_date_class = rb_const_get(rb_cObject, rb_intern("Date"));
+    rb_gc_register_mark_object(oj_date_class);
     oj_datetime_class = rb_const_get(rb_cObject, rb_intern("DateTime"));
+    rb_gc_register_mark_object(oj_datetime_class);
     oj_enumerable_class = rb_const_get(rb_cObject, rb_intern("Enumerable"));
+    rb_gc_register_mark_object(oj_enumerable_class);
     oj_parse_error_class = rb_const_get_at(Oj, rb_intern("ParseError"));
+    rb_gc_register_mark_object(oj_parse_error_class);
     oj_stringio_class = rb_const_get(rb_cObject, rb_intern("StringIO"));
+    rb_gc_register_mark_object(oj_stringio_class);
     oj_struct_class = rb_const_get(rb_cObject, rb_intern("Struct"));
+    rb_gc_register_mark_object(oj_struct_class);
     oj_json_parser_error_class = rb_eEncodingError;    // replaced if mimic is called
     oj_json_generator_error_class = rb_eEncodingError; // replaced if mimic is called
 

diff --git a/test/helper.rb b/test/helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+#
 # Ubuntu does not accept arguments to ruby when called using env. To get warnings to show up the -w options is
 # required. That can be set in the RUBYOPT environment variable.
 # export RUBYOPT=-w
@@ -16,6 +18,14 @@
 require 'pp'
 require 'oj'
 
+
+if defined?(GC.verify_compaction_references) == 'method'
+  # This method was added in Ruby 3.0.0. Calling it this way asks the GC to
+  # move objects around, helping to find object movement bugs.
+  GC.verify_compaction_references(double_heap: true, toward: :empty)
+end
+
+
 $ruby = RUBY_DESCRIPTION.split(' ')[0]
 $ruby = 'ree' if 'ruby' == $ruby && RUBY_DESCRIPTION.include?('Ruby Enterprise Edition')
 

diff --git a/test/json_gem/test_helper.rb b/test/json_gem/test_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $: << File.dirname(__FILE__)
 $oj_dir = File.dirname(File.dirname(File.expand_path(File.dirname(__FILE__))))
 %w(lib ext).each do |dir|
@@ -12,6 +14,12 @@
 else
   require 'oj'
   Oj.mimic_JSON
+
+  if defined?(GC.verify_compaction_references) == 'method'
+    # This method was added in Ruby 3.0.0. Calling it this way asks the GC to
+    # move objects around, helping to find object movement bugs.
+    GC.verify_compaction_references(double_heap: true, toward: :empty)
+  end
 end
 
 NaN = JSON::NaN if defined?(JSON::NaN)