ruby_multi_ractor was a flag that indicates the interpreter doesn't make any additional ractors (single ractor mode). Instead of boolean flag, ruby_single_main_ractor pointer is introduced which keeps main ractor's pointer if single ractor mode. If additional ractors are created, ruby_single_main_ractor becomes NULL.
Added by ko1 (Koichi Sasada) almost 5 years ago
ruby_single_main_ractor for single ractor mode
ruby_multi_ractor was a flag that indicates the interpreter doesn't
make any additional ractors (single ractor mode).
Instead of boolean flag, ruby_single_main_ractor pointer is introduced
which keeps main ractor's pointer if single ractor mode. If additional
ractors are created, ruby_single_main_ractor becomes NULL.