Recently we added lots of write barriers in core and in popular extensions. This is just a meta issue to reference these PRs.

• ruby/ruby
  • Mark "method" objects as protected by write barrier ruby/ruby#7237
  • Mark "mapping_buffer" as write barrier protected ruby/ruby#7238
  • Enable write barriers on File::Stat ruby/ruby#7239
  • Implement Write Barrier for Backtrace::Location ruby/ruby#7240
  • Avoid using OBJ_WB_UNPROTECT ruby/ruby#7241
  • Mark Encoding as Write Barrier protected ruby/ruby#7254
  • Consider DATA objects without a mark function as protected ruby/ruby#7255
  • Implement Write Barrier for RMatch objects ruby/ruby#7286
  • Implement Write Barrier for autoload_data ruby/ruby#7392
  • Implement Write Barrier for autoload_table_type ruby/ruby#7402
  • Mark weak maps as write barrier protected ruby/ruby#7498
  • Implement Write Barrier for autoload_const_type ruby/ruby#7404
  • Make Time objects WB protected  ruby/ruby#7244
  • Keep shared arrays WB protected ruby/ruby#7224
  • Use write barriers for Backtrace objects ruby/ruby#7253
• StringIO Implement write barrier on StringIO ruby/stringio#44
• BigDecimal Make BigDecimal WB protected ruby/bigdecimal#248
• google-protobuf Ruby: Implement Write Barriers protocolbuffers/protobuf#11793
• oj Avoid using RARRAY_PTR ohler55/oj#842
• semian Enable write barrier protection on Resource semian#469
• ffi
  • Implement Write Barrier and dsize for FFI::FunctionType ffi/ffi#1001
  • Implement Write Barrier and dsize for FFI::Function ffi/ffi#1003
  • Implement Write Barrier and dsize for FFI::DynamicLibrary ffi/ffi#1004
  • Implement Write Barrier and dsize for FFI::Type ffi/ffi#1005
  • Implement Write Barrier and dsize for FFI::StructLayout ffi/ffi#1006
  • Implement Write Barrier and dsize for FFI::Struct ffi/ffi#1007
  • Implement Write Barrier and dsize for FFI::VariadicInvoker ffi/ffi#1008
  • Implement Write Barrier and dsize for FFI::StructByValue ffi/ffi#1009
  • Implement Write Barrier and dsize for FFI::Pointer ffi/ffi#1010
  • Implement the last missing Write Barriers and dsize ffi/ffi#1011
  • Convert FFI::VariadicInvoker to TypedData ffi/ffi#994
  • Convert FFI::Type and descendants to TypedData ffi/ffi#995
  • Convert FFI::ThreadData to TypedData ffi/ffi#996
  • Convert FFI::Struct::InlineArray to TypedData ffi/ffi#997
  • Convert FFI::AbstractMemory and descendants to TypedData ffi/ffi#998
  • Convert FFI::Struct to TypedData ffi/ffi#999
• nokogiri epic: update C extension to use the TypedData API sparklemotion/nokogiri#2808
• hiredis-client Implement Write Barriers for HiredisConnection redis-rb/redis-client#99
• liquid-c Avoid using RARRAY_PTR liquid-c#186
• memcached Avoid using RARRAY_PTR memcached#22