diff options
| -rw-r--r-- | src/cow_ws.erl | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/src/cow_ws.erl b/src/cow_ws.erl index bf315eb..a4b7933 100644 --- a/src/cow_ws.erl +++ b/src/cow_ws.erl @@ -151,12 +151,27 @@ init_permessage_deflate(InflateWindowBits, DeflateWindowBits, Opts) -> maps:get(mem_level, Opts, 8), maps:get(strategy, Opts, default)), %% Set the owner pid of the zlib contexts if requested. + %% + %% The zlib port became a reference in OTP 20.1+. There + %% was however no way to change the controlling process + %% until the OTP 20.1.3 patch version. Since we can't + %% enable compression for 20.1, 20.1.1 and 20.1.2 we + %% explicitly crash. The caller should ignore this extension. _ = case Opts of - #{owner := Pid} -> + #{owner := Pid} when is_port(Inflate) -> true = erlang:port_connect(Inflate, Pid), true = unlink(Inflate), true = erlang:port_connect(Deflate, Pid), unlink(Deflate); + #{owner := Pid} -> + case erlang:function_exported(zlib, set_controlling_process, 2) of + true -> + zlib:set_controlling_process(Inflate, Pid), + zlib:set_controlling_process(Deflate, Pid); + false -> + exit({error, incompatible_zlib_version, + 'OTP 20.1, 20.1.1 and 20.1.2 are missing required functionality.'}) + end; _ -> true end, |