Listen backlog for stream servers


Listen backlog in Nginx defaults to NGX_LISTEN_BACKLOG=511 on Linux &
other platforms (excepting FreeBSD & MacOS), not to system somaxconn
(why does it differ for different OSes?).

It’s not a problem to increase it using «backlog» option of «listen»
directive for HTTP servers
(Module ngx_http_core_module),
but there is no such option for stream server
(Module ngx_stream_core_module).

Is there any proper way to increase listen queue length for stream
server (without patching source code) or globally? Seems to be a subject
to fix.