High CPU usage on macOS Sierra

I am experiencing high CPU (95%) on macOS when connecting to a local Icecast server. The high CPU starts when a source connects, and remains even afer sources are no longer connected, until I restart the server.

Versions tested:

1. homebrew 2.4.2 with my custom config,
2. compiled from source 2.4.3 with default config.

When running within a virtualbox Ubuntu server instance, Icecast is behaving nicely.

I've ran a Instruments time + counter trace, data is available from https://dl.dropboxusercontent.com/u/70903/Icecast%20Instruments.zip and attached to this ticket.

It seems to show that 97% of the time fserve_client_waiting is doing a poll, not sure if this is normal I'm not experienced with this subject. 1 every millisecond if I'm reading the counter correctly.

[12:28] <+tbr> I guess this is something we should definitely look into.