getiopolicy_np(3) on macOS

The text 87ad11f7ff03, as Mac OS X 10.8.5, Mac OS X 10.8.4, Mac OS X 10.8.3, Mac OS X 10.8.2, Mac OS X 10.8.1, Mac OS X 10.8 shipped it.

manipulate the I/O policy of a process or thread

getiopolicy_np(3) on macOS now