This section describes the Mach interface to a host executing a Mach kernel. The interface allows to query statistics about a host and control its behaviour.
A host is represented by two ports, a name port host used to query information about the host accessible to everyone, and a control port host_priv used to manipulate it. For example, you can query the current time using the name port, but to change the time you need to send a message to the host control port.
Everything described in this section is declared in the header file mach.h.