mach_msg_header_t

type mach_msg_header_t = record

  msgh_bits: mach_msg_bits_t;

  msgh_size: mach_msg_size_t;

  msgh_remote_port: mach_port_t;

  msgh_local_port: mach_port_t;

  msgh_reserved: mach_msg_size_t;

  msgh_id: mach_msg_id_t;

end;