-#include <mach/std_types.h>
-#include <mach/kern_return.h>
-#include <mach/port.h>
-#include <mach/message.h>
-#include <mach/clock_types.h>
-
-extern kern_return_t clock_sleep_trap(
- mach_port_name_t clock_name,
- sleep_type_t sleep_type,
- int sleep_sec,
- int sleep_nsec,
- mach_timespec_t *wakeup_time);
-
-extern kern_return_t thread_switch(
- mach_port_name_t thread_name,
- int option,
- mach_msg_timeout_t option_time);