KernelTime

Overview

#include <time.h>

Time in seconds

unix time() - just the same old true unix time(). not recommended, of course

Time in microseconds

bigtime_t hal_system_time(void); - useconds from kernel boot

bigtime_t hal_local_time(void); - absolute time in useconds - NB! Base?

Sleep

void hal_sleep_msec( int miliseconds ); - sleep (by switching to another thread) for given time. (In hal.h)

void phantom_spinwait(int millis); - wait some mseconds by spinning (not giving CPU away) - note that you have to disable interrupts to wait EXACTLY for given time.

void tenmicrosec(void); - wait by spinning, ~10 microsec

Polled timeouts

typedef bigtime_t polled_timeout_t;

void set_polled_timeout( polled_timeout_t *timer, bigtime_t timeout_uSec );
bool check_polled_timeout( polled_timeout_t *timer );

Use set_polled_timeout() to setup timeout (in microseconds). Use check_polled_timeout() to find out if time is passed. Note that interrupts must be enabled. This call depends on system timer interrupt granularity. (10 msec?)

Timed calls (callouts)

Call function after timeout from timer interrupt.

void phantom_request_timed_call( timedcall_t *entry, u_int32_t flags );
void phantom_request_timed_func( timedcall_func_t f, void *arg, int msecLater, u_int32_t flags );

timedcall_t is:

timedcall_func_t f; - func to call void *arg; - arg to pass to f long msecLater; - milliseconds to pass before call

flags are:

• TIMEDCALL_FLAG_PERIODIC - func will be called periodically
• TIMEDCALL_FLAG_AUTOFREE - entry will be freed automatically

NB! Call is done in timer interrupt! Be quick! Don't attempt to sleep (mutex/cond) or call functions that sleep.

NB! It is possible for callout to happen BEFORE the return from this function.

void phantom_request_cond_signal( int msec, hal_cond_t *cond);
void phantom_request_cond_broadcast( int msec, hal_cond_t *cond);

TODO

void phantom_request_timed_thread_wake( int tid, long timeMsec );

Implement copy of these, but working on separate thread.

Net Timer

Name is historical. Call function agfter timeout. Function is called in thread context, so it can call functions that block briefly (such as malloc/free). Still you can't sleep for long.

int set_net_timer(net_timer_event *e, unsigned int delay_ms, net_timer_callback callback, void *args, int flags);
int cancel_net_timer(net_timer_event *e);