static void subtract_em(
struct timespec *start,
struct timespec *stop,
struct timespec *t
)
{
t->tv_sec = 0;
t->tv_nsec = 0;
_Timespec_Subtract( start, stop, t );
}
int timer_gettime(
timer_t timerid,
struct itimerspec *value
)
{
/*
* IDEA: This function does not use functions of RTEMS to the handle
* of timers. It uses some functions for managing the time.
*
* A possible form to do this is the following:
*
* - When a timer is initialized, the value of the time in
* that moment is stored.
* - When this function is called, it returns the difference
* between the current time and the initialization time.
*/
POSIX_Timer_Control *ptimer;
Objects_Locations location;
struct timespec current_time;
/* Reads the current time */
_TOD_Get( ¤t_time );
ptimer = _POSIX_Timer_Get( timerid, &location );
switch ( location ) {
case OBJECTS_REMOTE:
#if defined(RTEMS_MULTIPROCESSING)
_Thread_Dispatch();
rtems_set_errno_and_return_minus_one( EINVAL );
#endif
case OBJECTS_ERROR:
rtems_set_errno_and_return_minus_one( EINVAL );
case OBJECTS_LOCAL:
/* Calculates the time left before the timer finishes */
_Timespec_Subtract(
&ptimer->timer_data.it_value,
¤t_time,
&value->it_value
);
value->it_interval = ptimer->timer_data.it_interval;
_Thread_Enable_dispatch();
return 0;
}
return -1; /* unreached - only to remove warnings */
}
/*
* The abstime is a walltime. We turn it into an interval.
*/
TOD_Absolute_timeout_conversion_results _TOD_Absolute_timeout_to_ticks(
const struct timespec *abstime,
Watchdog_Interval *ticks_out
)
{
struct timespec current_time;
struct timespec difference;
/*
* Make sure there is always a value returned.
*/
*ticks_out = 0;
/*
* Is the absolute time even valid?
*/
if ( !_Timespec_Is_valid(abstime) )
return TOD_ABSOLUTE_TIMEOUT_INVALID;
/*
* Is the absolute time in the past?
*/
_TOD_Get_as_timespec( ¤t_time );
if ( _Timespec_Less_than( abstime, ¤t_time ) )
return TOD_ABSOLUTE_TIMEOUT_IS_IN_PAST;
/*
* How long until the requested absolute time?
*/
_Timespec_Subtract( ¤t_time, abstime, &difference );
/*
* Internally the SuperCore uses ticks, so convert to them.
*/
*ticks_out = _Timespec_To_ticks( &difference );
/*
* If the difference was 0, then the future is now. It is so bright
* we better wear shades.
*/
if ( !*ticks_out )
return TOD_ABSOLUTE_TIMEOUT_IS_NOW;
/*
* This is the case we were expecting and it took this long to
* get here.
*/
return TOD_ABSOLUTE_TIMEOUT_IS_IN_FUTURE;
}
void _Rate_monotonic_Initiate_statistics(
Rate_monotonic_Control *the_period
)
{
Thread_Control *owning_thread = the_period->owner;
/*
* If using nanosecond statistics, we need to obtain the uptime.
*/
#ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
Timestamp_Control uptime;
_TOD_Get_uptime( &uptime );
#endif
/*
* Set the starting point and the CPU time used for the statistics.
*/
#ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
the_period->time_period_initiated = uptime;
#else
the_period->time_period_initiated = _Watchdog_Ticks_since_boot;
#endif
the_period->cpu_usage_period_initiated = owning_thread->cpu_time_used;
/*
* If using nanosecond statistics and the period's thread is currently
* executing, then we need to take into account how much time the
* executing thread has run since the last context switch. When this
* routine is invoked from rtems_rate_monotonic_period, the owner will
* be the executing thread. When this routine is invoked from
* _Rate_monotonic_Timeout, it will not.
*/
#ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
if (owning_thread == _Thread_Executing) {
rtems_thread_cpu_usage_t ran;
/*
* Adjust the CPU time used to account for the time since last
* context switch.
*/
_Timespec_Subtract(
&_Thread_Time_of_last_context_switch, &uptime, &ran
);
_Timespec_Add_to( &the_period->cpu_usage_period_initiated, &ran );
}
#endif
}
