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Event timers provides a way to generate timed events. More...
Files | |
file | etimer.c |
Event timer library implementation. | |
Data Structures | |
struct | etimer |
A timer. More... | |
Functions called from application programs | |
void | etimer_set (struct etimer *et, clock_time_t interval) |
Set an event timer. More... | |
void | etimer_reset_with_new_interval (struct etimer *et, clock_time_t interval) |
Reset an event timer with a new interval. More... | |
void | etimer_reset (struct etimer *et) |
Reset an event timer with the same interval as was previously set. More... | |
void | etimer_restart (struct etimer *et) |
Restart an event timer from the current point in time. More... | |
void | etimer_adjust (struct etimer *et, int td) |
Adjust the expiration time for an event timer. More... | |
int | etimer_expired (struct etimer *et) |
Check if an event timer has expired. More... | |
clock_time_t | etimer_expiration_time (struct etimer *et) |
Get the expiration time for the event timer. More... | |
clock_time_t | etimer_start_time (struct etimer *et) |
Get the start time for the event timer. More... | |
void | etimer_stop (struct etimer *et) |
Stop a pending event timer. More... | |
Functions called from timer interrupts, by the system | |
void | etimer_request_poll (void) |
Make the event timer aware that the clock has changed. More... | |
int | etimer_pending (void) |
Check if there are any non-expired event timers. More... | |
clock_time_t | etimer_next_expiration_time (void) |
Get next event timer expiration time. More... | |
Event timers provides a way to generate timed events.
An event timer will post an event to the process that set the timer when the event timer expires.
An event timer is declared as a struct
etimer
and all access to the event timer is made by a pointer to the declared event timer.
It is not safe to manipulate event timers within an interrupt context.
void etimer_adjust | ( | struct etimer * | et, |
int | td | ||
) |
Adjust the expiration time for an event timer.
et | A pointer to the event timer. |
td | The time difference to adjust the expiration time with. This function is used to adjust the time the event timer will expire. It can be used to synchronize periodic timers without the need to restart the timer or change the timer interval. \note This function should only be used for small adjustments. For large adjustments use etimer_set() instead. \note A periodic timer will drift unless the etimer_reset() function is used. |
clock_time_t etimer_expiration_time | ( | struct etimer * | et | ) |
int etimer_expired | ( | struct etimer * | et | ) |
clock_time_t etimer_next_expiration_time | ( | void | ) |
Get next event timer expiration time.
This functions returns next expiration time of all pending event timers.
Definition at line 237 of file etimer.c.
References etimer_pending().
int etimer_pending | ( | void | ) |
Check if there are any non-expired event timers.
This function checks if there are any active event timers that have not expired.
Definition at line 231 of file etimer.c.
Referenced by etimer_next_expiration_time(), and Java_org_contikios_cooja_corecomm_CLASSNAME_tick().
void etimer_request_poll | ( | void | ) |
Make the event timer aware that the clock has changed.
This function is used to inform the event timer module that the system clock has been updated. Typically, this function would be called from the timer interrupt handler when the clock has ticked.
Definition at line 145 of file etimer.c.
References process_poll().
Referenced by Java_org_contikios_cooja_corecomm_CLASSNAME_tick().
void etimer_reset | ( | struct etimer * | et | ) |
Reset an event timer with the same interval as was previously set.
et | A pointer to the event timer. This function resets the event timer with the same interval that was given to the event timer with the etimer_set() function. The start point of the interval is the exact time that the event timer last expired. Therefore, this function will cause the timer to be stable over time, unlike the etimer_restart() function. If this is executed before the timer expired, this function has no effect. |
void etimer_reset_with_new_interval | ( | struct etimer * | et, |
clock_time_t | interval | ||
) |
Reset an event timer with a new interval.
et | A pointer to the event timer. |
interval | The interval before the timer expires. This function very similar to etimer_reset. Opposed to etimer_reset it is possible to change the timout. This allows accurate, non-periodic timers without drift. |
void etimer_restart | ( | struct etimer * | et | ) |
Restart an event timer from the current point in time.
et | A pointer to the event timer. This function restarts the event timer with the same interval that was given to the etimer_set() function. The event timer will start at the current time. \note A periodic timer will drift if this function is used to reset it. For periodic timers, use the etimer_reset() function instead. |
void etimer_set | ( | struct etimer * | et, |
clock_time_t | interval | ||
) |
Set an event timer.
et | A pointer to the event timer |
interval | The interval before the timer expires. This function is used to set an event timer for a time sometime in the future. When the event timer expires, the event PROCESS_EVENT_TIMER will be posted to the process that called the etimer_set() function. |
clock_time_t etimer_start_time | ( | struct etimer * | et | ) |
void etimer_stop | ( | struct etimer * | et | ) |
Stop a pending event timer.
et | A pointer to the pending event timer. This function stops an event timer that has previously been set with etimer_set() or etimer_reset(). After this function has been called, the event timer will not emit any event when it expires. |