QTimeEvt implementation and QF system clock tick QF_tickX_())
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#include "qf_port.h"
#include "qf_pkg.h"
#include "qassert.h"
#include "qs_port.h"
Go to the source code of this file.
QTimeEvt implementation and QF system clock tick QF_tickX_())
Definition in file qf_time.c.
◆ QF_tickX_()
| void QF_tickX_ |
( |
uint_fast8_t const |
tickRate, |
|
|
void const *const |
sender |
|
) |
| |
Processes all armed time events at every clock tick.
- Description
- This function must be called periodically from a time-tick ISR or from a task so that QF can manage the timeout events assigned to the given system clock tick rate.
- Parameters
-
| [in] | tickRate | system clock tick rate serviced in this call [1..15]. |
- Note
- this function should be called only via the macro QF_TICK_X()
-
the calls to QF_tickX_() with different
tickRate parameter can preempt each other. For example, higher clock tick rates might be serviced from interrupts while others from tasks (active objects).
- See also
- QTimeEvt.
Definition at line 78 of file qf_time.c.
◆ QF_noTimeEvtsActiveX()
Returns 'true' if there are no armed time events at a given tick rate.
- Description
- Find out if any time events are armed at the given clock tick rate.
- Parameters
-
| [in] | tickRate | system clock tick rate to find out about. |
- Returns
- 'true' if no time events are armed at the given tick rate and 'false' otherwise.
- Note
- This function should be called in critical section.
Definition at line 204 of file qf_time.c.
◆ QTimeEvt_ctorX()
The extended "constructor" to initialize a Time Event.
- Description
- When creating a time event, you must commit it to a specific active object
act, tick rate tickRate and event signal sig. You cannot change these attributes later.
- Parameters
-
| [in,out] | me | pointer (see Object Orientation) |
| [in] | act | pointer to the active object associated with this time event. The time event will post itself to this AO. |
| [in] | sig | signal to associate with this time event. |
| [in] | tickRate | systemclock tick rate to associate with this time event in the range [0..15]. |
- Note
- You should call the constructor exactly once for every Time Event object before arming the Time Event. The ideal place for initializing the time event(s) associated with a given AO is the AO's constructor.
- Precondition
- The signal must be valid and the tick rate in range
Definition at line 237 of file qf_time.c.
◆ QTimeEvt_armX()
Arm a time event (one shot or periodic) for direct event posting.
- Description
- Arms a time event to fire in a specified number of clock ticks and with a specified interval. If the interval is zero, the time event is armed for one shot ('one-shot' time event). The time event gets directly posted (using the FIFO policy) into the event queue of the host active object.
- Parameters
-
| [in,out] | me | pointer (see Object Orientation) |
| [in] | nTicks | number of clock ticks (at the associated rate) to rearm the time event with. |
| [in] | interval | interval (in clock ticks) for periodic time event. |
- Note
- After posting, a one-shot time event gets automatically disarmed while a periodic time event (interval != 0) is automatically re-armed.
-
A time event can be disarmed at any time by calling the QTimeEvt_disarm() function. Also, a time event can be re-armed to fire in a different number of clock ticks by calling the QTimeEvt_rearm() function.
- Usage
- The following example shows how to arm a one-shot time event from a state machine of an active object:
QState Philo_eating(Philo *
const me,
QEvt const *
const e) {
break;
}
TableEvt *pe;
pe =
Q_NEW(TableEvt, DONE_SIG);
pe->philNum = me->num;
break;
}
case TIMEOUT_SIG: {
status =
Q_TRAN(&Philosopher_thinking);
break;
}
default: {
break;
}
}
return status;
}
- Precondition
- the host AO must be valid, time evnet must be disarmed, number of clock ticks cannot be zero, and the signal must be valid.
Definition at line 296 of file qf_time.c.
◆ QTimeEvt_disarm()
Disarm a time event.
- Description
- Disarm the time event so it can be safely reused.
- Parameters
-
- Returns
- 'true' if the time event was truly disarmed, that is, it was running. The return of 'false' means that the time event was not truly disarmed, because it was not running. The 'false' return is only possible for one- shot time events that have been automatically disarmed upon expiration. In this case the 'false' return means that the time event has already been posted or published and should be expected in the active object's state machine.
- Note
- there is no harm in disarming an already disarmed time event
Definition at line 371 of file qf_time.c.
◆ QTimeEvt_rearm()
Rearm a time event.
- Description
- Rearms a time event with a new number of clock ticks. This function can be used to adjust the current period of a periodic time event or to prevent a one-shot time event from expiring (e.g., a watchdog time event). Rearming a periodic timer leaves the interval unchanged and is a convenient method to adjust the phasing of a periodic time event.
- Parameters
-
| [in,out] | me | pointer (see Object Orientation) |
| [in] | nTicks | number of clock ticks (at the associated rate) to rearm the time event with. |
- Returns
- 'true' if the time event was running as it was re-armed. The 'false' return means that the time event was not truly rearmed because it was not running. The 'false' return is only possible for one-shot time events that have been automatically disarmed upon expiration. In this case the 'false' return means that the time event has already been posted or published and should be expected in the active object's state machine.
- Precondition
- AO must be valid, tick rate must be in range, nTicks must not be zero, and the signal of this time event must be valid
Definition at line 431 of file qf_time.c.
◆ QTimeEvt_wasDisarmed()
Check the "was disarmed" status of a time event.
- Description
- Useful for checking whether a one-shot time event was disarmed in the QTimeEvt_disarm() operation.
- Parameters
-
- Returns
- 'true' if the time event was truly disarmed in the last QTimeEvt_disarm() operation. The 'false' return means that the time event was not truly disarmed, because it was not running at that time. The 'false' return is only possible for one-shot time events that have been automatically disarmed upon expiration. In this case the 'false' return means that the time event has already been posted or published and should be expected in the active object's event queue.
- Note
- This function has a side effect of setting the "was disarmed" status, which means that the second and subsequent times this function is called the function will return 'true'.
Definition at line 513 of file qf_time.c.
◆ QTimeEvt_currCtr()
Get the current value of the down-counter of a time event.
- Description
- Useful for checking how many clock ticks (at the tick rate associated with the time event) remain until the time event expires.
- Parameters
-
- Returns
- For an armed time event, the function returns the current value of the down-counter of the given time event. If the time event is not armed, the function returns 0.
- Note
- The function is thread-safe.
Definition at line 535 of file qf_time.c.
◆ QF_timeEvtHead_
heads of linked lists of time events, one for every clock tick rate
Definition at line 53 of file qf_time.c.
