Collaboration diagram for Virtual Timers:

Detailed Description

Time and Virtual Timers related APIs and services.

Functions
static void	vt_insert_first (virtual_timers_list_t vtlp, virtual_timer_t vtp, systime_t now, sysinterval_t delay)
	Inserts a timer as first element in a delta list. More...

static void	vt_enqueue (virtual_timers_list_t vtlp, virtual_timer_t vtp, systime_t now, sysinterval_t delay)
	Enqueues a virtual timer in a virtual timers list. More...

void	chVTDoSetI (virtual_timer_t vtp, sysinterval_t delay, vtfunc_t vtfunc, void par)
	Enables a one-shot virtual timer. More...

void	chVTDoSetContinuousI (virtual_timer_t vtp, sysinterval_t delay, vtfunc_t vtfunc, void par)
	Enables a continuous virtual timer. More...

void	chVTDoResetI (virtual_timer_t *vtp)
	Disables a Virtual Timer. More...

sysinterval_t	chVTGetRemainingIntervalI (virtual_timer_t *vtp)
	Returns the remaining time interval before next timer trigger. More...

void	chVTDoTickI (void)
	Virtual timers ticker. More...

systimestamp_t	chVTGetTimeStampI (void)
	Generates a monotonic time stamp. More...

void	chVTResetTimeStampI (void)
	Resets and re-synchronizes the time stamps monotonic counter. More...

static void	chVTObjectInit (virtual_timer_t *vtp)
	Initializes a `virtual_timer_t` object. More...

static systime_t	chVTGetSystemTimeX (void)
	Current system time. More...

static systime_t	chVTGetSystemTime (void)
	Current system time. More...

static sysinterval_t	chVTTimeElapsedSinceX (systime_t start)
	Returns the elapsed time since the specified start time. More...

static bool	chVTIsSystemTimeWithinX (systime_t start, systime_t end)
	Checks if the current system time is within the specified time window. More...

static bool	chVTIsSystemTimeWithin (systime_t start, systime_t end)
	Checks if the current system time is within the specified time window. More...

static bool	chVTGetTimersStateI (sysinterval_t *timep)
	Returns the time interval until the next timer event. More...

static bool	chVTIsArmedI (const virtual_timer_t *vtp)
	Returns `true` if the specified timer is armed. More...

static bool	chVTIsArmed (const virtual_timer_t *vtp)
	Returns `true` if the specified timer is armed. More...

static void	chVTResetI (virtual_timer_t *vtp)
	Disables a Virtual Timer. More...

static void	chVTReset (virtual_timer_t *vtp)
	Disables a Virtual Timer. More...

static void	chVTSetI (virtual_timer_t vtp, sysinterval_t delay, vtfunc_t vtfunc, void par)
	Enables a one-shot virtual timer. More...

static void	chVTSet (virtual_timer_t vtp, sysinterval_t delay, vtfunc_t vtfunc, void par)
	Enables a one-shot virtual timer. More...

static void	chVTSetContinuousI (virtual_timer_t vtp, sysinterval_t delay, vtfunc_t vtfunc, void par)
	Enables a continuous virtual timer. More...

static void	chVTSetContinuous (virtual_timer_t vtp, sysinterval_t delay, vtfunc_t vtfunc, void par)
	Enables a continuous virtual timer. More...

static sysinterval_t	chVTGetReloadIntervalX (virtual_timer_t *vtp)
	Returns the current reload value. More...

static void	chVTSetReloadIntervalX (virtual_timer_t *vtp, sysinterval_t reload)
	Changes a timer reload time interval. More...

static systimestamp_t	chVTGetTimeStamp (void)
	Generates a monotonic time stamp. More...

static void	chVTResetTimeStamp (void)
	Resets and re-synchronizes the time stamps monotonic counter. More...

static void	__vt_object_init (virtual_timers_list_t *vtlp)
	Virtual Timers instance initialization. More...

Function Documentation

◆ vt_insert_first()

static void vt_insert_first	(	virtual_timers_list_t *	vtlp,
		virtual_timer_t *	vtp,
		systime_t	now,
		sysinterval_t	delay
	)

static

Inserts a timer as first element in a delta list.

Note: This is the special case when the delta list is initially empty.

Definition at line 56 of file chvt.c.

References ch_dlist_insert_after(), ch_virtual_timer::dlist, ch_virtual_timers_list::dlist, and ch_virtual_timers_list::lasttime.

Referenced by vt_enqueue().

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◆ vt_enqueue()

static void vt_enqueue	(	virtual_timers_list_t *	vtlp,
		virtual_timer_t *	vtp,
		systime_t	now,
		sysinterval_t	delay
	)

static

Enqueues a virtual timer in a virtual timers list.

Definition at line 90 of file chvt.c.

References ch_dlist_isempty(), chTimeDiffX, ch_virtual_timers_list::dlist, ch_virtual_timers_list::lasttime, and vt_insert_first().

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◆ chVTDoSetI()

void chVTDoSetI	(	virtual_timer_t *	vtp,
		sysinterval_t	delay,
		vtfunc_t	vtfunc,
		void *	par
	)

Enables a one-shot virtual timer.

The timer is enabled and programmed to trigger after the delay specified as parameter.

Precondition: The timer must not be already armed before calling this function.

Note: The callback function is invoked from interrupt context.

Parameters

[out]	vtp	the `virtual_timer_t` structure pointer
[in]	delay	the number of ticks before the operation timeouts, the special values are handled as follow: TIME_INFINITE is allowed but interpreted as a normal time specification. TIME_IMMEDIATE this value is not allowed.
[in]	vtfunc	the timer callback function. After invoking the callback the timer is disabled and the structure can be disposed or reused.
[in]	par	a parameter that will be passed to the callback function

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 179 of file chvt.c.

References currcore.

Referenced by chVTSetI().

◆ chVTDoSetContinuousI()

void chVTDoSetContinuousI	(	virtual_timer_t *	vtp,
		sysinterval_t	delay,
		vtfunc_t	vtfunc,
		void *	par
	)

Enables a continuous virtual timer.

The timer is enabled and programmed to trigger after the delay specified as parameter.

Precondition: The timer must not be already armed before calling this function.

Note: The callback function is invoked from interrupt context.

Parameters

[out]	vtp	the `virtual_timer_t` structure pointer
[in]	delay	the number of ticks before the operation timeouts, the special values are handled as follow: TIME_INFINITE is allowed but interpreted as a normal time specification. TIME_IMMEDIATE this value is not allowed.
[in]	vtfunc	the timer callback function. After invoking the callback the timer is disabled and the structure can be disposed or reused.
[in]	par	a parameter that will be passed to the callback function

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 217 of file chvt.c.

References currcore.

Referenced by chVTSetContinuousI().

◆ chVTDoResetI()

void chVTDoResetI ( virtual_timer_t * vtp )

Disables a Virtual Timer.

Precondition: The timer must be in armed state before calling this function.

Parameters

[in] vtp the virtual_timer_t structure pointer

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 241 of file chvt.c.

References currcore.

Referenced by chVTResetI().

◆ chVTGetRemainingIntervalI()

sysinterval_t chVTGetRemainingIntervalI ( virtual_timer_t * vtp )

Returns the remaining time interval before next timer trigger.

Note: This function can be called while the timer is active.

Parameters

[in] vtp the virtual_timer_t structure pointer

Returns: The remaining time interval.

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 337 of file chvt.c.

References currcore.

◆ chVTDoTickI()

void chVTDoTickI ( void )

Virtual timers ticker.

Note: The system lock is released before entering the callback and re-acquired immediately after. It is callback's responsibility to acquire the lock if needed. This is done in order to reduce interrupts jitter when many timers are in use.

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 377 of file chvt.c.

References currcore.

◆ chVTGetTimeStampI()

systimestamp_t chVTGetTimeStampI ( void )

Generates a monotonic time stamp.

This function generates a monotonic time stamp synchronized with the system time. The time stamp has the same resolution of system time.

Note: There is an assumption, this function must be called at least once before the system time wraps back to zero or synchronization is lost. You may use a periodic virtual timer with a very large interval in order to keep time stamps synchronized by calling this function.

Returns: The time stamp.

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 562 of file chvt.c.

References currcore.

Referenced by chVTGetTimeStamp().

◆ chVTResetTimeStampI()

void chVTResetTimeStampI ( void )

Resets and re-synchronizes the time stamps monotonic counter.

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 593 of file chvt.c.

◆ chVTObjectInit()

static void chVTObjectInit ( virtual_timer_t * vtp )

inlinestatic

Initializes a virtual_timer_t object.

Note: Initializing a timer object is not strictly required because the function chVTSetI() initializes the object too. This function is only useful if you need to perform a chVTIsArmed() check before calling chVTSetI().

Parameters

[out] vtp the virtual_timer_t structure pointer

Function Class:: Initializer, this function just initializes an object and can be invoked before the kernel is initialized.

Definition at line 104 of file chvt.h.

References ch_virtual_timer::dlist, and ch_delta_list::next.

◆ chVTGetSystemTimeX()

static systime_t chVTGetSystemTimeX ( void )

inlinestatic

Current system time.

Returns the number of system ticks since the chSysInit() invocation.

Note: The counter can reach its maximum and then restart from zero.; This function can be called from any context but its atomicity is not guaranteed on architectures whose word size is less than systime_t size.

Returns: The system time in ticks.

Function Class:: This is an X-Class API, this function can be invoked from any context.

Definition at line 122 of file chvt.h.

References currcore.

Referenced by __vt_object_init(), chVTGetSystemTime(), chVTIsSystemTimeWithinX(), and chVTTimeElapsedSinceX().

◆ chVTGetSystemTime()

static systime_t chVTGetSystemTime ( void )

inlinestatic

Current system time.

Returns the number of system ticks since the chSysInit() invocation.

Note: The counter can reach its maximum and then restart from zero.

Returns: The system time in ticks.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 141 of file chvt.h.

References chSysLock, chSysUnlock, and chVTGetSystemTimeX().

Referenced by chVTIsSystemTimeWithin().

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◆ chVTTimeElapsedSinceX()

static sysinterval_t chVTTimeElapsedSinceX ( systime_t start )

inlinestatic

Returns the elapsed time since the specified start time.

Parameters

[in] start start time

Returns: The elapsed time.

Function Class:: This is an X-Class API, this function can be invoked from any context.

Definition at line 159 of file chvt.h.

References chTimeDiffX, and chVTGetSystemTimeX().

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◆ chVTIsSystemTimeWithinX()

static bool chVTIsSystemTimeWithinX	(	systime_t	start,
		systime_t	end
	)

inlinestatic

Checks if the current system time is within the specified time window.

Note: When start==end then the function returns always false because the time window has zero size.

Parameters

[in]	start	the start of the time window (inclusive)
[in]	end	the end of the time window (non inclusive)

Return values

true	current time within the specified time window.
false	current time not within the specified time window.

Function Class:: This is an X-Class API, this function can be invoked from any context.

Definition at line 177 of file chvt.h.

References chTimeIsInRangeX(), and chVTGetSystemTimeX().

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◆ chVTIsSystemTimeWithin()

static bool chVTIsSystemTimeWithin	(	systime_t	start,
		systime_t	end
	)

inlinestatic

Checks if the current system time is within the specified time window.

Note: When start==end then the function returns always false because the time window has zero size.

Parameters

[in]	start	the start of the time window (inclusive)
[in]	end	the end of the time window (non inclusive)

Return values

true	current time within the specified time window.
false	current time not within the specified time window.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 195 of file chvt.h.

References chTimeIsInRangeX(), and chVTGetSystemTime().

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◆ chVTGetTimersStateI()

static bool chVTGetTimersStateI ( sysinterval_t * timep )

inlinestatic

Returns the time interval until the next timer event.

Note: The return value is not perfectly accurate and can report values in excess of CH_CFG_ST_TIMEDELTA ticks.; The interval returned by this function is only meaningful if more timers are not added to the list until the returned time.

Parameters

[out] timep pointer to a variable that will contain the time interval until the next timer elapses. This pointer can be NULL if the information is not required.

Returns: The time, in ticks, until next time event.

Return values

false	if the timers list is empty.
true	if the timers list contains at least one timer.

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 216 of file chvt.h.

References currcore, and ch_virtual_timers_list::dlist.

◆ chVTIsArmedI()

static bool chVTIsArmedI ( const virtual_timer_t * vtp )

inlinestatic

Returns true if the specified timer is armed.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in] vtp the virtual_timer_t structure pointer

Returns: true if the timer is armed.

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 248 of file chvt.h.

Referenced by chVTIsArmed(), and chVTResetI().

◆ chVTIsArmed()

static bool chVTIsArmed ( const virtual_timer_t * vtp )

inlinestatic

Returns true if the specified timer is armed.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in] vtp the virtual_timer_t structure pointer

Returns: true if the timer is armed.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 265 of file chvt.h.

References chSysLock, chSysUnlock, and chVTIsArmedI().

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◆ chVTResetI()

static void chVTResetI ( virtual_timer_t * vtp )

inlinestatic

Disables a Virtual Timer.

Note: The timer is first checked and disabled only if armed.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in] vtp the virtual_timer_t structure pointer

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 285 of file chvt.h.

References chVTDoResetI(), and chVTIsArmedI().

Referenced by chVTReset(), chVTSetContinuousI(), and chVTSetI().

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◆ chVTReset()

static void chVTReset ( virtual_timer_t * vtp )

inlinestatic

Disables a Virtual Timer.

Note: The timer is first checked and disabled only if armed.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in] vtp the virtual_timer_t structure pointer

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 302 of file chvt.h.

References chSysLock, chSysUnlock, and chVTResetI().

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◆ chVTSetI()

static void chVTSetI	(	virtual_timer_t *	vtp,
		sysinterval_t	delay,
		vtfunc_t	vtfunc,
		void *	par
	)

inlinestatic

Enables a one-shot virtual timer.

If the virtual timer was already enabled then it is re-enabled using the new parameters.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in]	vtp	the `virtual_timer_t` structure pointer
[in]	delay	the number of ticks before the operation timeouts, the special values are handled as follow: TIME_INFINITE is allowed but interpreted as a normal time specification. TIME_IMMEDIATE this value is not allowed.
[in]	vtfunc	the timer callback function. After invoking the callback the timer is disabled and the structure can be disposed or reused.
[in]	par	a parameter that will be passed to the callback function

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 331 of file chvt.h.

References chVTDoSetI(), and chVTResetI().

Referenced by chVTSet().

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◆ chVTSet()

static void chVTSet	(	virtual_timer_t *	vtp,
		sysinterval_t	delay,
		vtfunc_t	vtfunc,
		void *	par
	)

inlinestatic

Enables a one-shot virtual timer.

If the virtual timer was already enabled then it is re-enabled using the new parameters.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in]	vtp	the `virtual_timer_t` structure pointer
[in]	delay	the number of ticks before the operation timeouts, the special values are handled as follow: TIME_INFINITE is allowed but interpreted as a normal time specification. TIME_IMMEDIATE this value is not allowed.
[in]	vtfunc	the timer callback function. After invoking the callback the timer is disabled and the structure can be disposed or reused.
[in]	par	a parameter that will be passed to the callback function

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 360 of file chvt.h.

References chSysLock, chSysUnlock, and chVTSetI().

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◆ chVTSetContinuousI()

static void chVTSetContinuousI	(	virtual_timer_t *	vtp,
		sysinterval_t	delay,
		vtfunc_t	vtfunc,
		void *	par
	)

inlinestatic

Enables a continuous virtual timer.

If the virtual timer was already enabled then it is re-enabled using the new parameters.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in]	vtp	the `virtual_timer_t` structure pointer
[in]	delay	the number of ticks before the operation timeouts, the special values are handled as follow: TIME_INFINITE is allowed but interpreted as a normal time specification. TIME_IMMEDIATE this value is not allowed.
[in]	vtfunc	the timer callback function. After invoking the callback the timer is disabled and the structure can be disposed or reused.
[in]	par	a parameter that will be passed to the callback function

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 390 of file chvt.h.

References chVTDoSetContinuousI(), and chVTResetI().

Referenced by chVTSetContinuous().

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◆ chVTSetContinuous()

static void chVTSetContinuous	(	virtual_timer_t *	vtp,
		sysinterval_t	delay,
		vtfunc_t	vtfunc,
		void *	par
	)

inlinestatic

Enables a continuous virtual timer.

If the virtual timer was already enabled then it is re-enabled using the new parameters.

Precondition: The timer must have been initialized using chVTObjectInit() or chVTDoSetI().

Parameters

[in]	vtp	the `virtual_timer_t` structure pointer
[in]	delay	the number of ticks before the operation timeouts, the special values are handled as follow: TIME_INFINITE is allowed but interpreted as a normal time specification. TIME_IMMEDIATE this value is not allowed.
[in]	vtfunc	the timer callback function. After invoking the callback the timer is disabled and the structure can be disposed or reused.
[in]	par	a parameter that will be passed to the callback function

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 419 of file chvt.h.

References chSysLock, chSysUnlock, and chVTSetContinuousI().

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◆ chVTGetReloadIntervalX()

static sysinterval_t chVTGetReloadIntervalX ( virtual_timer_t * vtp )

inlinestatic

Returns the current reload value.

Parameters

[in] vtp the virtual_timer_t structure pointer

Returns: The reload value.

Function Class:: This is an X-Class API, this function can be invoked from any context.

Definition at line 435 of file chvt.h.

References ch_virtual_timer::reload.

◆ chVTSetReloadIntervalX()

static void chVTSetReloadIntervalX	(	virtual_timer_t *	vtp,
		sysinterval_t	reload
	)

inlinestatic

Changes a timer reload time interval.

Note: This function is meant to be called from a timer callback, it does nothing in any other context.; Calling this function from a one-shot timer callback turns it into a continuous timer.

Parameters

[in]	vtp	the `virtual_timer_t` structure pointer
[in]	reload	the new reload value, zero means no reload

Function Class:: This is an X-Class API, this function can be invoked from any context.

Definition at line 452 of file chvt.h.

References ch_virtual_timer::reload.

◆ chVTGetTimeStamp()

static systimestamp_t chVTGetTimeStamp ( void )

inlinestatic

Generates a monotonic time stamp.

This function generates a monotonic time stamp synchronized with the system time. The time stamp has the same resolution of system time.

Note: There is an assumption, this function must be called at least once before the system time wraps back to zero or synchronization is lost. You may use a periodic virtual timer with a very large interval in order to keep time stamps synchronized by calling this function.

Returns: The time stamp.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 474 of file chvt.h.

References chSysLock, chSysUnlock, and chVTGetTimeStampI().

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◆ chVTResetTimeStamp()

static void chVTResetTimeStamp ( void )

inlinestatic

Resets and re-synchronizes the time stamps monotonic counter.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 491 of file chvt.h.

◆ __vt_object_init()

static void __vt_object_init ( virtual_timers_list_t * vtlp )

inlinestatic

Virtual Timers instance initialization.

Note: Internal use only.

Parameters

[out] vtlp pointer to the virtual_timers_list_t structure

Function Class:: Not an API, this function is for internal use only.

Definition at line 511 of file chvt.h.

References ch_dlist_init(), chVTGetSystemTimeX(), ch_virtual_timers_list::dlist, ch_virtual_timers_list::laststamp, ch_virtual_timers_list::lasttime, and ch_virtual_timers_list::systime.

Referenced by chInstanceObjectInit().

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Detailed Description

Functions

Function Documentation

◆ vt_insert_first()

◆ vt_enqueue()

◆ chVTDoSetI()

◆ chVTDoSetContinuousI()

◆ chVTDoResetI()

◆ chVTGetRemainingIntervalI()

◆ chVTDoTickI()

◆ chVTGetTimeStampI()

◆ chVTResetTimeStampI()

◆ chVTObjectInit()

◆ chVTGetSystemTimeX()

◆ chVTGetSystemTime()

◆ chVTTimeElapsedSinceX()

◆ chVTIsSystemTimeWithinX()

◆ chVTIsSystemTimeWithin()

◆ chVTGetTimersStateI()

◆ chVTIsArmedI()

◆ chVTIsArmed()

◆ chVTResetI()

◆ chVTReset()

◆ chVTSetI()

◆ chVTSet()

◆ chVTSetContinuousI()

◆ chVTSetContinuous()

◆ chVTGetReloadIntervalX()

◆ chVTSetReloadIntervalX()

◆ chVTGetTimeStamp()

◆ chVTResetTimeStamp()

◆ __vt_object_init()