keyboard/qmk/lib/chibios/os/rt/include/chvt.h

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/*
ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chvt.h
* @brief Time and Virtual Timers module macros and structures.
*
* @addtogroup time
* @{
*/
#ifndef CHVT_H
#define CHVT_H
/*===========================================================================*/
/* Module constants. */
/*===========================================================================*/
/*===========================================================================*/
/* Module pre-compile time settings. */
/*===========================================================================*/
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
#if (CH_CFG_ST_TIMEDELTA < 0) || (CH_CFG_ST_TIMEDELTA == 1)
#error "invalid CH_CFG_ST_TIMEDELTA specified, must " \
"be zero or greater than one"
#endif
#if (CH_CFG_ST_TIMEDELTA > 0) && (CH_CFG_TIME_QUANTUM > 0)
#error "CH_CFG_TIME_QUANTUM not supported in tickless mode"
#endif
#if (CH_CFG_ST_TIMEDELTA > 0) && (CH_DBG_THREADS_PROFILING == TRUE)
#error "CH_DBG_THREADS_PROFILING not supported in tickless mode"
#endif
/*===========================================================================*/
/* Module data structures and types. */
/*===========================================================================*/
/*===========================================================================*/
/* Module macros. */
/*===========================================================================*/
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
/*
* Virtual Timers APIs.
*/
#ifdef __cplusplus
extern "C" {
#endif
void _vt_init(void);
void chVTDoSetI(virtual_timer_t *vtp, sysinterval_t delay,
vtfunc_t vtfunc, void *par);
void chVTDoResetI(virtual_timer_t *vtp);
#ifdef __cplusplus
}
#endif
/*===========================================================================*/
/* Module inline functions. */
/*===========================================================================*/
/**
* @brief Initializes a @p virtual_timer_t object.
* @note Initializing a timer object is not strictly required because
* the function @p chVTSetI() initializes the object too. This
* function is only useful if you need to perform a @p chVTIsArmed()
* check before calling @p chVTSetI().
*
* @param[out] vtp the @p virtual_timer_t structure pointer
*
* @init
*/
static inline void chVTObjectInit(virtual_timer_t *vtp) {
vtp->func = NULL;
}
/**
* @brief Current system time.
* @details Returns the number of system ticks since the @p chSysInit()
* invocation.
* @note The counter can reach its maximum and then restart from zero.
* @note This function can be called from any context but its atomicity
* is not guaranteed on architectures whose word size is less than
* @p systime_t size.
*
* @return The system time in ticks.
*
* @xclass
*/
static inline systime_t chVTGetSystemTimeX(void) {
#if CH_CFG_ST_TIMEDELTA == 0
return ch.vtlist.systime;
#else /* CH_CFG_ST_TIMEDELTA > 0 */
return port_timer_get_time();
#endif /* CH_CFG_ST_TIMEDELTA > 0 */
}
/**
* @brief Current system time.
* @details Returns the number of system ticks since the @p chSysInit()
* invocation.
* @note The counter can reach its maximum and then restart from zero.
*
* @return The system time in ticks.
*
* @api
*/
static inline systime_t chVTGetSystemTime(void) {
systime_t systime;
chSysLock();
systime = chVTGetSystemTimeX();
chSysUnlock();
return systime;
}
/**
* @brief Returns the elapsed time since the specified start time.
*
* @param[in] start start time
* @return The elapsed time.
*
* @xclass
*/
static inline sysinterval_t chVTTimeElapsedSinceX(systime_t start) {
return chTimeDiffX(start, chVTGetSystemTimeX());
}
/**
* @brief Checks if the current system time is within the specified time
* window.
* @note When start==end then the function returns always true because the
* whole time range is specified.
*
* @param[in] start the start of the time window (inclusive)
* @param[in] end the end of the time window (non inclusive)
* @retval true current time within the specified time window.
* @retval false current time not within the specified time window.
*
* @xclass
*/
static inline bool chVTIsSystemTimeWithinX(systime_t start, systime_t end) {
return chTimeIsInRangeX(chVTGetSystemTimeX(), start, end);
}
/**
* @brief Checks if the current system time is within the specified time
* window.
* @note When start==end then the function returns always true because the
* whole time range is specified.
*
* @param[in] start the start of the time window (inclusive)
* @param[in] end the end of the time window (non inclusive)
* @retval true current time within the specified time window.
* @retval false current time not within the specified time window.
*
* @api
*/
static inline bool chVTIsSystemTimeWithin(systime_t start, systime_t end) {
return chTimeIsInRangeX(chVTGetSystemTime(), start, end);
}
/**
* @brief Returns the time interval until the next timer event.
* @note The return value is not perfectly accurate and can report values
* in excess of @p CH_CFG_ST_TIMEDELTA ticks.
* @note The interval returned by this function is only meaningful if
* more timers are not added to the list until the returned time.
*
* @param[out] timep pointer to a variable that will contain the time
* interval until the next timer elapses. This pointer
* can be @p NULL if the information is not required.
* @return The time, in ticks, until next time event.
* @retval false if the timers list is empty.
* @retval true if the timers list contains at least one timer.
*
* @iclass
*/
static inline bool chVTGetTimersStateI(sysinterval_t *timep) {
chDbgCheckClassI();
if (&ch.vtlist == (virtual_timers_list_t *)ch.vtlist.next) {
return false;
}
if (timep != NULL) {
#if CH_CFG_ST_TIMEDELTA == 0
*timep = ch.vtlist.next->delta;
#else
*timep = (ch.vtlist.next->delta + (sysinterval_t)CH_CFG_ST_TIMEDELTA) -
chTimeDiffX(ch.vtlist.lasttime, chVTGetSystemTimeX());
#endif
}
return true;
}
/**
* @brief Returns @p true if the specified timer is armed.
* @pre The timer must have been initialized using @p chVTObjectInit()
* or @p chVTDoSetI().
*
* @param[in] vtp the @p virtual_timer_t structure pointer
* @return true if the timer is armed.
*
* @iclass
*/
static inline bool chVTIsArmedI(const virtual_timer_t *vtp) {
chDbgCheckClassI();
return (bool)(vtp->func != NULL);
}
/**
* @brief Returns @p true if the specified timer is armed.
* @pre The timer must have been initialized using @p chVTObjectInit()
* or @p chVTDoSetI().
*
* @param[in] vtp the @p virtual_timer_t structure pointer
* @return true if the timer is armed.
*
* @api
*/
static inline bool chVTIsArmed(const virtual_timer_t *vtp) {
bool b;
chSysLock();
b = chVTIsArmedI(vtp);
chSysUnlock();
return b;
}
/**
* @brief Disables a Virtual Timer.
* @note The timer is first checked and disabled only if armed.
* @pre The timer must have been initialized using @p chVTObjectInit()
* or @p chVTDoSetI().
*
* @param[in] vtp the @p virtual_timer_t structure pointer
*
* @iclass
*/
static inline void chVTResetI(virtual_timer_t *vtp) {
if (chVTIsArmedI(vtp)) {
chVTDoResetI(vtp);
}
}
/**
* @brief Disables a Virtual Timer.
* @note The timer is first checked and disabled only if armed.
* @pre The timer must have been initialized using @p chVTObjectInit()
* or @p chVTDoSetI().
*
* @param[in] vtp the @p virtual_timer_t structure pointer
*
* @api
*/
static inline void chVTReset(virtual_timer_t *vtp) {
chSysLock();
chVTResetI(vtp);
chSysUnlock();
}
/**
* @brief Enables a virtual timer.
* @details If the virtual timer was already enabled then it is re-enabled
* using the new parameters.
* @pre The timer must have been initialized using @p chVTObjectInit()
* or @p chVTDoSetI().
*
* @param[in] vtp the @p virtual_timer_t structure pointer
* @param[in] delay the number of ticks before the operation timeouts, the
* special values are handled as follow:
* - @a TIME_INFINITE is allowed but interpreted as a
* normal time specification.
* - @a TIME_IMMEDIATE this value is not allowed.
* .
* @param[in] vtfunc the timer callback function. After invoking the
* callback the timer is disabled and the structure can
* be disposed or reused.
* @param[in] par a parameter that will be passed to the callback
* function
*
* @iclass
*/
static inline void chVTSetI(virtual_timer_t *vtp, sysinterval_t delay,
vtfunc_t vtfunc, void *par) {
chVTResetI(vtp);
chVTDoSetI(vtp, delay, vtfunc, par);
}
/**
* @brief Enables a virtual timer.
* @details If the virtual timer was already enabled then it is re-enabled
* using the new parameters.
* @pre The timer must have been initialized using @p chVTObjectInit()
* or @p chVTDoSetI().
*
* @param[in] vtp the @p virtual_timer_t structure pointer
* @param[in] delay the number of ticks before the operation timeouts, the
* special values are handled as follow:
* - @a TIME_INFINITE is allowed but interpreted as a
* normal time specification.
* - @a TIME_IMMEDIATE this value is not allowed.
* .
* @param[in] vtfunc the timer callback function. After invoking the
* callback the timer is disabled and the structure can
* be disposed or reused.
* @param[in] par a parameter that will be passed to the callback
* function
*
* @api
*/
static inline void chVTSet(virtual_timer_t *vtp, sysinterval_t delay,
vtfunc_t vtfunc, void *par) {
chSysLock();
chVTSetI(vtp, delay, vtfunc, par);
chSysUnlock();
}
/**
* @brief 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.
*
* @iclass
*/
static inline void chVTDoTickI(void) {
chDbgCheckClassI();
#if CH_CFG_ST_TIMEDELTA == 0
ch.vtlist.systime++;
if (&ch.vtlist != (virtual_timers_list_t *)ch.vtlist.next) {
/* The list is not empty, processing elements on top.*/
--ch.vtlist.next->delta;
while (ch.vtlist.next->delta == (sysinterval_t)0) {
virtual_timer_t *vtp;
vtfunc_t fn;
vtp = ch.vtlist.next;
fn = vtp->func;
vtp->func = NULL;
vtp->next->prev = (virtual_timer_t *)&ch.vtlist;
ch.vtlist.next = vtp->next;
chSysUnlockFromISR();
fn(vtp->par);
chSysLockFromISR();
}
}
#else /* CH_CFG_ST_TIMEDELTA > 0 */
virtual_timer_t *vtp;
systime_t now;
sysinterval_t delta, nowdelta;
/* Looping through timers.*/
vtp = ch.vtlist.next;
while (true) {
/* Getting the system time as reference.*/
now = chVTGetSystemTimeX();
nowdelta = chTimeDiffX(ch.vtlist.lasttime, now);
/* The list scan is limited by the timers header having
"ch.vtlist.vt_delta == (sysinterval_t)-1" which is
greater than all deltas.*/
if (nowdelta < vtp->delta) {
break;
}
/* Consuming all timers between "vtp->lasttime" and now.*/
do {
vtfunc_t fn;
/* The "last time" becomes this timer's expiration time.*/
ch.vtlist.lasttime += vtp->delta;
nowdelta -= vtp->delta;
vtp->next->prev = (virtual_timer_t *)&ch.vtlist;
ch.vtlist.next = vtp->next;
fn = vtp->func;
vtp->func = NULL;
/* If the list becomes empty then the timer is stopped.*/
if (ch.vtlist.next == (virtual_timer_t *)&ch.vtlist) {
port_timer_stop_alarm();
}
/* The callback is invoked outside the kernel critical zone.*/
chSysUnlockFromISR();
fn(vtp->par);
chSysLockFromISR();
/* Next element in the list.*/
vtp = ch.vtlist.next;
}
while (vtp->delta <= nowdelta);
}
/* If the list is empty, nothing else to do.*/
if (ch.vtlist.next == (virtual_timer_t *)&ch.vtlist) {
return;
}
/* The "unprocessed nowdelta" time slice is added to "last time"
and subtracted to next timer's delta.*/
ch.vtlist.lasttime += nowdelta;
ch.vtlist.next->delta -= nowdelta;
/* Recalculating the next alarm time.*/
delta = vtp->delta - chTimeDiffX(ch.vtlist.lasttime, now);
if (delta < (sysinterval_t)CH_CFG_ST_TIMEDELTA) {
delta = (sysinterval_t)CH_CFG_ST_TIMEDELTA;
}
#if CH_CFG_INTERVALS_SIZE > CH_CFG_ST_RESOLUTION
/* The delta could be too large for the physical timer to handle.*/
else if (delta > (sysinterval_t)TIME_MAX_SYSTIME) {
delta = (sysinterval_t)TIME_MAX_SYSTIME;
}
#endif
port_timer_set_alarm(chTimeAddX(now, delta));
chDbgAssert(chTimeDiffX(ch.vtlist.lasttime, chVTGetSystemTimeX()) <=
chTimeDiffX(ch.vtlist.lasttime, chTimeAddX(now, delta)),
"exceeding delta");
#endif /* CH_CFG_ST_TIMEDELTA > 0 */
}
#endif /* CHVT_H */
/** @} */