/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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/RT 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 macros and structures.
*
* @addtogroup time
* @{
*/
#ifndef _CHVT_H_
#define _CHVT_H_
/**
* @brief Time conversion utility.
* @details Converts from seconds to system ticks number.
* @note The result is rounded upward to the next tick boundary.
*/
#define S2ST(sec) ((systime_t)((sec) * CH_FREQUENCY))
/**
* @brief Time conversion utility.
* @details Converts from milliseconds to system ticks number.
* @note The result is rounded upward to the next tick boundary.
*/
#define MS2ST(msec) ((systime_t)(((((msec) - 1L) * CH_FREQUENCY) / 1000L) + 1L))
/**
* @brief Time conversion utility.
* @details Converts from microseconds to system ticks number.
* @note The result is rounded upward to the next tick boundary.
*/
#define US2ST(usec) ((systime_t)(((((usec) - 1L) * CH_FREQUENCY) / 1000000L) + 1L))
/**
* @brief Virtual Timer callback function.
*/
typedef void (*vtfunc_t)(void *);
/**
* @brief Virtual Timer structure type.
*/
typedef struct VirtualTimer VirtualTimer;
/**
* @extends DeltaList
*
* @brief Virtual Timer descriptor structure.
*/
struct VirtualTimer {
VirtualTimer *vt_next; /**< @brief Next timer in the delta
list. */
VirtualTimer *vt_prev; /**< @brief Previous timer in the delta
list. */
systime_t vt_time; /**< @brief Time delta before timeout. */
vtfunc_t vt_func; /**< @brief Timer callback function
pointer. */
void *vt_par; /**< @brief Timer callback function
parameter. */
};
/**
* @brief Virtual timers list header.
* @note The delta list is implemented as a double link bidirectional list
* in order to make the unlink time constant, the reset of a virtual
* timer is often used in the code.
*/
typedef struct {
VirtualTimer *vt_next; /**< @brief Next timer in the delta
list. */
VirtualTimer *vt_prev; /**< @brief Last timer in the delta
list. */
systime_t vt_time; /**< @brief Must be initialized to -1. */
volatile systime_t vt_systime; /**< @brief System Time counter. */
} VTList;
extern VTList vtlist;
/**
* @brief Virtual timers ticker.
*
* @iclass
*/
#define chVTDoTickI() { \
vtlist.vt_systime++; \
if (&vtlist != (VTList *)vtlist.vt_next) { \
VirtualTimer *vtp; \
\
--vtlist.vt_next->vt_time; \
while (!(vtp = vtlist.vt_next)->vt_time) { \
vtfunc_t fn = vtp->vt_func; \
vtp->vt_func = (vtfunc_t)NULL; \
vtp->vt_next->vt_prev = (void *)&vtlist; \
(&vtlist)->vt_next = vtp->vt_next; \
fn(vtp->vt_par); \
} \
} \
}
/*
* Virtual Timers APIs.
*/
#ifdef __cplusplus
extern "C" {
#endif
void vt_init(void);
void chVTSetI(VirtualTimer *vtp, systime_t time, vtfunc_t vtfunc, void *par);
void chVTResetI(VirtualTimer *vtp);
bool_t chTimeIsWithin(systime_t start, systime_t end);
#ifdef __cplusplus
}
#endif
/**
* @brief Returns TRUE if the speciified timer is armed.
*
* @iclass
*/
#define chVTIsArmedI(vtp) ((vtp)->vt_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 is designed to work with the @p chThdSleepUntil().
*
* @return The system time in ticks.r
*
* @api
*/
#define chTimeNow() (vtlist.vt_systime)
#endif /* _CHVT_H_ */
/** @} */
