/** * \addtogroup sys * @{ */ /** * \defgroup ctimer Callback timer * @{ * * The ctimer module provides a timer mechanism that calls a specified * C function when a ctimer expires. * */ /* * Copyright (c) 2006, Swedish Institute of Computer Science. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * This file is part of the Contiki operating system. * */ /** * \file * Header file for the callback timer * \author * Adam Dunkels <adam@sics.se> */ #ifndef CTIMER_H_ #define CTIMER_H_ #include "sys/etimer.h" struct ctimer { struct ctimer *next; struct etimer etimer; struct process *p; void (*f)(void *); void *ptr; }; /** * \brief Reset a callback timer with the same interval as was * previously set. * \param c A pointer to the callback timer. * * This function resets the callback timer with the same * interval that was given to the callback timer with the * ctimer_set() function. The start point of the interval * is the exact time that the callback timer last * expired. Therefore, this function will cause the timer * to be stable over time, unlike the ctimer_restart() * function. * * \sa ctimer_restart() */ void ctimer_reset(struct ctimer *c); /** * \brief Restart a callback timer from the current point in time * \param c A pointer to the callback timer. * * This function restarts the callback timer with the same * interval that was given to the ctimer_set() * function. The callback 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 * ctimer_reset() function instead. * * \sa ctimer_reset() */ void ctimer_restart(struct ctimer *c); /** * \brief Set a callback timer. * \param c A pointer to the callback timer. * \param t The interval before the timer expires. * \param f A function to be called when the timer expires. * \param ptr An opaque pointer that will be supplied as an argument to the callback function. * * This function is used to set a callback timer for a time * sometime in the future. When the callback timer expires, * the callback function f will be called with ptr as argument. * */ void ctimer_set(struct ctimer *c, clock_time_t t, void (*f)(void *), void *ptr); /** * \brief Stop a pending callback timer. * \param c A pointer to the pending callback timer. * * This function stops a callback timer that has previously * been set with ctimer_set(), ctimer_reset(), or ctimer_restart(). * After this function has been called, the callback timer will be * expired and will not call the callback function. * */ void ctimer_stop(struct ctimer *c); /** * \brief Check if a callback timer has expired. * \param c A pointer to the callback timer * \return Non-zero if the timer has expired, zero otherwise. * * This function tests if a callback timer has expired and * returns true or false depending on its status. */ int ctimer_expired(struct ctimer *c); /** * \brief Initialize the callback timer library. * * This function initializes the callback timer library and * should be called from the system boot up code. */ void ctimer_init(void); #endif /* CTIMER_H_ */ /** @} */ /** @} */