/* * Copyright (C) 2016-17 Kaspar Schleiser * 2017 Freie Universität Berlin * * This file is subject to the terms and conditions of the GNU Lesser * General Public License v2.1. See the file LICENSE in the top level * directory for more details. */ /** * @defgroup sys_evtimer Millisecond interval event timers * @ingroup sys * @brief Provides timers for events up to @$2^{32}@$ milliseconds in the * future * * @note Experimental and likely to replaced with unified timer API * * RIOT's main timer subsystem is @ref sys_ztimer "ztimer" but compared to * @ref sys_ztimer "ztimer", evtimer offers: * * - only relative 32-bit millisecond timer values * Events can be scheduled with a relative offset of up to ~49.7 days in the * future. * **For time-critical stuff, use @ref sys_ztimer "ztimer"!** * - more flexible, "intrusive" timer type @ref evtimer_event_t only contains * the necessary fields, which can be extended as needed, and handlers define * actions taken on timer triggers. Check out @ref evtimer_msg_event_t as * example. * - when a number of timeouts with the same callback function need to be * scheduled, evtimer is using less RAM (due to storing the callback function * only once), while each ztimer has a function pointer for the callback. * @{ * * @file * @brief evtimer API definitions * * @author Kaspar Schleiser * @author Martine Lenders */ #ifndef EVTIMER_H #define EVTIMER_H #include #include "modules.h" #include "ztimer.h" #ifdef __cplusplus extern "C" { #endif /** * @brief Generic event */ typedef struct evtimer_event { struct evtimer_event *next; /**< the next event in the queue */ uint32_t offset; /**< offset in milliseconds from previous event */ } evtimer_event_t; /** * @brief Event timer callback type */ typedef void(*evtimer_callback_t)(evtimer_event_t* event); /** * @brief Event timer */ typedef struct { ztimer_t timer; /**< Timer */ uint32_t base; /**< Absolute time the first event is built on */ evtimer_callback_t callback; /**< Handler function for this evtimer's event type */ evtimer_event_t *events; /**< Event queue */ } evtimer_t; /** * @brief Initializes an event timer * * @warning BEWARE! Callbacks from evtimer_init() are being executed * in interrupt context. * DON'T USE THIS FUNCTION unless you know *exactly* what that means. * * @param[in] evtimer An event timer * @param[in] handler An event handler function */ void evtimer_init(evtimer_t *evtimer, evtimer_callback_t handler); /** * @brief Adds event to an event timer * * @param[in] evtimer An event timer * @param[in] event An event */ void evtimer_add(evtimer_t *evtimer, evtimer_event_t *event); /** * @brief Removes an event from an event timer * * @param[in] evtimer An event timer * @param[in] event An event */ void evtimer_del(evtimer_t *evtimer, evtimer_event_t *event); /** * @brief Print overview of current state of an event timer * * @param[in] evtimer An event timer */ void evtimer_print(const evtimer_t *evtimer); /** * @brief Return the current system time in msec */ static inline uint32_t evtimer_now_msec(void) { return ztimer_now(ZTIMER_MSEC); } #ifdef __cplusplus } #endif #endif /* EVTIMER_H */ /** @} */