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/*
ChibiOS/RT - Copyright (C) 2006-2007 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 chevents.c
* @brief Events code.
* @addtogroup Events
* @{
*/
#include <ch.h>
#if CH_USE_EVENTS
/**
* @brief Registers an Event Listener on an Event Source.
*
* @param[in] esp pointer to the @p EventSource structure
* @param[in] elp pointer to the @p EventListener structure
* @param[in] emask the mask of event flags to be pended to the thread when the
* event source is broadcasted
* @note Multiple Event Listeners can specify the same bits to be pended.
*/
void chEvtRegisterMask(EventSource *esp, EventListener *elp, eventmask_t emask) {
chDbgCheck((esp != NULL) && (elp != NULL), "chEvtRegisterMask");
chSysLock();
elp->el_next = esp->es_next;
esp->es_next = elp;
elp->el_listener = currp;
elp->el_mask = emask;
chSysUnlock();
}
/**
* @brief Unregisters an Event Listener from its Event Source.
*
* @param[in] esp pointer to the @p EventSource structure
* @param[in] elp pointer to the @p EventListener structure
* @note If the event listener is not registered on the specified event source
* then the function does nothing.
* @note For optimal performance it is better to perform the unregister
* operations in inverse order of the register operations (elements are
* found on top of the list).
*/
void chEvtUnregister(EventSource *esp, EventListener *elp) {
EventListener *p;
chDbgCheck((esp != NULL) && (elp != NULL), "chEvtUnregister");
p = (EventListener *)esp;
chSysLock();
while (p->el_next != (EventListener *)esp) {
if (p->el_next == elp) {
p->el_next = elp->el_next;
break;
}
p = p->el_next;
}
chSysUnlock();
}
/**
* @brief Clears the pending events specified in the mask.
*
* @param[in] mask the events to be cleared
* @return The pending events that were cleared.
*/
eventmask_t chEvtClear(eventmask_t mask) {
eventmask_t m;
chSysLock();
m = currp->p_epending & mask;
currp->p_epending &= ~mask;
chSysUnlock();
return m;
}
/**
* @brief Pends a set of event flags on the current thread, this is @b much
* faster than using @p chEvtBroadcast() or @p chEvtSignal().
*
* @param[in] mask the events to be pended
* @return The current pending events mask.
*/
eventmask_t chEvtPend(eventmask_t mask) {
chSysLock();
mask = (currp->p_epending |= mask);
chSysUnlock();
return mask;
}
/**
* @brief Pends a set of event flags on the specified @p Thread.
*
* @param[in] tp the thread to be signaled
* @param[in] mask the event flags set to be pended
*/
void chEvtSignal(Thread *tp, eventmask_t mask) {
chDbgCheck(tp != NULL, "chEvtSignal");
chSysLock();
chEvtSignalI(tp, mask);
chSysUnlock();
}
/**
* @brief Pends a set of event flags on the specified @p Thread.
*
* @param[in] tp the thread to be signaled
* @param[in] mask the event flags set to be pended
*/
void chEvtSignalI(Thread *tp, eventmask_t mask) {
chDbgCheck(tp != NULL, "chEvtSignalI");
tp->p_epending |= mask;
/* Test on the AND/OR conditions wait states.*/
if (((tp->p_state == PRWTOREVT) && ((tp->p_epending & tp->p_ewmask) != 0)) ||
((tp->p_state == PRWTANDEVT) && ((tp->p_epending & tp->p_ewmask) == tp->p_ewmask)))
chSchReadyI(tp)->p_rdymsg = RDY_OK;
}
/**
* @brief Signals all the Event Listeners registered on the specified Event
* Source.
*
* @param[in] esp pointer to the @p EventSource structure
*/
void chEvtBroadcast(EventSource *esp) {
chSysLock();
chEvtBroadcastI(esp);
chSchRescheduleS();
chSysUnlock();
}
/**
* @brief Signals all the Event Listeners registered on the specified Event
* Source.
*
* @param[in] esp pointer to the @p EventSource structure
*/
void chEvtBroadcastI(EventSource *esp) {
EventListener *elp;
chDbgCheck(esp != NULL, "chEvtBroadcastI");
elp = esp->es_next;
while (elp != (EventListener *)esp) {
chEvtSignalI(elp->el_listener, elp->el_mask);
elp = elp->el_next;
}
}
/**
* @brief Invokes the event handlers associated with a mask.
*
* @param[in] mask mask of the events to be dispatched
* @param[in] handlers an array of @p evhandler_t. The array must have size
* equal to the number of bits in eventmask_t.
*/
void chEvtDispatch(const evhandler_t handlers[], eventmask_t mask) {
eventid_t eid;
chDbgCheck(handlers != NULL, "chEvtDispatch");
eid = 0;
while (mask) {
if (mask & EVENT_MASK(eid)) {
chDbgAssert(handlers[eid] != NULL,
"chEvtDispatch(), #1",
"null handler");
mask &= ~EVENT_MASK(eid);
handlers[eid](eid);
}
eid++;
}
}
#if CH_OPTIMIZE_SPEED || !CH_USE_EVENTS_TIMEOUT || defined(__DOXYGEN__)
/**
* @brief Waits for exactly one of the specified events.
* @details The function waits for one event among those specified in
* @p ewmask to become pending then the event is cleared and returned.
*
* @param[in] ewmask mask of the events that the function should wait for,
* @p ALL_EVENTS enables all the events
* @return The mask of the lowest id served and cleared event.
* @note One and only one event is served in the function, the one with the
* lowest event id. The function is meant to be invoked into a loop in
* order to serve all the pending events.<br>
* This means that Event Listeners with a lower event identifier have
* an higher priority.
*/
eventmask_t chEvtWaitOne(eventmask_t ewmask) {
eventmask_t m;
chSysLock();
if ((m = (currp->p_epending & ewmask)) == 0) {
currp->p_ewmask = ewmask;
chSchGoSleepS(PRWTOREVT);
m = currp->p_epending & ewmask;
}
m &= -m;
currp->p_epending &= ~m;
chSysUnlock();
return m;
}
/**
* @brief Waits for any of the specified events.
* @details The function waits for any event among those specified in
* @p ewmask to become pending then the events are cleared and returned.
*
* @param[in] ewmask mask of the events that the function should wait for,
* @p ALL_EVENTS enables all the events
* @return The mask of the served and cleared events.
*/
eventmask_t chEvtWaitAny(eventmask_t ewmask) {
eventmask_t m;
chSysLock();
if ((m = (currp->p_epending & ewmask)) == 0) {
currp->p_ewmask = ewmask;
chSchGoSleepS(PRWTOREVT);
m = currp->p_epending & ewmask;
}
currp->p_epending &= ~m;
chSysUnlock();
return m;
}
/**
* @brief Waits for all the specified events.
* @details The function waits for all the events specified in @p ewmask to
* become pending then the events are cleared and returned.
*
* @param[in] ewmask mask of the event ids that the function should wait for
* @return The mask of the served and cleared events.
*/
eventmask_t chEvtWaitAll(eventmask_t ewmask) {
chSysLock();
if ((currp->p_epending & ewmask) != ewmask) {
currp->p_ewmask = ewmask;
chSchGoSleepS(PRWTANDEVT);
}
currp->p_epending &= ~ewmask;
chSysUnlock();
return ewmask;
}
#endif /* CH_OPTIMIZE_SPEED || !CH_USE_EVENTS_TIMEOUT */
#if CH_USE_EVENTS_TIMEOUT
/**
* @brief Waits for exactly one of the specified events.
* @details The function waits for one event among those specified in
* @p ewmask to become pending then the event is cleared and returned.
*
* @param[in] ewmask mask of the events that the function should wait for,
* @p ALL_EVENTS enables all the events
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The mask of the lowest id served and cleared event.
* @retval 0 if the specified timeout expired.
* @note One and only one event is served in the function, the one with the
* lowest event id. The function is meant to be invoked into a loop in
* order to serve all the pending events.<br>
* This means that Event Listeners with a lower event identifier have
* an higher priority.
*/
eventmask_t chEvtWaitOneTimeout(eventmask_t ewmask, systime_t time) {
eventmask_t m;
chSysLock();
if ((m = (currp->p_epending & ewmask)) == 0) {
if (TIME_IMMEDIATE == time)
return (eventmask_t)0;
currp->p_ewmask = ewmask;
if (chSchGoSleepTimeoutS(PRWTOREVT, time) < RDY_OK)
return (eventmask_t)0;
m = currp->p_epending & ewmask;
}
m &= -m;
currp->p_epending &= ~m;
chSysUnlock();
return m;
}
/**
* @brief Waits for any of the specified events.
* @details The function waits for any event among those specified in
* @p ewmask to become pending then the events are cleared and
* returned.
*
* @param[in] ewmask mask of the events that the function should wait for,
* @p ALL_EVENTS enables all the events
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The mask of the served and cleared events.
* @retval 0 if the specified timeout expired.
*/
eventmask_t chEvtWaitAnyTimeout(eventmask_t ewmask, systime_t time) {
eventmask_t m;
chSysLock();
if ((m = (currp->p_epending & ewmask)) == 0) {
if (TIME_IMMEDIATE == time)
return (eventmask_t)0;
currp->p_ewmask = ewmask;
if (chSchGoSleepTimeoutS(PRWTOREVT, time) < RDY_OK)
return (eventmask_t)0;
m = currp->p_epending & ewmask;
}
currp->p_epending &= ~m;
chSysUnlock();
return m;
}
/**
* @brief Waits for all the specified events.
* @details The function waits for all the events specified in @p ewmask to
* become pending then the events are cleared and returned.
*
* @param[in] ewmask mask of the event ids that the function should wait for
* @param[in] time the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The mask of the served and cleared events.
* @retval 0 if the specified timeout expired.
*/
eventmask_t chEvtWaitAllTimeout(eventmask_t ewmask, systime_t time) {
chSysLock();
if ((currp->p_epending & ewmask) != ewmask) {
if (TIME_IMMEDIATE == time)
return (eventmask_t)0;
currp->p_ewmask = ewmask;
if (chSchGoSleepTimeoutS(PRWTANDEVT, time) < RDY_OK)
return (eventmask_t)0;
}
currp->p_epending &= ~ewmask;
chSysUnlock();
return ewmask;
}
#endif /* CH_USE_EVENTS_TIMEOUT */
#endif /* CH_USE_EVENTS */
/** @} */
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