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ChibiOS/os/nil/src/ch.c

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/*
ChibiOS - Copyright (C) 2006..2016 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 ch.c
* @brief Nil RTOS main source file.
*
* @addtogroup NIL_KERNEL
* @{
*/
#include "ch.h"
/*===========================================================================*/
/* Module local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module exported variables. */
/*===========================================================================*/
/**
* @brief System data structures.
*/
nil_system_t nil;
/*===========================================================================*/
/* Module local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module interrupt handlers. */
/*===========================================================================*/
/*===========================================================================*/
/* Module exported functions. */
/*===========================================================================*/
#if (CH_DBG_SYSTEM_STATE_CHECK == TRUE) || defined(__DOXYGEN__)
/**
* @brief Guard code for @p chSysDisable().
*
* @notapi
*/
void _dbg_check_disable(void) {
if ((nil.isr_cnt != (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#1");
}
}
/**
* @brief Guard code for @p chSysSuspend().
*
* @notapi
*/
void _dbg_check_suspend(void) {
if ((nil.isr_cnt != (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#2");
}
}
/**
* @brief Guard code for @p chSysEnable().
*
* @notapi
*/
void _dbg_check_enable(void) {
if ((nil.isr_cnt != (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#3");
}
}
/**
* @brief Guard code for @p chSysLock().
*
* @notapi
*/
void _dbg_check_lock(void) {
if ((nil.isr_cnt != (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#4");
}
_dbg_enter_lock();
}
/**
* @brief Guard code for @p chSysUnlock().
*
* @notapi
*/
void _dbg_check_unlock(void) {
if ((nil.isr_cnt != (cnt_t)0) || (nil.lock_cnt <= (cnt_t)0)) {
chSysHalt("SV#5");
}
_dbg_leave_lock();
}
/**
* @brief Guard code for @p chSysLockFromIsr().
*
* @notapi
*/
void _dbg_check_lock_from_isr(void) {
if ((nil.isr_cnt <= (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#6");
}
_dbg_enter_lock();
}
/**
* @brief Guard code for @p chSysUnlockFromIsr().
*
* @notapi
*/
void _dbg_check_unlock_from_isr(void) {
if ((nil.isr_cnt <= (cnt_t)0) || (nil.lock_cnt <= (cnt_t)0)) {
chSysHalt("SV#7");
}
_dbg_leave_lock();
}
/**
* @brief Guard code for @p CH_IRQ_PROLOGUE().
*
* @notapi
*/
void _dbg_check_enter_isr(void) {
port_lock_from_isr();
if ((nil.isr_cnt < (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#8");
}
nil.isr_cnt++;
port_unlock_from_isr();
}
/**
* @brief Guard code for @p CH_IRQ_EPILOGUE().
*
* @notapi
*/
void _dbg_check_leave_isr(void) {
port_lock_from_isr();
if ((nil.isr_cnt <= (cnt_t)0) || (nil.lock_cnt != (cnt_t)0)) {
chSysHalt("SV#9");
}
nil.isr_cnt--;
port_unlock_from_isr();
}
/**
* @brief I-class functions context check.
* @details Verifies that the system is in an appropriate state for invoking
* an I-class API function. A panic is generated if the state is
* not compatible.
*
* @api
*/
void chDbgCheckClassI(void) {
if ((nil.isr_cnt < (cnt_t)0) || (nil.lock_cnt <= (cnt_t)0)) {
chSysHalt("SV#10");
}
}
/**
* @brief S-class functions context check.
* @details Verifies that the system is in an appropriate state for invoking
* an S-class API function. A panic is generated if the state is
* not compatible.
*
* @api
*/
void chDbgCheckClassS(void) {
if ((nil.isr_cnt != (cnt_t)0) || (nil.lock_cnt <= (cnt_t)0)) {
chSysHalt("SV#11");
}
}
#endif /* CH_DBG_SYSTEM_STATE_CHECK == TRUE */
/**
* @brief Initializes the kernel.
* @details Initializes the kernel structures, the current instructions flow
* becomes the idle thread upon return. The idle thread must not
* invoke any kernel primitive able to change state to not runnable.
* @note This function assumes that the @p nil global variable has been
* zeroed by the runtime environment. If this is not the case then
* make sure to clear it before calling this function.
*
* @special
*/
void chSysInit(void) {
thread_t *tp;
const thread_config_t *tcp;
#if CH_DBG_SYSTEM_STATE_CHECK == TRUE
nil.isr_cnt = (cnt_t)0;
nil.lock_cnt = (cnt_t)0;
#endif
/* System initialization hook.*/
CH_CFG_SYSTEM_INIT_HOOK();
/* Iterates through the list of defined threads.*/
tp = &nil.threads[0];
tcp = nil_thd_configs;
while (tp < &nil.threads[CH_CFG_NUM_THREADS]) {
#if CH_DBG_ENABLE_STACK_CHECK
tp->wabase = (stkalign_t *)tcp->wbase;
#endif
/* Port dependent thread initialization.*/
PORT_SETUP_CONTEXT(tp, tcp->wbase, tcp->wend, tcp->funcp, tcp->arg);
/* Initialization hook.*/
CH_CFG_THREAD_EXT_INIT_HOOK(tp);
tp++;
tcp++;
}
#if CH_DBG_ENABLE_STACK_CHECK
/* The idle thread is a special case because its stack is set up by the
runtime environment.*/
tp->wabase = THD_IDLE_BASE;
#endif
/* Interrupts partially enabled. It is equivalent to entering the
kernel critical zone.*/
chSysSuspend();
#if CH_DBG_SYSTEM_STATE_CHECK == TRUE
nil.lock_cnt = (cnt_t)1;
#endif
/* Heap initialization, if enabled.*/
#if CH_CFG_USE_HEAP == TRUE
_heap_init();
#endif
/* Port layer initialization last because it depend on some of the
initializations performed before.*/
port_init();
/* Runs the highest priority thread, the current one becomes the idle
thread.*/
nil.current = nil.next = nil.threads;
port_switch(nil.current, tp);
chSysUnlock();
}
/**
* @brief Halts the system.
* @details This function is invoked by the operating system when an
* unrecoverable error is detected, for example because a programming
* error in the application code that triggers an assertion while
* in debug mode.
* @note Can be invoked from any system state.
*
* @param[in] reason pointer to an error string
*
* @special
*/
void chSysHalt(const char *reason) {
port_disable();
#if NIL_DBG_ENABLED
nil.dbg_panic_msg = reason;
#else
(void)reason;
#endif
/* Halt hook code, usually empty.*/
CH_CFG_SYSTEM_HALT_HOOK(reason);
/* Harmless infinite loop.*/
while (true) {
}
}
/**
* @brief Time management handler.
* @note This handler has to be invoked by a periodic ISR in order to
* reschedule the waiting threads.
*
* @iclass
*/
void chSysTimerHandlerI(void) {
chDbgCheckClassI();
#if CH_CFG_ST_TIMEDELTA == 0
thread_t *tp = &nil.threads[0];
nil.systime++;
do {
/* Is the thread in a wait state with timeout?.*/
if (tp->timeout > (systime_t)0) {
chDbgAssert(!NIL_THD_IS_READY(tp), "is ready");
/* Did the timer reach zero?*/
if (--tp->timeout == (systime_t)0) {
/* Timeout on queues/semaphores requires a special handling because
the counter must be incremented.*/
/*lint -save -e9013 [15.7] There is no else because it is not needed.*/
if (NIL_THD_IS_WTQUEUE(tp)) {
tp->u1.semp->cnt++;
}
else if (NIL_THD_IS_SUSP(tp)) {
*tp->u1.trp = NULL;
}
/*lint -restore*/
(void) chSchReadyI(tp, MSG_TIMEOUT);
}
}
/* Lock released in order to give a preemption chance on those
architectures supporting IRQ preemption.*/
chSysUnlockFromISR();
tp++;
chSysLockFromISR();
} while (tp < &nil.threads[CH_CFG_NUM_THREADS]);
#else
thread_t *tp = &nil.threads[0];
systime_t next = (systime_t)0;
chDbgAssert(nil.nexttime == port_timer_get_alarm(), "time mismatch");
do {
systime_t timeout = tp->timeout;
/* Is the thread in a wait state with timeout?.*/
if (timeout > (systime_t)0) {
chDbgAssert(!NIL_THD_IS_READY(tp), "is ready");
chDbgAssert(timeout >= (nil.nexttime - nil.lasttime), "skipped one");
/* The volatile field is updated once, here.*/
timeout -= nil.nexttime - nil.lasttime;
tp->timeout = timeout;
if (timeout == (systime_t)0) {
/* Timeout on thread queues requires a special handling because the
counter must be incremented.*/
if (NIL_THD_IS_WTQUEUE(tp)) {
tp->u1.tqp->cnt++;
}
else {
if (NIL_THD_IS_SUSP(tp)) {
*tp->u1.trp = NULL;
}
}
(void) chSchReadyI(tp, MSG_TIMEOUT);
}
else {
if (timeout <= (systime_t)(next - (systime_t)1)) {
next = timeout;
}
}
}
/* Lock released in order to give a preemption chance on those
architectures supporting IRQ preemption.*/
chSysUnlockFromISR();
tp++;
chSysLockFromISR();
} while (tp < &nil.threads[CH_CFG_NUM_THREADS]);
nil.lasttime = nil.nexttime;
if (next > (systime_t)0) {
nil.nexttime += next;
port_timer_set_alarm(nil.nexttime);
}
else {
/* No tick event needed.*/
port_timer_stop_alarm();
}
#endif
}
/**
* @brief Unconditionally enters the kernel lock state.
* @note Can be called without previous knowledge of the current lock state.
* The final state is "s-locked".
*
* @special
*/
void chSysUnconditionalLock(void) {
if (port_irq_enabled(port_get_irq_status())) {
chSysLock();
}
}
/**
* @brief Unconditionally leaves the kernel lock state.
* @note Can be called without previous knowledge of the current lock state.
* The final state is "normal".
*
* @special
*/
void chSysUnconditionalUnlock(void) {
if (!port_irq_enabled(port_get_irq_status())) {
chSysUnlock();
}
}
/**
* @brief Returns the execution status and enters a critical zone.
* @details This functions enters into a critical zone and can be called
* from any context. Because its flexibility it is less efficient
* than @p chSysLock() which is preferable when the calling context
* is known.
* @post The system is in a critical zone.
*
* @return The previous system status, the encoding of this
* status word is architecture-dependent and opaque.
*
* @xclass
*/
syssts_t chSysGetStatusAndLockX(void) {
syssts_t sts = port_get_irq_status();
if (port_irq_enabled(sts)) {
if (port_is_isr_context()) {
chSysLockFromISR();
}
else {
chSysLock();
}
}
return sts;
}
/**
* @brief Restores the specified execution status and leaves a critical zone.
* @note A call to @p chSchRescheduleS() is automatically performed
* if exiting the critical zone and if not in ISR context.
*
* @param[in] sts the system status to be restored.
*
* @xclass
*/
void chSysRestoreStatusX(syssts_t sts) {
if (port_irq_enabled(sts)) {
if (port_is_isr_context()) {
chSysUnlockFromISR();
}
else {
chSchRescheduleS();
chSysUnlock();
}
}
}
#if (PORT_SUPPORTS_RT == TRUE) || defined(__DOXYGEN__)
/**
* @brief Realtime window test.
* @details This function verifies if the current realtime counter value
* lies within the specified range or not. The test takes care
* of the realtime counter wrapping to zero on overflow.
* @note When start==end then the function returns always true because the
* whole time range is specified.
* @note This function is only available if the port layer supports the
* option @p PORT_SUPPORTS_RT.
*
* @param[in] cnt the counter value to be tested
* @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
*/
bool chSysIsCounterWithinX(rtcnt_t cnt, rtcnt_t start, rtcnt_t end) {
return (bool)((cnt - start) < (end - start));
}
/**
* @brief Polled delay.
* @note The real delay is always few cycles in excess of the specified
* value.
* @note This function is only available if the port layer supports the
* option @p PORT_SUPPORTS_RT.
*
* @param[in] cycles number of cycles
*
* @xclass
*/
void chSysPolledDelayX(rtcnt_t cycles) {
rtcnt_t start = chSysGetRealtimeCounterX();
rtcnt_t end = start + cycles;
while (chSysIsCounterWithinX(chSysGetRealtimeCounterX(), start, end)) {
}
}
#endif /* PORT_SUPPORTS_RT == TRUE */
/**
* @brief Makes the specified thread ready for execution.
*
* @param[in] tp pointer to the @p thread_t object
* @param[in] msg the wakeup message
*
* @return The same reference passed as parameter.
*/
thread_t *chSchReadyI(thread_t *tp, msg_t msg) {
chDbgCheckClassI();
chDbgCheck((tp >= nil.threads) && (tp < &nil.threads[CH_CFG_NUM_THREADS]));
chDbgAssert(!NIL_THD_IS_READY(tp), "already ready");
chDbgAssert(nil.next <= nil.current, "priority ordering");
tp->u1.msg = msg;
tp->state = NIL_STATE_READY;
tp->timeout = (systime_t)0;
if (tp < nil.next) {
nil.next = tp;
}
return tp;
}
/**
* @brief Evaluates if preemption is required.
* @details The decision is taken by comparing the relative priorities and
* depending on the state of the round robin timeout counter.
* @note Not a user function, it is meant to be invoked by the scheduler
* itself or from within the port layer.
*
* @retval true if there is a thread that must go in running state
* immediately.
* @retval false if preemption is not required.
*
* @special
*/
bool chSchIsPreemptionRequired(void) {
return chSchIsRescRequiredI();
}
/**
* @brief Switches to the first thread on the runnable queue.
* @note Not a user function, it is meant to be invoked by the scheduler
* itself or from within the port layer.
*
* @special
*/
void chSchDoReschedule(void) {
thread_t *otp = nil.current;
nil.current = nil.next;
if (otp == &nil.threads[CH_CFG_NUM_THREADS]) {
CH_CFG_IDLE_LEAVE_HOOK();
}
port_switch(nil.next, otp);
}
/**
* @brief Reschedules if needed.
*
* @sclass
*/
void chSchRescheduleS(void) {
chDbgCheckClassS();
if (chSchIsRescRequiredI()) {
chSchDoReschedule();
}
}
/**
* @brief Puts the current thread to sleep into the specified state with
* timeout specification.
* @details The thread goes into a sleeping state, if it is not awakened
* explicitly within the specified system time then it is forcibly
* awakened with a @p NIL_MSG_TMO low level message.
*
* @param[in] newstate the new thread state or a semaphore pointer
* @param[in] timeout the number of ticks before the operation timeouts.
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The wakeup message.
* @retval NIL_MSG_TMO if a timeout occurred.
*
* @sclass
*/
msg_t chSchGoSleepTimeoutS(tstate_t newstate, systime_t timeout) {
thread_t *ntp, *otp = nil.current;
chDbgCheckClassS();
chDbgAssert(otp != &nil.threads[CH_CFG_NUM_THREADS],
"idle cannot sleep");
/* Storing the wait object for the current thread.*/
otp->state = newstate;
#if CH_CFG_ST_TIMEDELTA > 0
if (timeout != TIME_INFINITE) {
systime_t abstime;
/* TIMEDELTA makes sure to have enough time to reprogram the timer
before the free-running timer counter reaches the selected timeout.*/
if (timeout < (systime_t)CH_CFG_ST_TIMEDELTA) {
timeout = (systime_t)CH_CFG_ST_TIMEDELTA;
}
/* Absolute time of the timeout event.*/
abstime = chVTGetSystemTimeX() + timeout;
if (nil.lasttime == nil.nexttime) {
/* Special case, first thread asking for a timeout.*/
port_timer_start_alarm(abstime);
nil.nexttime = abstime;
}
else {
/* Special case, there are already other threads with a timeout
activated, evaluating the order.*/
if (chVTIsTimeWithinX(abstime, nil.lasttime, nil.nexttime)) {
port_timer_set_alarm(abstime);
nil.nexttime = abstime;
}
}
/* Timeout settings.*/
otp->timeout = abstime - nil.lasttime;
}
#else
/* Timeout settings.*/
otp->timeout = timeout;
#endif
/* Scanning the whole threads array.*/
ntp = nil.threads;
while (true) {
/* Is this thread ready to execute?*/
if (NIL_THD_IS_READY(ntp)) {
nil.current = nil.next = ntp;
if (ntp == &nil.threads[CH_CFG_NUM_THREADS]) {
CH_CFG_IDLE_ENTER_HOOK();
}
port_switch(ntp, otp);
return nil.current->u1.msg;
}
/* Points to the next thread in lowering priority order.*/
ntp++;
chDbgAssert(ntp <= &nil.threads[CH_CFG_NUM_THREADS],
"pointer out of range");
}
}
/**
* @brief Sends the current thread sleeping and sets a reference variable.
* @note This function must reschedule, it can only be called from thread
* context.
*
* @param[in] trp a pointer to a thread reference object
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The wake up message.
*
* @sclass
*/
msg_t chThdSuspendTimeoutS(thread_reference_t *trp, systime_t timeout) {
chDbgAssert(*trp == NULL, "not NULL");
*trp = nil.current;
nil.current->u1.trp = trp;
return chSchGoSleepTimeoutS(NIL_STATE_SUSP, timeout);
}
/**
* @brief Wakes up a thread waiting on a thread reference object.
* @note This function must not reschedule because it can be called from
* ISR context.
*
* @param[in] trp a pointer to a thread reference object
* @param[in] msg the message code
*
* @iclass
*/
void chThdResumeI(thread_reference_t *trp, msg_t msg) {
if (*trp != NULL) {
thread_reference_t tr = *trp;
chDbgAssert(NIL_THD_IS_SUSP(tr), "not suspended");
*trp = NULL;
(void) chSchReadyI(tr, msg);
}
}
/**
* @brief Suspends the invoking thread for the specified time.
*
* @param[in] timeout the delay in system ticks
*
* @api
*/
void chThdSleep(systime_t timeout) {
chSysLock();
chThdSleepS(timeout);
chSysUnlock();
}
/**
* @brief Suspends the invoking thread until the system time arrives to the
* specified value.
*
* @param[in] abstime absolute system time
*
* @api
*/
void chThdSleepUntil(systime_t abstime) {
chSysLock();
chThdSleepUntilS(abstime);
chSysUnlock();
}
/**
* @brief Dequeues and wakes up one thread from the threads queue object.
* @details Dequeues one thread from the queue without checking if the queue
* is empty.
* @pre The queue must contain at least an object.
*
* @param[in] tqp pointer to the threads queue object
* @param[in] msg the message code
*
* @iclass
*/
void chThdDoDequeueNextI(threads_queue_t *tqp, msg_t msg) {
thread_reference_t tr = nil.threads;
chDbgAssert(tqp->cnt > (cnt_t)0, "empty queue");
while (true) {
/* Is this thread waiting on this queue?*/
if (tr->u1.tqp == tqp) {
tqp->cnt++;
chDbgAssert(NIL_THD_IS_WTQUEUE(tr), "not waiting");
(void) chSchReadyI(tr, msg);
return;
}
tr++;
chDbgAssert(tr < &nil.threads[CH_CFG_NUM_THREADS],
"pointer out of range");
}
}
/**
* @brief Dequeues and wakes up one thread from the threads queue object,
* if any.
*
* @param[in] tqp pointer to the threads queue object
* @param[in] msg the message code
*
* @iclass
*/
void chThdDequeueNextI(threads_queue_t *tqp, msg_t msg) {
chDbgCheckClassI();
chDbgCheck(tqp != NULL);
if (tqp->cnt <= (cnt_t)0) {
chThdDoDequeueNextI(tqp, msg);
}
}
/**
* @brief Dequeues and wakes up all threads from the threads queue object.
*
* @param[in] tqp pointer to the threads queue object
* @param[in] msg the message code
*
* @iclass
*/
void chThdDequeueAllI(threads_queue_t *tqp, msg_t msg) {
thread_t *tp;
chDbgCheckClassI();
chDbgCheck(tqp != NULL);
tp = nil.threads;
while (tqp->cnt < (cnt_t)0) {
chDbgAssert(tp < &nil.threads[CH_CFG_NUM_THREADS],
"pointer out of range");
/* Is this thread waiting on this queue?*/
if (tp->u1.tqp == tqp) {
chDbgAssert(NIL_THD_IS_WTQUEUE(tp), "not waiting");
tqp->cnt++;
(void) chSchReadyI(tp, msg);
}
tp++;
}
}
#if (CH_CFG_USE_SEMAPHORES == TRUE) || defined(__DOXYGEN__)
/**
* @brief Performs a wait operation on a semaphore with timeout specification.
*
* @param[in] sp pointer to a @p semaphore_t structure
* @param[in] timeout 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 A message specifying how the invoking thread has been
* released from the semaphore.
* @retval NIL_MSG_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval NIL_MSG_RST if the semaphore has been reset using @p chSemReset().
* @retval NIL_MSG_TMO if the semaphore has not been signaled or reset within
* the specified timeout.
*
* @api
*/
msg_t chSemWaitTimeout(semaphore_t *sp, systime_t timeout) {
msg_t msg;
chSysLock();
msg = chSemWaitTimeoutS(sp, timeout);
chSysUnlock();
return msg;
}
/**
* @brief Performs a wait operation on a semaphore with timeout specification.
*
* @param[in] sp pointer to a @p semaphore_t structure
* @param[in] timeout 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 A message specifying how the invoking thread has been
* released from the semaphore.
* @retval NIL_MSG_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval NIL_MSG_RST if the semaphore has been reset using @p chSemReset().
* @retval NIL_MSG_TMO if the semaphore has not been signaled or reset within
* the specified timeout.
*
* @sclass
*/
msg_t chSemWaitTimeoutS(semaphore_t *sp, systime_t timeout) {
chDbgCheckClassS();
chDbgCheck(sp != NULL);
/* Note, the semaphore counter is a volatile variable so accesses are
manually optimized.*/
cnt_t cnt = sp->cnt;
if (cnt <= (cnt_t)0) {
if (TIME_IMMEDIATE == timeout) {
return MSG_TIMEOUT;
}
sp->cnt = cnt - (cnt_t)1;
nil.current->u1.tqp = (threads_queue_t *)sp;
return chSchGoSleepTimeoutS(NIL_STATE_WTQUEUE, timeout);
}
sp->cnt = cnt - (cnt_t)1;
return MSG_OK;
}
/**
* @brief Performs a signal operation on a semaphore.
*
* @param[in] sp pointer to a @p semaphore_t structure
*
* @api
*/
void chSemSignal(semaphore_t *sp) {
chSysLock();
chSemSignalI(sp);
chSchRescheduleS();
chSysUnlock();
}
/**
* @brief Performs a signal operation on a semaphore.
* @post This function does not reschedule so a call to a rescheduling
* function must be performed before unlocking the kernel. Note that
* interrupt handlers always reschedule on exit so an explicit
* reschedule must not be performed in ISRs.
*
* @param[in] sp pointer to a @p semaphore_t structure
*
* @iclass
*/
void chSemSignalI(semaphore_t *sp) {
chDbgCheckClassI();
chDbgCheck(sp != NULL);
if (++sp->cnt <= (cnt_t)0) {
chThdDoDequeueNextI((threads_queue_t *)sp, MSG_OK);
}
}
/**
* @brief Performs a reset operation on the semaphore.
* @post After invoking this function all the threads waiting on the
* semaphore, if any, are released and the semaphore counter is set
* to the specified, non negative, value.
*
* @param[in] sp pointer to a @p semaphore_t structure
* @param[in] n the new value of the semaphore counter. The value must
* be non-negative.
*
* @api
*/
void chSemReset(semaphore_t *sp, cnt_t n) {
chSysLock();
chSemResetI(sp, n);
chSchRescheduleS();
chSysUnlock();
}
/**
* @brief Performs a reset operation on the semaphore.
* @post After invoking this function all the threads waiting on the
* semaphore, if any, are released and the semaphore counter is set
* to the specified, non negative, value.
* @post This function does not reschedule so a call to a rescheduling
* function must be performed before unlocking the kernel. Note that
* interrupt handlers always reschedule on exit so an explicit
* reschedule must not be performed in ISRs.
*
* @param[in] sp pointer to a @p semaphore_t structure
* @param[in] n the new value of the semaphore counter. The value must
* be non-negative.
*
* @iclass
*/
void chSemResetI(semaphore_t *sp, cnt_t n) {
thread_t *tp;
cnt_t cnt;
chDbgCheckClassI();
chDbgCheck((sp != NULL) && (n >= (cnt_t)0));
cnt = sp->cnt;
sp->cnt = n;
tp = nil.threads;
while (cnt < (cnt_t)0) {
chDbgAssert(tp < &nil.threads[CH_CFG_NUM_THREADS],
"pointer out of range");
/* Is this thread waiting on this semaphore?*/
if (tp->u1.tqp == (threads_queue_t *)sp) {
chDbgAssert(NIL_THD_IS_WTQUEUE(tp), "not waiting");
cnt++;
(void) chSchReadyI(tp, MSG_RESET);
}
tp++;
}
}
#endif /* CH_CFG_USE_SEMAPHORES == TRUE */
#if (CH_CFG_USE_EVENTS == TRUE) || defined(__DOXYGEN__)
/**
* @brief Adds a set of event flags directly to the specified @p thread_t.
*
* @param[in] tp the thread to be signaled
* @param[in] mask the event flags set to be ORed
*
* @api
*/
void chEvtSignal(thread_t *tp, eventmask_t mask) {
chSysLock();
chEvtSignalI(tp, mask);
chSchRescheduleS();
chSysUnlock();
}
/**
* @brief Adds a set of event flags directly to the specified @p thread_t.
* @post This function does not reschedule so a call to a rescheduling
* function must be performed before unlocking the kernel. Note that
* interrupt handlers always reschedule on exit so an explicit
* reschedule must not be performed in ISRs.
*
* @param[in] tp the thread to be signaled
* @param[in] mask the event flags set to be ORed
*
* @iclass
*/
void chEvtSignalI(thread_t *tp, eventmask_t mask) {
chDbgCheckClassI();
chDbgCheck(tp != NULL);
tp->epmask |= mask;
if (NIL_THD_IS_WTOREVT(tp) &&
((tp->epmask & tp->u1.ewmask) != (eventmask_t)0)) {
(void) chSchReadyI(tp, MSG_OK);
}
}
/**
* @brief Waits for any of the specified events.
* @details The function waits for any event among those specified in
* @p mask to become pending then the events are cleared and
* returned.
*
* @param[in] mask mask of the event flags that the function should wait
* for, @p ALL_EVENTS enables all the events
* @param[in] timeout 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 operation has timed out.
*
* @api
*/
eventmask_t chEvtWaitAnyTimeout(eventmask_t mask, systime_t timeout) {
thread_t *ctp = nil.current;
eventmask_t m;
chSysLock();
if ((m = (ctp->epmask & mask)) == (eventmask_t)0) {
if (TIME_IMMEDIATE == timeout) {
chSysUnlock();
return (eventmask_t)0;
}
ctp->u1.ewmask = mask;
if (chSchGoSleepTimeoutS(NIL_STATE_WTOREVT, timeout) < MSG_OK) {
chSysUnlock();
return (eventmask_t)0;
}
m = ctp->epmask & mask;
}
ctp->epmask &= ~m;
chSysUnlock();
return m;
}
#endif /* CH_CFG_USE_EVENTS == TRUE */
/** @} */
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