/**
* @brief Performs atomic signal and wait operations on two semaphores.
*
* @param[in] sps pointer to a @p semaphore_t structure to be signaled
* @param[in] spw pointer to a @p semaphore_t structure to wait on
* @return A message specifying how the invoking thread has been
* released from the semaphore.
* @retval MSG_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval MSG_RESET if the semaphore has been reset using @p chSemReset().
*
* @api
*/
msg_t chSemSignalWait(semaphore_t *sps, semaphore_t *spw) {
msg_t msg;
chDbgCheck((sps != NULL) && (spw != NULL));
chDbgAssert(((sps->s_cnt >= (cnt_t)0) && queue_isempty(&sps->s_queue)) ||
((sps->s_cnt < (cnt_t)0) && queue_notempty(&sps->s_queue)),
"inconsistent semaphore");
chDbgAssert(((spw->s_cnt >= (cnt_t)0) && queue_isempty(&spw->s_queue)) ||
((spw->s_cnt < (cnt_t)0) && queue_notempty(&spw->s_queue)),
"inconsistent semaphore");
chSysLock();
if (++sps->s_cnt <= (cnt_t)0) {
chSchReadyI(queue_fifo_remove(&sps->s_queue))->p_u.rdymsg = MSG_OK;
}
if (--spw->s_cnt < (cnt_t)0) {
thread_t *ctp = currp;
sem_insert(ctp, &spw->s_queue);
ctp->p_u.wtsemp = spw;
chSchGoSleepS(CH_STATE_WTSEM);
msg = ctp->p_u.rdymsg;
}
else {
chSchRescheduleS();
msg = MSG_OK;
}
chSysUnlock();
return msg;
}
/**
* @brief Performs atomic signal and wait operations on two semaphores.
* @pre The configuration option @p CH_USE_SEMSW must be enabled in order
* to use this function.
*
* @param[in] sps pointer to a @p Semaphore structure to be signaled
* @param[in] spw pointer to a @p Semaphore structure to be wait on
* @return A message specifying how the invoking thread has been
* released from the semaphore.
* @retval RDY_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval RDY_RESET if the semaphore has been reset using @p chSemReset().
*
* @api
*/
msg_t chSemSignalWait(Semaphore *sps, Semaphore *spw) {
msg_t msg;
chDbgCheck((sps != NULL) && (spw != NULL), "chSemSignalWait");
chDbgAssert(((sps->s_cnt >= 0) && isempty(&sps->s_queue)) ||
((sps->s_cnt < 0) && notempty(&sps->s_queue)),
"chSemSignalWait(), #1",
"inconsistent semaphore");
chDbgAssert(((spw->s_cnt >= 0) && isempty(&spw->s_queue)) ||
((spw->s_cnt < 0) && notempty(&spw->s_queue)),
"chSemSignalWait(), #2",
"inconsistent semaphore");
chSysLock();
if (++sps->s_cnt <= 0)
chSchReadyI(fifo_remove(&sps->s_queue))->p_u.rdymsg = RDY_OK;
if (--spw->s_cnt < 0) {
Thread *ctp = currp;
sem_insert(ctp, &spw->s_queue);
ctp->p_u.wtobjp = spw;
chSchGoSleepS(THD_STATE_WTSEM);
msg = ctp->p_u.rdymsg;
}
else {
chSchRescheduleS();
msg = RDY_OK;
}
chSysUnlock();
return msg;
}
/**
* @brief Performs a wait operation on a semaphore.
*
* @param[in] sp pointer to a @p semaphore_t structure
* @return A message specifying how the invoking thread has been
* released from the semaphore.
* @retval MSG_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval MSG_RESET if the semaphore has been reset using @p chSemReset().
*
* @sclass
*/
msg_t chSemWaitS(semaphore_t *sp) {
chDbgCheckClassS();
chDbgCheck(sp != NULL);
chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
"inconsistent semaphore");
if (--sp->s_cnt < 0) {
currp->p_u.wtobjp = sp;
sem_insert(currp, &sp->s_queue);
chSchGoSleepS(CH_STATE_WTSEM);
return currp->p_u.rdymsg;
}
return MSG_OK;
}
/**
* @brief Performs a wait operation on a semaphore.
*
* @param[in] sp pointer to a @p Semaphore structure
* @return A message specifying how the invoking thread has been
* released from the semaphore.
* @retval RDY_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval RDY_RESET if the semaphore has been reset using @p chSemReset().
*
* @sclass
*/
msg_t chSemWaitS(Semaphore *sp) {
chDbgCheck(sp != NULL, "chSemWaitS");
chDbgAssert(((sp->s_cnt >= 0) && isempty(&sp->s_queue)) ||
((sp->s_cnt < 0) && notempty(&sp->s_queue)),
"chSemWaitS(), #1",
"inconsistent semaphore");
if (--sp->s_cnt < 0) {
currp->p_u.wtobjp = sp;
sem_insert(currp, &sp->s_queue);
chSchGoSleepS(THD_STATE_WTSEM);
return currp->p_u.rdymsg;
}
return RDY_OK;
}
/**
* @brief Performs a wait operation on a semaphore with timeout specification.
*
* @param[in] sp pointer to a @p semaphore_t structure
* @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 A message specifying how the invoking thread has been
* released from the semaphore.
* @retval MSG_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval MSG_RESET if the semaphore has been reset using @p chSemReset().
* @retval MSG_TIMEOUT if the semaphore has not been signaled or reset within
* the specified timeout.
*
* @sclass
*/
msg_t chSemWaitTimeoutS(semaphore_t *sp, systime_t time) {
chDbgCheckClassS();
chDbgCheck(sp != NULL);
chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
"inconsistent semaphore");
if (--sp->s_cnt < 0) {
if (TIME_IMMEDIATE == time) {
sp->s_cnt++;
return MSG_TIMEOUT;
}
currp->p_u.wtobjp = sp;
sem_insert(currp, &sp->s_queue);
return chSchGoSleepTimeoutS(CH_STATE_WTSEM, time);
}
return MSG_OK;
}
/**
* @brief Performs a wait operation on a semaphore with timeout specification.
*
* @param[in] sp pointer to a @p Semaphore structure
* @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 A message specifying how the invoking thread has been
* released from the semaphore.
* @retval RDY_OK if the thread has not stopped on the semaphore or the
* semaphore has been signaled.
* @retval RDY_RESET if the semaphore has been reset using @p chSemReset().
* @retval RDY_TIMEOUT if the semaphore has not been signaled or reset within
* the specified timeout.
*
* @sclass
*/
msg_t chSemWaitTimeoutS(Semaphore *sp, systime_t time) {
chDbgCheck(sp != NULL, "chSemWaitTimeoutS");
chDbgAssert(((sp->s_cnt >= 0) && isempty(&sp->s_queue)) ||
((sp->s_cnt < 0) && notempty(&sp->s_queue)),
"chSemWaitTimeoutS(), #1",
"inconsistent semaphore");
if (--sp->s_cnt < 0) {
if (TIME_IMMEDIATE == time) {
sp->s_cnt++;
return RDY_TIMEOUT;
}
currp->p_u.wtobjp = sp;
sem_insert(currp, &sp->s_queue);
return chSchGoSleepTimeoutS(THD_STATE_WTSEM, time);
}
return RDY_OK;
}