Esempio n. 1
0
/**
 * @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;
}
Esempio n. 2
0
/**
 * @brief   Signals one thread that is waiting on the condition variable.
 *
 * @param[in] cp        pointer to the @p condition_variable_t structure
 *
 * @api
 */
void chCondSignal(condition_variable_t *cp) {

  chDbgCheck(cp != NULL);

  chSysLock();
  if (queue_notempty(&cp->c_queue))
    chSchWakeupS(queue_fifo_remove(&cp->c_queue), MSG_OK);
  chSysUnlock();
}
Esempio n. 3
0
/**
 * @brief   Signals one thread that is waiting on the condition variable.
 * @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] cp        pointer to the @p condition_variable_t structure
 *
 * @iclass
 */
void chCondSignalI(condition_variable_t *cp) {

  chDbgCheckClassI();
  chDbgCheck(cp != NULL);

  if (queue_notempty(&cp->c_queue)) {
    thread_t *tp = queue_fifo_remove(&cp->c_queue);
    tp->p_u.rdymsg = MSG_OK;
    chSchReadyI(tp);
  }
}
Esempio n. 4
0
/**
 * @brief   Performs a signal operation on a semaphore.
 *
 * @param[in] sp        pointer to a @p semaphore_t structure
 *
 * @api
 */
void chSemSignal(semaphore_t *sp) {

  chDbgCheck(sp != NULL);
  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
              "inconsistent semaphore");

  chSysLock();
  if (++sp->s_cnt <= 0)
    chSchWakeupS(queue_fifo_remove(&sp->s_queue), MSG_OK);
  chSysUnlock();
}
Esempio n. 5
0
/**
 * @brief   Signals all threads that are waiting on the condition variable.
 * @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] cp        pointer to the @p condition_variable_t structure
 *
 * @iclass
 */
void chCondBroadcastI(condition_variable_t *cp) {

  chDbgCheckClassI();
  chDbgCheck(cp != NULL);

  /* Empties the condition variable queue and inserts all the threads into the
     ready list in FIFO order. The wakeup message is set to @p MSG_RESET in
     order to make a chCondBroadcast() detectable from a chCondSignal().*/
  while (queue_notempty(&cp->queue)) {
    chSchReadyI(queue_fifo_remove(&cp->queue))->u.rdymsg = MSG_RESET;
  }
}
Esempio n. 6
0
/**
 * @brief   Adds the specified value to the semaphore counter.
 * @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         value to be added to the semaphore counter. The value
 *                      must be positive.
 *
 * @iclass
 */
void chSemAddCounterI(semaphore_t *sp, cnt_t n) {

  chDbgCheckClassI();
  chDbgCheck((sp != NULL) && (n > 0));
  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
              "inconsistent semaphore");

  while (n > 0) {
    if (++sp->s_cnt <= 0)
      chSchReadyI(queue_fifo_remove(&sp->s_queue))->p_u.rdymsg = MSG_OK;
    n--;
  }
}
Esempio n. 7
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/**
 * @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.
 * @note    The released threads can recognize they were waked up by a reset
 *          rather than a signal because the @p chSemWait() will return
 *          @p MSG_RESET instead of @p MSG_OK.
 *
 * @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) {
  cnt_t cnt;

  chDbgCheckClassI();
  chDbgCheck((sp != NULL) && (n >= 0));
  chDbgAssert(((sp->s_cnt >= 0) && queue_isempty(&sp->s_queue)) ||
              ((sp->s_cnt < 0) && queue_notempty(&sp->s_queue)),
              "inconsistent semaphore");

  cnt = sp->s_cnt;
  sp->s_cnt = n;
  while (++cnt <= 0)
    chSchReadyI(queue_lifo_remove(&sp->s_queue))->p_u.rdymsg = MSG_RESET;
}
Esempio n. 8
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/**
 * @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);
  chDbgAssert(((sp->s_cnt >= (cnt_t)0) && queue_isempty(&sp->s_queue)) ||
              ((sp->s_cnt < (cnt_t)0) && queue_notempty(&sp->s_queue)),
              "inconsistent semaphore");

  if (++sp->s_cnt <= (cnt_t)0) {
    /* Note, it is done this way in order to allow a tail call on
             chSchReadyI().*/
    thread_t *tp = queue_fifo_remove(&sp->s_queue);
    tp->p_u.rdymsg = MSG_OK;
    (void) chSchReadyI(tp);
  }
}
Esempio n. 9
0
/**
 * @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;
}
Esempio n. 10
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/**
 * @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;
}
Esempio n. 11
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/**
 * @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) {

  while (queue_notempty(tqp)) {
    chThdDoDequeueNextI(tqp, msg);
  }
}
Esempio n. 12
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/**
 * @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) {

  if (queue_notempty(tqp))
    chThdDoDequeueNextI(tqp, msg);
}