/**
* @brief Retrieves a message from a mailbox.
* @details This variant is non-blocking, the function returns a timeout
* condition if the queue is empty.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[out] msgp pointer to a message variable for the received message
* @return The operation status.
* @retval MSG_OK if a message has been correctly fetched.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the mailbox is empty and a message cannot be
* fetched.
*
* @iclass
*/
msg_t chMBFetchI(mailbox_t *mbp, msg_t *msgp) {
chDbgCheckClassI();
chDbgCheck((mbp != NULL) && (msgp != NULL));
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a message in queue? if so then fetch.*/
if (chMBGetUsedCountI(mbp) > (size_t)0) {
*msgp = *mbp->rdptr++;
if (mbp->rdptr >= mbp->top) {
mbp->rdptr = mbp->buffer;
}
mbp->cnt--;
/* If there is a writer waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qw, MSG_OK);
return MSG_OK;
}
/* No message, immediate timeout.*/
return MSG_TIMEOUT;
}
/**
* @brief Retrieves a message from a mailbox.
* @details The invoking thread waits until a message is posted in the mailbox
* or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[out] msgp pointer to a message variable for the received message
* @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 operation status.
* @retval MSG_OK if a message has been correctly fetched.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @sclass
*/
msg_t chMBFetchTimeoutS(mailbox_t *mbp, msg_t *msgp, sysinterval_t timeout) {
msg_t rdymsg;
chDbgCheckClassS();
chDbgCheck((mbp != NULL) && (msgp != NULL));
do {
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a message in queue? if so then fetch.*/
if (chMBGetUsedCountI(mbp) > (size_t)0) {
*msgp = *mbp->rdptr++;
if (mbp->rdptr >= mbp->top) {
mbp->rdptr = mbp->buffer;
}
mbp->cnt--;
/* If there is a writer waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qw, MSG_OK);
chSchRescheduleS();
return MSG_OK;
}
/* No message in the queue, waiting for a message to become available.*/
rdymsg = chThdEnqueueTimeoutS(&mbp->qr, timeout);
} while (rdymsg == MSG_OK);
return rdymsg;
}
/**
* @brief Posts an high priority message into a mailbox.
* @details This variant is non-blocking, the function returns a timeout
* condition if the queue is full.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @return The operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the mailbox is full and the message cannot be
* posted.
*
* @iclass
*/
msg_t chMBPostAheadI(mailbox_t *mbp, msg_t msg) {
chDbgCheckClassI();
chDbgCheck(mbp != NULL);
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a free message slot in queue? if so then post.*/
if (chMBGetFreeCountI(mbp) > (size_t)0) {
if (--mbp->rdptr < mbp->buffer) {
mbp->rdptr = mbp->top - 1;
}
*mbp->rdptr = msg;
mbp->cnt++;
/* If there is a reader waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qr, MSG_OK);
return MSG_OK;
}
/* No space, immediate timeout.*/
return MSG_TIMEOUT;
}
/**
* @brief Posts an high priority message into a mailbox.
* @details The invoking thread waits until a empty slot in the mailbox becomes
* available or the specified time runs out.
*
* @param[in] mbp the pointer to an initialized @p mailbox_t object
* @param[in] msg the message to be posted on the mailbox
* @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 operation status.
* @retval MSG_OK if a message has been correctly posted.
* @retval MSG_RESET if the mailbox has been reset.
* @retval MSG_TIMEOUT if the operation has timed out.
*
* @sclass
*/
msg_t chMBPostAheadTimeoutS(mailbox_t *mbp, msg_t msg, sysinterval_t timeout) {
msg_t rdymsg;
chDbgCheckClassS();
chDbgCheck(mbp != NULL);
do {
/* If the mailbox is in reset state then returns immediately.*/
if (mbp->reset) {
return MSG_RESET;
}
/* Is there a free message slot in queue? if so then post.*/
if (chMBGetFreeCountI(mbp) > (size_t)0) {
if (--mbp->rdptr < mbp->buffer) {
mbp->rdptr = mbp->top - 1;
}
*mbp->rdptr = msg;
mbp->cnt++;
/* If there is a reader waiting then makes it ready.*/
chThdDequeueNextI(&mbp->qr, MSG_OK);
chSchRescheduleS();
return MSG_OK;
}
/* No space in the queue, waiting for a slot to become available.*/
rdymsg = chThdEnqueueTimeoutS(&mbp->qw, timeout);
} while (rdymsg == MSG_OK);
return rdymsg;
}
/**
* @brief Input queue write.
* @details A byte value is written into the low end of an input queue.
*
* @param[in] iqp pointer to an @p input_queue_t structure
* @param[in] b the byte value to be written in the queue
* @return The operation status.
* @retval Q_OK if the operation has been completed with success.
* @retval Q_FULL if the queue is full and the operation cannot be
* completed.
*
* @iclass
*/
msg_t chIQPutI(input_queue_t *iqp, uint8_t b) {
chDbgCheckClassI();
if (chIQIsFullI(iqp))
return Q_FULL;
iqp->q_counter++;
*iqp->q_wrptr++ = b;
if (iqp->q_wrptr >= iqp->q_top)
iqp->q_wrptr = iqp->q_buffer;
chThdDequeueNextI(&iqp->q_waiting, Q_OK);
return Q_OK;
}
/**
* @brief Output queue read.
* @details A byte value is read from the low end of an output queue.
*
* @param[in] oqp pointer to an @p output_queue_t structure
* @return The byte value from the queue.
* @retval Q_EMPTY if the queue is empty.
*
* @iclass
*/
msg_t chOQGetI(output_queue_t *oqp) {
uint8_t b;
chDbgCheckClassI();
if (chOQIsEmptyI(oqp))
return Q_EMPTY;
oqp->q_counter++;
b = *oqp->q_rdptr++;
if (oqp->q_rdptr >= oqp->q_top)
oqp->q_rdptr = oqp->q_buffer;
chThdDequeueNextI(&oqp->q_waiting, Q_OK);
return b;
}
/**
* @brief Input queue write.
* @details A byte value is written into the low end of an input queue.
*
* @param[in] iqp pointer to an @p input_queue_t structure
* @param[in] b the byte value to be written in the queue
* @return The operation status.
* @retval Q_OK if the operation has been completed with success.
* @retval Q_FULL if the queue is full and the operation cannot be
* completed.
*
* @iclass
*/
msg_t chIQPutI(input_queue_t *iqp, uint8_t b) {
chDbgCheckClassI();
if (chIQIsFullI(iqp)) {
return Q_FULL;
}
iqp->counter++;
*iqp->wrptr++ = b;
if (iqp->wrptr >= iqp->top) {
iqp->wrptr = iqp->buffer;
}
chThdDequeueNextI(&iqp->waiting, Q_OK);
return Q_OK;
}
/**
* @brief Output queue read.
* @details A byte value is read from the low end of an output queue.
*
* @param[in] oqp pointer to an @p output_queue_t structure
* @return The byte value from the queue.
* @retval Q_EMPTY if the queue is empty.
*
* @iclass
*/
msg_t chOQGetI(output_queue_t *oqp) {
uint8_t b;
chDbgCheckClassI();
if (chOQIsEmptyI(oqp)) {
return Q_EMPTY;
}
oqp->counter++;
b = *oqp->rdptr++;
if (oqp->rdptr >= oqp->top) {
oqp->rdptr = oqp->buffer;
}
chThdDequeueNextI(&oqp->waiting, Q_OK);
return (msg_t)b;
}