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| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2013-08-10 14:51:16 +0000 |
|---|---|---|
| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2013-08-10 14:51:16 +0000 |
| commit | a1435e018bfc9919cb76b1356509ecc883767fb4 (patch) | |
| tree | b82f74e9eee194c8b04ba4a0dd0b88810813caf8 /os/rt/src/chmboxes.c | |
| parent | eb7a1a15b23341693864c6fc13ac5eab5c1d6122 (diff) | |
| download | ChibiOS-a1435e018bfc9919cb76b1356509ecc883767fb4.tar.gz ChibiOS-a1435e018bfc9919cb76b1356509ecc883767fb4.tar.bz2 ChibiOS-a1435e018bfc9919cb76b1356509ecc883767fb4.zip | |
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/branches/kernel_3_dev@6123 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/rt/src/chmboxes.c')
| -rw-r--r-- | os/rt/src/chmboxes.c | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/os/rt/src/chmboxes.c b/os/rt/src/chmboxes.c new file mode 100644 index 000000000..003c779ec --- /dev/null +++ b/os/rt/src/chmboxes.c @@ -0,0 +1,398 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012,2013 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 chmboxes.c
+ * @brief Mailboxes code.
+ *
+ * @addtogroup mailboxes
+ * @details Asynchronous messages.
+ * <h2>Operation mode</h2>
+ * A mailbox is an asynchronous communication mechanism.<br>
+ * Operations defined for mailboxes:
+ * - <b>Post</b>: Posts a message on the mailbox in FIFO order.
+ * - <b>Post Ahead</b>: Posts a message on the mailbox with urgent
+ * priority.
+ * - <b>Fetch</b>: A message is fetched from the mailbox and removed
+ * from the queue.
+ * - <b>Reset</b>: The mailbox is emptied and all the stored messages
+ * are lost.
+ * .
+ * A message is a variable of type msg_t that is guaranteed to have
+ * the same size of and be compatible with (data) pointers (anyway an
+ * explicit cast is needed).
+ * If larger messages need to be exchanged then a pointer to a
+ * structure can be posted in the mailbox but the posting side has
+ * no predefined way to know when the message has been processed. A
+ * possible approach is to allocate memory (from a memory pool for
+ * example) from the posting side and free it on the fetching side.
+ * Another approach is to set a "done" flag into the structure pointed
+ * by the message.
+ * @pre In order to use the mailboxes APIs the @p CH_CFG_USE_MAILBOXES option
+ * must be enabled in @p chconf.h.
+ * @{
+ */
+
+#include "ch.h"
+
+#if CH_CFG_USE_MAILBOXES || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Module exported variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Initializes a @p mailbox_t object.
+ *
+ * @param[out] mbp the pointer to the @p mailbox_t structure to be
+ * initialized
+ * @param[in] buf pointer to the messages buffer as an array of @p msg_t
+ * @param[in] n number of elements in the buffer array
+ *
+ * @init
+ */
+void chMBObjectInit(mailbox_t *mbp, msg_t *buf, cnt_t n) {
+
+ chDbgCheck((mbp != NULL) && (buf != NULL) && (n > 0));
+
+ mbp->mb_buffer = mbp->mb_wrptr = mbp->mb_rdptr = buf;
+ mbp->mb_top = &buf[n];
+ chSemObjectInit(&mbp->mb_emptysem, n);
+ chSemObjectInit(&mbp->mb_fullsem, 0);
+}
+
+/**
+ * @brief Resets a @p mailbox_t object.
+ * @details All the waiting threads are resumed with status @p RDY_RESET and
+ * the queued messages are lost.
+ *
+ * @param[in] mbp the pointer to an initialized @p mailbox_t object
+ *
+ * @api
+ */
+void chMBReset(mailbox_t *mbp) {
+
+ chDbgCheck(mbp != NULL);
+
+ chSysLock();
+ mbp->mb_wrptr = mbp->mb_rdptr = mbp->mb_buffer;
+ chSemResetI(&mbp->mb_emptysem, mbp->mb_top - mbp->mb_buffer);
+ chSemResetI(&mbp->mb_fullsem, 0);
+ chSchRescheduleS();
+ chSysUnlock();
+}
+
+/**
+ * @brief Posts a 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] 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 operation status.
+ * @retval RDY_OK if a message has been correctly posted.
+ * @retval RDY_RESET if the mailbox has been reset while waiting.
+ * @retval RDY_TIMEOUT if the operation has timed out.
+ *
+ * @api
+ */
+msg_t chMBPost(mailbox_t *mbp, msg_t msg, systime_t time) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chMBPostS(mbp, msg, time);
+ chSysUnlock();
+ return rdymsg;
+}
+
+/**
+ * @brief Posts a 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] 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 operation status.
+ * @retval RDY_OK if a message has been correctly posted.
+ * @retval RDY_RESET if the mailbox has been reset while waiting.
+ * @retval RDY_TIMEOUT if the operation has timed out.
+ *
+ * @sclass
+ */
+msg_t chMBPostS(mailbox_t *mbp, msg_t msg, systime_t time) {
+ msg_t rdymsg;
+
+ chDbgCheckClassS();
+ chDbgCheck(mbp != NULL);
+
+ rdymsg = chSemWaitTimeoutS(&mbp->mb_emptysem, time);
+ if (rdymsg == RDY_OK) {
+ *mbp->mb_wrptr++ = msg;
+ if (mbp->mb_wrptr >= mbp->mb_top)
+ mbp->mb_wrptr = mbp->mb_buffer;
+ chSemSignalI(&mbp->mb_fullsem);
+ chSchRescheduleS();
+ }
+ return rdymsg;
+}
+
+/**
+ * @brief Posts a 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 RDY_OK if a message has been correctly posted.
+ * @retval RDY_TIMEOUT if the mailbox is full and the message cannot be
+ * posted.
+ *
+ * @iclass
+ */
+msg_t chMBPostI(mailbox_t *mbp, msg_t msg) {
+
+ chDbgCheckClassI();
+ chDbgCheck(mbp != NULL);
+
+ if (chSemGetCounterI(&mbp->mb_emptysem) <= 0)
+ return RDY_TIMEOUT;
+ chSemFastWaitI(&mbp->mb_emptysem);
+ *mbp->mb_wrptr++ = msg;
+ if (mbp->mb_wrptr >= mbp->mb_top)
+ mbp->mb_wrptr = mbp->mb_buffer;
+ chSemSignalI(&mbp->mb_fullsem);
+ return RDY_OK;
+}
+
+/**
+ * @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] 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 operation status.
+ * @retval RDY_OK if a message has been correctly posted.
+ * @retval RDY_RESET if the mailbox has been reset while waiting.
+ * @retval RDY_TIMEOUT if the operation has timed out.
+ *
+ * @api
+ */
+msg_t chMBPostAhead(mailbox_t *mbp, msg_t msg, systime_t time) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chMBPostAheadS(mbp, msg, time);
+ chSysUnlock();
+ return rdymsg;
+}
+
+/**
+ * @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] 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 operation status.
+ * @retval RDY_OK if a message has been correctly posted.
+ * @retval RDY_RESET if the mailbox has been reset while waiting.
+ * @retval RDY_TIMEOUT if the operation has timed out.
+ *
+ * @sclass
+ */
+msg_t chMBPostAheadS(mailbox_t *mbp, msg_t msg, systime_t time) {
+ msg_t rdymsg;
+
+ chDbgCheckClassS();
+ chDbgCheck(mbp != NULL);
+
+ rdymsg = chSemWaitTimeoutS(&mbp->mb_emptysem, time);
+ if (rdymsg == RDY_OK) {
+ if (--mbp->mb_rdptr < mbp->mb_buffer)
+ mbp->mb_rdptr = mbp->mb_top - 1;
+ *mbp->mb_rdptr = msg;
+ chSemSignalI(&mbp->mb_fullsem);
+ chSchRescheduleS();
+ }
+ 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 RDY_OK if a message has been correctly posted.
+ * @retval RDY_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 (chSemGetCounterI(&mbp->mb_emptysem) <= 0)
+ return RDY_TIMEOUT;
+ chSemFastWaitI(&mbp->mb_emptysem);
+ if (--mbp->mb_rdptr < mbp->mb_buffer)
+ mbp->mb_rdptr = mbp->mb_top - 1;
+ *mbp->mb_rdptr = msg;
+ chSemSignalI(&mbp->mb_fullsem);
+ return RDY_OK;
+}
+
+/**
+ * @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] 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 operation status.
+ * @retval RDY_OK if a message has been correctly fetched.
+ * @retval RDY_RESET if the mailbox has been reset while waiting.
+ * @retval RDY_TIMEOUT if the operation has timed out.
+ *
+ * @api
+ */
+msg_t chMBFetch(mailbox_t *mbp, msg_t *msgp, systime_t time) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chMBFetchS(mbp, msgp, time);
+ chSysUnlock();
+ return rdymsg;
+}
+
+/**
+ * @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] 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 operation status.
+ * @retval RDY_OK if a message has been correctly fetched.
+ * @retval RDY_RESET if the mailbox has been reset while waiting.
+ * @retval RDY_TIMEOUT if the operation has timed out.
+ *
+ * @sclass
+ */
+msg_t chMBFetchS(mailbox_t *mbp, msg_t *msgp, systime_t time) {
+ msg_t rdymsg;
+
+ chDbgCheckClassS();
+ chDbgCheck((mbp != NULL) && (msgp != NULL));
+
+ rdymsg = chSemWaitTimeoutS(&mbp->mb_fullsem, time);
+ if (rdymsg == RDY_OK) {
+ *msgp = *mbp->mb_rdptr++;
+ if (mbp->mb_rdptr >= mbp->mb_top)
+ mbp->mb_rdptr = mbp->mb_buffer;
+ chSemSignalI(&mbp->mb_emptysem);
+ chSchRescheduleS();
+ }
+ return rdymsg;
+}
+
+/**
+ * @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 RDY_OK if a message has been correctly fetched.
+ * @retval RDY_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 (chSemGetCounterI(&mbp->mb_fullsem) <= 0)
+ return RDY_TIMEOUT;
+ chSemFastWaitI(&mbp->mb_fullsem);
+ *msgp = *mbp->mb_rdptr++;
+ if (mbp->mb_rdptr >= mbp->mb_top)
+ mbp->mb_rdptr = mbp->mb_buffer;
+ chSemSignalI(&mbp->mb_emptysem);
+ return RDY_OK;
+}
+#endif /* CH_CFG_USE_MAILBOXES */
+
+/** @} */
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