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| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2009-02-17 19:58:46 +0000 |
|---|---|---|
| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2009-02-17 19:58:46 +0000 |
| commit | 3d2f2081cebee2936d8073ab6a55177b6549013e (patch) | |
| tree | 1e57283eece612d213add53d785ab5207b7d21af /src/chmboxes.c | |
| parent | 7fe2bf4789935d592c24dbbe2aaba18c34c021cf (diff) | |
| download | ChibiOS-3d2f2081cebee2936d8073ab6a55177b6549013e.tar.gz ChibiOS-3d2f2081cebee2936d8073ab6a55177b6549013e.tar.bz2 ChibiOS-3d2f2081cebee2936d8073ab6a55177b6549013e.zip | |
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@778 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'src/chmboxes.c')
| -rw-r--r-- | src/chmboxes.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/src/chmboxes.c b/src/chmboxes.c new file mode 100644 index 000000000..63ab01364 --- /dev/null +++ b/src/chmboxes.c @@ -0,0 +1,152 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006-2007 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
+ * @{
+ */
+
+#include <ch.h>
+
+#if CH_USE_MAILBOXES
+
+/**
+ * @brief Initializes a Mailbox object.
+ *
+ * @param[out] mbp the pointer to the Mailbox structure to be initialized
+ * @param[in] buf the circular messages buffer
+ * @param[in] n the buffer size as number of @p msg_t + */
+void chMBInit(Mailbox *mbp, msg_t *buf, cnt_t n) {
+
+ mbp->mb_buffer = mbp->mb_wrptr = mbp->mb_rdptr = buf;
+ mbp->mb_top = &buf[n];
+ chSemInit(&mbp->mb_emptysem, n);
+ chSemInit(&mbp->mb_fullsem, 0);
+}
+
+/**
+ * @brief Resets a Mailbox 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 Mailbox object
+ */
+void chMBReset(Mailbox *mbp) {
+
+ 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 Mailbox object
+ * @param[in] msg the message to be posted on the mailbox
+ * @param[in] timeout the number of ticks before the operation fails
+ * @return The operation status.
+ * @retval RDY_OK if the message was correctly posted.
+ * @retval RDY_RESET if the mailbox was reset while waiting.
+ * @retval RDY_TIMEOUT if the operation timed out.
+ */
+msg_t chMBPost(Mailbox *mbp, msg_t msg, systime_t timeout) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chSemWaitTimeoutS(&mbp->mb_emptysem, timeout);
+ 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();
+ }
+ 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 Mailbox object
+ * @param[in] msg the message to be posted on the mailbox
+ * @param[in] timeout the number of ticks before the operation timeouts
+ * @return The operation status.
+ * @retval RDY_OK if the message was correctly posted.
+ * @retval RDY_RESET if the mailbox was reset while waiting.
+ * @retval RDY_TIMEOUT if the operation timed out.
+ */
+msg_t chMBPostAhead(Mailbox *mbp, msg_t msg, systime_t timeout) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chSemWaitTimeoutS(&mbp->mb_emptysem, timeout);
+ 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();
+ }
+ 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 Mailbox object
+ * @param[out] msgp pointer to a message variable for the received message
+ * @param[in] timeout the number of ticks before the operation timeouts
+ * @return The operation status.
+ * @retval RDY_OK if a message was correctly fetched.
+ * @retval RDY_RESET if the mailbox was reset while waiting.
+ * @retval RDY_TIMEOUT if the operation timed out.
+ */
+msg_t chMBFetch(Mailbox *mbp, msg_t *msgp, systime_t timeout) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chSemWaitTimeoutS(&mbp->mb_fullsem, timeout);
+ 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();
+ }
+ chSysUnlock();
+ return rdymsg;
+}
+
+#endif /* CH_USE_MAILBOXES */
+
+/** @} */
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