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| author | Giovanni Di Sirio <gdisirio@gmail.com> | 2016-02-16 09:59:21 +0000 |
|---|---|---|
| committer | Giovanni Di Sirio <gdisirio@gmail.com> | 2016-02-16 09:59:21 +0000 |
| commit | 641f2c372605cf405f0dda8536b45a78e0e5e2e2 (patch) | |
| tree | f120afff37ef959b367a6023749700d5b618beff /os/common/oslib/src/chmboxes.c | |
| parent | 5e24a813bef8d7ac5ca79fe9079db0fc2d2bb8b2 (diff) | |
| download | ChibiOS-641f2c372605cf405f0dda8536b45a78e0e5e2e2.tar.gz ChibiOS-641f2c372605cf405f0dda8536b45a78e0e5e2e2.tar.bz2 ChibiOS-641f2c372605cf405f0dda8536b45a78e0e5e2e2.zip | |
Tree reorganization.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@8899 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/common/oslib/src/chmboxes.c')
| -rw-r--r-- | os/common/oslib/src/chmboxes.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/os/common/oslib/src/chmboxes.c b/os/common/oslib/src/chmboxes.c new file mode 100644 index 000000000..bb75fee6c --- /dev/null +++ b/os/common/oslib/src/chmboxes.c @@ -0,0 +1,435 @@ +/*
+ ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.
+
+ This file is part of ChibiOS.
+
+ ChibiOS 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 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.
+ * @note Compatible with RT and NIL.
+ * @{
+ */
+
+#include "ch.h"
+
+#if (CH_CFG_USE_MAILBOXES == TRUE) || 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 > (cnt_t)0));
+
+ mbp->buffer = buf;
+ mbp->rdptr = buf;
+ mbp->wrptr = buf;
+ mbp->top = &buf[n];
+ chSemObjectInit(&mbp->emptysem, n);
+ chSemObjectInit(&mbp->fullsem, (cnt_t)0);
+}
+
+/**
+ * @brief Resets a @p mailbox_t object.
+ * @details All the waiting threads are resumed with status @p MSG_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) {
+
+ chSysLock();
+ chMBResetI(mbp);
+ chSchRescheduleS();
+ chSysUnlock();
+}
+
+/**
+ * @brief Resets a @p mailbox_t object.
+ * @details All the waiting threads are resumed with status @p MSG_RESET and
+ * the queued messages are lost.
+ *
+ * @param[in] mbp the pointer to an initialized @p mailbox_t object
+ *
+ * @api
+ */
+void chMBResetI(mailbox_t *mbp) {
+
+ chDbgCheckClassI();
+ chDbgCheck(mbp != NULL);
+
+ mbp->wrptr = mbp->buffer;
+ mbp->rdptr = mbp->buffer;
+ chSemResetI(&mbp->emptysem, (cnt_t)(mbp->top - mbp->buffer));
+ chSemResetI(&mbp->fullsem, (cnt_t)0);
+}
+
+/**
+ * @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] 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 while waiting.
+ * @retval MSG_TIMEOUT if the operation has timed out.
+ *
+ * @api
+ */
+msg_t chMBPost(mailbox_t *mbp, msg_t msg, systime_t timeout) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chMBPostS(mbp, msg, timeout);
+ 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] 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 while waiting.
+ * @retval MSG_TIMEOUT if the operation has timed out.
+ *
+ * @sclass
+ */
+msg_t chMBPostS(mailbox_t *mbp, msg_t msg, systime_t timeout) {
+ msg_t rdymsg;
+
+ chDbgCheckClassS();
+ chDbgCheck(mbp != NULL);
+
+ rdymsg = chSemWaitTimeoutS(&mbp->emptysem, timeout);
+ if (rdymsg == MSG_OK) {
+ *mbp->wrptr++ = msg;
+ if (mbp->wrptr >= mbp->top) {
+ mbp->wrptr = mbp->buffer;
+ }
+ chSemSignalI(&mbp->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 MSG_OK if a message has been correctly posted.
+ * @retval MSG_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->emptysem) <= (cnt_t)0) {
+ return MSG_TIMEOUT;
+ }
+
+ chSemFastWaitI(&mbp->emptysem);
+ *mbp->wrptr++ = msg;
+ if (mbp->wrptr >= mbp->top) {
+ mbp->wrptr = mbp->buffer;
+ }
+ chSemSignalI(&mbp->fullsem);
+
+ return MSG_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] 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 while waiting.
+ * @retval MSG_TIMEOUT if the operation has timed out.
+ *
+ * @api
+ */
+msg_t chMBPostAhead(mailbox_t *mbp, msg_t msg, systime_t timeout) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chMBPostAheadS(mbp, msg, timeout);
+ 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] 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 while waiting.
+ * @retval MSG_TIMEOUT if the operation has timed out.
+ *
+ * @sclass
+ */
+msg_t chMBPostAheadS(mailbox_t *mbp, msg_t msg, systime_t timeout) {
+ msg_t rdymsg;
+
+ chDbgCheckClassS();
+ chDbgCheck(mbp != NULL);
+
+ rdymsg = chSemWaitTimeoutS(&mbp->emptysem, timeout);
+ if (rdymsg == MSG_OK) {
+ if (--mbp->rdptr < mbp->buffer) {
+ mbp->rdptr = mbp->top - 1;
+ }
+ *mbp->rdptr = msg;
+ chSemSignalI(&mbp->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 MSG_OK if a message has been correctly posted.
+ * @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 (chSemGetCounterI(&mbp->emptysem) <= (cnt_t)0) {
+ return MSG_TIMEOUT;
+ }
+ chSemFastWaitI(&mbp->emptysem);
+ if (--mbp->rdptr < mbp->buffer) {
+ mbp->rdptr = mbp->top - 1;
+ }
+ *mbp->rdptr = msg;
+ chSemSignalI(&mbp->fullsem);
+
+ return MSG_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] 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 while waiting.
+ * @retval MSG_TIMEOUT if the operation has timed out.
+ *
+ * @api
+ */
+msg_t chMBFetch(mailbox_t *mbp, msg_t *msgp, systime_t timeout) {
+ msg_t rdymsg;
+
+ chSysLock();
+ rdymsg = chMBFetchS(mbp, msgp, timeout);
+ 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] 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 while waiting.
+ * @retval MSG_TIMEOUT if the operation has timed out.
+ *
+ * @sclass
+ */
+msg_t chMBFetchS(mailbox_t *mbp, msg_t *msgp, systime_t timeout) {
+ msg_t rdymsg;
+
+ chDbgCheckClassS();
+ chDbgCheck((mbp != NULL) && (msgp != NULL));
+
+ rdymsg = chSemWaitTimeoutS(&mbp->fullsem, timeout);
+ if (rdymsg == MSG_OK) {
+ *msgp = *mbp->rdptr++;
+ if (mbp->rdptr >= mbp->top) {
+ mbp->rdptr = mbp->buffer;
+ }
+ chSemSignalI(&mbp->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 MSG_OK if a message has been correctly fetched.
+ * @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 (chSemGetCounterI(&mbp->fullsem) <= (cnt_t)0) {
+ return MSG_TIMEOUT;
+ }
+ chSemFastWaitI(&mbp->fullsem);
+ *msgp = *mbp->rdptr++;
+ if (mbp->rdptr >= mbp->top) {
+ mbp->rdptr = mbp->buffer;
+ }
+ chSemSignalI(&mbp->emptysem);
+
+ return MSG_OK;
+}
+#endif /* CH_CFG_USE_MAILBOXES == TRUE */
+
+/** @} */
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