From 3d2f2081cebee2936d8073ab6a55177b6549013e Mon Sep 17 00:00:00 2001 From: gdisirio Date: Tue, 17 Feb 2009 19:58:46 +0000 Subject: git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@778 35acf78f-673a-0410-8e92-d51de3d6d3f4 --- src/chmboxes.c | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 src/chmboxes.c (limited to 'src/chmboxes.c') 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 . +*/ + +/** + * @file chmboxes.c + * @brief Mailboxes code. + * @addtogroup Mailboxes + * @{ + */ + +#include + +#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 */ + +/** @} */ -- cgit v1.2.3