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Diffstat (limited to 'os/common/oslib/include/chmboxes.h')
| -rw-r--r-- | os/common/oslib/include/chmboxes.h | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/os/common/oslib/include/chmboxes.h b/os/common/oslib/include/chmboxes.h new file mode 100644 index 000000000..44d6f9904 --- /dev/null +++ b/os/common/oslib/include/chmboxes.h @@ -0,0 +1,207 @@ +/*
+ 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.h
+ * @brief Mailboxes macros and structures.
+ *
+ * @addtogroup mailboxes
+ * @{
+ */
+
+#ifndef _CHMBOXES_H_
+#define _CHMBOXES_H_
+
+#if (CH_CFG_USE_MAILBOXES == TRUE) || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Module constants. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module pre-compile time settings. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Derived constants and error checks. */
+/*===========================================================================*/
+
+#if CH_CFG_USE_SEMAPHORES == FALSE
+#error "CH_CFG_USE_MAILBOXES requires CH_CFG_USE_SEMAPHORES"
+#endif
+
+/*===========================================================================*/
+/* Module data structures and types. */
+/*===========================================================================*/
+
+/**
+ * @brief Structure representing a mailbox object.
+ */
+typedef struct {
+ msg_t *buffer; /**< @brief Pointer to the mailbox
+ buffer. */
+ msg_t *top; /**< @brief Pointer to the location
+ after the buffer. */
+ msg_t *wrptr; /**< @brief Write pointer. */
+ msg_t *rdptr; /**< @brief Read pointer. */
+ semaphore_t fullsem; /**< @brief Full counter
+ @p semaphore_t. */
+ semaphore_t emptysem; /**< @brief Empty counter
+ @p semaphore_t. */
+} mailbox_t;
+
+/*===========================================================================*/
+/* Module macros. */
+/*===========================================================================*/
+
+/**
+ * @brief Data part of a static mailbox initializer.
+ * @details This macro should be used when statically initializing a
+ * mailbox that is part of a bigger structure.
+ *
+ * @param[in] name the name of the mailbox variable
+ * @param[in] buffer pointer to the mailbox buffer area
+ * @param[in] size size of the mailbox buffer area
+ */
+#define _MAILBOX_DATA(name, buffer, size) { \
+ (msg_t *)(buffer), \
+ (msg_t *)(buffer) + size, \
+ (msg_t *)(buffer), \
+ (msg_t *)(buffer), \
+ _SEMAPHORE_DATA(name.fullsem, 0), \
+ _SEMAPHORE_DATA(name.emptysem, size), \
+}
+
+/**
+ * @brief Static mailbox initializer.
+ * @details Statically initialized mailboxes require no explicit
+ * initialization using @p chMBInit().
+ *
+ * @param[in] name the name of the mailbox variable
+ * @param[in] buffer pointer to the mailbox buffer area
+ * @param[in] size size of the mailbox buffer area
+ */
+#define MAILBOX_DECL(name, buffer, size) \
+ mailbox_t name = _MAILBOX_DATA(name, buffer, size)
+
+/*===========================================================================*/
+/* External declarations. */
+/*===========================================================================*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+ void chMBObjectInit(mailbox_t *mbp, msg_t *buf, cnt_t n);
+ void chMBReset(mailbox_t *mbp);
+ void chMBResetI(mailbox_t *mbp);
+ msg_t chMBPost(mailbox_t *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostS(mailbox_t *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostI(mailbox_t *mbp, msg_t msg);
+ msg_t chMBPostAhead(mailbox_t *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostAheadS(mailbox_t *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostAheadI(mailbox_t *mbp, msg_t msg);
+ msg_t chMBFetch(mailbox_t *mbp, msg_t *msgp, systime_t timeout);
+ msg_t chMBFetchS(mailbox_t *mbp, msg_t *msgp, systime_t timeout);
+ msg_t chMBFetchI(mailbox_t *mbp, msg_t *msgp);
+#ifdef __cplusplus
+}
+#endif
+
+/*===========================================================================*/
+/* Module inline functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Returns the mailbox buffer size.
+ *
+ * @param[in] mbp the pointer to an initialized mailbox_t object
+ * @return The size of the mailbox.
+ *
+ * @iclass
+ */
+static inline size_t chMBGetSizeI(mailbox_t *mbp) {
+
+ /*lint -save -e9033 [10.8] Perfectly safe pointers
+ arithmetic.*/
+ return (size_t)(mbp->top - mbp->buffer);
+ /*lint -restore*/
+}
+
+/**
+ * @brief Returns the number of free message slots into a mailbox.
+ * @note Can be invoked in any system state but if invoked out of a locked
+ * state then the returned value may change after reading.
+ * @note The returned value can be less than zero when there are waiting
+ * threads on the internal semaphore.
+ *
+ * @param[in] mbp the pointer to an initialized mailbox_t object
+ * @return The number of empty message slots.
+ *
+ * @iclass
+ */
+static inline cnt_t chMBGetFreeCountI(mailbox_t *mbp) {
+
+ chDbgCheckClassI();
+
+ return chSemGetCounterI(&mbp->emptysem);
+}
+
+/**
+ * @brief Returns the number of used message slots into a mailbox.
+ * @note Can be invoked in any system state but if invoked out of a locked
+ * state then the returned value may change after reading.
+ * @note The returned value can be less than zero when there are waiting
+ * threads on the internal semaphore.
+ *
+ * @param[in] mbp the pointer to an initialized mailbox_t object
+ * @return The number of queued messages.
+ *
+ * @iclass
+ */
+static inline cnt_t chMBGetUsedCountI(mailbox_t *mbp) {
+
+ chDbgCheckClassI();
+
+ return chSemGetCounterI(&mbp->fullsem);
+}
+
+/**
+ * @brief Returns the next message in the queue without removing it.
+ * @pre A message must be waiting in the queue for this function to work
+ * or it would return garbage. The correct way to use this macro is
+ * to use @p chMBGetFullCountI() and then use this macro, all within
+ * a lock state.
+ *
+ * @param[in] mbp the pointer to an initialized mailbox_t object
+ * @return The next message in queue.
+ *
+ * @iclass
+ */
+static inline msg_t chMBPeekI(mailbox_t *mbp) {
+
+ chDbgCheckClassI();
+
+ return *mbp->rdptr;
+}
+
+#endif /* CH_CFG_USE_MAILBOXES == TRUE */
+
+#endif /* _CHMBOXES_H_ */
+
+/** @} */
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