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Diffstat (limited to 'os/kernel/include/chmboxes.h')
| -rw-r--r-- | os/kernel/include/chmboxes.h | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/os/kernel/include/chmboxes.h b/os/kernel/include/chmboxes.h new file mode 100644 index 000000000..d2c71b6d8 --- /dev/null +++ b/os/kernel/include/chmboxes.h @@ -0,0 +1,143 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 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 mailboxes.h
+ * @brief Mailboxes macros and structures.
+ *
+ * @addtogroup mailboxes
+ * @{
+ */
+
+#ifndef _MAILBOXES_H_
+#define _MAILBOXES_H_
+
+#if CH_USE_MAILBOXES
+
+/*
+ * Module dependencies check.
+ */
+#if !CH_USE_SEMAPHORES
+#error "CH_USE_MAILBOXES requires CH_USE_SEMAPHORES"
+#endif
+
+typedef struct {
+ msg_t *mb_buffer; /**< @brief Pointer to the mailbox
+ buffer. */
+ msg_t *mb_top; /**< @brief Pointer to the location
+ after the buffer. */
+ msg_t *mb_wrptr; /**< @brief Write pointer. */
+ msg_t *mb_rdptr; /**< @brief Read pointer. */
+ Semaphore mb_fullsem; /**< @brief Full counter
+ @p Semaphore. */
+ Semaphore mb_emptysem; /**< @brief Empty counter
+ @p Semaphore. */
+} Mailbox;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+ void chMBInit(Mailbox *mbp, msg_t *buf, cnt_t n);
+ void chMBReset(Mailbox *mbp);
+ msg_t chMBPost(Mailbox *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostS(Mailbox *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostAhead(Mailbox *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBPostAheadS(Mailbox *mbp, msg_t msg, systime_t timeout);
+ msg_t chMBFetch(Mailbox *mbp, msg_t *msgp, systime_t timeout);
+ msg_t chMBFetchS(Mailbox *mbp, msg_t *msgp, systime_t timeout);
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ * @brief Returns the mailbox buffer size.
+ *
+ * @param[in] mbp the pointer to an initialized Mailbox object
+ */
+#define chMBSize(mbp) \
+ ((mbp)->mb_top - (mbp)->mb_buffer)
+
+/**
+ * @brief Returns the free space into the 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 object
+ * @return The number of empty message slots.
+ */
+#define chMBGetEmpty(mbp) chSemGetCounterI(&(mbp)->mb_emptysem)
+
+/**
+ * @brief Returns the number of messages into the 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 object
+ * @return The number of queued messages.
+ */
+#define chMBGetFull(mbp) chSemGetCounterI(&(mbp)->mb_fullsem)
+
+/**
+ * @brief Returns the next message in the queue without removing it.
+ * @note 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 chMBGetFull() and then use this macro, all within a lock
+ * state.
+ */
+#define chMBPeek(mbp) (*(mbp)->mb_rdptr)
+
+/**
+ * @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.mb_fullsem, 0), \
+ _SEMAPHORE_DATA(name.mb_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 name = _MAILBOX_DATA(name, buffer, size)
+
+#endif /* CH_USE_MAILBOXES */
+
+#endif /* _MAILBOXES_H_ */
+
+/** @} */
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