ChibiOS/os/kernel/include/chqueues.h

243 lines
9.6 KiB
C

/*
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 chqueues.h I/O
* @brief Queues macros and structures.
*
* @addtogroup io_queues
* @{
*/
#ifndef _CHQUEUES_H_
#define _CHQUEUES_H_
#if CH_USE_QUEUES
/*
* Module dependencies check.
*/
#if !CH_USE_SEMAPHORES
#error "CH_USE_QUEUES requires CH_USE_SEMAPHORES"
#endif
/** @brief Queue notification callback type.*/
typedef void (*qnotify_t)(void);
/** @brief Returned by the queue functions if the operation is successful.*/
#define Q_OK RDY_OK
/** @brief Returned by the queue functions if a timeout occurs.*/
#define Q_TIMEOUT RDY_TIMEOUT
/** @brief Returned by the queue functions if the queue is reset.*/
#define Q_RESET RDY_RESET
/** @brief Returned by the queue functions if the queue is empty.*/
#define Q_EMPTY -3
/** @brief Returned by the queue functions if the queue is full.*/
#define Q_FULL -4
/**
* @brief Generic I/O queue structure.
* @details This structure represents a generic Input or Output asymmetrical
* queue. The queue is asymmetrical because one end is meant to be
* accessed from a thread context, and thus can be blocking, the other
* end is accessible from interrupt handlers or from within a kernel
* lock zone (see <b>I-Locked</b> and <b>S-Locked</b> states in
* @ref system_states) and is non-blocking.
*/
typedef struct {
uint8_t *q_buffer; /**< @brief Pointer to the queue buffer.*/
uint8_t *q_top; /**< @brief Pointer to the first location
after the buffer. */
uint8_t *q_wrptr; /**< @brief Write pointer. */
uint8_t *q_rdptr; /**< @brief Read pointer. */
Semaphore q_sem; /**< @brief Counter @p Semaphore. */
qnotify_t q_notify; /**< @brief Data notification callback. */
} GenericQueue;
/**
* @brief Returns the queue's buffer size.
*/
#define chQSize(q) ((q)->q_top - (q)->q_buffer)
/**
* @brief Queue space.
* @details Returns the used space if used on an Input Queue and the empty
* space if used on an Output Queue.
* @note The returned value can be less than zero when there are waiting
* threads on the internal semaphore.
*/
#define chQSpace(q) chSemGetCounterI(&(q)->q_sem)
/**
* @extends GenericQueue
*
* @brief Input queue structure.
* @details This structure represents a generic asymmetrical input queue.
* Writing in the queue is non-blocking and can be performed from
* interrupt handlers or from within a kernel lock zone (see
* <b>I-Locked</b> and <b>S-Locked</b> states in @ref system_states).
* Reading the queue can be a blocking operation and is supposed to
* be performed by a system thread.
*/
typedef GenericQueue InputQueue;
/** @brief Evaluates to @p TRUE if the specified Input Queue is empty.*/
#define chIQIsEmpty(q) ((bool_t)(chQSpace(q) <= 0))
/** @brief Evaluates to @p TRUE if the specified Input Queue is full.*/
#define chIQIsFull(q) ((bool_t)(chQSpace(q) >= chQSize(q)))
/**
* @brief Input queue read.
* @details This function reads a byte value from an input queue. If the queue
* is empty then the calling thread is suspended until a byte arrives
* in the queue.
*
* @param[in] iqp pointer to an @p InputQueue structure
* @return A byte value from the queue or:
* @retval Q_RESET if the queue was reset.
*/
#define chIQGet(iqp) chIQGetTimeout(iqp, TIME_INFINITE)
/**
* @brief Data part of a static input queue initializer.
* @details This macro should be used when statically initializing an
* input queue that is part of a bigger structure.
*
* @param[in] name the name of the input queue variable
* @param[in] buffer pointer to the queue buffer area
* @param[in] size size of the queue buffer area
* @param[in] inotify input notification callback pointer
*/
#define _INPUTQUEUE_DATA(name, buffer, size, inotify) { \
(uint8_t *)(buffer), \
(uint8_t *)(buffer) + size, \
(uint8_t *)(buffer), \
(uint8_t *)(buffer), \
_SEMAPHORE_DATA(name.q_sem, 0), \
inotify \
}
/**
* @brief Static input queue initializer.
* @details Statically initialized input queues require no explicit
* initialization using @p chIQInit().
*
* @param[in] name the name of the input queue variable
* @param[in] buffer pointer to the queue buffer area
* @param[in] size size of the queue buffer area
* @param[in] inotify input notification callback pointer
*/
#define INPUTQUEUE_DECL(name, buffer, size, inotify) \
InputQueue name = _INPUTQUEUE_DATA(name, buffer, size, inotify)
/**
* @extends GenericQueue
*
* @brief Output queue structure.
* @details This structure represents a generic asymmetrical output queue.
* Reading from the queue is non-blocking and can be performed from
* interrupt handlers or from within a kernel lock zone (see
* <b>I-Locked</b> and <b>S-Locked</b> states in @ref system_states).
* Writing the queue can be a blocking operation and is supposed to
* be performed by a system thread.
*/
typedef GenericQueue OutputQueue;
/**
* @brief Evaluates to @p TRUE if the specified Output Queue is empty.
*/
#define chOQIsEmpty(q) ((bool_t)(chQSpace(q) >= chQSize(q)))
/**
* @brief Evaluates to @p TRUE if the specified Output Queue is full.
*/
#define chOQIsFull(q) ((bool_t)(chQSpace(q) <= 0))
/**
* @brief Output queue write.
* @details This function writes a byte value to an output queue. If the queue
* is full then the calling thread is suspended until there is space
* in the queue.
*
* @param[in] oqp pointer to an @p OutputQueue structure
* @param[in] b the byte value to be written in the queue
* @return The operation status:
* @retval Q_OK if the operation succeeded.
* @retval Q_RESET if the queue was reset.
*/
#define chOQPut(oqp, b) chOQPutTimeout(oqp, b, TIME_INFINITE)
/**
* @brief Data part of a static output queue initializer.
* @details This macro should be used when statically initializing an
* output queue that is part of a bigger structure.
*
* @param[in] name the name of the output queue variable.
* @param[in] buffer pointer to the queue buffer area
* @param[in] size size of the queue buffer area
* @param[in] onotify output notification callback pointer
*/
#define _OUTPUTQUEUE_DATA(name, buffer, size, onotify) { \
(uint8_t *)(buffer), \
(uint8_t *)(buffer) + size, \
(uint8_t *)(buffer), \
(uint8_t *)(buffer), \
_SEMAPHORE_DATA(name.q_sem, size), \
onotify \
}
/**
* @brief Static output queue initializer.
* @details Statically initialized output queues require no explicit
* initialization using @p chOQInit().
*
* @param[in] name the name of the output queue variable
* @param[in] buffer pointer to the queue buffer area
* @param[in] size size of the queue buffer area
* @param[in] onotify output notification callback pointer
*/
#define OUTPUTQUEUE_DECL(name, buffer, size, onotify) \
InputQueue name = _OUTPUTQUEUE_DATA(name, buffer, size, onotify)
#ifdef __cplusplus
extern "C" {
#endif
void chIQInit(InputQueue *qp, uint8_t *bp, size_t size, qnotify_t infy);
void chIQResetI(InputQueue *qp);
msg_t chIQPutI(InputQueue *qp, uint8_t b);
msg_t chIQGetTimeout(InputQueue *qp, systime_t time);
size_t chIQReadTimeout(InputQueue *qp, uint8_t *bp,
size_t n, systime_t time);
void chOQInit(OutputQueue *queue, uint8_t *bp, size_t size, qnotify_t onfy);
void chOQResetI(OutputQueue *queue);
msg_t chOQPutTimeout(OutputQueue *queue, uint8_t b, systime_t time);
msg_t chOQGetI(OutputQueue *queue);
size_t chOQWriteTimeout(OutputQueue *queue, const uint8_t *bp,
size_t n, systime_t time);
#ifdef __cplusplus
}
#endif
#endif /* CH_USE_QUEUES */
#endif /* _CHQUEUES_H_ */
/** @} */