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/*
ChibiOS - Copyright (C) 2006..2018 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 chpipes.h
* @brief Pipes macros and structures.
*
* @addtogroup oslib_pipes
* @{
*/
#ifndef CHPIPES_H
#define CHPIPES_H
#if (CH_CFG_USE_PIPES == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Module constants. */
/*===========================================================================*/
/*===========================================================================*/
/* Module pre-compile time settings. */
/*===========================================================================*/
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Module data structures and types. */
/*===========================================================================*/
/**
* @brief Structure representing a pipe object.
*/
typedef struct {
uint8_t *buffer; /**< @brief Pointer to the pipe
buffer. */
uint8_t *top; /**< @brief Pointer to the location
after the buffer. */
uint8_t *wrptr; /**< @brief Write pointer. */
uint8_t *rdptr; /**< @brief Read pointer. */
size_t cnt; /**< @brief Messages in queue. */
bool reset; /**< @brief True if in reset state. */
threads_queue_t qw; /**< @brief Queued writers. */
threads_queue_t qr; /**< @brief Queued readers. */
#if (CH_CFG_USE_MUTEXES == TRUE) || defined(__DOXYGEN__)
mutex_t mtx; /**< @brief Heap access mutex. */
#else
semaphore_t sem; /**< @brief Heap access semaphore. */
#endif
} pipe_t;
/*===========================================================================*/
/* Module macros. */
/*===========================================================================*/
/**
* @brief Data part of a static pipe initializer.
* @details This macro should be used when statically initializing a
* pipe that is part of a bigger structure.
*
* @param[in] name the name of the pipe variable
* @param[in] buffer pointer to the pipe buffer array of @p uint8_t
* @param[in] size number of @p uint8_t elements in the buffer array
*/
#if (CH_CFG_USE_MUTEXES == TRUE) || defined(__DOXYGEN__)
#define _PIPE_DATA(name, buffer, size) { \
(uint8_t *)(buffer), \
(uint8_t *)(buffer) + size, \
(uint8_t *)(buffer), \
(uint8_t *)(buffer), \
(size_t)0, \
false, \
_THREADS_QUEUE_DATA(name.qw), \
_THREADS_QUEUE_DATA(name.qr), \
_MUTEX_DATA(name.mtx), \
}
#else /* CH_CFG_USE_MUTEXES == FALSE */
#define _PIPE_DATA(name, buffer, size) { \
(uint8_t *)(buffer), \
(uint8_t *)(buffer) + size, \
(uint8_t *)(buffer), \
(uint8_t *)(buffer), \
(size_t)0, \
false, \
_THREADS_QUEUE_DATA(name.qw), \
_THREADS_QUEUE_DATA(name.qr), \
_SEMAPHORE_DATA(name.sem, (cnt_t)1), \
}
#endif /* CH_CFG_USE_MUTEXES == FALSE */
/**
* @brief Static pipe initializer.
* @details Statically initialized pipes require no explicit
* initialization using @p chPipeObjectInit().
*
* @param[in] name the name of the pipe variable
* @param[in] buffer pointer to the pipe buffer array of @p uint8_t
* @param[in] size number of @p uint8_t elements in the buffer array
*/
#define PIPE_DECL(name, buffer, size) \
pipe_t name = _PIPE_DATA(name, buffer, size)
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#ifdef __cplusplus
extern "C" {
#endif
void chPipeObjectInit(pipe_t *pp, uint8_t *buf, size_t n);
void chPipeReset(pipe_t *pp);
size_t chPipeWriteTimeout(pipe_t *pp, const uint8_t *bp,
size_t n, sysinterval_t timeout);
size_t chPipeReadTimeout(pipe_t *pp, uint8_t *bp,
size_t n, sysinterval_t timeout);
#ifdef __cplusplus
}
#endif
/*===========================================================================*/
/* Module inline functions. */
/*===========================================================================*/
/**
* @brief Returns the pipe buffer size as number of bytes.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
* @return The size of the pipe.
*
* @iclass
*/
static inline size_t chPipeGetSizeI(const pipe_t *pp) {
/*lint -save -e9033 [10.8] Perfectly safe pointers
arithmetic.*/
return (size_t)(pp->top - pp->buffer);
/*lint -restore*/
}
/**
* @brief Returns the number of used byte slots into a pipe.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
* @return The number of queued bytes.
*
* @iclass
*/
static inline size_t chPipeGetUsedCountI(const pipe_t *pp) {
chDbgCheckClassI();
return pp->cnt;
}
/**
* @brief Returns the number of free byte slots into a pipe.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
* @return The number of empty byte slots.
*
* @iclass
*/
static inline size_t chPipeGetFreeCountI(const pipe_t *pp) {
chDbgCheckClassI();
return chPipeGetSizeI(pp) - chPipeGetUsedCountI(pp);
}
/**
* @brief Returns the next byte in the queue without removing it.
* @pre A byte must be present in the queue for this function to work
* or it would return garbage. The correct way to use this macro is
* to use @p chPipeGetFullCountI() and then use this macro, all within
* a lock state.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
* @return The next byte in queue.
*
* @iclass
*/
static inline uint8_t chPipePeekI(const pipe_t *pp) {
chDbgCheckClassI();
return *pp->rdptr;
}
/**
* @brief Terminates the reset state.
*
* @param[in] pp the pointer to an initialized @p pipe_t object
*
* @xclass
*/
static inline void chPipeResumeX(pipe_t *pp) {
pp->reset = false;
}
#endif /* CH_CFG_USE_PIPES == TRUE */
#endif /* CHPIPES_H */
/** @} */
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