/* 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 . */ /** * @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 Bytes in the pipe. */ 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. * * @api */ static inline size_t chPipeGetSize(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. * * @api */ static inline size_t chPipeGetUsedCount(const pipe_t *pp) { 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. * * @api */ static inline size_t chPipeGetFreeCount(const pipe_t *pp) { return chPipeGetSize(pp) - chPipeGetUsedCount(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. * * @api */ static inline uint8_t chPipePeek(const pipe_t *pp) { return *pp->rdptr; } /** * @brief Terminates the reset state. * * @param[in] pp the pointer to an initialized @p pipe_t object * * @api */ static inline void chPipeResume(pipe_t *pp) { pp->reset = false; } #endif /* CH_CFG_USE_PIPES == TRUE */ #endif /* CHPIPES_H */ /** @} */