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/*
Copyright (C) 2014..2015 Andrea Zoppi
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* @file tribuf.h
* @brief Triple buffer handler header.
*
* @addtogroup TriBuf
* @{
*/
#ifndef _TRIBUF_H_
#define _TRIBUF_H_
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver pre-compile time settings. */
/*===========================================================================*/
/**
* @name Triple buffer configuration options
* @{
*/
/**
* @brief Triple buffers use blocking functions.
*/
#if !defined(TRIBUF_USE_WAIT) || defined(__DOXYGEN__)
#define TRIBUF_USE_WAIT TRUE
#endif
/** @} */
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver data structures and types. */
/*===========================================================================*/
/**
* @brief Triple buffer handler object.
*/
typedef struct {
void *front; /**< @brief Current front buffer pointer.*/
void *back; /**< @brief Current back buffer pointer.*/
void *orphan; /**< @brief Current orphan buffer pointer.*/
#if (TRIBUF_USE_WAIT == TRUE)
semaphore_t ready; /**< @brief A new front buffer is ready.*/
#else
bool ready; /**< @brief A new front buffer is ready.*/
#endif
} tribuf_t;
/*===========================================================================*/
/* Driver macros. */
/*===========================================================================*/
/**
* @brief Checks if a new front buffer is ready.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Availability of a new front buffer.
*
* @iclass
*/
static inline
bool tribufIsReadyI(tribuf_t *handler)
{
osalDbgCheckClassI();
#if (TRIBUF_USE_WAIT == TRUE)
return (0 != chSemGetCounterI(&handler->ready));
#else
return handler->ready;
#endif
}
#if (TRIBUF_USE_WAIT == TRUE) || defined(__DOXYGEN__)
/**
* @brief Waits until a new front buffer is ready, with timeout.
*
* @post The ready signal, result of the back buffer swap, is consumed.
*
* @param[in] handler Pointer to the tribuf handler object.
* @param[in] timeout Timeout of the wait operation.
* @return Timeout error code, as from @p chSemWaitTimeoutS.
*
* @see chSemWaitTimeoutS
* @sclass
*/
static inline
msg_t tribufWaitReadyTimeoutS(tribuf_t *handler, systime_t timeout)
{
osalDbgCheckClassS();
return chSemWaitTimeoutS(&handler->ready, timeout);
}
/**
* @brief Waits until a new front buffer is ready, with timeout.
*
* @post The ready signal, result of the back buffer swap, is consumed.
*
* @param[in] handler Pointer to the tribuf handler object.
* @param[in] timeout Timeout of the wait operation.
* @return Timeout error code, as from @p chSemWaitTimeout.
*
* @see chSemWaitTimeout
* @api
*/
static inline
msg_t tribufWaitReadyTimeout(tribuf_t *handler, systime_t timeout)
{
return chSemWaitTimeout(&handler->ready, timeout);
}
/**
* @brief Waits until a new front buffer is ready.
*
* @post The ready signal, result of the back buffer swap, is consumed.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Timeout error code, as from @p chSemWaitS.
*
* @see chSemWaitS
* @sclass
*/
static inline
void tribufWaitReadyS(tribuf_t *handler)
{
osalDbgCheckClassS();
chSemWaitS(&handler->ready);
}
/**
* @brief Waits until a new front buffer is ready.
*
* @post The ready signal, result of the back buffer swap, is consumed.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Timeout error code, as from @p chSemWait.
*
* @see chSemWait
* @api
*/
static inline
void tribufWaitReady(tribuf_t *handler)
{
chSemWait(&handler->ready);
}
#endif /* (TRIBUF_USE_WAIT == TRUE) || defined(__DOXYGEN__) */
/**
* @brief Gets the current front buffer.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Pointer to the current front buffer.
*
* @iclass
*/
static inline
void *tribufGetFrontI(tribuf_t *handler) {
osalDbgCheckClassI();
return handler->front;
}
/**
* @brief Gets the current back buffer.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Pointer to the current back buffer.
*
* @iclass
*/
static inline
void *tribufGetBackI(tribuf_t *handler) {
osalDbgCheckClassI();
return handler->back;
}
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#ifdef __cplusplus
extern "C" {
#endif
void tribufObjectInit(tribuf_t *handler, void *front, void *back, void *orphan);
void *tribufGetFront(tribuf_t *handler);
void tribufSwapFrontI(tribuf_t *handler);
void tribufSwapFront(tribuf_t *handler);
void *tribufGetBack(tribuf_t *handler);
void tribufSwapBackI(tribuf_t *handler);
void tribufSwapBack(tribuf_t *handler);
#ifdef __cplusplus
}
#endif
#endif /* _TRIBUF_H_ */
/** @} */
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