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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.
*/
#include "osal.h"
#include "tribuf.h"
/**
* @file tribuf.c
* @brief Triple buffer handler source.
*
* @addtogroup TriBuf
* @{
*/
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Initializes the tribuf handler object.
*
* @param[in] handler Pointer to the tribuf handler object.
* @param[in] front Pointer to the initial front buffer.
* @param[in] back Pointer to the initial back buffer.
* @param[in] orphan Pointer to the initial orphan buffer.
*
* @init
*/
void tribufObjectInit(tribuf_t *handler, void *front, void *back, void *orphan) {
handler->front = front;
handler->back = back;
handler->orphan = orphan;
#if (TRIBUF_USE_WAIT == TRUE)
chSemObjectInit(&handler->ready, (cnt_t)0);
#else
handler->ready = false;
#endif
}
/**
* @brief Gets the current front buffer.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Pointer to the current front buffer.
*
* @api
*/
void *tribufGetFront(tribuf_t *handler) {
void *front;
osalSysLock();
front = tribufGetFrontI(handler);
osalSysUnlock();
return front;
}
/**
* @brief Swaps the current front buffer.
*
* @details Exchanges the pointer of the current front buffer, which will be
* dismissed, with the pointer of the current orphan buffer, which
* holds the content of the new front buffer.
*
* @pre The orphan buffer holds new data, swapped by the back buffer.
* @pre The fron buffer is ready for swap.
* @post The orphan buffer can be used as new back buffer in the future.
*
* @param[in] handler Pointer to the tribuf handler object.
*
* @iclass
*/
void tribufSwapFrontI(tribuf_t *handler) {
void *front;
osalDbgCheckClassI();
front = handler->orphan;
handler->orphan = handler->front;
handler->front = front;
}
/**
* @brief Swaps the current front buffer.
*
* @details Exchanges the pointer of the current front buffer, which will be
* dismissed, with the pointer of the current orphan buffer, which
* holds the content of the new front buffer.
*
* @pre The orphan buffer holds new data, swapped by the back buffer.
* @pre The fron buffer is ready for swap.
* @post The orphan buffer can be used as new back buffer in the future.
*
* @param[in] handler Pointer to the tribuf handler object.
*
* @api
*/
void tribufSwapFront(tribuf_t *handler) {
osalSysLock();
tribufSwapFrontI(handler);
osalSysUnlock();
}
/**
* @brief Gets the current back buffer.
*
* @param[in] handler Pointer to the tribuf handler object.
* @return Pointer to the current back buffer.
*
* @api
*/
void *tribufGetBack(tribuf_t *handler) {
void *back;
osalSysLock();
back = tribufGetBackI(handler);
osalSysUnlock();
return back;
}
/**
* @brief Swaps the current back buffer.
*
* @details Exchanges the pointer of the current back buffer, which holds new
* useful data, with the pointer of the current orphan buffer.
*
* @pre The orphan buffer holds no meaningful data.
* @post The orphan buffer is candidate for new front buffer.
* @post A new front buffer is ready and signaled.
*
* @param[in] handler Pointer to the tribuf handler object.
*
* @iclass
*/
void tribufSwapBackI(tribuf_t *handler) {
void *back;
osalDbgCheckClassI();
back = handler->orphan;
handler->orphan = handler->back;
handler->back = back;
#if (TRIBUF_USE_WAIT == TRUE)
if (chSemGetCounterI(&handler->ready) < (cnt_t)1)
chSemSignalI(&handler->ready);
#else
handler->ready = true;
#endif
}
/**
* @brief Swaps the current back buffer.
*
* @details Exchanges the pointer of the current back buffer, which holds new
* useful data, with the pointer of the current orphan buffer.
*
* @pre The orphan buffer holds no meaningful data.
* @post The orphan buffer is candidate for new front buffer.
* @post A new front buffer is ready and signaled.
*
* @param[in] handler Pointer to the tribuf handler object.
*
* @api
*/
void tribufSwapBack(tribuf_t *handler) {
osalSysLock();
tribufSwapBackI(handler);
#if (TRIBUF_USE_WAIT == TRUE)
osalOsRescheduleS();
#endif
osalSysUnlock();
}
/** @} */
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