/* SPDX-License-Identifier: BSD-2-Clause */
/**
* @file
*
* @brief Simple Ring Buffer Functionality
*
* This file provides simple ring buffer functionality.
*/
/*
* COPYRIGHT (C) 1989-1999 On-Line Applications Research Corporation (OAR).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _RTEMS_RINGBUF_H
#define _RTEMS_RINGBUF_H
#include <rtems.h>
#ifndef RINGBUF_QUEUE_LENGTH
#define RINGBUF_QUEUE_LENGTH 128
#endif
typedef struct {
uint8_t buffer[RINGBUF_QUEUE_LENGTH];
volatile int head;
volatile int tail;
rtems_interrupt_lock lock;
} Ring_buffer_t;
#define Ring_buffer_Initialize( _buffer ) \
do { \
(_buffer)->head = (_buffer)->tail = 0; \
rtems_interrupt_lock_initialize(&(_buffer)->lock, "ring buffer"); \
} while ( 0 )
#define Ring_buffer_Destory( _buffer ) \
do { \
rtems_interrupt_lock_destroy(&(_buffer)->lock); \
} while ( 0 )
#define Ring_buffer_Is_empty( _buffer ) \
( (_buffer)->head == (_buffer)->tail )
#define Ring_buffer_Is_full( _buffer ) \
( (_buffer)->head == ((_buffer)->tail + 1) % RINGBUF_QUEUE_LENGTH )
#define Ring_buffer_Add_character( _buffer, _ch ) \
do { \
rtems_interrupt_lock_context lock_context; \
\
rtems_interrupt_lock_acquire( &(_buffer)->lock, &lock_context ); \
(_buffer)->tail = ((_buffer)->tail+1) % RINGBUF_QUEUE_LENGTH; \
(_buffer)->buffer[ (_buffer)->tail ] = (_ch); \
rtems_interrupt_lock_release( &(_buffer)->lock, &lock_context ); \
} while ( 0 )
#define Ring_buffer_Remove_character( _buffer, _ch ) \
do { \
rtems_interrupt_lock_context lock_context; \
\
rtems_interrupt_lock_acquire( &(_buffer)->lock, &lock_context ); \
(_buffer)->head = ((_buffer)->head+1) % RINGBUF_QUEUE_LENGTH; \
(_ch) = (_buffer)->buffer[ (_buffer)->head ]; \
rtems_interrupt_lock_release( &(_buffer)->lock, &lock_context ); \
} while ( 0 )
#endif
