mirror of
https://github.com/mist-devel/mist-firmware.git
synced 2026-04-19 17:02:53 +00:00
82 lines
3.2 KiB
C
82 lines
3.2 KiB
C
/* ----------------------------------------------------------------------------
|
|
* ATMEL Microcontroller Software Support
|
|
* ----------------------------------------------------------------------------
|
|
* Copyright (c) 2015, Atmel Corporation
|
|
*
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright notice,
|
|
* this list of conditions and the disclaimer below.
|
|
*
|
|
* Atmel's name may not be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL ATMEL 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 _RING_H_
|
|
#define _RING_H_
|
|
|
|
#include "intmath.h"
|
|
|
|
/*------------------------------------------------------------------------------
|
|
* Exported functions
|
|
*------------------------------------------------------------------------------*/
|
|
|
|
/** Return count in buffer */
|
|
#define RING_CNT(head,tail,size) fixed_mod((head) - (tail), (size))
|
|
|
|
/** Return space available, 0..size-1. always leave one free char as a
|
|
* completely full buffer has head == tail, which is the same as empty */
|
|
#define RING_SPACE(head,tail,size) RING_CNT((tail),((head) + 1),(size))
|
|
|
|
/** Return count up to the end of the buffer. Carefully avoid accessing head
|
|
* and tail more than once, so they can change underneath us without returning
|
|
* inconsistent results */
|
|
#define RING_CNT_TO_END(head,tail,size) \
|
|
({int end = (size) - (tail); \
|
|
int n = fixed_mod((head) + end, (size)); \
|
|
n < end ? n : end;})
|
|
|
|
/** Return space available up to the end of the buffer */
|
|
#define RING_SPACE_TO_END(head,tail,size) \
|
|
({int end = (size) - 1 - (head); \
|
|
int n = fixed_mod(end + (tail), (size)); \
|
|
n <= end ? n : end+1;})
|
|
|
|
/** Increment head or tail */
|
|
#define RING_INC(headortail,size) \
|
|
(headortail)++; \
|
|
if((headortail) >= (size)) { \
|
|
(headortail) = 0; \
|
|
}
|
|
|
|
/** Decrement head or tail */
|
|
#define RING_DEC(headortail,size) \
|
|
if((headortail) == 0) { \
|
|
(headortail) = (size) - 1; \
|
|
} else { \
|
|
(headortail)--; \
|
|
}
|
|
|
|
/** Circular buffer is empty ? */
|
|
#define RING_EMPTY(head, tail) ((head) == (tail))
|
|
|
|
/** Clear circular buffer */
|
|
#define RING_CLEAR(head, tail) ((head) = (tail) = 0)
|
|
|
|
#endif /* _RING_H_ */
|