mirror of
https://github.com/oliverschmidt/contiki.git
synced 2024-11-19 03:05:14 +00:00
133 lines
4.6 KiB
C
133 lines
4.6 KiB
C
/** \addtogroup lib
|
|
* @{ */
|
|
|
|
/**
|
|
* \defgroup ringbuf Ring buffer library
|
|
* @{
|
|
*
|
|
* The ring buffer library implements ring (circular) buffer where
|
|
* bytes can be read and written independently. A ring buffer is
|
|
* particularly useful in device drivers where data can come in
|
|
* through interrupts.
|
|
*
|
|
*/
|
|
/*
|
|
* Copyright (c) 2008, Swedish Institute of Computer Science.
|
|
* All rights reserved.
|
|
*
|
|
* 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.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
* $Id: ringbuf.h,v 1.1 2009/03/01 20:23:56 adamdunkels Exp $
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Header file for the ring buffer library
|
|
* \author
|
|
* Adam Dunkels <adam@sics.se>
|
|
*/
|
|
|
|
#ifndef __RINGBUF_H__
|
|
#define __RINGBUF_H__
|
|
|
|
#include "contiki-conf.h"
|
|
|
|
/**
|
|
* \brief Structure that holds the state of a ring buffer.
|
|
*
|
|
* This structure holds the state of a ring buffer. The
|
|
* actual buffer needs to be defined separately. This
|
|
* struct is an opaque structure with no user-visible
|
|
* elements.
|
|
*
|
|
*/
|
|
struct ringbuf {
|
|
uint8_t *data;
|
|
uint8_t mask;
|
|
|
|
/* XXX these must be 8-bit quantities to avoid race conditions. */
|
|
uint8_t put_ptr, get_ptr;
|
|
};
|
|
|
|
/**
|
|
* \brief Initialize a ring buffer
|
|
* \param r A pointer to a struct ringbuf to hold the state of the ring buffer
|
|
* \param a A pointer to an array to hold the data in the buffer
|
|
* \param size_power_of_two The size of the ring buffer, which must be a power of two
|
|
*
|
|
* This function initiates a ring buffer. The data in the
|
|
* buffer is stored in an external array, to which a
|
|
* pointer must be supplied. The size of the ring buffer
|
|
* must be a power of two and cannot be larger than 128
|
|
* bytes.
|
|
*
|
|
*/
|
|
void ringbuf_init(struct ringbuf *r, uint8_t *a,
|
|
uint8_t size_power_of_two);
|
|
|
|
/**
|
|
* \brief Insert a byte into the ring buffer
|
|
* \param r A pointer to a struct ringbuf to hold the state of the ring buffer
|
|
* \param c The byte to be written to the buffer
|
|
* \return Non-zero if there data could be written, or zero if the buffer was full.
|
|
*
|
|
* This function inserts a byte into the ring buffer. It
|
|
* is safe to call this function from an interrupt
|
|
* handler.
|
|
*
|
|
*/
|
|
int ringbuf_put(struct ringbuf *r, uint8_t c);
|
|
|
|
|
|
/**
|
|
* \brief Get a byte from the ring buffer
|
|
* \param r A pointer to a struct ringbuf to hold the state of the ring buffer
|
|
* \return The data from the buffer, or -1 if the buffer was empty
|
|
*
|
|
* This function removes a byte from the ring buffer. It
|
|
* is safe to call this function from an interrupt
|
|
* handler.
|
|
*
|
|
*/
|
|
int ringbuf_get(struct ringbuf *r);
|
|
|
|
/**
|
|
* \brief Get the size of a ring buffer
|
|
* \param r A pointer to a struct ringbuf to hold the state of the ring buffer
|
|
* \return The size of the buffer.
|
|
*/
|
|
int ringbuf_size(struct ringbuf *r);
|
|
|
|
/**
|
|
* \brief Get the number of elements currently in the ring buffer
|
|
* \param r A pointer to a struct ringbuf to hold the state of the ring buffer
|
|
* \return The number of elements in the buffer.
|
|
*/
|
|
int ringbuf_elements(struct ringbuf *r);
|
|
|
|
#endif /* __RINGBUF_H__ */
|