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ring_buffer.h
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1/*
2 * Copyright (c) 2015 Intel Corporation
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7#ifndef ZEPHYR_INCLUDE_SYS_RING_BUFFER_H_
8#define ZEPHYR_INCLUDE_SYS_RING_BUFFER_H_
9
10#include <zephyr/sys/util.h>
11#include <errno.h>
12
13#ifdef __cplusplus
14extern "C" {
15#endif
16
29/* The limit is used by algorithm for distinguishing between empty and full
30 * state.
31 */
32#ifdef CONFIG_RING_BUFFER_LARGE
33typedef uint32_t ring_buf_idx_t;
34#define RING_BUFFER_MAX_SIZE (UINT32_MAX / 2)
35#else
36typedef uint16_t ring_buf_idx_t;
37#define RING_BUFFER_MAX_SIZE (UINT16_MAX / 2)
38#endif
39
40#define RING_BUFFER_SIZE_ASSERT_MSG "Size too big"
41
42struct ring_buf_index { ring_buf_idx_t head, tail, base; };
43
49struct ring_buf {
51 uint8_t *buffer;
52 struct ring_buf_index put;
53 struct ring_buf_index get;
54 uint32_t size;
56};
57
60uint32_t ring_buf_area_claim(struct ring_buf *buf, struct ring_buf_index *ring,
61 uint8_t **data, uint32_t size);
62int ring_buf_area_finish(struct ring_buf *buf, struct ring_buf_index *ring,
63 uint32_t size);
64
70static inline void ring_buf_internal_reset(struct ring_buf *buf, ring_buf_idx_t value)
71{
72 buf->put.head = buf->put.tail = buf->put.base = value;
73 buf->get.head = buf->get.tail = buf->get.base = value;
74}
75
78#define RING_BUF_INIT(buf, size8) \
79{ \
80 .buffer = buf, \
81 .size = size8, \
82}
83
98#define RING_BUF_DECLARE(name, size8) \
99 BUILD_ASSERT(size8 <= RING_BUFFER_MAX_SIZE,\
100 RING_BUFFER_SIZE_ASSERT_MSG); \
101 static uint8_t __noinit _ring_buffer_data_##name[size8]; \
102 struct ring_buf name = RING_BUF_INIT(_ring_buffer_data_##name, size8)
103
119#define RING_BUF_ITEM_DECLARE(name, size32) \
120 BUILD_ASSERT((size32) <= RING_BUFFER_MAX_SIZE / 4, \
121 RING_BUFFER_SIZE_ASSERT_MSG); \
122 static uint32_t __noinit _ring_buffer_data_##name[size32]; \
123 struct ring_buf name = { \
124 .buffer = (uint8_t *) _ring_buffer_data_##name, \
125 .size = 4 * (size32) \
126 }
127
137#define RING_BUF_ITEM_DECLARE_SIZE(name, size32) \
138 RING_BUF_ITEM_DECLARE(name, size32)
139
150#define RING_BUF_ITEM_DECLARE_POW2(name, pow) \
151 RING_BUF_ITEM_DECLARE(name, BIT(pow))
152
161#define RING_BUF_ITEM_SIZEOF(expr) DIV_ROUND_UP(sizeof(expr), sizeof(uint32_t))
162
173static inline void ring_buf_init(struct ring_buf *buf,
174 uint32_t size,
175 uint8_t *data)
176{
177 __ASSERT(size <= RING_BUFFER_MAX_SIZE, RING_BUFFER_SIZE_ASSERT_MSG);
178
179 buf->size = size;
180 buf->buffer = data;
181 ring_buf_internal_reset(buf, 0);
182}
183
197static inline void ring_buf_item_init(struct ring_buf *buf,
198 uint32_t size,
199 uint32_t *data)
200{
201 __ASSERT(size <= RING_BUFFER_MAX_SIZE / 4, RING_BUFFER_SIZE_ASSERT_MSG);
202 ring_buf_init(buf, 4 * size, (uint8_t *)data);
203}
204
212static inline bool ring_buf_is_empty(const struct ring_buf *buf)
213{
214 return buf->get.head == buf->put.tail;
215}
216
222static inline void ring_buf_reset(struct ring_buf *buf)
223{
224 ring_buf_internal_reset(buf, 0);
225}
226
234static inline uint32_t ring_buf_space_get(const struct ring_buf *buf)
235{
236 ring_buf_idx_t allocated = buf->put.head - buf->get.tail;
237
238 return buf->size - allocated;
239}
240
248static inline uint32_t ring_buf_item_space_get(const struct ring_buf *buf)
249{
250 return ring_buf_space_get(buf) / 4;
251}
252
260static inline uint32_t ring_buf_capacity_get(const struct ring_buf *buf)
261{
262 return buf->size;
263}
264
272static inline uint32_t ring_buf_size_get(const struct ring_buf *buf)
273{
274 ring_buf_idx_t available = buf->put.tail - buf->get.head;
275
276 return available;
277}
278
303static inline uint32_t ring_buf_put_claim(struct ring_buf *buf,
304 uint8_t **data,
305 uint32_t size)
306{
307 uint32_t space = ring_buf_space_get(buf);
308 return ring_buf_area_claim(buf, &buf->put, data,
309 MIN(size, space));
310}
311
334static inline int ring_buf_put_finish(struct ring_buf *buf, uint32_t size)
335{
336 return ring_buf_area_finish(buf, &buf->put, size);
337}
338
359uint32_t ring_buf_put(struct ring_buf *buf, const uint8_t *data, uint32_t size);
360
385static inline uint32_t ring_buf_get_claim(struct ring_buf *buf,
386 uint8_t **data,
387 uint32_t size)
388{
389 uint32_t buf_size = ring_buf_size_get(buf);
390 return ring_buf_area_claim(buf, &buf->get, data,
391 MIN(size, buf_size));
392}
393
416static inline int ring_buf_get_finish(struct ring_buf *buf, uint32_t size)
417{
418 return ring_buf_area_finish(buf, &buf->get, size);
419}
420
442
470
492int ring_buf_item_put(struct ring_buf *buf, uint16_t type, uint8_t value,
493 uint32_t *data, uint8_t size32);
494
519int ring_buf_item_get(struct ring_buf *buf, uint16_t *type, uint8_t *value,
520 uint32_t *data, uint8_t *size32);
521
526#ifdef __cplusplus
527}
528#endif
529
530#endif /* ZEPHYR_INCLUDE_SYS_RING_BUFFER_H_ */
System error numbers.
static uint32_t ring_buf_put_claim(struct ring_buf *buf, uint8_t **data, uint32_t size)
Allocate buffer for writing data to a ring buffer.
Definition ring_buffer.h:303
uint32_t ring_buf_get(struct ring_buf *buf, uint8_t *data, uint32_t size)
Read data from a ring buffer.
static uint32_t ring_buf_item_space_get(const struct ring_buf *buf)
Determine free space in an "item based" ring buffer.
Definition ring_buffer.h:248
static uint32_t ring_buf_space_get(const struct ring_buf *buf)
Determine free space in a ring buffer.
Definition ring_buffer.h:234
static uint32_t ring_buf_size_get(const struct ring_buf *buf)
Determine size of available data in a ring buffer.
Definition ring_buffer.h:272
uint32_t ring_buf_put(struct ring_buf *buf, const uint8_t *data, uint32_t size)
Write (copy) data to a ring buffer.
int ring_buf_item_put(struct ring_buf *buf, uint16_t type, uint8_t value, uint32_t *data, uint8_t size32)
Write a data item to a ring buffer.
uint32_t ring_buf_peek(struct ring_buf *buf, uint8_t *data, uint32_t size)
Peek at data from a ring buffer.
static int ring_buf_get_finish(struct ring_buf *buf, uint32_t size)
Indicate number of bytes read from claimed buffer.
Definition ring_buffer.h:416
static uint32_t ring_buf_capacity_get(const struct ring_buf *buf)
Return ring buffer capacity.
Definition ring_buffer.h:260
static void ring_buf_reset(struct ring_buf *buf)
Reset ring buffer state.
Definition ring_buffer.h:222
static void ring_buf_item_init(struct ring_buf *buf, uint32_t size, uint32_t *data)
Initialize an "item based" ring buffer.
Definition ring_buffer.h:197
static void ring_buf_init(struct ring_buf *buf, uint32_t size, uint8_t *data)
Initialize a ring buffer for byte data.
Definition ring_buffer.h:173
static bool ring_buf_is_empty(const struct ring_buf *buf)
Determine if a ring buffer is empty.
Definition ring_buffer.h:212
static uint32_t ring_buf_get_claim(struct ring_buf *buf, uint8_t **data, uint32_t size)
Get address of a valid data in a ring buffer.
Definition ring_buffer.h:385
int ring_buf_item_get(struct ring_buf *buf, uint16_t *type, uint8_t *value, uint32_t *data, uint8_t *size32)
Read a data item from a ring buffer.
static int ring_buf_put_finish(struct ring_buf *buf, uint32_t size)
Indicate number of bytes written to allocated buffers.
Definition ring_buffer.h:334
#define MIN(a, b)
Obtain the minimum of two values.
Definition util.h:402
__UINT32_TYPE__ uint32_t
Definition stdint.h:90
__UINT8_TYPE__ uint8_t
Definition stdint.h:88
__UINT16_TYPE__ uint16_t
Definition stdint.h:89
A structure to represent a ring buffer.
Definition ring_buffer.h:49
Misc utilities.