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mm/circbuf: support circular buffer managerment

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Change-Id: Ib1fc009b9ce3af5815920f22221fe8a7262299ef
Signed-off-by: dongjiuzhu <dongjiuzhu1@xiaomi.com>
This commit is contained in:
dongjiuzhu 2020-11-12 18:40:06 +08:00 committed by Xiang Xiao
parent 93ff68e75a
commit 23ddeaf3be
5 changed files with 819 additions and 0 deletions
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308
include/nuttx/mm/circbuf.h Normal file
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@ -0,0 +1,308 @@
/****************************************************************************
* include/nuttx/mm/circbuf.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_MM_CIRCBUF_H
#define __INCLUDE_NUTTX_MM_CIRCBUF_H
/* Note about locking: There is no locking required while only one reader
* and one writer is using the circular buffer.
* For multiple writer and one reader there is only a need to lock the
* writer. And vice versa for only one writer and multiple reader there is
* only a need to lock the reader.
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdbool.h>
#include <sys/types.h>
/****************************************************************************
* Public Types
****************************************************************************/
/* This structure describes circular buffer */
struct circbuf_s
{
FAR void *base; /* The pointer to buffer space */
size_t size; /* The size of buffer space */
size_t head; /* The head of buffer space */
size_t tail; /* The tail of buffer space */
bool external; /* The flag for external buffer */
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: circbuf_init
*
* Description:
* Initialize a circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* base - A pointer to circular buffer's internal buffer. It can be
* provided by caller because sometimes the creation of buffer
* is special or needs to preallocated, eg: DMA buffer.
* If NULL, a buffer of the given size will be allocated.
* bytes - The size of the internal buffer.
*
* Returned Value:
* Zero on success; A negated errno value is returned on any failure.
*
****************************************************************************/
int circbuf_init(FAR struct circbuf_s *circ,
FAR void *base, size_t bytes);
/****************************************************************************
* Name: circbuf_resize
*
* Description:
* Resize a circular buffer (change buffer size).
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* bytes - The size of the internal buffer.
*
* Returned Value:
* Zero on success; A negated errno value is returned on any failure.
*
****************************************************************************/
int circbuf_resize(FAR struct circbuf_s *circ, size_t bytes);
/****************************************************************************
* Name: circbuf_uninit
*
* Description:
* Free the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
void circbuf_uninit(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_reset
*
* Description:
* Remove the entire circular buffer content.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
void circbuf_reset(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_is_full
*
* Description:
* Return true if the circular buffer is full.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
bool circbuf_is_full(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_is_empty
*
* Description:
* Return true if the circular buffer is empty.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
bool circbuf_is_empty(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_size
*
* Description:
* Return size of the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
size_t circbuf_size(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_used
*
* Description:
* Return the used bytes of the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
size_t circbuf_used(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_space
*
* Description:
* Return the remaing space of the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
size_t circbuf_space(FAR struct circbuf_s *circ);
/****************************************************************************
* Name: circbuf_peek
*
* Description:
* Get data form the circular buffer without removing
*
* Note :
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* dst - Address where to store the data.
* bytes - Number of bytes to get.
*
* Returned Value:
* The bytes of get data is returned if the peek data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_peek(FAR struct circbuf_s *circ,
FAR void *dst, size_t bytes);
/****************************************************************************
* Name: circbuf_read
*
* Description:
* Get data form the circular buffer.
*
* Note :
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* dst - Address where to store the data.
* bytes - Number of bytes to get.
*
* Returned Value:
* The bytes of get data is returned if the read data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_read(FAR struct circbuf_s *circ,
FAR void *dst, size_t bytes);
/****************************************************************************
* Name: circbuf_skip
*
* Description:
* Skip data form the circular buffer.
*
* Note:
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* bytes - Number of bytes to skip.
*
* Returned Value:
* The bytes of get data is returned if the skip data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_skip(FAR struct circbuf_s *circ, size_t bytes);
/****************************************************************************
* Name: circbuf_write
*
* Description:
* Write data to the circular buffer.
*
* Note:
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* src - The data to be added.
* bytes - Number of bytes to be added.
*
* Returned Value:
* The bytes of get data is returned if the write data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_write(FAR struct circbuf_s *circ,
FAR const void *src, size_t bytes);
/****************************************************************************
* Name: circbuf_overwrite
*
* Description:
* Write data to the circular buffer. It can overwrite old data when
* circular buffer don't have enough space to store data.
*
* Note:
* Usage circbuf_overwrite () is dangerous. It should be only called
* when the buffer is exclusived locked or when it is secured that no
* other thread is accessing the buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* src - The data to be added.
* bytes - Number of bytes to be added.
*
* Returned Value:
* The bytes length of overwrite is returned if it's successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_overwrite(FAR struct circbuf_s *circ,
FAR const void *src, size_t bytes);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif

6
mm/Kconfig
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@ -155,4 +155,10 @@ config MM_FILL_ALLOCATIONS
Fill all malloc() allocations with 0xAA. This helps Fill all malloc() allocations with 0xAA. This helps
detecting uninitialized variable errors. detecting uninitialized variable errors.
config MM_CIRCBUF
bool "Circular buffer support"
default n
---help---
Build in support for the circular buffer management.
source "mm/iob/Kconfig" source "mm/iob/Kconfig"

1
mm/Makefile
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@ -43,6 +43,7 @@ include kmm_heap/Make.defs
include mm_gran/Make.defs include mm_gran/Make.defs
include shm/Make.defs include shm/Make.defs
include iob/Make.defs include iob/Make.defs
include circbuf/Make.defs
BINDIR ?= bin BINDIR ?= bin

30
mm/circbuf/Make.defs Normal file
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@ -0,0 +1,30 @@
############################################################################
# mm/circbuf/Make.defs
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership. The
# ASF licenses this file to you 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.
#
############################################################################
# Circular buffer management
ifeq ($(CONFIG_MM_CIRCBUF),y)
CSRCS += circbuf.c
# Add the circular buffer directory to the build
DEPPATH += --dep-path circbuf
VPATH += :circbuf
endif

474
mm/circbuf/circbuf.c Normal file
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@ -0,0 +1,474 @@
/****************************************************************************
* mm/circbuf/circbuf.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you 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.
*
****************************************************************************/
/* Note about locking: There is no locking required while only one reader
* and one writer is using the circular buffer.
* For multiple writer and one reader there is only a need to lock the
* writer. And vice versa for only one writer and multiple reader there is
* only a need to lock the reader.
*/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/kmalloc.h>
#include <nuttx/mm/circbuf.h>
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: circbuf_init
*
* Description:
* Initialize a circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* base - A pointer to circular buffer's internal buffer. It can be
* provided by caller because sometimes the creation of buffer
* is special or needs to preallocated, eg: DMA buffer.
* If NULL, a buffer of the given size will be allocated.
* bytes - The size of the internal buffer.
*
* Returned Value:
* Zero on success; A negated errno value is returned on any failure.
*
****************************************************************************/
int circbuf_init(FAR struct circbuf_s *circ, FAR void *base, size_t bytes)
{
DEBUGASSERT(circ);
DEBUGASSERT(!base || bytes);
circ->external = !!base;
if (!base && bytes)
{
base = kmm_malloc(bytes);
if (!base)
{
return -ENOMEM;
}
}
circ->base = base;
circ->size = bytes;
circ->head = 0;
circ->tail = 0;
return 0;
}
/****************************************************************************
* Name: circbuf_resize
*
* Description:
* Resize a circular buffer (change buffer size).
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* bytes - The size of the internal buffer.
*
* Returned Value:
* Zero on success; A negated errno value is returned on any failure.
*
****************************************************************************/
int circbuf_resize(FAR struct circbuf_s *circ, size_t bytes)
{
FAR void *tmp;
size_t len;
DEBUGASSERT(circ);
DEBUGASSERT(!circ->external);
tmp = kmm_malloc(bytes);
if (!tmp)
{
return -ENOMEM;
}
len = circbuf_used(circ);
if (bytes < len)
{
circbuf_skip(circ, len - bytes);
len = bytes;
}
circbuf_read(circ, tmp, len);
kmm_free(circ->base);
circ->base = tmp;
circ->size = bytes;
circ->head = len;
circ->tail = 0;
return 0;
}
/****************************************************************************
* Name: circbuf_reset
*
* Description:
* Remove the entire circular buffer content.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
void circbuf_reset(FAR struct circbuf_s *circ)
{
DEBUGASSERT(circ);
circ->head = circ->tail = 0;
}
/****************************************************************************
* Name: circbuf_uninit
*
* Description:
* Free the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
void circbuf_uninit(FAR struct circbuf_s *circ)
{
DEBUGASSERT(circ);
if (!circ->external)
{
kmm_free(circ->base);
}
memset(circ, 0, sizeof(*circ));
}
/****************************************************************************
* Name: circbuf_size
*
* Description:
* Return size of the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
size_t circbuf_size(FAR struct circbuf_s *circ)
{
DEBUGASSERT(circ);
return circ->size;
}
/****************************************************************************
* Name: circbuf_used
*
* Description:
* Return the used bytes of the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
size_t circbuf_used(FAR struct circbuf_s *circ)
{
DEBUGASSERT(circ);
return circ->head - circ->tail;
}
/****************************************************************************
* Name: circbuf_space
*
* Description:
* Return the remaing space of the circular buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
size_t circbuf_space(FAR struct circbuf_s *circ)
{
return circbuf_size(circ) - circbuf_used(circ);
}
/****************************************************************************
* Name: circbuf_is_empty
*
* Description:
* Return true if the circular buffer is empty.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
bool circbuf_is_empty(FAR struct circbuf_s *circ)
{
return !circbuf_used(circ);
}
/****************************************************************************
* Name: circbuf_is_full
*
* Description:
* Return true if the circular buffer is full.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
****************************************************************************/
bool circbuf_is_full(FAR struct circbuf_s *circ)
{
return !circbuf_space(circ);
}
/****************************************************************************
* Name: circbuf_peek
*
* Description:
* Get data form the circular buffer without removing
*
* Note :
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* dst - Address where to store the data.
* bytes - Number of bytes to get.
*
* Returned Value:
* The bytes of get data is returned if the peek data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_peek(FAR struct circbuf_s *circ,
FAR void *dst, size_t bytes)
{
size_t len;
size_t off;
DEBUGASSERT(circ);
len = circbuf_used(circ);
off = circ->tail % circ->size;
if (bytes > len)
{
bytes = len;
}
len = circ->size - off;
if (bytes < len)
{
len = bytes;
}
memcpy(dst, circ->base + off, len);
memcpy(dst + len, circ->base, bytes - len);
return bytes;
}
/****************************************************************************
* Name: circbuf_read
*
* Description:
* Get data form the circular buffer.
*
* Note :
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* dst - Address where to store the data.
* bytes - Number of bytes to get.
*
* Returned Value:
* The bytes of get data is returned if the read data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_read(FAR struct circbuf_s *circ,
FAR void *dst, size_t bytes)
{
DEBUGASSERT(circ);
DEBUGASSERT(dst || !bytes);
bytes = circbuf_peek(circ, dst, bytes);
circ->tail += bytes;
return bytes;
}
/****************************************************************************
* Name: circbuf_skip
*
* Description:
* Skip data form the circular buffer.
*
* Note :
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* bytes - Number of bytes to skip.
*
* Returned Value:
* The bytes of get data is returned if the skip data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_skip(FAR struct circbuf_s *circ, size_t bytes)
{
size_t len;
DEBUGASSERT(circ);
len = circbuf_used(circ);
if (bytes > len)
{
bytes = len;
}
circ->tail += bytes;
return bytes;
}
/****************************************************************************
* Name: circbuf_write
*
* Description:
* Write data to the circular buffer.
*
* Note :
* That with only one concurrent reader and one concurrent writer,
* you don't need extra locking to use these api.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* src - The data to be added.
* bytes - Number of bytes to be added.
*
* Returned Value:
* The bytes of get data is returned if the write data is successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_write(FAR struct circbuf_s *circ,
FAR const void *src, size_t bytes)
{
size_t space;
size_t off;
DEBUGASSERT(circ);
DEBUGASSERT(src || !bytes);
space = circbuf_space(circ);
off = circ->head % circ->size;
if (bytes > space)
{
bytes = space;
}
space = circ->size - off;
if (bytes < space)
{
space = bytes;
}
memcpy(circ->base + off, src, space);
memcpy(circ->base, src + space, bytes - space);
circ->head += bytes;
return bytes;
}
/****************************************************************************
* Name: circbuf_overwrite
*
* Description:
* Write data to the circular buffer. It can overwrite old data when
* circular buffer don't have enough space to store data.
*
* Note:
* Usage circbuf_overwrite () is dangerous. It should be only called
* when the buffer is exclusived locked or when it is secured that no
* other thread is accessing the buffer.
*
* Input Parameters:
* circ - Address of the circular buffer to be used.
* src - The data to be added.
* bytes - Number of bytes to be added.
*
* Returned Value:
* The bytes length of overwrite is returned if it's successful;
* A negated errno value is returned on any failure.
****************************************************************************/
ssize_t circbuf_overwrite(FAR struct circbuf_s *circ,
FAR const void *src, size_t bytes)
{
size_t overwrite = 0;
size_t space;
size_t off;
DEBUGASSERT(circ);
DEBUGASSERT(src || !bytes);
if (bytes > circ->size)
{
src += bytes - circ->size;
bytes = circ->size;
}
space = circbuf_space(circ);
if (bytes > space)
{
overwrite = bytes - space;
}
off = circ->head % circ->size;
space = circ->size - off;
if (bytes < space)
{
space = bytes;
}
memcpy(circ->base + off, src, space);
memcpy(circ->base, src + space, bytes - space);
circ->head += bytes;
circ->tail += overwrite;
return overwrite;
}