/**
* Copyright (c) 2017 - 2019, Nordic Semiconductor ASA
*
* 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, except as embedded into a Nordic
* Semiconductor ASA integrated circuit in a product or a software update for
* such product, 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 Nordic Semiconductor ASA nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* 4. This software, with or without modification, must only be used with a
* Nordic Semiconductor ASA integrated circuit.
*
* 5. Any software provided in binary form under this license must not be reverse
* engineered, decompiled, modified and/or disassembled.
*
* THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA 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 NRF_MEMOBJ_H
#define NRF_MEMOBJ_H
/**
* @defgroup nrf_memobj Memory Object module
* @{
* @ingroup app_common
* @brief Functions for controlling a memory object.
*/
#include <stdint.h>
#include <stdlib.h>
#include "sdk_errors.h"
#include "nrf_balloc.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* A memory object can consist of multiple chunks with the same size. Each object has a header part
* and a data part. The first element in a memory object is memory object head which has a special header.
* The remaining objects have a header of the same size.
*
@verbatim
_____________________ _____________________ _____________________
| | | | | |
|4 B head header | --> |4 B p_next |------->|4 B p_memobj_pool |
|_____________________| | |_____________________| |_____________________|
| | | | | | |
|4 B p_next |--| | | | |
|_____________________| | | .... | |
| | | data | | data |
| | | | | |
| data | | | | |
| | | | | |
|_____________________| |_____________________| |_____________________|
head mid_element last_element
@endverbatim
*
*/
#define NRF_MEMOBJ_STD_HEADER_SIZE sizeof(uint32_t)
/**
* @brief Macro for creating an nrf_memobj pool.
*
* This macro declares an nrf_balloc object. The element in the pool contains a user-defined data part and
* a memory object header.
*
* @param _name Name of the instance.
* @param _chunk_size Size of a single chunk.
* @param _pool_size Number of chunks in the pool.
*/
#define NRF_MEMOBJ_POOL_DEF(_name, _chunk_size, _pool_size) \
STATIC_ASSERT((_chunk_size) > sizeof(uint32_t)); \
NRF_BALLOC_DEF(_name, ((_chunk_size)+NRF_MEMOBJ_STD_HEADER_SIZE), (_pool_size))
/**
* @brief Pool of memory objects.
*/
typedef nrf_balloc_t nrf_memobj_pool_t;
/**
* @brief Memory object handle.
*/
typedef void * nrf_memobj_t;
/**
* @brief Function for initializing the memobj pool instance.
*
* This function initializes the pool.
*
* @param[in] p_pool Pointer to the memobj pool instance structure.
*
* @return NRF_SUCCESS on success, otherwise an error code.
*/
ret_code_t nrf_memobj_pool_init(nrf_memobj_pool_t const * p_pool);
/**
* @brief Function for allocating a memobj with a requested size.
*
* Fixed length elements in the pool are linked together to provide the amount of memory requested by
* the user. If a memory object is successfully allocated, then the users can use the memory.
* However, it is fragmented into multiple objects so it must be accessed through the API:
* @ref nrf_memobj_write and @ref nrf_memobj_read.
*
* @param[in] p_pool Pointer to the memobj pool instance structure.
* @param[in] size Data size of requested object.
*
* @return Pointer to a memory object or NULL if the requested size cannot be allocated.
*/
nrf_memobj_t * nrf_memobj_alloc(nrf_memobj_pool_t const * p_pool,
size_t size);
/**
* @brief Function for indicating that a memory object is used and cannot be freed.
*
* Memory object can be shared and reused between multiple modules and this mechanism ensures that
* object is freed when no longer used by any module. Memory object has a counter which is incremented
* whenever this function is called. @ref nrf_memobj_put function decrements the counter.
*
* @param[in] p_obj Pointer to memory object.
*/
void nrf_memobj_get(nrf_memobj_t const * p_obj);
/**
* @brief Function for indicated that memory object is no longer used by the module and can be freed
* if no other module is using it.
*
* Memory object is returned to the pool if internal counter reaches 0 after decrementing. It means
* that no other module is needing it anymore.
*
* @note Memory object holds pointer to the pool which was used to allocate it so it does not have
* to be provided explicitly to this function.
*
* @param[in] p_obj Pointer to memory object.
*/
void nrf_memobj_put(nrf_memobj_t * p_obj);
/**
* @brief Function for forcing freeing of the memory object.
*
* @note This function should be use with caution because it can lead to undefined behavior of the
* modules since modules using the memory object are not aware that it has been freed.
*
* @param[in] p_obj Pointer to memory object.
*/
void nrf_memobj_free(nrf_memobj_t * p_obj);
/**
* @brief Function for writing data to the memory object.
*
* @param[in] p_obj Pointer to memory object.
* @param[in] p_data Pointer to data to be written to the memory object.
* @param[in] len Amount of data to be written to the memory object.
* @param[in] offset Offset.
*/
void nrf_memobj_write(nrf_memobj_t * p_obj,
void * p_data,
size_t len,
size_t offset);
/**
* @brief Function for reading data from the memory object.
*
* @param[in] p_obj Pointer to memory object.
* @param[in] p_data Pointer to the destination buffer.
* @param[in] len Amount of data to be read from the memory object.
* @param[in] offset Offset.
*/
void nrf_memobj_read(nrf_memobj_t * p_obj,
void * p_data,
size_t len,
size_t offset);
#ifdef __cplusplus
}
#endif
#endif //NRF_MEMOBJ_H
/** @} */