owner-nrf52sdk/nRF5_SDK_15.3.0/components/ble/peer_manager/pm_buffer.h

/**
 * Copyright (c) 2015 - 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
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 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
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 */
#ifndef BUFFER_H__
#define BUFFER_H__

#include <stdint.h>
#include "compiler_abstraction.h"
#include "sdk_errors.h"
#include "nrf_atflags.h"

#ifdef __cplusplus
extern "C" {
#endif


/**
 * @cond NO_DOXYGEN
 * @defgroup pm_buffer Buffer
 * @ingroup peer_manager
 * @{
 * @brief An internal module of @ref peer_manager. This module provides a simple buffer.
 */


#define PM_BUFFER_INVALID_ID 0xFF //!< Invalid buffer block ID.


/**@brief Convenience macro for declaring memory and initializing a buffer instance.
 *
 * @param[out] p_buffer    The buffer instance to initialize.
 * @param[in]  n_blocks    The desired number of blocks in the buffer.
 * @param[in]  block_size  The desired block size of the buffer.
 * @param[out] err_code    The return code from @ref pm_buffer_init.
 */
#define PM_BUFFER_INIT(p_buffer, n_blocks, block_size, err_code)          \
do                                                                        \
{                                                                         \
    __ALIGN(4) static uint8_t buffer_memory[(n_blocks) * (block_size)];   \
    static NRF_ATFLAGS_DEF(mutex_memory, n_blocks);                       \
    err_code = pm_buffer_init((p_buffer),                                 \
                               buffer_memory,                             \
                              (n_blocks) * (block_size),                  \
                               mutex_memory,                              \
                              (n_blocks),                                 \
                              (block_size));                              \
} while (0)


typedef struct
{
    uint8_t       * p_memory;   /**< The storage for all buffer entries. The size of the buffer must be n_blocks*block_size. */
    nrf_atflags_t * p_mutex;    /**< A mutex group with one mutex for each buffer entry. */
    uint32_t        n_blocks;   /**< The number of allocatable blocks in the buffer. */
    uint32_t        block_size; /**< The size of each block in the buffer. */
} pm_buffer_t;

/**@brief Function for initializing a buffer instance.
 *
 * @param[out] p_buffer            The buffer instance to initialize.
 * @param[in]  p_buffer_memory     The memory this buffer will use.
 * @param[in]  buffer_memory_size  The size of p_buffer_memory. This must be at least
 *                                 n_blocks*block_size.
 * @param[in]  p_mutex_memory      The memory for the mutexes. This must be at least
 *                                 @ref NRF_ATFLAGS_ARRAY_LEN(n_blocks).
 * @param[in]  n_blocks            The number of blocks in the buffer.
 * @param[in]  block_size          The size of each block.
 *
 * @retval NRF_SUCCESS              Successfully initialized buffer instance.
 * @retval NRF_ERROR_INVALID_PARAM  A parameter was 0 or NULL or a size was too small.
 */
ret_code_t pm_buffer_init(pm_buffer_t   * p_buffer,
                          uint8_t       * p_buffer_memory,
                          uint32_t        buffer_memory_size,
                          nrf_atflags_t * p_mutex_memory,
                          uint32_t        n_blocks,
                          uint32_t        block_size);


/**@brief Function for acquiring a buffer block in a buffer.
 *
 * @param[in]  p_buffer  The buffer instance acquire from.
 * @param[in]  n_blocks  The number of contiguous blocks to acquire.
 *
 * @return The id of the acquired block, if successful.
 * @retval PM_BUFFER_INVALID_ID  If unsuccessful.
 */
uint8_t pm_buffer_block_acquire(pm_buffer_t * p_buffer, uint32_t n_blocks);


/**@brief Function for getting a pointer to a specific buffer block.
 *
 * @param[in]  p_buffer  The buffer instance get from.
 * @param[in]  id        The id of the buffer to get the pointer for.
 *
 * @return A pointer to the buffer for the specified id, if the id is valid.
 * @retval NULL  If the id is invalid.
 */
uint8_t * pm_buffer_ptr_get(pm_buffer_t * p_buffer, uint8_t id);


/**@brief Function for releasing a buffer block.
 *
 * @param[in]  p_buffer  The buffer instance containing the block to release.
 * @param[in]  id        The id of the block to release.
 */
void pm_buffer_release(pm_buffer_t * p_buffer, uint8_t id);



#ifdef __cplusplus
}
#endif

#endif // BUFFER_H__

/**
 * @}
 * @endcond
 */