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25ade36 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 | /* The Clear BSD License
*
* Copyright (c) 2025 EdgeImpulse Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted (subject to the limitations in the disclaimer
* below) provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED BY
* THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 _EDGE_IMPULSE_ALIGNED_MALLOC_H_
#define _EDGE_IMPULSE_ALIGNED_MALLOC_H_
#include <assert.h>
#include "../porting/ei_classifier_porting.h"
#ifdef __cplusplus
namespace {
#endif // __cplusplus
/**
* Based on https://github.com/embeddedartistry/embedded-resources/blob/master/examples/c/malloc_aligned.c
*/
/**
* Simple macro for making sure memory addresses are aligned
* to the nearest power of two
*/
#ifndef align_up
#define align_up(num, align) \
(((num) + ((align) - 1)) & ~((align) - 1))
#endif
//Number of bytes we're using for storing the aligned pointer offset
typedef uint16_t offset_t;
#define PTR_OFFSET_SZ sizeof(offset_t)
/**
* aligned_malloc takes in the requested alignment and size
* We will call malloc with extra bytes for our header and the offset
* required to guarantee the desired alignment.
*/
__attribute__((unused)) void * ei_aligned_calloc(size_t align, size_t size)
{
void * ptr = NULL;
//We want it to be a power of two since align_up operates on powers of two
assert((align & (align - 1)) == 0);
if(align && size)
{
/*
* We know we have to fit an offset value
* We also allocate extra bytes to ensure we can meet the alignment
*/
uint32_t hdr_size = PTR_OFFSET_SZ + (align - 1);
void * p = ei_calloc(size + hdr_size, 1);
if(p)
{
/*
* Add the offset size to malloc's pointer (we will always store that)
* Then align the resulting value to the arget alignment
*/
ptr = (void *) align_up(((uintptr_t)p + PTR_OFFSET_SZ), align);
//Calculate the offset and store it behind our aligned pointer
*((offset_t *)ptr - 1) = (offset_t)((uintptr_t)ptr - (uintptr_t)p);
} // else NULL, could not malloc
} //else NULL, invalid arguments
return ptr;
}
/**
* aligned_free works like free(), but we work backwards from the returned
* pointer to find the correct offset and pointer location to return to free()
* Note that it is VERY BAD to call free() on an aligned_malloc() pointer.
*/
__attribute__((unused)) void ei_aligned_free(void * ptr)
{
assert(ptr);
/*
* Walk backwards from the passed-in pointer to get the pointer offset
* We convert to an offset_t pointer and rely on pointer math to get the data
*/
offset_t offset = *((offset_t *)ptr - 1);
/*
* Once we have the offset, we can get our original pointer and call free
*/
void * p = (void *)((uint8_t *)ptr - offset);
ei_free(p);
}
#ifdef __cplusplus
}
#endif // __cplusplus
#endif // _EDGE_IMPULSE_ALIGNED_MALLOC_H_
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