[164] | 1 | //#include <assert.h>
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| 2 | //#include <limits.h>
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| 3 | //#include <stddef.h>
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| 4 | //#include <stdio.h>
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| 5 | //#include <stdlib.h>
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| 6 | #include <string.h>
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| 7 | #include <stdarg.h>
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| 8 |
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| 9 | #include "tlsf.h"
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| 10 | #include "tlsfbits.h"
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| 11 | #include "t_syslog.h"
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| 12 |
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| 13 | #ifdef __RX
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| 14 | #define printf(...)
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| 15 | #else
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| 16 | void printf(const char *format, ...)
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| 17 | {
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| 18 | va_list va;
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| 19 | va_start(va, format);
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| 20 | vsyslog(LOG_DEBUG, format, va);
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| 21 | va_end(va);
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| 22 | }
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| 23 | #endif
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| 24 |
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| 25 | /*
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| 26 | ** Constants.
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| 27 | */
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| 28 |
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| 29 | /* Public constants: may be modified. */
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| 30 | enum tlsf_public
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| 31 | {
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| 32 | /* log2 of number of linear subdivisions of block sizes. */
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| 33 | SL_INDEX_COUNT_LOG2 = 5,
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| 34 | };
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| 35 |
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| 36 | /* Private constants: do not modify. */
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| 37 | enum tlsf_private
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| 38 | {
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| 39 | #if defined (TLSF_64BIT)
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| 40 | /* All allocation sizes and addresses are aligned to 8 bytes. */
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| 41 | ALIGN_SIZE_LOG2 = 3,
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| 42 | #else
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| 43 | /* All allocation sizes and addresses are aligned to 4 bytes. */
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| 44 | ALIGN_SIZE_LOG2 = 2,
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| 45 | #endif
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| 46 | ALIGN_SIZE = (1 << ALIGN_SIZE_LOG2),
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| 47 |
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| 48 | /*
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| 49 | ** We support allocations of sizes up to (1 << FL_INDEX_MAX) bits.
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| 50 | ** However, because we linearly subdivide the second-level lists, and
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| 51 | ** our minimum size granularity is 4 bytes, it doesn't make sense to
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| 52 | ** create first-level lists for sizes smaller than SL_INDEX_COUNT * 4,
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| 53 | ** or (1 << (SL_INDEX_COUNT_LOG2 + 2)) bytes, as there we will be
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| 54 | ** trying to split size ranges into more slots than we have available.
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| 55 | ** Instead, we calculate the minimum threshold size, and place all
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| 56 | ** blocks below that size into the 0th first-level list.
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| 57 | */
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| 58 |
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| 59 | #if defined (TLSF_64BIT)
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| 60 | /*
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| 61 | ** TODO: We can increase this to support larger sizes, at the expense
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| 62 | ** of more overhead in the TLSF structure.
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| 63 | */
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| 64 | FL_INDEX_MAX = 32,
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| 65 | #else
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| 66 | FL_INDEX_MAX = 30,
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| 67 | #endif
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| 68 | SL_INDEX_COUNT = (1 << SL_INDEX_COUNT_LOG2),
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| 69 | FL_INDEX_SHIFT = (SL_INDEX_COUNT_LOG2 + ALIGN_SIZE_LOG2),
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| 70 | FL_INDEX_COUNT = (FL_INDEX_MAX - FL_INDEX_SHIFT + 1),
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| 71 |
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| 72 | SMALL_BLOCK_SIZE = (1 << FL_INDEX_SHIFT),
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| 73 | };
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| 74 |
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| 75 | /*
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| 76 | ** Cast and min/max macros.
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| 77 | */
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| 78 |
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| 79 | #define tlsf_cast(t, exp) ((t) (exp))
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| 80 | #define tlsf_min(a, b) ((a) < (b) ? (a) : (b))
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| 81 | #define tlsf_max(a, b) ((a) > (b) ? (a) : (b))
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| 82 |
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| 83 | /*
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| 84 | ** Set assert macro, if it has not been provided by the user.
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| 85 | */
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| 86 | #if !defined (tlsf_assert)
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| 87 | #define tlsf_assert assert
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| 88 | #endif
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| 89 |
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| 90 | /*
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| 91 | ** Static assertion mechanism.
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| 92 | */
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| 93 |
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| 94 | #define _tlsf_glue2(x, y) x ## y
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| 95 | #define _tlsf_glue(x, y) _tlsf_glue2(x, y)
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| 96 | #define tlsf_static_assert(exp) \
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| 97 | typedef char _tlsf_glue(static_assert, __LINE__) [(exp) ? 1 : -1]
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| 98 |
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| 99 | /* This code has been tested on 32- and 64-bit (LP/LLP) architectures. */
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| 100 | tlsf_static_assert(sizeof(int) * CHAR_BIT == 32);
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| 101 | tlsf_static_assert(sizeof(size_t) * CHAR_BIT >= 32);
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| 102 | tlsf_static_assert(sizeof(size_t) * CHAR_BIT <= 64);
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| 103 |
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| 104 | /* SL_INDEX_COUNT must be <= number of bits in sl_bitmap's storage type. */
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| 105 | tlsf_static_assert(sizeof(unsigned int) * CHAR_BIT >= SL_INDEX_COUNT);
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| 106 |
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| 107 | /* Ensure we've properly tuned our sizes. */
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| 108 | tlsf_static_assert(ALIGN_SIZE == SMALL_BLOCK_SIZE / SL_INDEX_COUNT);
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| 109 |
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| 110 | /*
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| 111 | ** Data structures and associated constants.
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| 112 | */
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| 113 |
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| 114 | /*
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| 115 | ** Block header structure.
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| 116 | **
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| 117 | ** There are several implementation subtleties involved:
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| 118 | ** - The prev_phys_block field is only valid if the previous block is free.
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| 119 | ** - The prev_phys_block field is actually stored at the end of the
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| 120 | ** previous block. It appears at the beginning of this structure only to
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| 121 | ** simplify the implementation.
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| 122 | ** - The next_free / prev_free fields are only valid if the block is free.
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| 123 | */
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| 124 | typedef struct block_header_t
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| 125 | {
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| 126 | /* Points to the previous physical block. */
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| 127 | struct block_header_t* prev_phys_block;
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| 128 |
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| 129 | /* The size of this block, excluding the block header. */
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| 130 | size_t size;
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| 131 |
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| 132 | /* Next and previous free blocks. */
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| 133 | struct block_header_t* next_free;
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| 134 | struct block_header_t* prev_free;
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| 135 | } block_header_t;
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| 136 |
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| 137 | /*
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| 138 | ** Since block sizes are always at least a multiple of 4, the two least
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| 139 | ** significant bits of the size field are used to store the block status:
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| 140 | ** - bit 0: whether block is busy or free
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| 141 | ** - bit 1: whether previous block is busy or free
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| 142 | */
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| 143 | static const size_t block_header_free_bit = 1 << 0;
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| 144 | static const size_t block_header_prev_free_bit = 1 << 1;
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| 145 |
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| 146 | /*
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| 147 | ** The size of the block header exposed to used blocks is the size field.
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| 148 | ** The prev_phys_block field is stored *inside* the previous free block.
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| 149 | */
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| 150 | static const size_t block_header_overhead = sizeof(size_t);
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| 151 |
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| 152 | /* User data starts directly after the size field in a used block. */
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| 153 | static const size_t block_start_offset =
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| 154 | offsetof(block_header_t, size) + sizeof(size_t);
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| 155 |
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| 156 | /*
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| 157 | ** A free block must be large enough to store its header minus the size of
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| 158 | ** the prev_phys_block field, and no larger than the number of addressable
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| 159 | ** bits for FL_INDEX.
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| 160 | */
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| 161 | static const size_t block_size_min =
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| 162 | sizeof(block_header_t) - sizeof(block_header_t*);
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| 163 | static const size_t block_size_max = tlsf_cast(size_t, 1) << FL_INDEX_MAX;
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| 164 |
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| 165 |
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| 166 | /* The TLSF control structure. */
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| 167 | typedef struct control_t
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| 168 | {
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| 169 | /* Empty lists point at this block to indicate they are free. */
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| 170 | block_header_t block_null;
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| 171 |
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| 172 | /* Bitmaps for free lists. */
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| 173 | unsigned int fl_bitmap;
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| 174 | unsigned int sl_bitmap[FL_INDEX_COUNT];
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| 175 |
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| 176 | /* Head of free lists. */
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| 177 | block_header_t* blocks[FL_INDEX_COUNT][SL_INDEX_COUNT];
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| 178 | } control_t;
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| 179 |
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| 180 | /* A type used for casting when doing pointer arithmetic. */
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| 181 | typedef ptrdiff_t tlsfptr_t;
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| 182 |
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| 183 | /*
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| 184 | ** block_header_t member functions.
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| 185 | */
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| 186 |
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| 187 | static size_t block_size(const block_header_t* block)
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| 188 | {
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| 189 | return block->size & ~(block_header_free_bit | block_header_prev_free_bit);
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| 190 | }
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| 191 |
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| 192 | static void block_set_size(block_header_t* block, size_t size)
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| 193 | {
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| 194 | const size_t oldsize = block->size;
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| 195 | block->size = size | (oldsize & (block_header_free_bit | block_header_prev_free_bit));
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| 196 | }
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| 197 |
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| 198 | static int block_is_last(const block_header_t* block)
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| 199 | {
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| 200 | return 0 == block_size(block);
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| 201 | }
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| 202 |
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| 203 | static int block_is_free(const block_header_t* block)
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| 204 | {
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| 205 | return tlsf_cast(int, block->size & block_header_free_bit);
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| 206 | }
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| 207 |
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| 208 | static void block_set_free(block_header_t* block)
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| 209 | {
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| 210 | block->size |= block_header_free_bit;
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| 211 | }
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| 212 |
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| 213 | static void block_set_used(block_header_t* block)
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| 214 | {
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| 215 | block->size &= ~block_header_free_bit;
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| 216 | }
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| 217 |
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| 218 | static int block_is_prev_free(const block_header_t* block)
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| 219 | {
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| 220 | return tlsf_cast(int, block->size & block_header_prev_free_bit);
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| 221 | }
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| 222 |
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| 223 | static void block_set_prev_free(block_header_t* block)
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| 224 | {
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| 225 | block->size |= block_header_prev_free_bit;
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| 226 | }
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| 227 |
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| 228 | static void block_set_prev_used(block_header_t* block)
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| 229 | {
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| 230 | block->size &= ~block_header_prev_free_bit;
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| 231 | }
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| 232 |
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| 233 | static block_header_t* block_from_ptr(const void* ptr)
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| 234 | {
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| 235 | return tlsf_cast(block_header_t*,
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| 236 | tlsf_cast(unsigned char*, ptr) - block_start_offset);
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| 237 | }
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| 238 |
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| 239 | static void* block_to_ptr(const block_header_t* block)
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| 240 | {
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| 241 | return tlsf_cast(void*,
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| 242 | tlsf_cast(unsigned char*, block) + block_start_offset);
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| 243 | }
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| 244 |
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| 245 | /* Return location of next block after block of given size. */
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| 246 | static block_header_t* offset_to_block(const void* ptr, size_t size)
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| 247 | {
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| 248 | return tlsf_cast(block_header_t*, tlsf_cast(tlsfptr_t, ptr) + size);
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| 249 | }
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| 250 |
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| 251 | /* Return location of previous block. */
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| 252 | static block_header_t* block_prev(const block_header_t* block)
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| 253 | {
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| 254 | return block->prev_phys_block;
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| 255 | }
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| 256 |
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| 257 | /* Return location of next existing block. */
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| 258 | static block_header_t* block_next(const block_header_t* block)
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| 259 | {
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| 260 | block_header_t* next = offset_to_block(block_to_ptr(block),
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| 261 | block_size(block) - block_header_overhead);
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| 262 | tlsf_assert(!block_is_last(block));
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| 263 | return next;
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| 264 | }
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| 265 |
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| 266 | /* Link a new block with its physical neighbor, return the neighbor. */
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| 267 | static block_header_t* block_link_next(block_header_t* block)
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| 268 | {
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| 269 | block_header_t* next = block_next(block);
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| 270 | next->prev_phys_block = block;
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| 271 | return next;
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| 272 | }
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| 273 |
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| 274 | static void block_mark_as_free(block_header_t* block)
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| 275 | {
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| 276 | /* Link the block to the next block, first. */
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| 277 | block_header_t* next = block_link_next(block);
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| 278 | block_set_prev_free(next);
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| 279 | block_set_free(block);
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| 280 | }
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| 281 |
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| 282 | static void block_mark_as_used(block_header_t* block)
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| 283 | {
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| 284 | block_header_t* next = block_next(block);
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| 285 | block_set_prev_used(next);
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| 286 | block_set_used(block);
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| 287 | }
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| 288 |
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| 289 | static size_t align_up(size_t x, size_t align)
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| 290 | {
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| 291 | tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");
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| 292 | return (x + (align - 1)) & ~(align - 1);
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| 293 | }
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| 294 |
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| 295 | static size_t align_down(size_t x, size_t align)
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| 296 | {
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| 297 | tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");
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| 298 | return x - (x & (align - 1));
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| 299 | }
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| 300 |
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| 301 | static void* align_ptr(const void* ptr, size_t align)
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| 302 | {
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| 303 | const tlsfptr_t aligned =
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| 304 | (tlsf_cast(tlsfptr_t, ptr) + (align - 1)) & ~(align - 1);
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| 305 | tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");
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| 306 | return tlsf_cast(void*, aligned);
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| 307 | }
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| 308 |
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| 309 | /*
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| 310 | ** Adjust an allocation size to be aligned to word size, and no smaller
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| 311 | ** than internal minimum.
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| 312 | */
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| 313 | static size_t adjust_request_size(size_t size, size_t align)
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| 314 | {
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| 315 | size_t adjust = 0;
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| 316 | if (size && size < block_size_max)
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| 317 | {
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| 318 | const size_t aligned = align_up(size, align);
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| 319 | adjust = tlsf_max(aligned, block_size_min);
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| 320 | }
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| 321 | return adjust;
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| 322 | }
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| 323 |
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| 324 | /*
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| 325 | ** TLSF utility functions. In most cases, these are direct translations of
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| 326 | ** the documentation found in the white paper.
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| 327 | */
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| 328 |
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| 329 | static void mapping_insert(size_t size, int* fli, int* sli)
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| 330 | {
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| 331 | int fl, sl;
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| 332 | if (size < SMALL_BLOCK_SIZE)
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| 333 | {
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| 334 | /* Store small blocks in first list. */
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| 335 | fl = 0;
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| 336 | sl = tlsf_cast(int, size) / (SMALL_BLOCK_SIZE / SL_INDEX_COUNT);
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| 337 | }
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| 338 | else
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| 339 | {
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| 340 | fl = tlsf_fls_sizet(size);
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| 341 | sl = tlsf_cast(int, size >> (fl - SL_INDEX_COUNT_LOG2)) ^ (1 << SL_INDEX_COUNT_LOG2);
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| 342 | fl -= (FL_INDEX_SHIFT - 1);
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| 343 | }
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| 344 | *fli = fl;
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| 345 | *sli = sl;
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| 346 | }
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| 347 |
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| 348 | /* This version rounds up to the next block size (for allocations) */
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| 349 | static void mapping_search(size_t size, int* fli, int* sli)
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| 350 | {
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| 351 | if (size >= (1 << SL_INDEX_COUNT_LOG2))
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| 352 | {
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| 353 | const size_t round = (1 << (tlsf_fls_sizet(size) - SL_INDEX_COUNT_LOG2)) - 1;
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| 354 | size += round;
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| 355 | }
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| 356 | mapping_insert(size, fli, sli);
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| 357 | }
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| 358 |
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| 359 | static block_header_t* search_suitable_block(control_t* control, int* fli, int* sli)
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| 360 | {
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| 361 | int fl = *fli;
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| 362 | int sl = *sli;
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| 363 |
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| 364 | /*
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| 365 | ** First, search for a block in the list associated with the given
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| 366 | ** fl/sl index.
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| 367 | */
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| 368 | unsigned int sl_map = control->sl_bitmap[fl] & (~0 << sl);
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| 369 | if (!sl_map)
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| 370 | {
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| 371 | /* No block exists. Search in the next largest first-level list. */
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| 372 | const unsigned int fl_map = control->fl_bitmap & (~0 << (fl + 1));
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| 373 | if (!fl_map)
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| 374 | {
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| 375 | /* No free blocks available, memory has been exhausted. */
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| 376 | return 0;
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| 377 | }
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| 378 |
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| 379 | fl = tlsf_ffs(fl_map);
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| 380 | *fli = fl;
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| 381 | sl_map = control->sl_bitmap[fl];
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| 382 | }
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| 383 | tlsf_assert(sl_map && "internal error - second level bitmap is null");
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| 384 | sl = tlsf_ffs(sl_map);
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| 385 | *sli = sl;
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| 386 |
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| 387 | /* Return the first block in the free list. */
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| 388 | return control->blocks[fl][sl];
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| 389 | }
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| 390 |
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| 391 | /* Remove a free block from the free list.*/
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| 392 | static void remove_free_block(control_t* control, block_header_t* block, int fl, int sl)
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| 393 | {
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| 394 | block_header_t* prev = block->prev_free;
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| 395 | block_header_t* next = block->next_free;
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| 396 | tlsf_assert(prev && "prev_free field can not be null");
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| 397 | tlsf_assert(next && "next_free field can not be null");
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| 398 | next->prev_free = prev;
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| 399 | prev->next_free = next;
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| 400 |
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| 401 | /* If this block is the head of the free list, set new head. */
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| 402 | if (control->blocks[fl][sl] == block)
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| 403 | {
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| 404 | control->blocks[fl][sl] = next;
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| 405 |
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| 406 | /* If the new head is null, clear the bitmap. */
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| 407 | if (next == &control->block_null)
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| 408 | {
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| 409 | control->sl_bitmap[fl] &= ~(1 << sl);
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| 410 |
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| 411 | /* If the second bitmap is now empty, clear the fl bitmap. */
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| 412 | if (!control->sl_bitmap[fl])
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| 413 | {
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| 414 | control->fl_bitmap &= ~(1 << fl);
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| 415 | }
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| 416 | }
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| 417 | }
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| 418 | }
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| 419 |
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| 420 | /* Insert a free block into the free block list. */
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| 421 | static void insert_free_block(control_t* control, block_header_t* block, int fl, int sl)
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| 422 | {
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| 423 | block_header_t* current = control->blocks[fl][sl];
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| 424 | tlsf_assert(current && "free list cannot have a null entry");
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| 425 | tlsf_assert(block && "cannot insert a null entry into the free list");
|
---|
| 426 | block->next_free = current;
|
---|
| 427 | block->prev_free = &control->block_null;
|
---|
| 428 | current->prev_free = block;
|
---|
| 429 |
|
---|
| 430 | tlsf_assert(block_to_ptr(block) == align_ptr(block_to_ptr(block), ALIGN_SIZE)
|
---|
| 431 | && "block not aligned properly");
|
---|
| 432 | /*
|
---|
| 433 | ** Insert the new block at the head of the list, and mark the first-
|
---|
| 434 | ** and second-level bitmaps appropriately.
|
---|
| 435 | */
|
---|
| 436 | control->blocks[fl][sl] = block;
|
---|
| 437 | control->fl_bitmap |= (1 << fl);
|
---|
| 438 | control->sl_bitmap[fl] |= (1 << sl);
|
---|
| 439 | }
|
---|
| 440 |
|
---|
| 441 | /* Remove a given block from the free list. */
|
---|
| 442 | static void block_remove(control_t* control, block_header_t* block)
|
---|
| 443 | {
|
---|
| 444 | int fl, sl;
|
---|
| 445 | mapping_insert(block_size(block), &fl, &sl);
|
---|
| 446 | remove_free_block(control, block, fl, sl);
|
---|
| 447 | }
|
---|
| 448 |
|
---|
| 449 | /* Insert a given block into the free list. */
|
---|
| 450 | static void block_insert(control_t* control, block_header_t* block)
|
---|
| 451 | {
|
---|
| 452 | int fl, sl;
|
---|
| 453 | mapping_insert(block_size(block), &fl, &sl);
|
---|
| 454 | insert_free_block(control, block, fl, sl);
|
---|
| 455 | }
|
---|
| 456 |
|
---|
| 457 | static int block_can_split(block_header_t* block, size_t size)
|
---|
| 458 | {
|
---|
| 459 | return block_size(block) >= sizeof(block_header_t) + size;
|
---|
| 460 | }
|
---|
| 461 |
|
---|
| 462 | /* Split a block into two, the second of which is free. */
|
---|
| 463 | static block_header_t* block_split(block_header_t* block, size_t size)
|
---|
| 464 | {
|
---|
| 465 | /* Calculate the amount of space left in the remaining block. */
|
---|
| 466 | block_header_t* remaining =
|
---|
| 467 | offset_to_block(block_to_ptr(block), size - block_header_overhead);
|
---|
| 468 |
|
---|
| 469 | const size_t remain_size = block_size(block) - (size + block_header_overhead);
|
---|
| 470 |
|
---|
| 471 | tlsf_assert(block_to_ptr(remaining) == align_ptr(block_to_ptr(remaining), ALIGN_SIZE)
|
---|
| 472 | && "remaining block not aligned properly");
|
---|
| 473 |
|
---|
| 474 | tlsf_assert(block_size(block) == remain_size + size + block_header_overhead);
|
---|
| 475 | block_set_size(remaining, remain_size);
|
---|
| 476 | tlsf_assert(block_size(remaining) >= block_size_min && "block split with invalid size");
|
---|
| 477 |
|
---|
| 478 | block_set_size(block, size);
|
---|
| 479 | block_mark_as_free(remaining);
|
---|
| 480 |
|
---|
| 481 | return remaining;
|
---|
| 482 | }
|
---|
| 483 |
|
---|
| 484 | /* Absorb a free block's storage into an adjacent previous free block. */
|
---|
| 485 | static block_header_t* block_absorb(block_header_t* prev, block_header_t* block)
|
---|
| 486 | {
|
---|
| 487 | tlsf_assert(!block_is_last(prev) && "previous block can't be last!");
|
---|
| 488 | /* Note: Leaves flags untouched. */
|
---|
| 489 | prev->size += block_size(block) + block_header_overhead;
|
---|
| 490 | block_link_next(prev);
|
---|
| 491 | return prev;
|
---|
| 492 | }
|
---|
| 493 |
|
---|
| 494 | /* Merge a just-freed block with an adjacent previous free block. */
|
---|
| 495 | static block_header_t* block_merge_prev(control_t* control, block_header_t* block)
|
---|
| 496 | {
|
---|
| 497 | if (block_is_prev_free(block))
|
---|
| 498 | {
|
---|
| 499 | block_header_t* prev = block_prev(block);
|
---|
| 500 | tlsf_assert(prev && "prev physical block can't be null");
|
---|
| 501 | tlsf_assert(block_is_free(prev) && "prev block is not free though marked as such");
|
---|
| 502 | block_remove(control, prev);
|
---|
| 503 | block = block_absorb(prev, block);
|
---|
| 504 | }
|
---|
| 505 |
|
---|
| 506 | return block;
|
---|
| 507 | }
|
---|
| 508 |
|
---|
| 509 | /* Merge a just-freed block with an adjacent free block. */
|
---|
| 510 | static block_header_t* block_merge_next(control_t* control, block_header_t* block)
|
---|
| 511 | {
|
---|
| 512 | block_header_t* next = block_next(block);
|
---|
| 513 | tlsf_assert(next && "next physical block can't be null");
|
---|
| 514 |
|
---|
| 515 | if (block_is_free(next))
|
---|
| 516 | {
|
---|
| 517 | tlsf_assert(!block_is_last(block) && "previous block can't be last!");
|
---|
| 518 | block_remove(control, next);
|
---|
| 519 | block = block_absorb(block, next);
|
---|
| 520 | }
|
---|
| 521 |
|
---|
| 522 | return block;
|
---|
| 523 | }
|
---|
| 524 |
|
---|
| 525 | /* Trim any trailing block space off the end of a block, return to pool. */
|
---|
| 526 | static void block_trim_free(control_t* control, block_header_t* block, size_t size)
|
---|
| 527 | {
|
---|
| 528 | tlsf_assert(block_is_free(block) && "block must be free");
|
---|
| 529 | if (block_can_split(block, size))
|
---|
| 530 | {
|
---|
| 531 | block_header_t* remaining_block = block_split(block, size);
|
---|
| 532 | block_link_next(block);
|
---|
| 533 | block_set_prev_free(remaining_block);
|
---|
| 534 | block_insert(control, remaining_block);
|
---|
| 535 | }
|
---|
| 536 | }
|
---|
| 537 |
|
---|
| 538 | /* Trim any trailing block space off the end of a used block, return to pool. */
|
---|
| 539 | static void block_trim_used(control_t* control, block_header_t* block, size_t size)
|
---|
| 540 | {
|
---|
| 541 | tlsf_assert(!block_is_free(block) && "block must be used");
|
---|
| 542 | if (block_can_split(block, size))
|
---|
| 543 | {
|
---|
| 544 | /* If the next block is free, we must coalesce. */
|
---|
| 545 | block_header_t* remaining_block = block_split(block, size);
|
---|
| 546 | block_set_prev_used(remaining_block);
|
---|
| 547 |
|
---|
| 548 | remaining_block = block_merge_next(control, remaining_block);
|
---|
| 549 | block_insert(control, remaining_block);
|
---|
| 550 | }
|
---|
| 551 | }
|
---|
| 552 |
|
---|
| 553 | static block_header_t* block_trim_free_leading(control_t* control, block_header_t* block, size_t size)
|
---|
| 554 | {
|
---|
| 555 | block_header_t* remaining_block = block;
|
---|
| 556 | if (block_can_split(block, size))
|
---|
| 557 | {
|
---|
| 558 | /* We want the 2nd block. */
|
---|
| 559 | remaining_block = block_split(block, size - block_header_overhead);
|
---|
| 560 | block_set_prev_free(remaining_block);
|
---|
| 561 |
|
---|
| 562 | block_link_next(block);
|
---|
| 563 | block_insert(control, block);
|
---|
| 564 | }
|
---|
| 565 |
|
---|
| 566 | return remaining_block;
|
---|
| 567 | }
|
---|
| 568 |
|
---|
| 569 | static block_header_t* block_locate_free(control_t* control, size_t size)
|
---|
| 570 | {
|
---|
| 571 | int fl = 0, sl = 0;
|
---|
| 572 | block_header_t* block = 0;
|
---|
| 573 |
|
---|
| 574 | if (size)
|
---|
| 575 | {
|
---|
| 576 | mapping_search(size, &fl, &sl);
|
---|
| 577 | block = search_suitable_block(control, &fl, &sl);
|
---|
| 578 | }
|
---|
| 579 |
|
---|
| 580 | if (block)
|
---|
| 581 | {
|
---|
| 582 | tlsf_assert(block_size(block) >= size);
|
---|
| 583 | remove_free_block(control, block, fl, sl);
|
---|
| 584 | }
|
---|
| 585 |
|
---|
| 586 | return block;
|
---|
| 587 | }
|
---|
| 588 |
|
---|
| 589 | static void* block_prepare_used(control_t* control, block_header_t* block, size_t size)
|
---|
| 590 | {
|
---|
| 591 | void* p = 0;
|
---|
| 592 | if (block)
|
---|
| 593 | {
|
---|
| 594 | block_trim_free(control, block, size);
|
---|
| 595 | block_mark_as_used(block);
|
---|
| 596 | p = block_to_ptr(block);
|
---|
| 597 | }
|
---|
| 598 | return p;
|
---|
| 599 | }
|
---|
| 600 |
|
---|
| 601 | /* Clear structure and point all empty lists at the null block. */
|
---|
| 602 | static void control_construct(control_t* control)
|
---|
| 603 | {
|
---|
| 604 | int i, j;
|
---|
| 605 |
|
---|
| 606 | control->block_null.next_free = &control->block_null;
|
---|
| 607 | control->block_null.prev_free = &control->block_null;
|
---|
| 608 |
|
---|
| 609 | control->fl_bitmap = 0;
|
---|
| 610 | for (i = 0; i < FL_INDEX_COUNT; ++i)
|
---|
| 611 | {
|
---|
| 612 | control->sl_bitmap[i] = 0;
|
---|
| 613 | for (j = 0; j < SL_INDEX_COUNT; ++j)
|
---|
| 614 | {
|
---|
| 615 | control->blocks[i][j] = &control->block_null;
|
---|
| 616 | }
|
---|
| 617 | }
|
---|
| 618 | }
|
---|
| 619 |
|
---|
| 620 | /*
|
---|
| 621 | ** Debugging utilities.
|
---|
| 622 | */
|
---|
| 623 |
|
---|
| 624 | typedef struct integrity_t
|
---|
| 625 | {
|
---|
| 626 | int prev_status;
|
---|
| 627 | int status;
|
---|
| 628 | } integrity_t;
|
---|
| 629 |
|
---|
| 630 | #define tlsf_insist(x) { tlsf_assert(x); if (!(x)) { status--; } }
|
---|
| 631 |
|
---|
| 632 | static void integrity_walker(void* ptr, size_t size, int used, void* user)
|
---|
| 633 | {
|
---|
| 634 | block_header_t* block = block_from_ptr(ptr);
|
---|
| 635 | integrity_t* integ = tlsf_cast(integrity_t*, user);
|
---|
| 636 | const int this_prev_status = block_is_prev_free(block) ? 1 : 0;
|
---|
| 637 | const int this_status = block_is_free(block) ? 1 : 0;
|
---|
| 638 | const size_t this_block_size = block_size(block);
|
---|
| 639 |
|
---|
| 640 | int status = 0;
|
---|
| 641 | tlsf_insist(integ->prev_status == this_prev_status && "prev status incorrect");
|
---|
| 642 | tlsf_insist(size == this_block_size && "block size incorrect");
|
---|
| 643 |
|
---|
| 644 | integ->prev_status = this_status;
|
---|
| 645 | integ->status += status;
|
---|
| 646 | }
|
---|
| 647 |
|
---|
| 648 | int tlsf_check(tlsf_t tlsf)
|
---|
| 649 | {
|
---|
| 650 | int i, j;
|
---|
| 651 |
|
---|
| 652 | control_t* control = tlsf_cast(control_t*, tlsf);
|
---|
| 653 | int status = 0;
|
---|
| 654 |
|
---|
| 655 | /* Check that the free lists and bitmaps are accurate. */
|
---|
| 656 | for (i = 0; i < FL_INDEX_COUNT; ++i)
|
---|
| 657 | {
|
---|
| 658 | for (j = 0; j < SL_INDEX_COUNT; ++j)
|
---|
| 659 | {
|
---|
| 660 | const int fl_map = control->fl_bitmap & (1 << i);
|
---|
| 661 | const int sl_list = control->sl_bitmap[i];
|
---|
| 662 | const int sl_map = sl_list & (1 << j);
|
---|
| 663 | const block_header_t* block = control->blocks[i][j];
|
---|
| 664 |
|
---|
| 665 | /* Check that first- and second-level lists agree. */
|
---|
| 666 | if (!fl_map)
|
---|
| 667 | {
|
---|
| 668 | tlsf_insist(!sl_map && "second-level map must be null");
|
---|
| 669 | }
|
---|
| 670 |
|
---|
| 671 | if (!sl_map)
|
---|
| 672 | {
|
---|
| 673 | tlsf_insist(block == &control->block_null && "block list must be null");
|
---|
| 674 | continue;
|
---|
| 675 | }
|
---|
| 676 |
|
---|
| 677 | /* Check that there is at least one free block. */
|
---|
| 678 | tlsf_insist(sl_list && "no free blocks in second-level map");
|
---|
| 679 | tlsf_insist(block != &control->block_null && "block should not be null");
|
---|
| 680 |
|
---|
| 681 | while (block != &control->block_null)
|
---|
| 682 | {
|
---|
| 683 | int fli, sli;
|
---|
| 684 | tlsf_insist(block_is_free(block) && "block should be free");
|
---|
| 685 | tlsf_insist(!block_is_prev_free(block) && "blocks should have coalesced");
|
---|
| 686 | tlsf_insist(!block_is_free(block_next(block)) && "blocks should have coalesced");
|
---|
| 687 | tlsf_insist(block_is_prev_free(block_next(block)) && "block should be free");
|
---|
| 688 | tlsf_insist(block_size(block) >= block_size_min && "block not minimum size");
|
---|
| 689 |
|
---|
| 690 | mapping_insert(block_size(block), &fli, &sli);
|
---|
| 691 | tlsf_insist(fli == i && sli == j && "block size indexed in wrong list");
|
---|
| 692 | block = block->next_free;
|
---|
| 693 | }
|
---|
| 694 | }
|
---|
| 695 | }
|
---|
| 696 |
|
---|
| 697 | return status;
|
---|
| 698 | }
|
---|
| 699 |
|
---|
| 700 | #undef tlsf_insist
|
---|
| 701 |
|
---|
| 702 | static void default_walker(void* ptr, size_t size, int used, void* user)
|
---|
| 703 | {
|
---|
| 704 | (void)user;
|
---|
| 705 | printf("\t%p %s size: %x (%p)\n", ptr, used ? "used" : "free", (unsigned int)size, block_from_ptr(ptr));
|
---|
| 706 | }
|
---|
| 707 |
|
---|
| 708 | void tlsf_walk_pool(pool_t pool, tlsf_walker walker, void* user)
|
---|
| 709 | {
|
---|
| 710 | tlsf_walker pool_walker = walker ? walker : default_walker;
|
---|
| 711 | block_header_t* block =
|
---|
| 712 | offset_to_block(pool, -(int)block_header_overhead);
|
---|
| 713 |
|
---|
| 714 | while (block && !block_is_last(block))
|
---|
| 715 | {
|
---|
| 716 | pool_walker(
|
---|
| 717 | block_to_ptr(block),
|
---|
| 718 | block_size(block),
|
---|
| 719 | !block_is_free(block),
|
---|
| 720 | user);
|
---|
| 721 | block = block_next(block);
|
---|
| 722 | }
|
---|
| 723 | }
|
---|
| 724 |
|
---|
| 725 | size_t tlsf_block_size(void* ptr)
|
---|
| 726 | {
|
---|
| 727 | size_t size = 0;
|
---|
| 728 | if (ptr)
|
---|
| 729 | {
|
---|
| 730 | const block_header_t* block = block_from_ptr(ptr);
|
---|
| 731 | size = block_size(block);
|
---|
| 732 | }
|
---|
| 733 | return size;
|
---|
| 734 | }
|
---|
| 735 |
|
---|
| 736 | int tlsf_check_pool(pool_t pool)
|
---|
| 737 | {
|
---|
| 738 | /* Check that the blocks are physically correct. */
|
---|
| 739 | integrity_t integ = { 0, 0 };
|
---|
| 740 | tlsf_walk_pool(pool, integrity_walker, &integ);
|
---|
| 741 |
|
---|
| 742 | return integ.status;
|
---|
| 743 | }
|
---|
| 744 |
|
---|
| 745 | /*
|
---|
| 746 | ** Size of the TLSF structures in a given memory block passed to
|
---|
| 747 | ** tlsf_create, equal to the size of a control_t
|
---|
| 748 | */
|
---|
| 749 | size_t tlsf_size()
|
---|
| 750 | {
|
---|
| 751 | return sizeof(control_t);
|
---|
| 752 | }
|
---|
| 753 |
|
---|
| 754 | size_t tlsf_align_size()
|
---|
| 755 | {
|
---|
| 756 | return ALIGN_SIZE;
|
---|
| 757 | }
|
---|
| 758 |
|
---|
| 759 | size_t tlsf_block_size_min()
|
---|
| 760 | {
|
---|
| 761 | return block_size_min;
|
---|
| 762 | }
|
---|
| 763 |
|
---|
| 764 | size_t tlsf_block_size_max()
|
---|
| 765 | {
|
---|
| 766 | return block_size_max;
|
---|
| 767 | }
|
---|
| 768 |
|
---|
| 769 | /*
|
---|
| 770 | ** Overhead of the TLSF structures in a given memory block passes to
|
---|
| 771 | ** tlsf_add_pool, equal to the overhead of a free block and the
|
---|
| 772 | ** sentinel block.
|
---|
| 773 | */
|
---|
| 774 | size_t tlsf_pool_overhead()
|
---|
| 775 | {
|
---|
| 776 | return 2 * block_header_overhead;
|
---|
| 777 | }
|
---|
| 778 |
|
---|
| 779 | size_t tlsf_alloc_overhead()
|
---|
| 780 | {
|
---|
| 781 | return block_header_overhead;
|
---|
| 782 | }
|
---|
| 783 |
|
---|
| 784 | pool_t tlsf_add_pool(tlsf_t tlsf, void* mem, size_t bytes)
|
---|
| 785 | {
|
---|
| 786 | block_header_t* block;
|
---|
| 787 | block_header_t* next;
|
---|
| 788 |
|
---|
| 789 | const size_t pool_overhead = tlsf_pool_overhead();
|
---|
| 790 | const size_t pool_bytes = align_down(bytes - pool_overhead, ALIGN_SIZE);
|
---|
| 791 |
|
---|
| 792 | if (((ptrdiff_t)mem % ALIGN_SIZE) != 0)
|
---|
| 793 | {
|
---|
| 794 | printf("tlsf_add_pool: Memory must be aligned by %u bytes.\n",
|
---|
| 795 | (unsigned int)ALIGN_SIZE);
|
---|
| 796 | return 0;
|
---|
| 797 | }
|
---|
| 798 |
|
---|
| 799 | if (pool_bytes < block_size_min || pool_bytes > block_size_max)
|
---|
| 800 | {
|
---|
| 801 | #if defined (TLSF_64BIT)
|
---|
| 802 | printf("tlsf_add_pool: Memory size must be between 0x%x and 0x%x00 bytes.\n",
|
---|
| 803 | (unsigned int)(pool_overhead + block_size_min),
|
---|
| 804 | (unsigned int)((pool_overhead + block_size_max) / 256));
|
---|
| 805 | #else
|
---|
| 806 | printf("tlsf_add_pool: Memory size must be between %u and %u bytes.\n",
|
---|
| 807 | (unsigned int)(pool_overhead + block_size_min),
|
---|
| 808 | (unsigned int)(pool_overhead + block_size_max));
|
---|
| 809 | #endif
|
---|
| 810 | return 0;
|
---|
| 811 | }
|
---|
| 812 |
|
---|
| 813 | /*
|
---|
| 814 | ** Create the main free block. Offset the start of the block slightly
|
---|
| 815 | ** so that the prev_phys_block field falls outside of the pool -
|
---|
| 816 | ** it will never be used.
|
---|
| 817 | */
|
---|
| 818 | block = offset_to_block(mem, -(tlsfptr_t)block_header_overhead);
|
---|
| 819 | block_set_size(block, pool_bytes);
|
---|
| 820 | block_set_free(block);
|
---|
| 821 | block_set_prev_used(block);
|
---|
| 822 | block_insert(tlsf_cast(control_t*, tlsf), block);
|
---|
| 823 |
|
---|
| 824 | /* Split the block to create a zero-size sentinel block. */
|
---|
| 825 | next = block_link_next(block);
|
---|
| 826 | block_set_size(next, 0);
|
---|
| 827 | block_set_used(next);
|
---|
| 828 | block_set_prev_free(next);
|
---|
| 829 |
|
---|
| 830 | return mem;
|
---|
| 831 | }
|
---|
| 832 |
|
---|
| 833 | void tlsf_remove_pool(tlsf_t tlsf, pool_t pool)
|
---|
| 834 | {
|
---|
| 835 | control_t* control = tlsf_cast(control_t*, tlsf);
|
---|
| 836 | block_header_t* block = offset_to_block(pool, -(int)block_header_overhead);
|
---|
| 837 |
|
---|
| 838 | int fl = 0, sl = 0;
|
---|
| 839 |
|
---|
| 840 | tlsf_assert(block_is_free(block) && "block should be free");
|
---|
| 841 | tlsf_assert(!block_is_free(block_next(block)) && "next block should not be free");
|
---|
| 842 | tlsf_assert(block_size(block_next(block)) == 0 && "next block size should be zero");
|
---|
| 843 |
|
---|
| 844 | mapping_insert(block_size(block), &fl, &sl);
|
---|
| 845 | remove_free_block(control, block, fl, sl);
|
---|
| 846 | }
|
---|
| 847 |
|
---|
| 848 | /*
|
---|
| 849 | ** TLSF main interface.
|
---|
| 850 | */
|
---|
| 851 |
|
---|
| 852 | #if _DEBUG
|
---|
| 853 | int test_ffs_fls()
|
---|
| 854 | {
|
---|
| 855 | /* Verify ffs/fls work properly. */
|
---|
| 856 | int rv = 0;
|
---|
| 857 | rv += (tlsf_ffs(0) == -1) ? 0 : 0x1;
|
---|
| 858 | rv += (tlsf_fls(0) == -1) ? 0 : 0x2;
|
---|
| 859 | rv += (tlsf_ffs(1) == 0) ? 0 : 0x4;
|
---|
| 860 | rv += (tlsf_fls(1) == 0) ? 0 : 0x8;
|
---|
| 861 | rv += (tlsf_ffs(0x80000000) == 31) ? 0 : 0x10;
|
---|
| 862 | rv += (tlsf_ffs(0x80008000) == 15) ? 0 : 0x20;
|
---|
| 863 | rv += (tlsf_fls(0x80000008) == 31) ? 0 : 0x40;
|
---|
| 864 | rv += (tlsf_fls(0x7FFFFFFF) == 30) ? 0 : 0x80;
|
---|
| 865 |
|
---|
| 866 | #if defined (TLSF_64BIT)
|
---|
| 867 | rv += (tlsf_fls_sizet(0x80000000) == 31) ? 0 : 0x100;
|
---|
| 868 | rv += (tlsf_fls_sizet(0x100000000) == 32) ? 0 : 0x200;
|
---|
| 869 | rv += (tlsf_fls_sizet(0xffffffffffffffff) == 63) ? 0 : 0x400;
|
---|
| 870 | #endif
|
---|
| 871 |
|
---|
| 872 | if (rv)
|
---|
| 873 | {
|
---|
| 874 | printf("tlsf_create: %x ffs/fls tests failed!\n", rv);
|
---|
| 875 | }
|
---|
| 876 | return rv;
|
---|
| 877 | }
|
---|
| 878 | #endif
|
---|
| 879 |
|
---|
| 880 | tlsf_t tlsf_create(void* mem)
|
---|
| 881 | {
|
---|
| 882 | #if _DEBUG
|
---|
| 883 | if (test_ffs_fls())
|
---|
| 884 | {
|
---|
| 885 | return 0;
|
---|
| 886 | }
|
---|
| 887 | #endif
|
---|
| 888 |
|
---|
| 889 | if (((tlsfptr_t)mem % ALIGN_SIZE) != 0)
|
---|
| 890 | {
|
---|
| 891 | printf("tlsf_create: Memory must be aligned to %u bytes.\n",
|
---|
| 892 | (unsigned int)ALIGN_SIZE);
|
---|
| 893 | return 0;
|
---|
| 894 | }
|
---|
| 895 |
|
---|
| 896 | control_construct(tlsf_cast(control_t*, mem));
|
---|
| 897 |
|
---|
| 898 | return tlsf_cast(tlsf_t, mem);
|
---|
| 899 | }
|
---|
| 900 |
|
---|
| 901 | tlsf_t tlsf_create_with_pool(void* mem, size_t bytes)
|
---|
| 902 | {
|
---|
| 903 | tlsf_t tlsf = tlsf_create(mem);
|
---|
| 904 | tlsf_add_pool(tlsf, (char*)mem + tlsf_size(), bytes - tlsf_size());
|
---|
| 905 | return tlsf;
|
---|
| 906 | }
|
---|
| 907 |
|
---|
| 908 | void tlsf_destroy(tlsf_t tlsf)
|
---|
| 909 | {
|
---|
| 910 | /* Nothing to do. */
|
---|
| 911 | (void)tlsf;
|
---|
| 912 | }
|
---|
| 913 |
|
---|
| 914 | pool_t tlsf_get_pool(tlsf_t tlsf)
|
---|
| 915 | {
|
---|
| 916 | return tlsf_cast(pool_t, (char*)tlsf + tlsf_size());
|
---|
| 917 | }
|
---|
| 918 |
|
---|
| 919 | void* tlsf_malloc(tlsf_t tlsf, size_t size)
|
---|
| 920 | {
|
---|
| 921 | control_t* control = tlsf_cast(control_t*, tlsf);
|
---|
| 922 | const size_t adjust = adjust_request_size(size, ALIGN_SIZE);
|
---|
| 923 | block_header_t* block = block_locate_free(control, adjust);
|
---|
| 924 | return block_prepare_used(control, block, adjust);
|
---|
| 925 | }
|
---|
| 926 |
|
---|
| 927 | void* tlsf_memalign(tlsf_t tlsf, size_t align, size_t size)
|
---|
| 928 | {
|
---|
| 929 | control_t* control = tlsf_cast(control_t*, tlsf);
|
---|
| 930 | const size_t adjust = adjust_request_size(size, ALIGN_SIZE);
|
---|
| 931 |
|
---|
| 932 | /*
|
---|
| 933 | ** We must allocate an additional minimum block size bytes so that if
|
---|
| 934 | ** our free block will leave an alignment gap which is smaller, we can
|
---|
| 935 | ** trim a leading free block and release it back to the pool. We must
|
---|
| 936 | ** do this because the previous physical block is in use, therefore
|
---|
| 937 | ** the prev_phys_block field is not valid, and we can't simply adjust
|
---|
| 938 | ** the size of that block.
|
---|
| 939 | */
|
---|
| 940 | const size_t gap_minimum = sizeof(block_header_t);
|
---|
| 941 | const size_t size_with_gap = adjust_request_size(adjust + align + gap_minimum, align);
|
---|
| 942 |
|
---|
| 943 | /* If alignment is less than or equals base alignment, we're done. */
|
---|
| 944 | const size_t aligned_size = (align <= ALIGN_SIZE) ? adjust : size_with_gap;
|
---|
| 945 |
|
---|
| 946 | block_header_t* block = block_locate_free(control, aligned_size);
|
---|
| 947 |
|
---|
| 948 | /* This can't be a static assert. */
|
---|
| 949 | tlsf_assert(sizeof(block_header_t) == block_size_min + block_header_overhead);
|
---|
| 950 |
|
---|
| 951 | if (block)
|
---|
| 952 | {
|
---|
| 953 | void* ptr = block_to_ptr(block);
|
---|
| 954 | void* aligned = align_ptr(ptr, align);
|
---|
| 955 | size_t gap = tlsf_cast(size_t,
|
---|
| 956 | tlsf_cast(tlsfptr_t, aligned) - tlsf_cast(tlsfptr_t, ptr));
|
---|
| 957 |
|
---|
| 958 | /* If gap size is too small, offset to next aligned boundary. */
|
---|
| 959 | if (gap && gap < gap_minimum)
|
---|
| 960 | {
|
---|
| 961 | const size_t gap_remain = gap_minimum - gap;
|
---|
| 962 | const size_t offset = tlsf_max(gap_remain, align);
|
---|
| 963 | const void* next_aligned = tlsf_cast(void*,
|
---|
| 964 | tlsf_cast(tlsfptr_t, aligned) + offset);
|
---|
| 965 |
|
---|
| 966 | aligned = align_ptr(next_aligned, align);
|
---|
| 967 | gap = tlsf_cast(size_t,
|
---|
| 968 | tlsf_cast(tlsfptr_t, aligned) - tlsf_cast(tlsfptr_t, ptr));
|
---|
| 969 | }
|
---|
| 970 |
|
---|
| 971 | if (gap)
|
---|
| 972 | {
|
---|
| 973 | tlsf_assert(gap >= gap_minimum && "gap size too small");
|
---|
| 974 | block = block_trim_free_leading(control, block, gap);
|
---|
| 975 | }
|
---|
| 976 | }
|
---|
| 977 |
|
---|
| 978 | return block_prepare_used(control, block, adjust);
|
---|
| 979 | }
|
---|
| 980 |
|
---|
| 981 | void tlsf_free(tlsf_t tlsf, void* ptr)
|
---|
| 982 | {
|
---|
| 983 | /* Don't attempt to free a NULL pointer. */
|
---|
| 984 | if (ptr)
|
---|
| 985 | {
|
---|
| 986 | control_t* control = tlsf_cast(control_t*, tlsf);
|
---|
| 987 | block_header_t* block = block_from_ptr(ptr);
|
---|
| 988 | tlsf_assert(!block_is_free(block) && "block already marked as free");
|
---|
| 989 | block_mark_as_free(block);
|
---|
| 990 | block = block_merge_prev(control, block);
|
---|
| 991 | block = block_merge_next(control, block);
|
---|
| 992 | block_insert(control, block);
|
---|
| 993 | }
|
---|
| 994 | }
|
---|
| 995 |
|
---|
| 996 | /*
|
---|
| 997 | ** The TLSF block information provides us with enough information to
|
---|
| 998 | ** provide a reasonably intelligent implementation of realloc, growing or
|
---|
| 999 | ** shrinking the currently allocated block as required.
|
---|
| 1000 | **
|
---|
| 1001 | ** This routine handles the somewhat esoteric edge cases of realloc:
|
---|
| 1002 | ** - a non-zero size with a null pointer will behave like malloc
|
---|
| 1003 | ** - a zero size with a non-null pointer will behave like free
|
---|
| 1004 | ** - a request that cannot be satisfied will leave the original buffer
|
---|
| 1005 | ** untouched
|
---|
| 1006 | ** - an extended buffer size will leave the newly-allocated area with
|
---|
| 1007 | ** contents undefined
|
---|
| 1008 | */
|
---|
| 1009 | void* tlsf_realloc(tlsf_t tlsf, void* ptr, size_t size)
|
---|
| 1010 | {
|
---|
| 1011 | control_t* control = tlsf_cast(control_t*, tlsf);
|
---|
| 1012 | void* p = 0;
|
---|
| 1013 |
|
---|
| 1014 | /* Zero-size requests are treated as free. */
|
---|
| 1015 | if (ptr && size == 0)
|
---|
| 1016 | {
|
---|
| 1017 | tlsf_free(tlsf, ptr);
|
---|
| 1018 | }
|
---|
| 1019 | /* Requests with NULL pointers are treated as malloc. */
|
---|
| 1020 | else if (!ptr)
|
---|
| 1021 | {
|
---|
| 1022 | p = tlsf_malloc(tlsf, size);
|
---|
| 1023 | }
|
---|
| 1024 | else
|
---|
| 1025 | {
|
---|
| 1026 | block_header_t* block = block_from_ptr(ptr);
|
---|
| 1027 | block_header_t* next = block_next(block);
|
---|
| 1028 |
|
---|
| 1029 | const size_t cursize = block_size(block);
|
---|
| 1030 | const size_t combined = cursize + block_size(next) + block_header_overhead;
|
---|
| 1031 | const size_t adjust = adjust_request_size(size, ALIGN_SIZE);
|
---|
| 1032 |
|
---|
| 1033 | tlsf_assert(!block_is_free(block) && "block already marked as free");
|
---|
| 1034 |
|
---|
| 1035 | /*
|
---|
| 1036 | ** If the next block is used, or when combined with the current
|
---|
| 1037 | ** block, does not offer enough space, we must reallocate and copy.
|
---|
| 1038 | */
|
---|
| 1039 | if (adjust > cursize && (!block_is_free(next) || adjust > combined))
|
---|
| 1040 | {
|
---|
| 1041 | p = tlsf_malloc(tlsf, size);
|
---|
| 1042 | if (p)
|
---|
| 1043 | {
|
---|
| 1044 | const size_t minsize = tlsf_min(cursize, size);
|
---|
| 1045 | memcpy(p, ptr, minsize);
|
---|
| 1046 | tlsf_free(tlsf, ptr);
|
---|
| 1047 | }
|
---|
| 1048 | }
|
---|
| 1049 | else
|
---|
| 1050 | {
|
---|
| 1051 | /* Do we need to expand to the next block? */
|
---|
| 1052 | if (adjust > cursize)
|
---|
| 1053 | {
|
---|
| 1054 | block_merge_next(control, block);
|
---|
| 1055 | block_mark_as_used(block);
|
---|
| 1056 | }
|
---|
| 1057 |
|
---|
| 1058 | /* Trim the resulting block and return the original pointer. */
|
---|
| 1059 | block_trim_used(control, block, adjust);
|
---|
| 1060 | p = ptr;
|
---|
| 1061 | }
|
---|
| 1062 | }
|
---|
| 1063 |
|
---|
| 1064 | return p;
|
---|
| 1065 | }
|
---|