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#include "../../global.h"#include "../include/assert.h"#include <limits.h>#include <stddef.h>#include "../include/stdio.h"#include "../include/stdlib.h"#include "../include/string.h"#include "../../console.h"#include "../../thread.h"#include "tlsf.h"#include "tlsfbits.h"/*** Constants.*//* Public constants: may be modified. */enum tlsf_public{/* log2 of number of linear subdivisions of block sizes. */SL_INDEX_COUNT_LOG2 = 5,};/* Private constants: do not modify. */enum tlsf_private{/* All allocation sizes and addresses are aligned to 4 bytes. */ALIGN_SIZE_LOG2 = 2,ALIGN_SIZE = (1 << ALIGN_SIZE_LOG2),/*** We support allocations of sizes up to (1 << FL_INDEX_MAX) bits.** However, because we linearly subdivide the second-level lists, and** our minimum size granularity is 4 bytes, it doesn't make sense to** create first-level lists for sizes smaller than SL_INDEX_COUNT * 4,** or (1 << (SL_INDEX_COUNT_LOG2 + 2)) bytes, as there we will be** trying to split size ranges into more slots than we have available.** Instead, we calculate the minimum threshold size, and place all** blocks below that size into the 0th first-level list.*/FL_INDEX_MAX = 30,SL_INDEX_COUNT = (1 << SL_INDEX_COUNT_LOG2),FL_INDEX_SHIFT = (SL_INDEX_COUNT_LOG2 + ALIGN_SIZE_LOG2),FL_INDEX_COUNT = (FL_INDEX_MAX - FL_INDEX_SHIFT + 1),SMALL_BLOCK_SIZE = (1 << FL_INDEX_SHIFT),};/*** Cast and min/max macros.*/#define tlsf_cast(t, exp) ((t) (exp))#define tlsf_min(a, b) ((a) < (b) ? (a) : (b))#define tlsf_max(a, b) ((a) > (b) ? (a) : (b))/*** Set assert macro, if it has not been provided by the user.*/#if !defined (tlsf_assert)#define tlsf_assert assert#endif/*** Static assertion mechanism.*/#define _tlsf_glue2(x, y) x ## y#define _tlsf_glue(x, y) _tlsf_glue2(x, y)#define tlsf_static_assert(exp) \typedef char _tlsf_glue(static_assert, __LINE__) [(exp) ? 1 : -1]/* FIXME: This code only currently supports 32-bit architectures. */tlsf_static_assert(sizeof(size_t) * CHAR_BIT == 32);/* SL_INDEX_COUNT must be <= number of bits in sl_bitmap's storage type. */tlsf_static_assert(sizeof(unsigned int) * CHAR_BIT >= SL_INDEX_COUNT);/* sizeof fl_bitmap must be >= FL_INDEX_COUNT. */tlsf_static_assert(sizeof(unsigned int) * CHAR_BIT >= FL_INDEX_COUNT);/* Ensure we've properly tuned our sizes. */tlsf_static_assert(ALIGN_SIZE == SMALL_BLOCK_SIZE / SL_INDEX_COUNT);/*** Data structures and associated constants.*//*** Block header structure.**** There are several implementation subtleties involved:** - The prev_phys_block field is only valid if the previous block is free.** - The prev_phys_block field is actually stored in the last word of the** previous block. It appears at the beginning of this structure only to** simplify the implementation.** - The next_free / prev_free fields are only valid if the block is free.*/typedef struct block_header_t{/* Points to the previous physical block. */struct block_header_t* prev_phys_block;/* The size of this block, excluding the block header. */size_t size;/* Next and previous free blocks. */struct block_header_t* next_free;struct block_header_t* prev_free;} block_header_t;/*** Since block sizes are always a multiple of 4, the two least significant** bits of the size field are used to store the block status:** - bit 0: whether block is busy or free** - bit 1: whether previous block is busy or free*/static const size_t block_header_free_bit = 1 << 0;static const size_t block_header_prev_free_bit = 1 << 1;/*** The size of the block header exposed to used blocks is the size field.** The prev_phys_block field is stored *inside* the previous free block.*/static const size_t block_header_overhead = sizeof(size_t);/* User data starts directly after the size field in a used block. */static const size_t block_start_offset =offsetof(block_header_t, size) + sizeof(size_t);/*** A free block must be large enough to store its header minus the size of** the prev_phys_block field, and no larger than the number of addressable** bits for FL_INDEX.*/static const size_t block_size_min =sizeof(block_header_t) - sizeof(block_header_t*);static const size_t block_size_max = 1 << FL_INDEX_MAX;/* Empty lists point at this block to indicate they are free. */static block_header_t block_null;/* The TLSF pool structure. */typedef struct pool_t{/* Bitmaps for free lists. */unsigned int fl_bitmap;unsigned int sl_bitmap[FL_INDEX_COUNT];/* Head of free lists. */block_header_t* blocks[FL_INDEX_COUNT][SL_INDEX_COUNT];} pool_t;/* A type used for casting when doing pointer arithmetic. */typedef unsigned int tlsfptr_t;/*** block_header_t member functions.*/static size_t block_size(const block_header_t* block) ICODE_ATTR;static size_t block_size(const block_header_t* block){return block->size & ~(block_header_free_bit | block_header_prev_free_bit);}static void block_set_size(block_header_t* block, size_t size) ICODE_ATTR;static void block_set_size(block_header_t* block, size_t size){const size_t oldsize = block->size;block->size = size | (oldsize & (block_header_free_bit | block_header_prev_free_bit));}static int block_is_last(const block_header_t* block) ICODE_ATTR;static int block_is_last(const block_header_t* block){return 0 == block_size(block);}static int block_is_free(const block_header_t* block) ICODE_ATTR;static int block_is_free(const block_header_t* block){return block->size & block_header_free_bit;}static void block_set_free(block_header_t* block) ICODE_ATTR;static void block_set_free(block_header_t* block){block->size |= block_header_free_bit;}static void block_set_used(block_header_t* block) ICODE_ATTR;static void block_set_used(block_header_t* block){block->size &= ~block_header_free_bit;}static int block_is_prev_free(const block_header_t* block) ICODE_ATTR;static int block_is_prev_free(const block_header_t* block){return block->size & block_header_prev_free_bit;}static void block_set_prev_free(block_header_t* block) ICODE_ATTR;static void block_set_prev_free(block_header_t* block){block->size |= block_header_prev_free_bit;}static void block_set_prev_used(block_header_t* block) ICODE_ATTR;static void block_set_prev_used(block_header_t* block){block->size &= ~block_header_prev_free_bit;}static block_header_t* block_from_ptr(const void* ptr) ICODE_ATTR;static block_header_t* block_from_ptr(const void* ptr){return tlsf_cast(block_header_t*,tlsf_cast(unsigned char*, ptr) - block_start_offset);}static void* block_to_ptr(const block_header_t* block) ICODE_ATTR;static void* block_to_ptr(const block_header_t* block){return tlsf_cast(void*,tlsf_cast(unsigned char*, block) + block_start_offset);}/* Return location of next block after block of given size. */static block_header_t* offset_to_block(const void* ptr, size_t size) ICODE_ATTR;static block_header_t* offset_to_block(const void* ptr, size_t size){return tlsf_cast(block_header_t*,tlsf_cast(unsigned char*, ptr) + size);}/* Return location of previous block. */static block_header_t* block_prev(const block_header_t* block) ICODE_ATTR;static block_header_t* block_prev(const block_header_t* block){return block->prev_phys_block;}/* Return location of next existing block. */static block_header_t* block_next(const block_header_t* block) ICODE_ATTR;static block_header_t* block_next(const block_header_t* block){block_header_t* next = offset_to_block(block_to_ptr(block),block_size(block) - block_header_overhead);tlsf_assert(!block_is_last(block));return next;}/* Link a new block with its physical neighbor, return the neighbor. */static block_header_t* block_link_next(block_header_t* block) ICODE_ATTR;static block_header_t* block_link_next(block_header_t* block){block_header_t* next = block_next(block);next->prev_phys_block = block;return next;}static void block_mark_as_free(block_header_t* block) ICODE_ATTR;static void block_mark_as_free(block_header_t* block){/* Link the block to the next block, first. */block_header_t* next = block_link_next(block);block_set_prev_free(next);block_set_free(block);}static void block_mark_as_used(block_header_t* block) ICODE_ATTR;static void block_mark_as_used(block_header_t* block){block_header_t* next = block_next(block);block_set_prev_used(next);block_set_used(block);}static size_t align_up(size_t x, size_t align) ICODE_ATTR;static size_t align_up(size_t x, size_t align){tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");return (x + (align - 1)) & ~(align - 1);}static size_t align_down(size_t x, size_t align) ICODE_ATTR;static size_t align_down(size_t x, size_t align){tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");return x - (x & (align - 1));}static void* align_ptr(void* ptr, size_t align) ICODE_ATTR;static void* align_ptr(void* ptr, size_t align){const tlsfptr_t aligned =(tlsf_cast(tlsfptr_t, ptr) + (align - 1)) & ~(align - 1);tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");return tlsf_cast(void*, aligned);}/*** Adjust an allocation size to be aligned to word size, and no smaller** than internal minimum.*/static size_t adjust_request_size(size_t size, size_t align) ICODE_ATTR;static size_t adjust_request_size(size_t size, size_t align){size_t adjust = 0;if (size && size < block_size_max){const size_t aligned = align_up(size, align);adjust = tlsf_max(aligned, block_size_min);}return adjust;}/*** TLSF utility functions. In most cases, these are direct translations of** the documentation found in the white paper.*/static void mapping_insert(size_t size, int* fli, int* sli) ICODE_ATTR;static void mapping_insert(size_t size, int* fli, int* sli){int fl, sl;if (size < SMALL_BLOCK_SIZE){/* Store small blocks in first list. */fl = 0;sl = size / (SMALL_BLOCK_SIZE / SL_INDEX_COUNT);}else{fl = tlsf_fls(size);sl = (size >> (fl - SL_INDEX_COUNT_LOG2)) ^ (1 << SL_INDEX_COUNT_LOG2);fl -= (FL_INDEX_SHIFT - 1);}*fli = fl;*sli = sl;}/* This version rounds up to the next block size (for allocations) */static void mapping_search(size_t size, int* fli, int* sli) ICODE_ATTR;static void mapping_search(size_t size, int* fli, int* sli){if (size >= (1 << SL_INDEX_COUNT_LOG2)){const size_t round = (1 << (tlsf_fls(size) - SL_INDEX_COUNT_LOG2)) - 1;size += round;}mapping_insert(size, fli, sli);}static block_header_t* search_suitable_block(pool_t* pool, int* fli, int* sli) ICODE_ATTR;static block_header_t* search_suitable_block(pool_t* pool, int* fli, int* sli){int fl = *fli;int sl = *sli;/*** First, search for a block in the list associated with the given** fl/sl index.*/unsigned int sl_map = pool->sl_bitmap[fl] & (0xffffffff << sl);if (!sl_map){/* No block exists. Search in the next largest first-level list. */const unsigned int fl_map = pool->fl_bitmap & (0xffffffff << (fl + 1));if (!fl_map){/* No free blocks available, memory has been exhausted. */return 0;}fl = tlsf_ffs(fl_map);*fli = fl;sl_map = pool->sl_bitmap[fl];}tlsf_assert(sl_map && "internal error - second level bitmap is null");sl = tlsf_ffs(sl_map);*sli = sl;/* Return the first block in the free list. */return pool->blocks[fl][sl];}/* Remove a free block from the free list.*/static void remove_free_block(pool_t* pool, block_header_t* block, int fl, int sl) ICODE_ATTR;static void remove_free_block(pool_t* pool, block_header_t* block, int fl, int sl){block_header_t* prev = block->prev_free;block_header_t* next = block->next_free;tlsf_assert(prev && "prev_free field can not be null");tlsf_assert(next && "next_free field can not be null");next->prev_free = prev;prev->next_free = next;/* If this block is the head of the free list, set new head. */if (pool->blocks[fl][sl] == block){pool->blocks[fl][sl] = next;/* If the new head is null, clear the bitmap. */if (next == &block_null){pool->sl_bitmap[fl] &= ~(1 << sl);/* If the second bitmap is now empty, clear the fl bitmap. */if (!pool->sl_bitmap[fl]){pool->fl_bitmap &= ~(1 << fl);}}}}/* Insert a free block into the free block list. */static void insert_free_block(pool_t* pool, block_header_t* block, int fl, int sl) ICODE_ATTR;static void insert_free_block(pool_t* pool, block_header_t* block, int fl, int sl){block_header_t* current = pool->blocks[fl][sl];tlsf_assert(current && "free list cannot have a null entry");tlsf_assert(block && "cannot insert a null entry into the free list");block->next_free = current;block->prev_free = &block_null;current->prev_free = block;/*** Insert the new block at the head of the list, and mark the first-** and second-level bitmaps appropriately.*/pool->blocks[fl][sl] = block;pool->fl_bitmap |= (1 << fl);pool->sl_bitmap[fl] |= (1 << sl);}/* Remove a given block from the free list. */static void block_remove(pool_t* pool, block_header_t* block) ICODE_ATTR;static void block_remove(pool_t* pool, block_header_t* block){int fl, sl;mapping_insert(block_size(block), &fl, &sl);remove_free_block(pool, block, fl, sl);}/* Insert a given block into the free list. */static void block_insert(pool_t* pool, block_header_t* block) ICODE_ATTR;static void block_insert(pool_t* pool, block_header_t* block){int fl, sl;mapping_insert(block_size(block), &fl, &sl);insert_free_block(pool, block, fl, sl);}static int block_can_split(block_header_t* block, size_t size) ICODE_ATTR;static int block_can_split(block_header_t* block, size_t size){return block_size(block) >= sizeof(block_header_t) + size;}/* Split a block into two, the second of which is free. */static block_header_t* block_split(block_header_t* block, size_t size) ICODE_ATTR;static block_header_t* block_split(block_header_t* block, size_t size){/* Calculate the amount of space left in the remaining block. */block_header_t* remaining =offset_to_block(block_to_ptr(block), size - block_header_overhead);const size_t remain_size = block_size(block) - (size + block_header_overhead);tlsf_assert(block_size(block) == remain_size + size + block_header_overhead);block_set_size(remaining, remain_size);tlsf_assert(block_size(remaining) >= block_size_min && "block split with invalid size");block_set_size(block, size);block_mark_as_free(remaining);return remaining;}/* Absorb a free block's storage into an adjacent previous free block. */static block_header_t* block_absorb(block_header_t* prev, block_header_t* block) ICODE_ATTR;static block_header_t* block_absorb(block_header_t* prev, block_header_t* block){tlsf_assert(!block_is_last(prev) && "previous block can't be last!");/* Note: Leaves flags untouched. */prev->size += block_size(block) + block_header_overhead;block_link_next(prev);return prev;}/* Merge a just-freed block with an adjacent previous free block. */static block_header_t* block_merge_prev(pool_t* pool, block_header_t* block) ICODE_ATTR;static block_header_t* block_merge_prev(pool_t* pool, block_header_t* block){if (block_is_prev_free(block)){block_header_t* prev = block_prev(block);tlsf_assert(prev && "prev physical block can't be null");tlsf_assert(block_is_free(prev) && "prev block is not free though marked as such");block_remove(pool, prev);block = block_absorb(prev, block);}return block;}/* Merge a just-freed block with an adjacent free block. */static block_header_t* block_merge_next(pool_t* pool, block_header_t* block) ICODE_ATTR;static block_header_t* block_merge_next(pool_t* pool, block_header_t* block){block_header_t* next = block_next(block);tlsf_assert(next && "next physical block can't be null");if (block_is_free(next)){tlsf_assert(!block_is_last(block) && "previous block can't be last!");block_remove(pool, next);block = block_absorb(block, next);}return block;}/* Trim any trailing block space off the end of a block, return to pool. */static void block_trim_free(pool_t* pool, block_header_t* block, size_t size) ICODE_ATTR;static void block_trim_free(pool_t* pool, block_header_t* block, size_t size){tlsf_assert(block_is_free(block) && "block must be free");if (block_can_split(block, size)){block_header_t* remaining_block = block_split(block, size);block_link_next(block);block_set_prev_free(remaining_block);block_insert(pool, remaining_block);}}/* Trim any trailing block space off the end of a used block, return to pool. */static void block_trim_used(pool_t* pool, block_header_t* block, size_t size) ICODE_ATTR;static void block_trim_used(pool_t* pool, block_header_t* block, size_t size){tlsf_assert(!block_is_free(block) && "block must be used");if (block_can_split(block, size)){/* If the next block is free, we must coalesce. */block_header_t* remaining_block = block_split(block, size);block_set_prev_used(remaining_block);remaining_block = block_merge_next(pool, remaining_block);block_insert(pool, remaining_block);}}static block_header_t* block_trim_free_leading(pool_t* pool, block_header_t* block, size_t size) ICODE_ATTR;static block_header_t* block_trim_free_leading(pool_t* pool, block_header_t* block, size_t size){block_header_t* remaining_block = block;if (block_can_split(block, size)){/* We want the 2nd block. */remaining_block = block_split(block, size - block_header_overhead);block_set_prev_free(remaining_block);block_link_next(block);block_insert(pool, block);}return remaining_block;}static block_header_t* block_locate_free(pool_t* pool, size_t size) ICODE_ATTR;static block_header_t* block_locate_free(pool_t* pool, size_t size){int fl, sl;block_header_t* block = 0;if (size){mapping_search(size, &fl, &sl);block = search_suitable_block(pool, &fl, &sl);}if (block){tlsf_assert(block_size(block) >= size);remove_free_block(pool, block, fl, sl);}return block;}static void* block_prepare_used(pool_t* pool, block_header_t* block, size_t size) ICODE_ATTR;static void* block_prepare_used(pool_t* pool, block_header_t* block, size_t size){void* p = 0;if (block){block_trim_free(pool, block, size);block_mark_as_used(block);p = block_to_ptr(block);}return p;}/* Clear structure and point all empty lists at the null block. */static void pool_construct(pool_t* pool) ICODE_ATTR;static void pool_construct(pool_t* pool){int i, j;block_null.next_free = &block_null;block_null.prev_free = &block_null;pool->fl_bitmap = 0;for (i = 0; i < FL_INDEX_COUNT; ++i){pool->sl_bitmap[i] = 0;for (j = 0; j < SL_INDEX_COUNT; ++j){pool->blocks[i][j] = &block_null;}}}/*** Debugging utilities.*/typedef struct integrity_t{int prev_status;int status;} integrity_t;#define tlsf_insist(x) { tlsf_assert(x); if (!(x)) { status--; } }static void integrity_walker(void* ptr, size_t size, int used, void* user){block_header_t* block = block_from_ptr(ptr);integrity_t* integ = tlsf_cast(integrity_t*, user);const int this_prev_status = block_is_prev_free(block) ? 1 : 0;const int this_status = block_is_free(block) ? 1 : 0;const size_t this_block_size = block_size(block);int status = 0;tlsf_insist(integ->prev_status == this_prev_status && "prev status incorrect");tlsf_insist(size == this_block_size && "block size incorrect");integ->prev_status = this_status;integ->status += status;}int tlsf_check_heap(tlsf_pool tlsf){int i, j;pool_t* pool = tlsf_cast(pool_t*, tlsf);int status = 0;/* Check that the blocks are physically correct. */integrity_t integ = { 0, 0 };tlsf_walk_heap(tlsf, integrity_walker, &integ);status = integ.status;/* Check that the free lists and bitmaps are accurate. */for (i = 0; i < FL_INDEX_COUNT; ++i){for (j = 0; j < SL_INDEX_COUNT; ++j){const int fl_map = pool->fl_bitmap & (1 << i);const int sl_list = pool->sl_bitmap[i];const int sl_map = sl_list & (1 << j);const block_header_t* block = pool->blocks[i][j];/* Check that first- and second-level lists agree. */if (!fl_map){tlsf_insist(!sl_map && "second-level map must be null");}if (!sl_map){tlsf_insist((block == &block_null) && "block list must be null");continue;}/* Check that there is at least one free block. */tlsf_insist(sl_list && "no free blocks in second-level map");tlsf_insist((block != &block_null) && "block should not be null");while (block != &block_null){int fli, sli;tlsf_insist(block_is_free(block) && "block should be free");tlsf_insist(!block_is_prev_free(block) && "blocks should have coalesced");tlsf_insist(!block_is_free(block_next(block)) && "blocks should have coalesced");tlsf_insist(block_is_prev_free(block_next(block)) && "block should be free");tlsf_insist(block_size(block) >= block_size_min && "block not minimum size");mapping_insert(block_size(block), &fli, &sli);tlsf_insist(fli == i && sli == j && "block size indexed in wrong list");block = block->next_free;}}}return status;}#undef tlsf_insiststatic void default_walker(void* ptr, size_t size, int used, void* user){if (used){struct scheduler_thread* owner = *((struct scheduler_thread**)(ptr + size - 4));cprintf((int)user, "%08X: %08X+8 bytes owned by %08X%s\n", ptr,size - 4, owner, owner == current_thread ? " (self)" : "");}else cprintf((int)user, "%08X: %08X bytes free\n", ptr, size + 4);}void tlsf_walk_heap(tlsf_pool pool, tlsf_walker walker, void* user){tlsf_walker heap_walker = walker ? walker : default_walker;block_header_t* block =offset_to_block(pool, sizeof(pool_t) - block_header_overhead);while (block && !block_is_last(block)){heap_walker(block_to_ptr(block),block_size(block),!block_is_free(block),user);block = block_next(block);}}size_t tlsf_block_size(void* ptr){size_t size = 0;if (ptr){const block_header_t* block = block_from_ptr(ptr);size = block_size(block);}return size;}/*** Overhead of the TLSF structures in a given memory block passed to** tlsf_create, equal to the size of a pool_t plus overhead of the initial** free block and the sentinel block.*/size_t tlsf_overhead(){const size_t pool_overhead = sizeof(pool_t) + 2 * block_header_overhead;return pool_overhead;}/*** TLSF main interface. Right out of the white paper.*/tlsf_pool tlsf_create(void* mem, size_t bytes){block_header_t* block;block_header_t* next;const size_t pool_overhead = tlsf_overhead();const size_t pool_bytes = align_down(bytes - pool_overhead, ALIGN_SIZE);pool_t* pool = tlsf_cast(pool_t*, mem);if (pool_bytes < block_size_min || pool_bytes > block_size_max){cprintf(CONSOLE_BOOT, "tlsf_create: Pool size must be between %d and %d bytes.\n",pool_overhead + block_size_min, pool_overhead + block_size_max);return 0;}/* Construct a valid pool object. */pool_construct(pool);/*** Create the main free block. Offset the start of the block slightly** so that the prev_phys_block field falls inside of the pool** structure - it will never be used.*/block = offset_to_block(tlsf_cast(void*, pool), sizeof(pool_t) - block_header_overhead);block_set_size(block, align_down(pool_bytes, ALIGN_SIZE));block_set_free(block);block_set_prev_used(block);block_insert(pool, block);/* Split the block to create a zero-size pool sentinel block. */next = block_link_next(block);block_set_size(next, 0);block_set_used(next);block_set_prev_free(next);return tlsf_cast(tlsf_pool, pool);}void tlsf_destroy(tlsf_pool pool){/* Nothing to do. */pool = pool;}void* tlsf_malloc(tlsf_pool tlsf, size_t size){pool_t* pool = tlsf_cast(pool_t*, tlsf);const size_t adjust = adjust_request_size(size, ALIGN_SIZE);block_header_t* block = block_locate_free(pool, adjust);return block_prepare_used(pool, block, adjust);}void* tlsf_memalign(tlsf_pool tlsf, size_t align, size_t size){pool_t* pool = tlsf_cast(pool_t*, tlsf);const size_t adjust = adjust_request_size(size, ALIGN_SIZE);/*** We must allocate an additional minimum block size bytes so that if** our free block will leave an alignment gap which is smaller, we can** trim a leading free block and release it back to the heap. We must** do this because the previous physical block is in use, therefore** the prev_phys_block field is not valid, and we can't simply adjust** the size of that block.*/const ptrdiff_t gap_minimum = tlsf_cast(ptrdiff_t, sizeof(block_header_t));const size_t size_with_gap = adjust_request_size(adjust + align + gap_minimum, align);/* If alignment is less than or equals base alignment, we're done. */const size_t aligned_size = (align <= ALIGN_SIZE) ? adjust : size_with_gap;block_header_t* block = block_locate_free(pool, aligned_size);/* This can't be a static assert. */tlsf_assert(sizeof(block_header_t) == block_size_min + block_header_overhead);if (block){void* ptr = block_to_ptr(block);void* aligned = align_ptr(ptr, align);ptrdiff_t gap = tlsf_cast(ptrdiff_t,tlsf_cast(tlsfptr_t, aligned) - tlsf_cast(tlsfptr_t, ptr));/* If gap size is too small, offset to next aligned boundary. */if (gap && gap < gap_minimum){const ptrdiff_t gap_remain = gap_minimum - gap;const ptrdiff_t offset = tlsf_max(gap_remain, tlsf_cast(ptrdiff_t, align));void* next_aligned = tlsf_cast(void*,tlsf_cast(tlsfptr_t, aligned) + tlsf_cast(tlsfptr_t, offset));aligned = align_ptr(next_aligned, align);gap = tlsf_cast(ptrdiff_t,tlsf_cast(tlsfptr_t, aligned) - tlsf_cast(tlsfptr_t, ptr));}if (gap){tlsf_assert(gap >= gap_minimum && "gap size too small");block = block_trim_free_leading(pool, block, gap);}}return block_prepare_used(pool, block, adjust);}void tlsf_free(tlsf_pool tlsf, void* ptr){/* Don't attempt to free a NULL pointer. */if (ptr){pool_t* pool = tlsf_cast(pool_t*, tlsf);block_header_t* block = block_from_ptr(ptr);block_mark_as_free(block);block = block_merge_prev(pool, block);block = block_merge_next(pool, block);block_insert(pool, block);}}/*** The TLSF block information provides us with enough information to** provide a reasonably intelligent implementation of realloc, growing or** shrinking the currently allocated block as required.**** This routine handles the somewhat esoteric edge cases of realloc:** - a non-zero size with a null pointer will behave like malloc** - a zero size with a non-null pointer will behave like free** - a request that cannot be satisfied will leave the original buffer** untouched** - an extended buffer size will leave the newly-allocated area with** contents undefined*/void* tlsf_realign(tlsf_pool tlsf, void* ptr, size_t align, size_t size){pool_t* pool = tlsf_cast(pool_t*, tlsf);void* p = 0;/* Zero-size requests are treated as free. */if (ptr && size == 0){tlsf_free(tlsf, ptr);}/* Requests with NULL pointers are treated as malloc. */else if (!ptr){p = tlsf_malloc(tlsf, size);}else{block_header_t* block = block_from_ptr(ptr);block_header_t* next = block_next(block);const size_t cursize = block_size(block);const size_t combined = cursize + block_size(next) + block_header_overhead;const size_t adjust = adjust_request_size(size, ALIGN_SIZE);/*** If the next block is used, or when combined with the current** block, does not offer enough space, we must reallocate and copy.*/if (adjust > cursize && (!block_is_free(next) || adjust > combined)){if (align > 4) p = tlsf_memalign(tlsf, align, size);else p = tlsf_malloc(tlsf, size);if (p){const size_t minsize = tlsf_min(cursize, size);memcpy(p, ptr, minsize);tlsf_free(tlsf, ptr);}}else{/* Do we need to expand to the next block? */if (adjust > cursize){block_merge_next(pool, block);block_mark_as_used(block);}/* Trim the resulting block and return the original pointer. */block_trim_used(pool, block, adjust);p = ptr;}}return p;}void* tlsf_realloc(tlsf_pool tlsf, void* ptr, size_t size){return tlsf_realign(tlsf, ptr, 4, size);}