Merge pull request #1 from yangjie11/main

【增加】tlsf 软件包

README.md

@@ -1,2 +1,116 @@
-# tlsf
-TLSF is a dynamic memory allocation algorithm with predictable execution time and low fragmentation.
+# TLSF
+
+Two-Level Segregated Fit memory allocator implementation.
+Written by Matthew Conte (matt@baisoku.org).
+Released under the BSD license.
+
+## Features
+
+  * O(1) cost for malloc, free, realloc, memalign
+  * Extremely low overhead per allocation (4 bytes)
+  * Low overhead per TLSF management of pools (~3kB)
+  * Low fragmentation
+  * Compiles to only a few kB of code and data
+  * Support for adding and removing memory pool regions on the fly
+
+## Caveats
+
+  * Currently, assumes architecture can make 4-byte aligned accesses
+  * Not designed to be thread safe; the user must provide this
+
+## Notes
+
+This code was based on the TLSF 1.4 spec and documentation found at:
+
+	http://www.gii.upv.es/tlsf/main/docs
+
+It also leverages the TLSF 2.0 improvement to shrink the per-block overhead from 8 to 4 bytes.
+
+## History
+
+2016/04/10 - v3.1
+  * Code moved to github
+  * tlsfbits.h rolled into tlsf.c
+  * License changed to BSD
+
+2014/02/08 - v3.0
+  * This version is based on improvements from 3DInteractive GmbH
+  * Interface changed to allow more than one memory pool
+  * Separated pool handling from control structure (adding, removing, debugging)
+  * Control structure and pools can still be constructed in the same memory block
+  * Memory blocks for control structure and pools are checked for alignment
+  * Added functions to retrieve control structure size, alignment size, min and max block size, overhead of pool structure, and overhead of a single allocation
+  * Minimal Pool size is tlsf_block_size_min() + tlsf_pool_overhead()
+  * Pool must be empty when it is removed, in order to allow O(1) removal
+
+2011/10/20 - v2.0
+  * 64-bit support
+  * More compiler intrinsics for ffs/fls
+  * ffs/fls verification during TLSF creation in debug builds
+
+2008/04/04 - v1.9
+  * Add tlsf_heap_check, a heap integrity check
+  * Support a predefined tlsf_assert macro
+  * Fix realloc case where block should shrink; if adjacent block is in use, execution would go down the slow path
+
+2007/02/08 - v1.8
+  * Fix for unnecessary reallocation in tlsf_realloc
+
+2007/02/03 - v1.7
+  * tlsf_heap_walk takes a callback
+  * tlsf_realloc now returns NULL on failure
+  * tlsf_memalign optimization for 4-byte alignment
+  * Usage of size_t where appropriate
+
+2006/11/21 - v1.6
+  * ffs/fls broken out into tlsfbits.h
+  * tlsf_overhead queries per-pool overhead
+
+2006/11/07 - v1.5
+  * Smart realloc implementation
+  * Smart memalign implementation
+
+2006/10/11 - v1.4
+  * Add some ffs/fls implementations
+  * Minor code footprint reduction
+
+2006/09/14 - v1.3
+  * Profiling indicates heavy use of blocks of size 1-128, so implement small block handling
+  * Reduce pool overhead by about 1kb
+  * Reduce minimum block size from 32 to 12 bytes
+  * Realloc bug fix
+
+2006/09/09 - v1.2
+  * Add tlsf_block_size
+  * Static assertion mechanism for invariants
+  * Minor bugfixes 
+
+2006/09/01 - v1.1
+  * Add tlsf_realloc
+  * Add tlsf_walk_heap
+
+2006/08/25 - v1.0
+  * First release
+
+-----
+## How to use tlsf package
+
+Enable the user heap algorithm:
+
+```                                   
+  -> RT-Thread Kernel                             
+    -> Memory Management                          
+      -> Dynamic Memory Management 
+            ( ) Disable Heap                                 
+            ( ) Small Memory Algorithm                      
+            ( ) SLAB Algorithm for large memory             
+            ( ) Use all of memheap objects as heap          
+            (X) Use user heap
+```
+And enable the tlsf packages:
+
+```
+-> RT-Thread online packages 
+    -> system packages  
+        [*]  TLSF: A dynamic memory allocation algorithm with predictable execution time and low fragmentation.
+```

SConscript

@@ -0,0 +1,16 @@
+import os
+from building import *
+
+src = []
+group = []
+
+cwd = GetCurrentDir()
+src = Split("""
+rt_tlsf.c
+src/tlsf.c
+""")
+CPPPATH = [cwd + '/src']
+
+group = DefineGroup('tlsf', src, depend = [''], CPPPATH = CPPPATH)
+
+Return('group')

rt_tlsf.c

@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2006-2021, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ */
+
+#include <rtthread.h>
+#include "rt_tlsf.h"
+
+#if defined (RT_USING_USERHEAP) && defined (PKG_USING_TLSF)
+
+static tlsf_t tlsf_ptr = 0;
+static struct rt_semaphore heap_sem;
+
+#ifdef RT_USING_HOOK
+static void (*rt_malloc_hook)(void *ptr, rt_size_t size);
+static void (*rt_free_hook)(void *ptr);
+
+void rt_malloc_sethook(void (*hook)(void *ptr, rt_size_t size))
+{
+    rt_malloc_hook = hook;
+}
+
+void rt_free_sethook(void (*hook)(void *ptr))
+{
+    rt_free_hook = hook;
+}
+#endif
+
+void rt_system_heap_init(void *begin_addr, void *end_addr)
+{
+    size_t size;
+    if (begin_addr < end_addr)
+    {
+        size = (rt_uint32_t)end_addr - (rt_uint32_t)begin_addr;
+    }
+    else
+    {
+        return;
+    }
+    if (!tlsf_ptr)
+    {
+        tlsf_ptr = (tlsf_t)tlsf_create_with_pool(begin_addr, size);
+    }
+
+    rt_sem_init(&heap_sem, "heap", 1, RT_IPC_FLAG_FIFO);
+}
+
+void *rt_malloc(rt_size_t nbytes)
+{
+    void *ptr;
+
+    if (tlsf_ptr)
+    {
+        rt_sem_take(&heap_sem, RT_WAITING_FOREVER);
+
+        ptr = tlsf_malloc(tlsf_ptr, nbytes);
+        RT_OBJECT_HOOK_CALL(rt_malloc_hook, ((void *)ptr, nbytes));
+
+        rt_sem_release(&heap_sem);
+    }
+    return ptr;
+}
+
+void rt_free(void *ptr)
+{
+    if (tlsf_ptr)
+    {
+        rt_sem_take(&heap_sem, RT_WAITING_FOREVER);
+
+        tlsf_free(tlsf_ptr, ptr);
+        RT_OBJECT_HOOK_CALL(rt_free_hook, (ptr));
+
+        rt_sem_release(&heap_sem);
+    }
+}
+
+void *rt_realloc(void *ptr, rt_size_t nbytes)
+{
+    if (tlsf_ptr)
+    {
+        rt_sem_take(&heap_sem, RT_WAITING_FOREVER);
+
+        tlsf_realloc(tlsf_ptr, ptr, nbytes);
+
+        rt_sem_release(&heap_sem);
+    }
+    return ptr;
+}
+
+void *rt_calloc(rt_size_t count, rt_size_t size)
+{
+    void *ptr;
+    rt_size_t total_size;
+
+    total_size = count * size;
+    ptr = rt_malloc(total_size);
+    if (ptr != RT_NULL)
+    {
+        /* clean memory */
+        rt_memset(ptr, 0, total_size);
+    }
+
+    return ptr;
+}
+
+static size_t used_mem = 0;
+static size_t total_mem = 0;
+
+static void mem_info(void *ptr, size_t size, int used, void *user)
+{
+    if (used)
+    {
+        used_mem += size;
+    }
+    total_mem += size;
+}
+
+void rt_memory_info(rt_uint32_t *total,
+                    rt_uint32_t *used,
+                    rt_uint32_t *max_used)
+{
+    used_mem = 0;
+    total_mem = 0;
+
+    tlsf_walk_pool(tlsf_get_pool(tlsf_ptr), mem_info, 0);
+
+    *total = total_mem;
+    *used = used_mem;
+    *max_used = used_mem;
+}
+
+void list_mem(void)
+{
+    used_mem = 0;
+    total_mem = 0;
+
+    tlsf_walk_pool(tlsf_get_pool(tlsf_ptr), mem_info, 0);
+
+    rt_kprintf("total memory: %d\n", total_mem);
+    rt_kprintf("used memory : %d\n", used_mem);
+}
+
+#endif

src/tlsf.c

@@ -0,0 +1,1286 @@
+#include <assert.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <rtthread.h>
+#include "tlsf.h"
+
+#if defined(__cplusplus)
+    #define tlsf_decl inline
+#else
+    #define tlsf_decl static
+#endif
+
+/*
+** Architecture-specific bit manipulation routines.
+**
+** TLSF achieves O(1) cost for malloc and free operations by limiting
+** the search for a free block to a free list of guaranteed size
+** adequate to fulfill the request, combined with efficient free list
+** queries using bitmasks and architecture-specific bit-manipulation
+** routines.
+**
+** Most modern processors provide instructions to count leading zeroes
+** in a word, find the lowest and highest set bit, etc. These
+** specific implementations will be used when available, falling back
+** to a reasonably efficient generic implementation.
+**
+** NOTE: TLSF spec relies on ffs/fls returning value 0..31.
+** ffs/fls return 1-32 by default, returning 0 for error.
+*/
+
+/*
+** Detect whether or not we are building for a 32- or 64-bit (LP/LLP)
+** architecture. There is no reliable portable method at compile-time.
+*/
+#if defined (__alpha__) || defined (__ia64__) || defined (__x86_64__) \
+    || defined (_WIN64) || defined (__LP64__) || defined (__LLP64__)
+    #define TLSF_64BIT
+#endif
+
+/*
+** gcc 3.4 and above have builtin support, specialized for architecture.
+** Some compilers masquerade as gcc; patchlevel test filters them out.
+*/
+#if defined (__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)) \
+    && defined (__GNUC_PATCHLEVEL__)
+
+#if defined (__SNC__)
+/* SNC for Playstation 3. */
+
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    const unsigned int reverse = word & (~word + 1);
+    const int bit = 32 - __builtin_clz(reverse);
+    return bit - 1;
+}
+
+#else
+
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    return __builtin_ffs(word) - 1;
+}
+
+#endif
+
+tlsf_decl int tlsf_fls(unsigned int word)
+{
+    const int bit = word ? 32 - __builtin_clz(word) : 0;
+    return bit - 1;
+}
+
+#elif defined (_MSC_VER) && (_MSC_VER >= 1400) && (defined (_M_IX86) || defined (_M_X64))
+/* Microsoft Visual C++ support on x86/X64 architectures. */
+
+#include <intrin.h>
+
+#pragma intrinsic(_BitScanReverse)
+#pragma intrinsic(_BitScanForward)
+
+tlsf_decl int tlsf_fls(unsigned int word)
+{
+    unsigned long index;
+    return _BitScanReverse(&index, word) ? index : -1;
+}
+
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    unsigned long index;
+    return _BitScanForward(&index, word) ? index : -1;
+}
+
+#elif defined (_MSC_VER) && defined (_M_PPC)
+/* Microsoft Visual C++ support on PowerPC architectures. */
+
+#include <ppcintrinsics.h>
+
+tlsf_decl int tlsf_fls(unsigned int word)
+{
+    const int bit = 32 - _CountLeadingZeros(word);
+    return bit - 1;
+}
+
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    const unsigned int reverse = word & (~word + 1);
+    const int bit = 32 - _CountLeadingZeros(reverse);
+    return bit - 1;
+}
+
+#elif defined (__ARMCC_VERSION)
+/* RealView Compilation Tools for ARM */
+
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    const unsigned int reverse = word & (~word + 1);
+    const int bit = 32 - __clz(reverse);
+    return bit - 1;
+}
+
+tlsf_decl int tlsf_fls(unsigned int word)
+{
+    const int bit = word ? 32 - __clz(word) : 0;
+    return bit - 1;
+}
+
+#elif defined (__ghs__)
+/* Green Hills support for PowerPC */
+
+#include <ppc_ghs.h>
+
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    const unsigned int reverse = word & (~word + 1);
+    const int bit = 32 - __CLZ32(reverse);
+    return bit - 1;
+}
+
+tlsf_decl int tlsf_fls(unsigned int word)
+{
+    const int bit = word ? 32 - __CLZ32(word) : 0;
+    return bit - 1;
+}
+
+#else
+/* Fall back to generic implementation. */
+
+tlsf_decl int tlsf_fls_generic(unsigned int word)
+{
+    int bit = 32;
+
+    if (!word) bit -= 1;
+    if (!(word & 0xffff0000))
+    {
+        word <<= 16;
+        bit -= 16;
+    }
+    if (!(word & 0xff000000))
+    {
+        word <<= 8;
+        bit -= 8;
+    }
+    if (!(word & 0xf0000000))
+    {
+        word <<= 4;
+        bit -= 4;
+    }
+    if (!(word & 0xc0000000))
+    {
+        word <<= 2;
+        bit -= 2;
+    }
+    if (!(word & 0x80000000))
+    {
+        word <<= 1;
+        bit -= 1;
+    }
+
+    return bit;
+}
+
+/* Implement ffs in terms of fls. */
+tlsf_decl int tlsf_ffs(unsigned int word)
+{
+    return tlsf_fls_generic(word & (~word + 1)) - 1;
+}
+
+tlsf_decl int tlsf_fls(unsigned int word)
+{
+    return tlsf_fls_generic(word) - 1;
+}
+
+#endif
+
+/* Possibly 64-bit version of tlsf_fls. */
+#if defined (TLSF_64BIT)
+tlsf_decl int tlsf_fls_sizet(size_t size)
+{
+    int high = (int)(size >> 32);
+    int bits = 0;
+    if (high)
+    {
+        bits = 32 + tlsf_fls(high);
+    }
+    else
+    {
+        bits = tlsf_fls((int)size & 0xffffffff);
+
+    }
+    return bits;
+}
+#else
+#define tlsf_fls_sizet tlsf_fls
+#endif
+
+#undef tlsf_decl
+
+/*
+** Constants.
+*/
+
+/* Public constants: may be modified. */
+enum tlsf_public
+{
+    /* log2 of number of linear subdivisions of block sizes. Larger
+    ** values require more memory in the control structure. Values of
+    ** 4 or 5 are typical.
+    */
+    SL_INDEX_COUNT_LOG2 = 5,
+};
+
+/* Private constants: do not modify. */
+enum tlsf_private
+{
+#if defined (TLSF_64BIT)
+    /* All allocation sizes and addresses are aligned to 8 bytes. */
+    ALIGN_SIZE_LOG2 = 3,
+#else
+    /* All allocation sizes and addresses are aligned to 4 bytes. */
+    ALIGN_SIZE_LOG2 = 2,
+#endif
+    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.
+    */
+
+#if defined (TLSF_64BIT)
+    /*
+    ** TODO: We can increase this to support larger sizes, at the expense
+    ** of more overhead in the TLSF structure.
+    */
+    FL_INDEX_MAX = 32,
+#else
+    FL_INDEX_MAX = 30,
+#endif
+    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))
+
+#define tlsf_assert RT_ASSERT
+/*
+** 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]
+
+/* This code has been tested on 32- and 64-bit (LP/LLP) architectures. */
+tlsf_static_assert(sizeof(int) * CHAR_BIT == 32);
+tlsf_static_assert(sizeof(size_t) * CHAR_BIT >= 32);
+tlsf_static_assert(sizeof(size_t) * CHAR_BIT <= 64);
+
+/* 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);
+
+/* 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 at the end 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 at least 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 = tlsf_cast(size_t, 1) << FL_INDEX_MAX;
+
+
+/* The TLSF control structure. */
+typedef struct control_t
+{
+    /* Empty lists point at this block to indicate they are free. */
+    block_header_t block_null;
+
+    /* 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];
+} control_t;
+
+/* A type used for casting when doing pointer arithmetic. */
+typedef ptrdiff_t tlsfptr_t;
+
+/*
+** block_header_t member functions.
+*/
+
+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)
+{
+    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)
+{
+    return block_size(block) == 0;
+}
+
+static int block_is_free(const block_header_t *block)
+{
+    return tlsf_cast(int, block->size & block_header_free_bit);
+}
+
+static void block_set_free(block_header_t *block)
+{
+    block->size |= block_header_free_bit;
+}
+
+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)
+{
+    return tlsf_cast(int, block->size & block_header_prev_free_bit);
+}
+
+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)
+{
+    block->size &= ~block_header_prev_free_bit;
+}
+
+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)
+{
+    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)
+{
+    return tlsf_cast(block_header_t *, tlsf_cast(tlsfptr_t, ptr) + size);
+}
+
+/* Return location of previous block. */
+static block_header_t *block_prev(const block_header_t *block)
+{
+    tlsf_assert(block_is_prev_free(block) && "previous block must be free");
+    return block->prev_phys_block;
+}
+
+/* Return location of next existing block. */
+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)
+{
+    block_header_t *next = block_next(block);
+    next->prev_phys_block = block;
+    return next;
+}
+
+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)
+{
+    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)
+{
+    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)
+{
+    tlsf_assert(0 == (align & (align - 1)) && "must align to a power of two");
+    return x - (x & (align - 1));
+}
+
+static void *align_ptr(const 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)
+{
+    size_t adjust = 0;
+    if (size)
+    {
+        const size_t aligned = align_up(size, align);
+
+        /* aligned sized must not exceed block_size_max or we'll go out of bounds on sl_bitmap */
+        if (aligned < block_size_max)
+        {
+            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)
+{
+    int fl, sl;
+    if (size < SMALL_BLOCK_SIZE)
+    {
+        /* Store small blocks in first list. */
+        fl = 0;
+        sl = tlsf_cast(int, size) / (SMALL_BLOCK_SIZE / SL_INDEX_COUNT);
+    }
+    else
+    {
+        fl = tlsf_fls_sizet(size);
+        sl = tlsf_cast(int, 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)
+{
+    if (size >= SMALL_BLOCK_SIZE)
+    {
+        const size_t round = (1 << (tlsf_fls_sizet(size) - SL_INDEX_COUNT_LOG2)) - 1;
+        size += round;
+    }
+    mapping_insert(size, fli, sli);
+}
+
+static block_header_t *search_suitable_block(control_t *control, 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 = control->sl_bitmap[fl] & (~0U << sl);
+    if (!sl_map)
+    {
+        /* No block exists. Search in the next largest first-level list. */
+        const unsigned int fl_map = control->fl_bitmap & (~0U << (fl + 1));
+        if (!fl_map)
+        {
+            /* No free blocks available, memory has been exhausted. */
+            return 0;
+        }
+
+        fl = tlsf_ffs(fl_map);
+        *fli = fl;
+        sl_map = control->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 control->blocks[fl][sl];
+}
+
+/* Remove a free block from the free list.*/
+static void remove_free_block(control_t *control, 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 (control->blocks[fl][sl] == block)
+    {
+        control->blocks[fl][sl] = next;
+
+        /* If the new head is null, clear the bitmap. */
+        if (next == &control->block_null)
+        {
+            control->sl_bitmap[fl] &= ~(1U << sl);
+
+            /* If the second bitmap is now empty, clear the fl bitmap. */
+            if (!control->sl_bitmap[fl])
+            {
+                control->fl_bitmap &= ~(1U << fl);
+            }
+        }
+    }
+}
+
+/* Insert a free block into the free block list. */
+static void insert_free_block(control_t *control, block_header_t *block, int fl, int sl)
+{
+    block_header_t *current = control->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 = &control->block_null;
+    current->prev_free = block;
+
+    tlsf_assert(block_to_ptr(block) == align_ptr(block_to_ptr(block), ALIGN_SIZE)
+                && "block not aligned properly");
+    /*
+    ** Insert the new block at the head of the list, and mark the first-
+    ** and second-level bitmaps appropriately.
+    */
+    control->blocks[fl][sl] = block;
+    control->fl_bitmap |= (1U << fl);
+    control->sl_bitmap[fl] |= (1U << sl);
+}
+
+/* Remove a given block from the free list. */
+static void block_remove(control_t *control, block_header_t *block)
+{
+    int fl, sl;
+    mapping_insert(block_size(block), &fl, &sl);
+    remove_free_block(control, block, fl, sl);
+}
+
+/* Insert a given block into the free list. */
+static void block_insert(control_t *control, block_header_t *block)
+{
+    int fl, sl;
+    mapping_insert(block_size(block), &fl, &sl);
+    insert_free_block(control, block, fl, sl);
+}
+
+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)
+{
+    /* 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_to_ptr(remaining) == align_ptr(block_to_ptr(remaining), ALIGN_SIZE)
+                && "remaining block not aligned properly");
+
+    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)
+{
+    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(control_t *control, 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(control, 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(control_t *control, 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(control, 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(control_t *control, 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(control, remaining_block);
+    }
+}
+
+/* Trim any trailing block space off the end of a used block, return to pool. */
+static void block_trim_used(control_t *control, 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(control, remaining_block);
+        block_insert(control, remaining_block);
+    }
+}
+
+static block_header_t *block_trim_free_leading(control_t *control, 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(control, block);
+    }
+
+    return remaining_block;
+}
+
+static block_header_t *block_locate_free(control_t *control, size_t size)
+{
+    int fl = 0, sl = 0;
+    block_header_t *block = 0;
+
+    if (size)
+    {
+        mapping_search(size, &fl, &sl);
+
+        /*
+        ** mapping_search can futz with the size, so for excessively large sizes it can sometimes wind up
+        ** with indices that are off the end of the block array.
+        ** So, we protect against that here, since this is the only callsite of mapping_search.
+        ** Note that we don't need to check sl, since it comes from a modulo operation that guarantees it's always in range.
+        */
+        if (fl < FL_INDEX_COUNT)
+        {
+            block = search_suitable_block(control, &fl, &sl);
+        }
+    }
+
+    if (block)
+    {
+        tlsf_assert(block_size(block) >= size);
+        remove_free_block(control, block, fl, sl);
+    }
+
+    return block;
+}
+
+static void *block_prepare_used(control_t *control, block_header_t *block, size_t size)
+{
+    void *p = 0;
+    if (block)
+    {
+        tlsf_assert(size && "size must be non-zero");
+        block_trim_free(control, 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 control_construct(control_t *control)
+{
+    int i, j;
+
+    control->block_null.next_free = &control->block_null;
+    control->block_null.prev_free = &control->block_null;
+
+    control->fl_bitmap = 0;
+    for (i = 0; i < FL_INDEX_COUNT; ++i)
+    {
+        control->sl_bitmap[i] = 0;
+        for (j = 0; j < SL_INDEX_COUNT; ++j)
+        {
+            control->blocks[i][j] = &control->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;
+    (void)used;
+    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(tlsf_t tlsf)
+{
+    int i, j;
+
+    control_t *control = tlsf_cast(control_t *, tlsf);
+    int status = 0;
+
+    /* 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 = control->fl_bitmap & (1U << i);
+            const int sl_list = control->sl_bitmap[i];
+            const int sl_map = sl_list & (1U << j);
+            const block_header_t *block = control->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 == &control->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 != &control->block_null && "block should not be null");
+
+            while (block != &control->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_insist
+
+static void default_walker(void *ptr, size_t size, int used, void *user)
+{
+    (void)user;
+    rt_kprintf("\t%x %s size: %x (%x)\n", ptr, used ? "used" : "free", (unsigned int)size, block_from_ptr(ptr));
+}
+
+void tlsf_walk_pool(pool_t pool, tlsf_walker walker, void *user)
+{
+    tlsf_walker pool_walker = walker ? walker : default_walker;
+    block_header_t *block =
+        offset_to_block(pool, -(int)block_header_overhead);
+
+    while (block && !block_is_last(block))
+    {
+        pool_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;
+}
+
+int tlsf_check_pool(pool_t pool)
+{
+    /* Check that the blocks are physically correct. */
+    integrity_t integ = { 0, 0 };
+    tlsf_walk_pool(pool, integrity_walker, &integ);
+
+    return integ.status;
+}
+
+/*
+** Size of the TLSF structures in a given memory block passed to
+** tlsf_create, equal to the size of a control_t
+*/
+size_t tlsf_size(void)
+{
+    return sizeof(control_t);
+}
+
+size_t tlsf_align_size(void)
+{
+    return ALIGN_SIZE;
+}
+
+size_t tlsf_block_size_min(void)
+{
+    return block_size_min;
+}
+
+size_t tlsf_block_size_max(void)
+{
+    return block_size_max;
+}
+
+/*
+** Overhead of the TLSF structures in a given memory block passed to
+** tlsf_add_pool, equal to the overhead of a free block and the
+** sentinel block.
+*/
+size_t tlsf_pool_overhead(void)
+{
+    return 2 * block_header_overhead;
+}
+
+size_t tlsf_alloc_overhead(void)
+{
+    return block_header_overhead;
+}
+
+pool_t tlsf_add_pool(tlsf_t tlsf, void *mem, size_t bytes)
+{
+    block_header_t *block;
+    block_header_t *next;
+
+    const size_t pool_overhead = tlsf_pool_overhead();
+    const size_t pool_bytes = align_down(bytes - pool_overhead, ALIGN_SIZE);
+
+    if (((ptrdiff_t)mem % ALIGN_SIZE) != 0)
+    {
+        rt_kprintf("tlsf_add_pool: Memory must be aligned by %u bytes.\n",
+               (unsigned int)ALIGN_SIZE);
+        return 0;
+    }
+
+    if (pool_bytes < block_size_min || pool_bytes > block_size_max)
+    {
+#if defined (TLSF_64BIT)
+        rt_kprintf("tlsf_add_pool: Memory size must be between 0x%x and 0x%x00 bytes.\n",
+               (unsigned int)(pool_overhead + block_size_min),
+               (unsigned int)((pool_overhead + block_size_max) / 256));
+#else
+        rt_kprintf("tlsf_add_pool: Memory size must be between %u and %u bytes.\n",
+               (unsigned int)(pool_overhead + block_size_min),
+               (unsigned int)(pool_overhead + block_size_max));
+#endif
+        return 0;
+    }
+
+    /*
+    ** Create the main free block. Offset the start of the block slightly
+    ** so that the prev_phys_block field falls outside of the pool -
+    ** it will never be used.
+    */
+    block = offset_to_block(mem, -(tlsfptr_t)block_header_overhead);
+    block_set_size(block, pool_bytes);
+    block_set_free(block);
+    block_set_prev_used(block);
+    block_insert(tlsf_cast(control_t *, tlsf), block);
+
+    /* Split the block to create a zero-size sentinel block. */
+    next = block_link_next(block);
+    block_set_size(next, 0);
+    block_set_used(next);
+    block_set_prev_free(next);
+
+    return mem;
+}
+
+void tlsf_remove_pool(tlsf_t tlsf, pool_t pool)
+{
+    control_t *control = tlsf_cast(control_t *, tlsf);
+    block_header_t *block = offset_to_block(pool, -(int)block_header_overhead);
+
+    int fl = 0, sl = 0;
+
+    tlsf_assert(block_is_free(block) && "block should be free");
+    tlsf_assert(!block_is_free(block_next(block)) && "next block should not be free");
+    tlsf_assert(block_size(block_next(block)) == 0 && "next block size should be zero");
+
+    mapping_insert(block_size(block), &fl, &sl);
+    remove_free_block(control, block, fl, sl);
+}
+
+/*
+** TLSF main interface.
+*/
+
+#if _DEBUG
+int test_ffs_fls()
+{
+    /* Verify ffs/fls work properly. */
+    int rv = 0;
+    rv += (tlsf_ffs(0) == -1) ? 0 : 0x1;
+    rv += (tlsf_fls(0) == -1) ? 0 : 0x2;
+    rv += (tlsf_ffs(1) == 0) ? 0 : 0x4;
+    rv += (tlsf_fls(1) == 0) ? 0 : 0x8;
+    rv += (tlsf_ffs(0x80000000) == 31) ? 0 : 0x10;
+    rv += (tlsf_ffs(0x80008000) == 15) ? 0 : 0x20;
+    rv += (tlsf_fls(0x80000008) == 31) ? 0 : 0x40;
+    rv += (tlsf_fls(0x7FFFFFFF) == 30) ? 0 : 0x80;
+
+#if defined (TLSF_64BIT)
+    rv += (tlsf_fls_sizet(0x80000000) == 31) ? 0 : 0x100;
+    rv += (tlsf_fls_sizet(0x100000000) == 32) ? 0 : 0x200;
+    rv += (tlsf_fls_sizet(0xffffffffffffffff) == 63) ? 0 : 0x400;
+#endif
+
+    if (rv)
+    {
+        rt_kprintf("test_ffs_fls: %x ffs/fls tests failed.\n", rv);
+    }
+    return rv;
+}
+#endif
+
+tlsf_t tlsf_create(void *mem)
+{
+#if _DEBUG
+    if (test_ffs_fls())
+    {
+        return 0;
+    }
+#endif
+
+    if (((tlsfptr_t)mem % ALIGN_SIZE) != 0)
+    {
+        rt_kprintf("tlsf_create: Memory must be aligned to %u bytes.\n",
+               (unsigned int)ALIGN_SIZE);
+        return 0;
+    }
+
+    control_construct(tlsf_cast(control_t *, mem));
+
+    return tlsf_cast(tlsf_t, mem);
+}
+
+tlsf_t tlsf_create_with_pool(void *mem, size_t bytes)
+{
+    tlsf_t tlsf = tlsf_create(mem);
+    tlsf_add_pool(tlsf, (char *)mem + tlsf_size(), bytes - tlsf_size());
+    return tlsf;
+}
+
+void tlsf_destroy(tlsf_t tlsf)
+{
+    /* Nothing to do. */
+    (void)tlsf;
+}
+
+pool_t tlsf_get_pool(tlsf_t tlsf)
+{
+    return tlsf_cast(pool_t, (char *)tlsf + tlsf_size());
+}
+
+void *tlsf_malloc(tlsf_t tlsf, size_t size)
+{
+    control_t *control = tlsf_cast(control_t *, tlsf);
+    const size_t adjust = adjust_request_size(size, ALIGN_SIZE);
+    block_header_t *block = block_locate_free(control, adjust);
+    return block_prepare_used(control, block, adjust);
+}
+
+void *tlsf_memalign(tlsf_t tlsf, size_t align, size_t size)
+{
+    control_t *control = tlsf_cast(control_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 pool. 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 size_t gap_minimum = 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.
+    ** If we requested 0 bytes, return null, as tlsf_malloc(0) does.
+    */
+    const size_t aligned_size = (adjust && align > ALIGN_SIZE) ? size_with_gap : adjust;
+
+    block_header_t *block = block_locate_free(control, 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);
+        size_t gap = tlsf_cast(size_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 size_t gap_remain = gap_minimum - gap;
+            const size_t offset = tlsf_max(gap_remain, align);
+            const void *next_aligned = tlsf_cast(void *,
+                                                 tlsf_cast(tlsfptr_t, aligned) + offset);
+
+            aligned = align_ptr(next_aligned, align);
+            gap = tlsf_cast(size_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(control, block, gap);
+        }
+    }
+
+    return block_prepare_used(control, block, adjust);
+}
+
+void tlsf_free(tlsf_t tlsf, void *ptr)
+{
+    /* Don't attempt to free a NULL pointer. */
+    if (ptr)
+    {
+        control_t *control = tlsf_cast(control_t *, tlsf);
+        block_header_t *block = block_from_ptr(ptr);
+        tlsf_assert(!block_is_free(block) && "block already marked as free");
+        block_mark_as_free(block);
+        block = block_merge_prev(control, block);
+        block = block_merge_next(control, block);
+        block_insert(control, 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_realloc(tlsf_t tlsf, void *ptr, size_t size)
+{
+    control_t *control = tlsf_cast(control_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);
+
+        tlsf_assert(!block_is_free(block) && "block already marked as free");
+
+        /*
+        ** 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))
+        {
+            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(control, block);
+                block_mark_as_used(block);
+            }
+
+            /* Trim the resulting block and return the original pointer. */
+            block_trim_used(control, block, adjust);
+            p = ptr;
+        }
+    }
+
+    return p;
+}

src/tlsf.h

@@ -0,0 +1,90 @@
+#ifndef INCLUDED_tlsf
+#define INCLUDED_tlsf
+
+/*
+** Two Level Segregated Fit memory allocator, version 3.1.
+** Written by Matthew Conte
+**  http://tlsf.baisoku.org
+**
+** Based on the original documentation by Miguel Masmano:
+**  http://www.gii.upv.es/tlsf/main/docs
+**
+** This implementation was written to the specification
+** of the document, therefore no GPL restrictions apply.
+**
+** Copyright (c) 2006-2016, Matthew Conte
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted 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.
+**
+** 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 MATTHEW CONTE 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.
+*/
+
+#include <stddef.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+/* tlsf_t: a TLSF structure. Can contain 1 to N pools. */
+/* pool_t: a block of memory that TLSF can manage. */
+typedef void *tlsf_t;
+typedef void *pool_t;
+
+/* Create/destroy a memory pool. */
+tlsf_t tlsf_create(void *mem);
+tlsf_t tlsf_create_with_pool(void *mem, size_t bytes);
+void tlsf_destroy(tlsf_t tlsf);
+pool_t tlsf_get_pool(tlsf_t tlsf);
+
+/* Add/remove memory pools. */
+pool_t tlsf_add_pool(tlsf_t tlsf, void *mem, size_t bytes);
+void tlsf_remove_pool(tlsf_t tlsf, pool_t pool);
+
+/* malloc/memalign/realloc/free replacements. */
+void *tlsf_malloc(tlsf_t tlsf, size_t bytes);
+void *tlsf_memalign(tlsf_t tlsf, size_t align, size_t bytes);
+void *tlsf_realloc(tlsf_t tlsf, void *ptr, size_t size);
+void tlsf_free(tlsf_t tlsf, void *ptr);
+
+/* Returns internal block size, not original request size */
+size_t tlsf_block_size(void *ptr);
+
+/* Overheads/limits of internal structures. */
+size_t tlsf_size(void);
+size_t tlsf_align_size(void);
+size_t tlsf_block_size_min(void);
+size_t tlsf_block_size_max(void);
+size_t tlsf_pool_overhead(void);
+size_t tlsf_alloc_overhead(void);
+
+/* Debugging. */
+typedef void (*tlsf_walker)(void *ptr, size_t size, int used, void *user);
+void tlsf_walk_pool(pool_t pool, tlsf_walker walker, void *user);
+/* Returns nonzero if any internal consistency check fails. */
+int tlsf_check(tlsf_t tlsf);
+int tlsf_check_pool(pool_t pool);
+
+#if defined(__cplusplus)
+};
+#endif
+
+#endif