move block_header_t, control_t, tlsfptr_t to tlsf_common.h and block function to tlsf_block_functions.h

This commit is contained in:
Guillaume Souchere
2022-07-14 13:25:41 +02:00
parent bfd855894d
commit 81cecf2e0d
3 changed files with 180 additions and 187 deletions

189
tlsf.c
View File

@@ -8,6 +8,8 @@
#include <limits.h>
#include <stdio.h>
#include "tlsf.h"
#include "tlsf_common.h"
#include "tlsf_block_functions.h"
#if defined(__cplusplus)
#define tlsf_decl inline
@@ -199,13 +201,6 @@ tlsf_decl int tlsf_fls_sizet(size_t size)
#undef tlsf_decl
/*
** Set assert macro, if it has not been provided by the user.
*/
#if !defined (tlsf_assert)
#define tlsf_assert assert
#endif
/*
** Static assertion mechanism.
*/
@@ -226,186 +221,6 @@ 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");

View File

@@ -5,11 +5,119 @@
*/
#pragma once
#include "tlsf_common.h"
#if defined(__cplusplus)
extern "C" {
#endif
/*
** 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);
}
#if defined(__cplusplus)
};
#endif

View File

@@ -5,6 +5,7 @@
*/
#pragma once
#include <stddef.h>
#if defined __has_include && __has_include("tlsf_platform.h")
#include "tlsf_platform.h"
@@ -21,6 +22,13 @@ extern "C" {
#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
enum tlsf_config
{
/* log2 of number of linear subdivisions of block sizes. Larger
@@ -60,6 +68,68 @@ enum tlsf_config
SMALL_BLOCK_SIZE = (1 << FL_INDEX_SHIFT),
};
/*
** Data structures and associated constants.
*/
/* A type used for casting when doing pointer arithmetic. */
typedef ptrdiff_t tlsfptr_t;
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;
/* 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;
/*
** 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;
#if defined(__cplusplus)
};
#endif