void _Heap_Get_free_information(
Heap_Control *the_heap,
Heap_Information *info
)
{
Heap_Block *the_block;
Heap_Block *const tail = _Heap_Free_list_tail(the_heap);
info->number = 0;
info->largest = 0;
info->total = 0;
for(the_block = _Heap_Free_list_first(the_heap);
the_block != tail;
the_block = the_block->next)
{
uint32_t const the_size = _Heap_Block_size(the_block);
/* As we always coalesce free blocks, prev block must have been used. */
_HAssert(_Heap_Is_prev_used(the_block));
info->number++;
info->total += the_size;
if ( info->largest < the_size )
info->largest = the_size;
}
}
Heap_Block *_Heap_Greedy_allocate(
Heap_Control *heap,
const uintptr_t *block_sizes,
size_t block_count
)
{
Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap );
Heap_Block *allocated_blocks = NULL;
Heap_Block *blocks = NULL;
Heap_Block *current;
size_t i;
_Heap_Protection_free_all_delayed_blocks( heap );
for (i = 0; i < block_count; ++i) {
void *next = _Heap_Allocate( heap, block_sizes [i] );
if ( next != NULL ) {
Heap_Block *next_block = _Heap_Block_of_alloc_area(
(uintptr_t) next,
heap->page_size
);
next_block->next = allocated_blocks;
allocated_blocks = next_block;
}
}
while ( (current = _Heap_Free_list_first( heap )) != free_list_tail ) {
_Heap_Block_allocate(
heap,
current,
_Heap_Alloc_area_of_block( current ),
_Heap_Block_size( current ) - HEAP_BLOCK_HEADER_SIZE
);
current->next = blocks;
blocks = current;
}
while ( allocated_blocks != NULL ) {
current = allocated_blocks;
allocated_blocks = allocated_blocks->next;
_Heap_Free( heap, (void *) _Heap_Alloc_area_of_block( current ) );
}
return blocks;
}
static bool _Heap_Walk_is_in_free_list(
Heap_Control *heap,
Heap_Block *block
)
{
const Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap );
const Heap_Block *free_block = _Heap_Free_list_first( heap );
while ( free_block != free_list_tail ) {
if ( free_block == block ) {
return true;
}
free_block = free_block->next;
}
return false;
}
static void _Heap_Free_block( Heap_Control *heap, Heap_Block *block )
{
Heap_Statistics *const stats = &heap->stats;
Heap_Block *first_free;
/* Statistics */
++stats->used_blocks;
--stats->frees;
/*
* The _Heap_Free() will place the block to the head of free list. We want
* the new block at the end of the free list. So that initial and earlier
* areas are consumed first.
*/
_Heap_Free( heap, (void *) _Heap_Alloc_area_of_block( block ) );
_Heap_Protection_free_all_delayed_blocks( heap );
first_free = _Heap_Free_list_first( heap );
_Heap_Free_list_remove( first_free );
_Heap_Free_list_insert_before( _Heap_Free_list_tail( heap ), first_free );
}
void *_Heap_Allocate_aligned_with_boundary(
Heap_Control *heap,
uintptr_t alloc_size,
uintptr_t alignment,
uintptr_t boundary
)
{
Heap_Statistics *const stats = &heap->stats;
uintptr_t const block_size_floor = alloc_size + HEAP_BLOCK_HEADER_SIZE
- HEAP_ALLOC_BONUS;
uintptr_t const page_size = heap->page_size;
Heap_Block *block = NULL;
uintptr_t alloc_begin = 0;
uint32_t search_count = 0;
bool search_again = false;
if ( block_size_floor < alloc_size ) {
/* Integer overflow occured */
return NULL;
}
if ( boundary != 0 ) {
if ( boundary < alloc_size ) {
return NULL;
}
if ( alignment == 0 ) {
alignment = page_size;
}
}
do {
Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap );
block = _Heap_Free_list_first( heap );
while ( block != free_list_tail ) {
_HAssert( _Heap_Is_prev_used( block ) );
_Heap_Protection_block_check( heap, block );
/*
* The HEAP_PREV_BLOCK_USED flag is always set in the block size_and_flag
* field. Thus the value is about one unit larger than the real block
* size. The greater than operator takes this into account.
*/
if ( block->size_and_flag > block_size_floor ) {
if ( alignment == 0 ) {
alloc_begin = _Heap_Alloc_area_of_block( block );
} else {
alloc_begin = _Heap_Check_block(
heap,
block,
alloc_size,
alignment,
boundary
);
}
}
/* Statistics */
++search_count;
if ( alloc_begin != 0 ) {
break;
}
block = block->next;
}
search_again = _Heap_Protection_free_delayed_blocks( heap, alloc_begin );
} while ( search_again );
if ( alloc_begin != 0 ) {
/* Statistics */
++stats->allocs;
stats->searches += search_count;
block = _Heap_Block_allocate( heap, block, alloc_begin, alloc_size );
_Heap_Check_allocation(
heap,
block,
alloc_begin,
alloc_size,
alignment,
boundary
);
}
/* Statistics */
if ( stats->max_search < search_count ) {
stats->max_search = search_count;
}
return (void *) alloc_begin;
}
static bool _Heap_Walk_check_free_list(
int source,
Heap_Walk_printer printer,
Heap_Control *heap
)
{
uintptr_t const page_size = heap->page_size;
const Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap );
const Heap_Block *const first_free_block = _Heap_Free_list_first( heap );
const Heap_Block *prev_block = free_list_tail;
const Heap_Block *free_block = first_free_block;
while ( free_block != free_list_tail ) {
if ( !_Heap_Is_block_in_heap( heap, free_block ) ) {
(*printer)(
source,
true,
"free block 0x%08x: not in heap\n",
free_block
);
return false;
}
if (
!_Heap_Is_aligned( _Heap_Alloc_area_of_block( free_block ), page_size )
) {
(*printer)(
source,
true,
"free block 0x%08x: alloc area not page aligned\n",
free_block
);
return false;
}
if ( _Heap_Is_used( free_block ) ) {
(*printer)(
source,
true,
"free block 0x%08x: is used\n",
free_block
);
return false;
}
if ( free_block->prev != prev_block ) {
(*printer)(
source,
true,
"free block 0x%08x: invalid previous block 0x%08x\n",
free_block,
free_block->prev
);
return false;
}
prev_block = free_block;
free_block = free_block->next;
}
return true;
}
static bool _Heap_Walk_check_free_block(
int source,
Heap_Walk_printer printer,
Heap_Control *heap,
Heap_Block *block
)
{
Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap );
Heap_Block *const free_list_head = _Heap_Free_list_head( heap );
Heap_Block *const first_free_block = _Heap_Free_list_first( heap );
Heap_Block *const last_free_block = _Heap_Free_list_last( heap );
bool const prev_used = _Heap_Is_prev_used( block );
uintptr_t const block_size = _Heap_Block_size( block );
Heap_Block *const next_block = _Heap_Block_at( block, block_size );
(*printer)(
source,
false,
"block 0x%08x: size %u, prev 0x%08x%s, next 0x%08x%s\n",
block,
block_size,
block->prev,
block->prev == first_free_block ?
" (= first free)"
: (block->prev == free_list_head ? " (= head)" : ""),
block->next,
block->next == last_free_block ?
" (= last free)"
: (block->next == free_list_tail ? " (= tail)" : "")
);
if ( block_size != next_block->prev_size ) {
(*printer)(
source,
true,
"block 0x%08x: size %u != size %u (in next block 0x%08x)\n",
block,
block_size,
next_block->prev_size,
next_block
);
return false;
}
if ( !prev_used ) {
(*printer)(
source,
true,
"block 0x%08x: two consecutive blocks are free\n",
block
);
return false;
}
if ( !_Heap_Walk_is_in_free_list( heap, block ) ) {
(*printer)(
source,
true,
"block 0x%08x: free block not in free list\n",
block
);
return false;
}
return true;
}
uintptr_t _Heap_Initialize(
Heap_Control *heap,
void *heap_area_begin_ptr,
uintptr_t heap_area_size,
uintptr_t page_size
)
{
Heap_Statistics *const stats = &heap->stats;
uintptr_t const heap_area_begin = (uintptr_t) heap_area_begin_ptr;
uintptr_t const heap_area_end = heap_area_begin + heap_area_size;
uintptr_t alloc_area_begin = heap_area_begin + HEAP_BLOCK_HEADER_SIZE;
uintptr_t alloc_area_size = 0;
uintptr_t first_block_begin = 0;
uintptr_t first_block_size = 0;
uintptr_t min_block_size = 0;
uintptr_t overhead = 0;
Heap_Block *first_block = NULL;
Heap_Block *last_block = NULL;
if ( page_size == 0 ) {
page_size = CPU_ALIGNMENT;
} else {
page_size = _Heap_Align_up( page_size, CPU_ALIGNMENT );
if ( page_size < CPU_ALIGNMENT ) {
/* Integer overflow */
return 0;
}
}
min_block_size = _Heap_Align_up( sizeof( Heap_Block ), page_size );
alloc_area_begin = _Heap_Align_up( alloc_area_begin, page_size );
first_block_begin = alloc_area_begin - HEAP_BLOCK_HEADER_SIZE;
overhead = HEAP_BLOCK_HEADER_SIZE + (first_block_begin - heap_area_begin);
first_block_size = heap_area_size - overhead;
first_block_size = _Heap_Align_down ( first_block_size, page_size );
alloc_area_size = first_block_size - HEAP_BLOCK_HEADER_SIZE;
if (
heap_area_end < heap_area_begin
|| heap_area_size <= overhead
|| first_block_size < min_block_size
) {
/* Invalid area or area too small */
return 0;
}
/* First block */
first_block = (Heap_Block *) first_block_begin;
first_block->prev_size = page_size;
first_block->size_and_flag = first_block_size | HEAP_PREV_BLOCK_USED;
first_block->next = _Heap_Free_list_tail( heap );
first_block->prev = _Heap_Free_list_head( heap );
/*
* Last block.
*
* The next block of the last block is the first block. Since the first
* block indicates that the previous block is used, this ensures that the
* last block appears as used for the _Heap_Is_used() and _Heap_Is_free()
* functions.
*/
last_block = _Heap_Block_at( first_block, first_block_size );
last_block->prev_size = first_block_size;
last_block->size_and_flag = first_block_begin - (uintptr_t) last_block;
/* Heap control */
heap->page_size = page_size;
heap->min_block_size = min_block_size;
heap->area_begin = heap_area_begin;
heap->area_end = heap_area_end;
heap->first_block = first_block;
heap->last_block = last_block;
_Heap_Free_list_head( heap )->next = first_block;
_Heap_Free_list_tail( heap )->prev = first_block;
/* Statistics */
stats->size = first_block_size;
stats->free_size = first_block_size;
stats->min_free_size = first_block_size;
stats->free_blocks = 1;
stats->max_free_blocks = 1;
stats->used_blocks = 0;
stats->max_search = 0;
stats->allocs = 0;
stats->searches = 0;
stats->frees = 0;
stats->resizes = 0;
stats->instance = instance++;
_HAssert( _Heap_Is_aligned( heap->page_size, CPU_ALIGNMENT ) );
_HAssert( _Heap_Is_aligned( heap->min_block_size, page_size ) );
_HAssert(
_Heap_Is_aligned( _Heap_Alloc_area_of_block( first_block ), page_size )
);
_HAssert(
_Heap_Is_aligned( _Heap_Alloc_area_of_block( last_block ), page_size )
);
return alloc_area_size;
}
