noselasd/libucore
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix inital alignment

Browse Source
This commit is contained in:
Nils O. Selåsdal
2026-04-09 16:06:22 +02:00
parent 0ca7f64c83
commit 0073924050
1 changed files with 9 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/small_allocator.c
+9 -7
View File
@@ -19,7 +19,9 @@
#define ALIGNMENT 16 #define ALIGNMENT 16
#define ALIGN(n) (((n) + (ALIGNMENT - 1)) & ~(ALIGNMENT - 1)) #define ALIGN_UP(n) (((n) + (ALIGNMENT - 1)) & ~(ALIGNMENT - 1))
#define ALIGN_DOWN(n) ((n) & ~(ALIGNMENT - 1))
#define NULL_BLOCK (0xffffffff) #define NULL_BLOCK (0xffffffff)
#define BLOCK_FREE ((uint32_t)1) #define BLOCK_FREE ((uint32_t)1)
@@ -103,7 +105,7 @@ void small_allocator_init(SmallAllocator* a, void* backing_store, uint32_t size)
a->size = size; a->size = size;
BlockHeader* first = backing_store; BlockHeader* first = backing_store;
uint32_t usable = ALIGN(size - sizeof(BlockHeader)); uint32_t usable = ALIGN_DOWN(size - sizeof(BlockHeader));
block_set_free(first); block_set_free(first);
block_set_size(first, usable); block_set_size(first, usable);
first->next = NULL_BLOCK; first->next = NULL_BLOCK;
@@ -115,7 +117,7 @@ void small_allocator_init(SmallAllocator* a, void* backing_store, uint32_t size)
static void split_block(SmallAllocator *a, BlockHeader* block, uint32_t size) static void split_block(SmallAllocator *a, BlockHeader* block, uint32_t size)
{ {
size = ALIGN(size); size = ALIGN_UP(size);
uint32_t bsize = block_size(block); uint32_t bsize = block_size(block);
if (bsize < size + sizeof(BlockHeader) + ALIGNMENT) if (bsize < size + sizeof(BlockHeader) + ALIGNMENT)
@@ -125,7 +127,7 @@ static void split_block(SmallAllocator *a, BlockHeader* block, uint32_t size)
BlockHeader* new_block = BlockHeader* new_block =
(BlockHeader*)(base + sizeof(BlockHeader) + size); (BlockHeader*)(base + sizeof(BlockHeader) + size);
uint32_t new_size = ALIGN(bsize - size - sizeof(BlockHeader)); uint32_t new_size = ALIGN_UP(bsize - size - sizeof(BlockHeader));
block_set_size(block, size); block_set_size(block, size);
block_set_used(block); block_set_used(block);
@@ -149,7 +151,7 @@ static void merge_with_next(SmallAllocator *a, BlockHeader* block)
if (!next || !block_is_free(next)) if (!next || !block_is_free(next))
return; return;
uint32_t new_size = ALIGN(block_size(block) + uint32_t new_size = ALIGN_UP(block_size(block) +
sizeof(BlockHeader) + sizeof(BlockHeader) +
block_size(next)); block_size(next));
@@ -162,7 +164,7 @@ static void merge_with_next(SmallAllocator *a, BlockHeader* block)
void* small_alloc(SmallAllocator* a, uint32_t size) void* small_alloc(SmallAllocator* a, uint32_t size)
{ {
size = ALIGN(size); size = ALIGN_UP(size);
BlockHeader* start = a->last_alloc ? a->last_alloc : a->heap_start; BlockHeader* start = a->last_alloc ? a->last_alloc : a->heap_start;
BlockHeader* curr = start; BlockHeader* curr = start;
@@ -221,7 +223,7 @@ void debug_alloc(const SmallAllocator *a)
puts("--debug end--"); puts("--debug end--");
} }
char buff[1024*1024]; char buff[1023*1023];
int main(void) int main(void)
{ {
printf("bh size %zu\n", sizeof(BlockHeader)); printf("bh size %zu\n", sizeof(BlockHeader));