static void
wmem_block_free(void *private_data, void *ptr)
{
wmem_block_allocator_t *allocator = (wmem_block_allocator_t*) private_data;
wmem_block_chunk_t *chunk;
chunk = WMEM_DATA_TO_CHUNK(ptr);
if (chunk->jumbo) {
wmem_block_free_jumbo(allocator, chunk);
return;
}
g_assert(chunk->used);
/* mark it as unused */
chunk->used = FALSE;
/* merge it with any other free chunks adjacent to it, so that contiguous
* free space doesn't get fragmented */
wmem_block_merge_free(allocator, chunk);
/* Now cycle the recycler */
wmem_block_cycle_recycler(allocator);
}
static void *
wmem_block_fast_realloc(void *private_data, void *ptr, const size_t size)
{
wmem_block_fast_chunk_t *chunk;
chunk = WMEM_DATA_TO_CHUNK(ptr);
/* grow */
if (chunk->len < size) {
void *newptr;
/* need to alloc and copy; free is no-op, so don't call it */
newptr = wmem_block_fast_alloc(private_data, size);
memcpy(newptr, ptr, chunk->len);
return newptr;
}
/* shrink or same space - great we can do nothing */
return ptr;
}
static void *
wmem_block_fast_realloc(void *private_data, void *ptr, const size_t size)
{
wmem_block_fast_chunk_t *chunk;
chunk = WMEM_DATA_TO_CHUNK(ptr);
if (chunk->len == JUMBO_MAGIC) {
wmem_block_fast_jumbo_t *block;
block = ((wmem_block_fast_jumbo_t*)((guint8*)(chunk) - WMEM_JUMBO_HEADER_SIZE));
block = (wmem_block_fast_jumbo_t*)wmem_realloc(NULL, block,
size + WMEM_JUMBO_HEADER_SIZE + WMEM_CHUNK_HEADER_SIZE);
if (block->prev) {
block->prev->next = block;
}
else {
wmem_block_fast_allocator_t *allocator = (wmem_block_fast_allocator_t*) private_data;
allocator->jumbo_list = block;
}
if (block->next) {
block->next->prev = block;
}
return ((void*)((guint8*)(block) + WMEM_JUMBO_HEADER_SIZE + WMEM_CHUNK_HEADER_SIZE));
}
else if (chunk->len < size) {
/* grow */
void *newptr;
/* need to alloc and copy; free is no-op, so don't call it */
newptr = wmem_block_fast_alloc(private_data, size);
memcpy(newptr, ptr, chunk->len);
return newptr;
}
/* shrink or same space - great we can do nothing */
return ptr;
}
static void *
wmem_block_realloc(void *private_data, void *ptr, const size_t size)
{
wmem_block_allocator_t *allocator = (wmem_block_allocator_t*) private_data;
wmem_block_chunk_t *chunk;
chunk = WMEM_DATA_TO_CHUNK(ptr);
if (chunk->jumbo) {
return wmem_block_realloc_jumbo(allocator, chunk, size);
}
if (size > WMEM_CHUNK_DATA_LEN(chunk)) {
/* grow */
wmem_block_chunk_t *tmp;
tmp = WMEM_CHUNK_NEXT(chunk);
if (tmp && (!tmp->used) &&
(size < WMEM_CHUNK_DATA_LEN(chunk) + tmp->len)) {
/* the next chunk is free and has enough extra, so just grab
* from that */
size_t split_size;
/* we ask for the next chunk to be split, but we don't end up
* using the split chunk header (it just gets merged into this one),
* so we want the split to be of (size - curdatalen - header_size).
* However, this can underflow by header_size, so we do a quick
* check here and floor the value to 0. */
split_size = size - WMEM_CHUNK_DATA_LEN(chunk);
if (split_size < WMEM_CHUNK_HEADER_SIZE) {
split_size = 0;
}
else {
split_size -= WMEM_CHUNK_HEADER_SIZE;
}
wmem_block_split_free_chunk(allocator, tmp, split_size);
/* Now do a 'quickie' merge between the current block and the left-
* hand side of the split. Simply calling wmem_block_merge_free
* might confuse things, since we may temporarily have two blocks
* to our right that are both free (and it isn't guaranteed to
* handle that case). Update our 'next' count and last flag, and
* our (new) successor's 'prev' count */
chunk->len += tmp->len;
chunk->last = tmp->last;
tmp = WMEM_CHUNK_NEXT(chunk);
if (tmp) {
tmp->prev = chunk->len;
}
/* Now cycle the recycler */
wmem_block_cycle_recycler(allocator);
/* And return the same old pointer */
return ptr;
}
else {
/* no room to grow, need to alloc, copy, free */
void *newptr;
newptr = wmem_block_alloc(private_data, size);
memcpy(newptr, ptr, WMEM_CHUNK_DATA_LEN(chunk));
wmem_block_free(private_data, ptr);
/* No need to cycle the recycler, alloc and free both did that
* already */
return newptr;
}
}
else if (size < WMEM_CHUNK_DATA_LEN(chunk)) {
/* shrink */
wmem_block_split_used_chunk(allocator, chunk, size);
/* Now cycle the recycler */
wmem_block_cycle_recycler(allocator);
return ptr;
}
/* no-op */
return ptr;
}
