void *
tfw_pool_alloc(TfwPool *p, size_t n)
{
void *a;
n = TFW_POOL_ALIGN_SZ(n);
if (unlikely(p->off + n > TFW_POOL_CHUNK_SZ(p))) {
TfwPoolChunk *c, *curr = p->curr;
unsigned int off = TFW_POOL_ALIGN_SZ(sizeof(TfwPoolChunk)) + n;
unsigned int order = get_order(off);
c = (TfwPoolChunk *)tfw_pool_alloc_pages(order);
if (!c)
return NULL;
c->next = curr;
c->order = order;
curr->off = p->off;
p->order = order;
p->off = off;
p->curr = c;
return (void *)TFW_POOL_ALIGN_SZ((unsigned long)(c + 1));
}
a = (char *)TFW_POOL_CHUNK_END(p);
p->off += n;
return a;
}
void
tfw_pool_free(TfwPool *p, void *ptr, size_t n)
{
TfwPoolChunk *c = p->curr;
n = TFW_POOL_ALIGN_SZ(n);
/* Stack-like usage is expected. */
if (likely((char *)ptr + n == (char *)TFW_POOL_CHUNK_END(c)))
c->off -= n;
/* Free empty chunk which doesn't contain the pool header. */
if (unlikely(c != tfw_pool_chunk_first(p)
&& c->off == TFW_POOL_ALIGN_SZ(sizeof(*c))))
{
p->curr = c->next;
tfw_pool_free_pages(TFW_POOL_CHUNK_BASE(c), c->order);
}
}
/**
* It's good to call the function against just allocated chunk in stack-manner.
* Consequent free calls can empty the whole pool but the first chunk with
* the pool header.
*/
void
tfw_pool_free(TfwPool *p, void *ptr, size_t n)
{
n = TFW_POOL_ALIGN_SZ(n);
/* Stack-like usage is expected. */
if (unlikely((char *)ptr + n != (char *)TFW_POOL_CHUNK_END(p)))
return;
p->off -= n;
/* Free empty chunk which doesn't contain the pool header. */
if (unlikely(p->off == TFW_POOL_ALIGN_SZ(sizeof(TfwPoolChunk)))) {
TfwPoolChunk *next = p->curr->next;
tfw_pool_free_pages(TFW_POOL_CHUNK_BASE(p->curr), p->order);
p->curr = next;
p->order = next->order;
p->off = next->off;
}
}
void *
tfw_pool_realloc(TfwPool *p, void *ptr, size_t old_n, size_t new_n)
{
void *a;
BUG_ON(new_n < old_n);
old_n = TFW_POOL_ALIGN_SZ(old_n);
new_n = TFW_POOL_ALIGN_SZ(new_n);
if ((char *)ptr + old_n == (char *)TFW_POOL_CHUNK_END(p)
&& p->off - old_n + new_n <= TFW_POOL_CHUNK_SZ(p))
{
p->off += new_n - old_n;
return ptr;
}
a = tfw_pool_alloc(p, new_n);
if (likely(a))
memcpy(a, ptr, old_n);
return a;
}