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/*
* UCW Library -- Fast Allocator for Fixed-Size Elements
*
* (c) 2007 Martin Mares <mj@ucw.cz>
*
* This software may be freely distributed and used according to the terms
* of the GNU Lesser General Public License.
*/
#ifndef _UCW_ELTPOOL_H
#define _UCW_ELTPOOL_H
#ifdef CONFIG_UCW_CLEAN_ABI
#define ep_alloc_slow ucw_ep_alloc_slow
#define ep_delete ucw_ep_delete
#define ep_new ucw_ep_new
#define ep_total_size ucw_ep_total_size
#endif
/***
* [[defs]]
* Definitions
* -----------
***/
/**
* Memory pool of fixed-sized elements.
* You should use this one as an opaque handle only, the insides are internal.
**/
struct eltpool {
struct eltpool_chunk *first_chunk;
struct eltpool_free *first_free;
uint elt_size;
uint chunk_size;
uint elts_per_chunk;
uint num_allocated; // Just for debugging
uint num_chunks;
};
struct eltpool_chunk {
struct eltpool_chunk *next;
/* Chunk data continue here */
};
struct eltpool_free {
struct eltpool_free *next;
};
/***
* [[basic]]
* Basic manipulation
* ------------------
***/
/**
* Create a new memory pool for elements of @elt_size bytes.
* The pool will allocate chunks of at least @elts_per_chunk elements.
* Higher numbers lead to better allocation times but also to bigger
* unused memory blocks. Call @ep_delete() to free all pool's resources.
*
* Element pools can be treated as <<trans:respools,resources>>, see <<trans:res_eltpool()>>.
**/
struct eltpool *ep_new(uint elt_size, uint elts_per_chunk);
/**
* Release a memory pool created by @ep_new() including all
* elements allocated from that pool.
**/
void ep_delete(struct eltpool *pool);
/**
* Return the total number of bytes allocated by a given
* memory pool including all internals.
**/
u64 ep_total_size(struct eltpool *pool);
/***
* [[alloc]]
* Allocation routines
* -------------------
***/
void *ep_alloc_slow(struct eltpool *pool); /* Internal. Do not call directly. */
/**
* Allocate a new element on a given memory pool.
* The results is always aligned to a multiple of the element's size.
**/
static inline void *ep_alloc(struct eltpool *pool)
{
pool->num_allocated++;
#ifdef CONFIG_UCW_FAKE_ELTPOOL
return xmalloc(pool->elt_size);
#else
struct eltpool_free *elt;
if (elt = pool->first_free)
pool->first_free = elt->next;
else
elt = ep_alloc_slow(pool);
return elt;
#endif
}
/**
* Release an element previously allocated by @ep_alloc().
* Note thet the memory is not really freed (until @mp_delete()),
* but it can be reused by future @ep_alloc()'s.
**/
static inline void ep_free(struct eltpool *pool, void *p)
{
pool->num_allocated--;
#ifdef CONFIG_UCW_FAKE_ELTPOOL
(void) pool;
xfree(p);
#else
struct eltpool_free *elt = p;
elt->next = pool->first_free;
pool->first_free = elt;
#endif
}
#endif