/*
* include/common/memory.h
* Memory management definitions..
*
* Copyright (C) 2000-2014 Willy Tarreau - w@1wt.eu
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_MEMORY_H
#define _COMMON_MEMORY_H
#include <stdlib.h>
#include <string.h>
#include <common/config.h>
#include <common/mini-clist.h>
#ifndef DEBUG_DONT_SHARE_POOLS
#define MEM_F_SHARED 0x1
#else
#define MEM_F_SHARED 0
#endif
#define MEM_F_EXACT 0x2
/* reserve an extra void* at the end of a pool for linking */
#ifdef DEBUG_MEMORY_POOLS
#define POOL_EXTRA (sizeof(void *))
#define POOL_LINK(pool, item) (void **)(((char *)item) + (pool->size))
#else
#define POOL_EXTRA (0)
#define POOL_LINK(pool, item) ((void **)(item))
#endif
struct pool_head {
void **free_list;
struct list list; /* list of all known pools */
unsigned int used; /* how many chunks are currently in use */
unsigned int allocated; /* how many chunks have been allocated */
unsigned int limit; /* hard limit on the number of chunks */
unsigned int minavail; /* how many chunks are expected to be used */
unsigned int size; /* chunk size */
unsigned int flags; /* MEM_F_* */
unsigned int users; /* number of pools sharing this zone */
unsigned int failed; /* failed allocations */
char name[12]; /* name of the pool */
};
/* poison each newly allocated area with this byte if >= 0 */
extern int mem_poison_byte;
/*
* This function destroys a pull by freeing it completely.
* This should be called only under extreme circumstances.
*/
static inline void pool_destroy(void **pool)
{
void *temp, *next;
next = pool;
while (next) {
temp = next;
next = *(void **)temp;
free(temp);
}
}
/* Allocates new entries for pool <pool> until there are at least <avail> + 1
* available, then returns the last one for immediate use, so that at least
* <avail> are left available in the pool upon return. NULL is returned if the
* last entry could not be allocated. It's important to note that at least one
* allocation is always performed even if there are enough entries in the pool.
* A call to the garbage collector is performed at most once in case malloc()
* returns an error, before returning NULL.
*/
void *pool_refill_alloc(struct pool_head *pool, unsigned int avail);
/* Try to find an existing shared pool with the same characteristics and
* returns it, otherwise creates this one. NULL is returned if no memory
* is available for a new creation.
*/
struct pool_head *create_pool(char *name, unsigned int size, unsigned int flags);
/* Dump statistics on pools usage.
*/
void dump_pools_to_trash();
void dump_pools(void);
int pool_total_failures();
unsigned long pool_total_allocated();
unsigned long pool_total_used();
/*
* This function frees whatever can be freed in pool <pool>.
*/
void pool_flush2(struct pool_head *pool);
/*
* This function frees whatever can be freed in all pools, but respecting
* the minimum thresholds imposed by owners.
*/
void pool_gc2();
/*
* This function destroys a pull by freeing it completely.
* This should be called only under extreme circumstances.
*/
void *pool_destroy2(struct pool_head *pool);
/*
* Returns a pointer to type <type> taken from the pool <pool_type> if
* available, otherwise returns NULL. No malloc() is attempted, and poisonning
* is never performed. The purpose is to get the fastest possible allocation.
*/
static inline void *pool_get_first(struct pool_head *pool)
{
void *p;
if ((p = pool->free_list) != NULL) {
pool->free_list = *POOL_LINK(pool, p);
pool->used++;
#ifdef DEBUG_MEMORY_POOLS
/* keep track of where the element was allocated from */
*POOL_LINK(pool, p) = (void *)pool;
#endif
}
return p;
}
/*
* Returns a pointer to type <type> taken from the pool <pool_type> or
* dynamically allocated. In the first case, <pool_type> is updated to point to
* the next element in the list. No memory poisonning is ever performed on the
* returned area.
*/
static inline void *pool_alloc_dirty(struct pool_head *pool)
{
void *p;
if ((p = pool_get_first(pool)) == NULL)
p = pool_refill_alloc(pool, 0);
return p;
}
/*
* Returns a pointer to type <type> taken from the pool <pool_type> or
* dynamically allocated. In the first case, <pool_type> is updated to point to
* the next element in the list. Memory poisonning is performed if enabled.
*/
static inline void *pool_alloc2(struct pool_head *pool)
{
void *p;
p = pool_alloc_dirty(pool);
#ifdef DEBUG_MEMORY_POOLS
if (p) {
/* keep track of where the element was allocated from */
*POOL_LINK(pool, p) = (void *)pool;
}
#endif
if (p && mem_poison_byte >= 0) {
memset(p, mem_poison_byte, pool->size);
}
return p;
}
/*
* Puts a memory area back to the corresponding pool.
* Items are chained directly through a pointer that
* is written in the beginning of the memory area, so
* there's no need for any carrier cell. This implies
* that each memory area is at least as big as one
* pointer. Just like with the libc's free(), nothing
* is done if <ptr> is NULL.
*/
static inline void pool_free2(struct pool_head *pool, void *ptr)
{
if (likely(ptr != NULL)) {
#ifdef DEBUG_MEMORY_POOLS
/* we'll get late corruption if we refill to the wrong pool or double-free */
if (*POOL_LINK(pool, ptr) != (void *)pool)
*(int *)0 = 0;
#endif
*POOL_LINK(pool, ptr) = (void *)pool->free_list;
pool->free_list = (void *)ptr;
pool->used--;
}
}
#endif /* _COMMON_MEMORY_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/