blob: d9cef64b6e6944780d29a802e33c77fa051d8917 [file] [log] [blame]
/*
* Memory management functions.
*
* Copyright 2000-2007 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <types/global.h>
#include <common/config.h>
#include <common/debug.h>
#include <common/memory.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <proto/log.h>
static struct list pools = LIST_HEAD_INIT(pools);
int mem_poison_byte = -1;
/* 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)
{
struct pool_head *pool;
struct pool_head *entry;
struct list *start;
unsigned int align;
/* We need to store at least a (void *) in the chunks. Since we know
* that the malloc() function will never return such a small size,
* let's round the size up to something slightly bigger, in order to
* ease merging of entries. Note that the rounding is a power of two.
*/
align = 16;
size = (size + align - 1) & -align;
start = &pools;
pool = NULL;
list_for_each_entry(entry, &pools, list) {
if (entry->size == size) {
/* either we can share this place and we take it, or
* we look for a sharable one or for the next position
* before which we will insert a new one.
*/
if (flags & entry->flags & MEM_F_SHARED) {
/* we can share this one */
pool = entry;
DPRINTF(stderr, "Sharing %s with %s\n", name, pool->name);
break;
}
}
else if (entry->size > size) {
/* insert before this one */
start = &entry->list;
break;
}
}
if (!pool) {
pool = CALLOC(1, sizeof(*pool));
if (!pool)
return NULL;
if (name)
strlcpy2(pool->name, name, sizeof(pool->name));
pool->size = size;
pool->flags = flags;
LIST_ADDQ(start, &pool->list);
}
pool->users++;
return pool;
}
/* 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)
{
void *ptr = NULL;
int failed = 0;
/* stop point */
avail += pool->used;
while (1) {
if (pool->limit && pool->allocated >= pool->limit)
return NULL;
ptr = MALLOC(pool->size);
if (!ptr) {
if (failed)
return NULL;
failed++;
pool_gc2();
continue;
}
if (++pool->allocated > avail)
break;
*(void **)ptr = (void *)pool->free_list;
pool->free_list = ptr;
}
pool->used++;
return ptr;
}
/*
* This function frees whatever can be freed in pool <pool>.
*/
void pool_flush2(struct pool_head *pool)
{
void *temp, *next;
if (!pool)
return;
next = pool->free_list;
while (next) {
temp = next;
next = *(void **)temp;
pool->allocated--;
FREE(temp);
}
pool->free_list = next;
/* here, we should have pool->allocate == pool->used */
}
/*
* This function frees whatever can be freed in all pools, but respecting
* the minimum thresholds imposed by owners. It takes care of avoiding
* recursion because it may be called from a signal handler.
*/
void pool_gc2()
{
static int recurse;
struct pool_head *entry;
if (recurse++)
goto out;
list_for_each_entry(entry, &pools, list) {
void *temp, *next;
//qfprintf(stderr, "Flushing pool %s\n", entry->name);
next = entry->free_list;
while (next &&
(int)(entry->allocated - entry->used) > (int)entry->minavail) {
temp = next;
next = *(void **)temp;
entry->allocated--;
FREE(temp);
}
entry->free_list = next;
}
out:
recurse--;
}
/*
* This function destroys a pool by freeing it completely, unless it's still
* in use. This should be called only under extreme circumstances. It always
* returns NULL if the resulting pool is empty, easing the clearing of the old
* pointer, otherwise it returns the pool.
* .
*/
void *pool_destroy2(struct pool_head *pool)
{
if (pool) {
pool_flush2(pool);
if (pool->used)
return pool;
pool->users--;
if (!pool->users) {
LIST_DEL(&pool->list);
FREE(pool);
}
}
return NULL;
}
/* This function dumps memory usage information into the trash buffer. */
void dump_pools_to_trash()
{
struct pool_head *entry;
unsigned long allocated, used;
int nbpools;
allocated = used = nbpools = 0;
chunk_printf(&trash, "Dumping pools usage. Use SIGQUIT to flush them.\n");
list_for_each_entry(entry, &pools, list) {
chunk_appendf(&trash, " - Pool %s (%d bytes) : %d allocated (%u bytes), %d used, %d users%s\n",
entry->name, entry->size, entry->allocated,
entry->size * entry->allocated, entry->used,
entry->users, (entry->flags & MEM_F_SHARED) ? " [SHARED]" : "");
allocated += entry->allocated * entry->size;
used += entry->used * entry->size;
nbpools++;
}
chunk_appendf(&trash, "Total: %d pools, %lu bytes allocated, %lu used.\n",
nbpools, allocated, used);
}
/* Dump statistics on pools usage. */
void dump_pools(void)
{
dump_pools_to_trash();
qfprintf(stderr, "%s", trash.str);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/