LUMIERA.clone/src/backend/mmapcache.c
2008-12-15 01:17:23 +01:00

171 lines
3.7 KiB
C

/*
mmapcache.c - handle aging of mmap objects
Copyright (C) Lumiera.org
2008, Christian Thaeter <ct@pipapo.org>
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.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "lib/safeclib.h"
#include "backend/mmapcache.h"
/**
* @file
*
*/
NOBUG_DEFINE_FLAG_PARENT (mmapcache, mmap_all);
LumieraMMapcache lumiera_mcache = NULL;
void
lumiera_mmapcache_new (size_t limit)
{
TRACE (mmapcache);
lumiera_mcache = lumiera_malloc (sizeof (*lumiera_mcache));
lumiera_mrucache_init (&lumiera_mcache->cache, lumiera_mmap_destroy_node);
lumiera_mcache->limit = limit;
lumiera_mcache->total = 0;
lumiera_mcache->cached = 0;
lumiera_mutex_init (&lumiera_mcache->lock, "mmapcache", &NOBUG_FLAG (mmapcache));
}
void
lumiera_mmapcache_delete (void)
{
TRACE (mmapcache);
if (lumiera_mcache)
{
REQUIRE (lumiera_mcache->total == lumiera_mcache->cached, "MMaps still checked out at shutdown");
lumiera_mrucache_destroy (&lumiera_mcache->cache);
lumiera_mutex_destroy (&lumiera_mcache->lock, &NOBUG_FLAG (mmapcache));
free (lumiera_mcache);
lumiera_mcache = NULL;
}
}
void*
lumiera_mmapcache_mmap_acquire (LumieraMMapcache self)
{
TRACE (mmapcache);
void* map = NULL;
LUMIERA_MUTEX_SECTION (mmapcache, &self->lock)
{
map = lumiera_mrucache_pop (&self->cache);
}
if (!map)
{
map = lumiera_malloc (sizeof (*self));
TRACE (mmapcache, "allocated new mmap");
}
else
{
TRACE (mmapcache, "poped mmap from cache");
}
return map;
}
void
lumiera_mmapcache_announce (LumieraMMapcache self, LumieraMMap map)
{
TRACE (mmapcache);
LUMIERA_MUTEX_SECTION (mmapcache, &self->lock)
{
self->total += map->size;
}
}
void
lumiera_mmapcache_forget (LumieraMMapcache self, LumieraMMap map)
{
TRACE (mmapcache);
LUMIERA_MUTEX_SECTION (mmapcache, &self->lock)
{
if (!llist_is_empty (&map->cachenode))
{
TODO ("cached stats");
REQUIRE (llist_is_member (&self->cache.cache_list, &map->cachenode), "Map object not in cache");
llist_unlink (&map->cachenode);
}
self->total -= map->size;
}
}
#if 0
int
lumiera_mmapcache_age (LumieraMMapcache self)
{
TRACE (mmapcache);
int ret = 0;
LUMIERA_MUTEX_SECTION (mmapcache, &self->lock)
{
ret = lumiera_mrucache_age (&self->cache, 10); TODO ("age nelem == 20%(configureable) of the cache");
}
return ret;
}
#endif
LumieraMMap
lumiera_mmapcache_checkout (LumieraMMapcache self, LumieraMMap handle)
{
TRACE (mmapcache);
LUMIERA_MUTEX_SECTION (mmapcache, &self->lock)
{
TODO ("cached stats");
lumiera_mrucache_checkout (&self->cache, &handle->cachenode);
++handle->refcnt;
}
return handle;
}
void
lumiera_mmapcache_checkin (LumieraMMapcache self, LumieraMMap handle)
{
TRACE (mmapcache);
LUMIERA_MUTEX_SECTION (mmapcache, &self->lock)
{
TODO ("cached stats");
--handle->refcnt;
lumiera_mrucache_checkin (&self->cache, &handle->cachenode);
}
}
/*
// Local Variables:
// mode: C
// c-file-style: "gnu"
// indent-tabs-mode: nil
// End:
*/