/** prealloc some entries in the cache. To minimize contention.
* Result is 1 lock per alloc_max newly created entries.
* @param alloc: the structure to fill up.
*/
static void
prealloc(struct alloc_cache* alloc)
{
alloc_special_t* p;
int i;
for(i=0; i<ALLOC_SPECIAL_MAX; i++) {
if(!(p = (alloc_special_t*)malloc(sizeof(alloc_special_t)))) {
log_err("prealloc: out of memory");
return;
}
alloc_setup_special(p);
alloc_set_special_next(p, alloc->quar);
alloc->quar = p;
alloc->num_quar++;
}
}
alloc_special_type*
alloc_special_obtain(struct alloc_cache* alloc)
{
alloc_special_type* p;
log_assert(alloc);
/* see if in local cache */
if(alloc->quar) {
p = alloc->quar;
alloc->quar = alloc_special_next(p);
alloc->num_quar--;
p->id = alloc_get_id(alloc);
return p;
}
/* see if in global cache */
if(alloc->super) {
/* could maybe grab alloc_max/2 entries in one go,
* but really, isn't that just as fast as this code? */
lock_quick_lock(&alloc->super->lock);
if((p = alloc->super->quar)) {
alloc->super->quar = alloc_special_next(p);
alloc->super->num_quar--;
}
lock_quick_unlock(&alloc->super->lock);
if(p) {
p->id = alloc_get_id(alloc);
return p;
}
}
/* allocate new */
prealloc_setup(alloc);
if(!(p = (alloc_special_type*)malloc(sizeof(alloc_special_type)))) {
log_err("alloc_special_obtain: out of memory");
return NULL;
}
alloc_setup_special(p);
p->id = alloc_get_id(alloc);
return p;
}
