int
slab_arena_create(struct slab_arena *arena, struct quota *quota,
size_t prealloc, uint32_t slab_size, int flags)
{
assert(flags & (MAP_PRIVATE | MAP_SHARED));
lf_lifo_init(&arena->cache);
/*
* Round up the user supplied data - it can come in
* directly from the configuration file. Allow
* zero-size arena for testing purposes.
*/
arena->slab_size = small_round(MAX(slab_size, SLAB_MIN_SIZE));
arena->quota = quota;
/** Prealloc can not be greater than the quota */
prealloc = MIN(prealloc, quota_total(quota));
/** Extremely large sizes can not be aligned properly */
prealloc = MIN(prealloc, SIZE_MAX - arena->slab_size);
/* Align prealloc around a fixed number of slabs. */
arena->prealloc = small_align(prealloc, arena->slab_size);
arena->used = 0;
arena->flags = flags;
if (arena->prealloc) {
arena->arena = mmap_checked(arena->prealloc,
arena->slab_size,
arena->flags);
} else {
arena->arena = NULL;
}
return arena->prealloc && !arena->arena ? -1 : 0;
}
void *
slab_map(struct slab_arena *arena)
{
void *ptr;
if ((ptr = lf_lifo_pop(&arena->cache)))
return ptr;
/** Need to allocate a new slab. */
size_t used = __sync_add_and_fetch(&arena->used, arena->slab_size);
if (used <= arena->prealloc)
return arena->arena + used - arena->slab_size;
if (used > arena->maxalloc) {
__sync_sub_and_fetch(&arena->used, arena->slab_size);
return NULL;
}
return mmap_checked(arena->slab_size, arena->slab_size,
arena->flags);
}
int
slab_arena_create(struct slab_arena *arena,
size_t prealloc, size_t maxalloc,
uint32_t slab_size, int flags)
{
assert(flags & (MAP_PRIVATE | MAP_SHARED));
lf_lifo_init(&arena->cache);
/*
* Round up the user supplied data - it can come in
* directly from the configuration file. Allow
* zero-size arena for testing purposes.
*/
arena->slab_size = small_round(MAX(slab_size, SLAB_MIN_SIZE));
if (maxalloc) {
arena->maxalloc = small_round(MAX(maxalloc,
arena->slab_size));
} else {
arena->maxalloc = 0;
}
/* Align arena around a fixed number of slabs. */
arena->prealloc = small_align(small_round(prealloc),
arena->slab_size);
if (arena->maxalloc < arena->prealloc)
arena->prealloc = arena->maxalloc;
arena->used = 0;
arena->flags = flags;
if (arena->prealloc) {
arena->arena = mmap_checked(arena->prealloc,
arena->slab_size,
arena->flags);
} else {
arena->arena = NULL;
}
return arena->prealloc && !arena->arena ? -1 : 0;
}
void *
slab_map(struct slab_arena *arena)
{
void *ptr;
if ((ptr = lf_lifo_pop(&arena->cache)))
return ptr;
if (quota_use(arena->quota, arena->slab_size) < 0)
return NULL;
/** Need to allocate a new slab. */
size_t used = __sync_add_and_fetch(&arena->used, arena->slab_size);
if (used <= arena->prealloc)
return arena->arena + used - arena->slab_size;
ptr = mmap_checked(arena->slab_size, arena->slab_size,
arena->flags);
if (!ptr) {
__sync_sub_and_fetch(&arena->used, arena->slab_size);
quota_release(arena->quota, arena->slab_size);
}
return ptr;
}
