/*
* heap_buckets_init -- (internal) initializes bucket instances
*/
int
heap_buckets_init(struct palloc_heap *heap)
{
struct heap_rt *h = heap->rt;
for (uint8_t i = 0; i < MAX_ALLOCATION_CLASSES; ++i) {
struct alloc_class *c = alloc_class_by_id(h->alloc_classes, i);
if (c != NULL) {
if (heap_create_alloc_class_buckets(heap, c) != 0)
goto error_bucket_create;
}
}
h->default_bucket = bucket_new(container_new_ctree(heap),
alloc_class_by_id(h->alloc_classes, DEFAULT_ALLOC_CLASS_ID));
if (h->default_bucket == NULL)
goto error_bucket_create;
heap_populate_buckets(heap);
return 0;
error_bucket_create:
for (unsigned i = 0; i < h->ncaches; ++i)
bucket_group_destroy(h->caches[i].buckets);
return -1;
}
/*
* CTL_READ_HANDLER(desc) -- reads the information about allocation class
*/
static int
CTL_READ_HANDLER(desc)(void *ctx,
enum ctl_query_source source, void *arg, struct ctl_indexes *indexes)
{
PMEMobjpool *pop = ctx;
uint8_t id;
struct ctl_index *idx = SLIST_FIRST(indexes);
ASSERTeq(strcmp(idx->name, "class_id"), 0);
if (idx->value < 0 || idx->value >= MAX_ALLOCATION_CLASSES) {
ERR("class id outside of the allowed range");
errno = ERANGE;
return -1;
}
id = (uint8_t)idx->value;
struct alloc_class *c = alloc_class_by_id(
heap_alloc_classes(&pop->heap), id);
if (c == NULL) {
ERR("class with the given id does not exist");
errno = ENOENT;
return -1;
}
enum pobj_header_type user_htype = MAX_POBJ_HEADER_TYPES;
switch (c->header_type) {
case HEADER_LEGACY:
user_htype = POBJ_HEADER_LEGACY;
break;
case HEADER_COMPACT:
user_htype = POBJ_HEADER_COMPACT;
break;
case HEADER_NONE:
user_htype = POBJ_HEADER_NONE;
break;
default:
ASSERT(0); /* unreachable */
break;
}
struct pobj_alloc_class_desc *p = arg;
p->units_per_block = c->type == CLASS_HUGE ? 0 : c->run.nallocs;
p->header_type = user_htype;
p->unit_size = c->unit_size;
p->class_id = c->id;
p->alignment = c->flags & CHUNK_FLAG_ALIGNED ? c->run.alignment : 0;
return 0;
}
/*
* palloc_reservation_create -- creates a volatile reservation of a
* memory block.
*
* The first step in the allocation of a new block is reserving it in
* the transient heap - which is represented by the bucket abstraction.
*
* To provide optimal scaling for multi-threaded applications and reduce
* fragmentation the appropriate bucket is chosen depending on the
* current thread context and to which allocation class the requested
* size falls into.
*
* Once the bucket is selected, just enough memory is reserved for the
* requested size. The underlying block allocation algorithm
* (best-fit, next-fit, ...) varies depending on the bucket container.
*/
static int
palloc_reservation_create(struct palloc_heap *heap, size_t size,
palloc_constr constructor, void *arg,
uint64_t extra_field, uint16_t object_flags, uint16_t class_id,
struct pobj_action_internal *out)
{
int err = 0;
struct memory_block *new_block = &out->m;
ASSERT(class_id < UINT8_MAX);
struct alloc_class *c = class_id == 0 ?
heap_get_best_class(heap, size) :
alloc_class_by_id(heap_alloc_classes(heap),
(uint8_t)class_id);
if (c == NULL) {
ERR("no allocation class for size %lu bytes", size);
errno = EINVAL;
return -1;
}
/*
* The caller provided size in bytes, but buckets operate in
* 'size indexes' which are multiples of the block size in the
* bucket.
*
* For example, to allocate 500 bytes from a bucket that
* provides 256 byte blocks two memory 'units' are required.
*/
ssize_t size_idx = alloc_class_calc_size_idx(c, size);
if (size_idx < 0) {
ERR("allocation class not suitable for size %lu bytes",
size);
errno = EINVAL;
return -1;
}
ASSERT(size_idx <= UINT32_MAX);
new_block->size_idx = (uint32_t)size_idx;
struct bucket *b = heap_bucket_acquire(heap, c);
err = heap_get_bestfit_block(heap, b, new_block);
if (err != 0)
goto out;
if (alloc_prep_block(heap, new_block, constructor, arg,
extra_field, object_flags, &out->offset) != 0) {
/*
* Constructor returned non-zero value which means
* the memory block reservation has to be rolled back.
*/
if (new_block->type == MEMORY_BLOCK_HUGE) {
bucket_insert_block(b, new_block);
}
err = ECANCELED;
goto out;
}
/*
* Each as of yet unfulfilled reservation needs to be tracked in the
* runtime state.
* The memory block cannot be put back into the global state unless
* there are no active reservations.
*/
if ((out->resvp = bucket_current_resvp(b)) != NULL)
util_fetch_and_add64(out->resvp, 1);
out->lock = new_block->m_ops->get_lock(new_block);
out->new_state = MEMBLOCK_ALLOCATED;
out:
heap_bucket_release(heap, b);
if (err == 0)
return 0;
errno = err;
return -1;
}
