static struct pb_buffer *
pb_cache_manager_create_buffer(struct pb_manager *_mgr,
pb_size size,
const struct pb_desc *desc)
{
struct pb_cache_manager *mgr = pb_cache_manager(_mgr);
struct pb_cache_buffer *buf;
struct pb_cache_buffer *curr_buf;
struct list_head *curr, *next;
int64_t now;
pipe_mutex_lock(mgr->mutex);
buf = NULL;
curr = mgr->delayed.next;
next = curr->next;
/* search in the expired buffers, freeing them in the process */
now = os_time_get();
while(curr != &mgr->delayed) {
curr_buf = LIST_ENTRY(struct pb_cache_buffer, curr, head);
if(!buf && pb_cache_is_buffer_compat(curr_buf, size, desc))
buf = curr_buf;
else if(os_time_timeout(curr_buf->start, curr_buf->end, now))
_pb_cache_buffer_destroy(curr_buf);
else
/* This buffer (and all hereafter) are still hot in cache */
break;
curr = next;
next = curr->next;
}
/* keep searching in the hot buffers */
if(!buf) {
while(curr != &mgr->delayed) {
curr_buf = LIST_ENTRY(struct pb_cache_buffer, curr, head);
if(pb_cache_is_buffer_compat(curr_buf, size, desc)) {
buf = curr_buf;
break;
}
/* no need to check the timeout here */
curr = next;
next = curr->next;
}
}
if(buf) {
LIST_DEL(&buf->head);
pipe_mutex_unlock(mgr->mutex);
/* Increase refcount */
pipe_reference_init(&buf->base.base.reference, 1);
return &buf->base;
}
pipe_mutex_unlock(mgr->mutex);
buf = CALLOC_STRUCT(pb_cache_buffer);
if(!buf)
return NULL;
buf->buffer = mgr->provider->create_buffer(mgr->provider, size, desc);
if(!buf->buffer) {
FREE(buf);
return NULL;
}
assert(pipe_is_referenced(&buf->buffer->base.reference));
assert(pb_check_alignment(desc->alignment, buf->buffer->base.alignment));
assert(pb_check_usage(desc->usage, buf->buffer->base.usage));
assert(buf->buffer->base.size >= size);
pipe_reference_init(&buf->base.base.reference, 1);
buf->base.base.alignment = buf->buffer->base.alignment;
buf->base.base.usage = buf->buffer->base.usage;
buf->base.base.size = buf->buffer->base.size;
buf->base.vtbl = &pb_cache_buffer_vtbl;
buf->mgr = mgr;
return &buf->base;
}
/**
* Find a compatible buffer in the cache, return it, and remove it
* from the cache.
*/
struct pb_buffer *
pb_cache_reclaim_buffer(struct pb_cache *mgr, pb_size size,
unsigned alignment, unsigned usage,
unsigned bucket_index)
{
struct pb_cache_entry *entry;
struct pb_cache_entry *cur_entry;
struct list_head *cur, *next;
int64_t now;
int ret = 0;
struct list_head *cache = &mgr->buckets[bucket_index];
pipe_mutex_lock(mgr->mutex);
entry = NULL;
cur = cache->next;
next = cur->next;
/* search in the expired buffers, freeing them in the process */
now = os_time_get();
while (cur != cache) {
cur_entry = LIST_ENTRY(struct pb_cache_entry, cur, head);
if (!entry && (ret = pb_cache_is_buffer_compat(cur_entry, size,
alignment, usage) > 0))
entry = cur_entry;
else if (os_time_timeout(cur_entry->start, cur_entry->end, now))
destroy_buffer_locked(cur_entry);
else
/* This buffer (and all hereafter) are still hot in cache */
break;
/* the buffer is busy (and probably all remaining ones too) */
if (ret == -1)
break;
cur = next;
next = cur->next;
}
/* keep searching in the hot buffers */
if (!entry && ret != -1) {
while (cur != cache) {
cur_entry = LIST_ENTRY(struct pb_cache_entry, cur, head);
ret = pb_cache_is_buffer_compat(cur_entry, size, alignment, usage);
if (ret > 0) {
entry = cur_entry;
break;
}
if (ret == -1)
break;
/* no need to check the timeout here */
cur = next;
next = cur->next;
}
}
/* found a compatible buffer, return it */
if (entry) {
struct pb_buffer *buf = entry->buffer;
mgr->cache_size -= buf->size;
LIST_DEL(&entry->head);
--mgr->num_buffers;
pipe_mutex_unlock(mgr->mutex);
/* Increase refcount */
pipe_reference_init(&buf->reference, 1);
return buf;
}
pipe_mutex_unlock(mgr->mutex);
return NULL;
}
