/**
* Empty the cache. Useful when there is not enough memory.
*/
void
pb_cache_release_all_buffers(struct pb_cache *mgr)
{
struct list_head *curr, *next;
struct pb_cache_entry *buf;
pipe_mutex_lock(mgr->mutex);
curr = mgr->cache.next;
next = curr->next;
while (curr != &mgr->cache) {
buf = LIST_ENTRY(struct pb_cache_entry, curr, head);
destroy_buffer_locked(buf);
curr = next;
next = curr->next;
}
pipe_mutex_unlock(mgr->mutex);
}
/**
* Empty the cache. Useful when there is not enough memory.
*/
void
pb_cache_release_all_buffers(struct pb_cache *mgr)
{
struct list_head *curr, *next;
struct pb_cache_entry *buf;
unsigned i;
pipe_mutex_lock(mgr->mutex);
for (i = 0; i < ARRAY_SIZE(mgr->buckets); i++) {
struct list_head *cache = &mgr->buckets[i];
curr = cache->next;
next = curr->next;
while (curr != cache) {
buf = LIST_ENTRY(struct pb_cache_entry, curr, head);
destroy_buffer_locked(buf);
curr = next;
next = curr->next;
}
}
pipe_mutex_unlock(mgr->mutex);
}
/**
* Free as many cache buffers from the list head as possible.
*/
static void
release_expired_buffers_locked(struct list_head *cache)
{
struct list_head *curr, *next;
struct pb_cache_entry *entry;
int64_t now;
now = os_time_get();
curr = cache->next;
next = curr->next;
while (curr != cache) {
entry = LIST_ENTRY(struct pb_cache_entry, curr, head);
if (!os_time_timeout(entry->start, entry->end, now))
break;
destroy_buffer_locked(entry);
curr = next;
next = curr->next;
}
}
/**
* 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;
}
