/*
* __split_safe_free --
* Free a buffer if we can be sure no thread is accessing it, or schedule
* it to be freed otherwise.
*/
static int
__split_safe_free(WT_SESSION_IMPL *session, int exclusive, void *p, size_t s)
{
/*
* We have swapped something in a page: if we don't have exclusive
* access, check whether there are other threads in the same tree.
*/
if (!exclusive &&
__split_oldest_gen(session) == S2C(session)->split_gen + 1)
exclusive = 1;
if (exclusive) {
__wt_free(session, p);
return (0);
}
return (__split_stash_add(session, p, s));
}
/*
* __split_safe_free --
* Free a buffer if we can be sure no thread is accessing it, or schedule
* it to be freed otherwise.
*/
static int
__split_safe_free(WT_SESSION_IMPL *session,
uint64_t split_gen, bool exclusive, void *p, size_t s)
{
/* We should only call safe free if we aren't pinning the memory. */
WT_ASSERT(session, session->split_gen != split_gen);
/*
* We have swapped something in a page: if we don't have exclusive
* access, check whether there are other threads in the same tree.
*/
if (!exclusive && __split_oldest_gen(session) > split_gen)
exclusive = true;
if (exclusive) {
__wt_free(session, p);
return (0);
}
return (__split_stash_add(session, split_gen, p, s));
}
/*
* __wt_split_stash_discard --
* Discard any memory from a session's split stash that we can.
*/
void
__wt_split_stash_discard(WT_SESSION_IMPL *session)
{
WT_CONNECTION_IMPL *conn;
WT_SPLIT_STASH *stash;
uint64_t oldest;
size_t i;
conn = S2C(session);
/* Get the oldest split generation. */
oldest = __split_oldest_gen(session);
for (i = 0, stash = session->split_stash;
i < session->split_stash_cnt;
++i, ++stash) {
if (stash->p == NULL)
continue;
else if (stash->split_gen >= oldest)
break;
/*
* It's a bad thing if another thread is in this memory after
* we free it, make sure nothing good happens to that thread.
*/
(void)__wt_atomic_sub64(&conn->split_stashed_bytes, stash->len);
(void)__wt_atomic_sub64(&conn->split_stashed_objects, 1);
__wt_overwrite_and_free_len(session, stash->p, stash->len);
}
/*
* If there are enough free slots at the beginning of the list, shuffle
* everything down.
*/
if (i > 100 || i == session->split_stash_cnt)
if ((session->split_stash_cnt -= i) > 0)
memmove(session->split_stash, stash,
session->split_stash_cnt * sizeof(*stash));
}
