ibool
buf_LRU_free_block(
/*===============*/
/* out: TRUE if freed */
buf_block_t* block) /* in/out: block to be freed */
{
if (!buf_flush_ready_for_replace(block)) {
return(FALSE);
}
#ifdef UNIV_DEBUG
if (buf_debug_prints) {
fprintf(stderr,
"Putting space %lu page %lu"
" to free list\n",
(ulong) block->space,
(ulong) block->offset);
}
#endif /* UNIV_DEBUG */
buf_LRU_block_remove_hashed_page(block);
mutex_exit(&(buf_pool->mutex));
mutex_exit(&block->mutex);
/* Remove possible adaptive hash index built on the
page; in the case of AWE the block may not have a
frame at all */
if (block->frame) {
/* The page was declared uninitialized
by buf_LRU_block_remove_hashed_page().
We need to flag the contents of the
page valid (which it still is) in
order to avoid bogus Valgrind
warnings. */
UNIV_MEM_VALID(block->frame, UNIV_PAGE_SIZE);
btr_search_drop_page_hash_index(block->frame);
UNIV_MEM_INVALID(block->frame, UNIV_PAGE_SIZE);
}
ut_a(block->buf_fix_count == 0);
mutex_enter(&(buf_pool->mutex));
mutex_enter(&block->mutex);
buf_LRU_block_free_hashed_page(block);
return(TRUE);
}
/**********************************************************************
Gives a recommendation of how many blocks should be flushed to establish
a big enough margin of replaceable blocks near the end of the LRU list
and in the free list. */
static
ulint
buf_flush_LRU_recommendation(void)
/*==============================*/
/* out: number of blocks which should be flushed
from the end of the LRU list */
{
buf_block_t* block;
ulint n_replaceable;
ulint distance = 0;
mutex_enter(&(buf_pool->mutex));
n_replaceable = UT_LIST_GET_LEN(buf_pool->free);
block = UT_LIST_GET_LAST(buf_pool->LRU);
while ((block != NULL)
&& (n_replaceable < BUF_FLUSH_FREE_BLOCK_MARGIN
+ BUF_FLUSH_EXTRA_MARGIN)
&& (distance < BUF_LRU_FREE_SEARCH_LEN)) {
mutex_enter(&block->mutex);
if (buf_flush_ready_for_replace(block)) {
n_replaceable++;
}
mutex_exit(&block->mutex);
distance++;
block = UT_LIST_GET_PREV(LRU, block);
}
mutex_exit(&(buf_pool->mutex));
if (n_replaceable >= BUF_FLUSH_FREE_BLOCK_MARGIN) {
return(0);
}
return(BUF_FLUSH_FREE_BLOCK_MARGIN + BUF_FLUSH_EXTRA_MARGIN
- n_replaceable);
}
