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buf_block_alloc(): Define as an alias in buf0lru.h, which defines the underlying buf_LRU_get_free_block(). buf_block_free(): Define as an alias of the non-inline function buf_pool.free_block(block). Reviewed by: Vladislav Lesin
98 lines
3.6 KiB
C++
98 lines
3.6 KiB
C++
/*****************************************************************************
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Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
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Copyright (c) 2014, 2021, MariaDB Corporation.
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free Software
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Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
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*****************************************************************************/
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/**************************************************//**
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@file include/buf0buf.ic
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The database buffer buf_pool
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Created 11/5/1995 Heikki Tuuri
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*******************************************************/
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#include "buf0lru.h"
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/** Determine if a block is still close enough to the MRU end of the LRU list
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meaning that it is not in danger of getting evicted and also implying
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that it has been accessed recently.
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The page must be either buffer-fixed, or its page hash must be locked.
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@param[in] bpage buffer pool page
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@return whether bpage is close to MRU end of LRU */
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inline bool buf_page_peek_if_young(const buf_page_t *bpage)
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{
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/* FIXME: bpage->freed_page_clock is 31 bits */
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return((buf_pool.freed_page_clock & ((1UL << 31) - 1))
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< (bpage->freed_page_clock
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+ (buf_pool.curr_size
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* (BUF_LRU_OLD_RATIO_DIV - buf_pool.LRU_old_ratio)
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/ (BUF_LRU_OLD_RATIO_DIV * 4))));
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}
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/** Determine if a block should be moved to the start of the LRU list if
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there is danger of dropping from the buffer pool.
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@param[in] bpage buffer pool page
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@return true if bpage should be made younger */
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inline bool buf_page_peek_if_too_old(const buf_page_t *bpage)
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{
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if (buf_pool.freed_page_clock == 0) {
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/* If eviction has not started yet, do not update the
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statistics or move blocks in the LRU list. This is
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either the warm-up phase or an in-memory workload. */
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return(FALSE);
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} else if (buf_LRU_old_threshold_ms && bpage->old) {
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uint32_t access_time = bpage->is_accessed();
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/* It is possible that the below comparison returns an
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unexpected result. 2^32 milliseconds pass in about 50 days,
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so if the difference between ut_time_ms() and access_time
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is e.g. 50 days + 15 ms, then the below will behave as if
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it is 15 ms. This is known and fixing it would require to
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increase buf_page_t::access_time from 32 to 64 bits. */
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if (access_time
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&& ((ib_uint32_t) (ut_time_ms() - access_time))
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>= buf_LRU_old_threshold_ms) {
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return(TRUE);
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}
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buf_pool.stat.n_pages_not_made_young++;
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return false;
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} else {
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return !buf_page_peek_if_young(bpage);
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}
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}
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/********************************************************************//**
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Increments the modify clock of a frame by 1. The caller must (1) own the
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buf_pool mutex and block bufferfix count has to be zero, (2) or own an x-lock
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on the block. */
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UNIV_INLINE
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void
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buf_block_modify_clock_inc(
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/*=======================*/
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buf_block_t* block) /*!< in: block */
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{
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#ifdef SAFE_MUTEX
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ut_ad((mysql_mutex_is_owner(&buf_pool.mutex)
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&& !block->page.buf_fix_count())
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|| block->page.lock.have_u_or_x());
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#else /* SAFE_MUTEX */
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ut_ad(!block->page.buf_fix_count() || block->page.lock.have_u_or_x());
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#endif /* SAFE_MUTEX */
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assert_block_ahi_valid(block);
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block->modify_clock++;
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}
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