/***************************************************************************** Copyright (c) 1995, 2010, Innobase Oy. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA *****************************************************************************/ /**************************************************//** @file include/buf0buf.h The database buffer pool high-level routines Created 11/5/1995 Heikki Tuuri *******************************************************/ #ifndef buf0buf_h #define buf0buf_h #include "univ.i" #include "fil0fil.h" #include "mtr0types.h" #include "buf0types.h" #include "hash0hash.h" #include "ut0byte.h" #include "page0types.h" #ifndef UNIV_HOTBACKUP #include "ut0rbt.h" #include "os0proc.h" /** @name Modes for buf_page_get_gen */ /* @{ */ #define BUF_GET 10 /*!< get always */ #define BUF_GET_IF_IN_POOL 11 /*!< get if in pool */ #define BUF_GET_NO_LATCH 14 /*!< get and bufferfix, but set no latch; we have separated this case, because it is error-prone programming not to set a latch, and it should be used with care */ #define BUF_GET_IF_IN_POOL_OR_WATCH 15 /*!< Get the page only if it's in the buffer pool, if not then set a watch on the page. */ /* @} */ /** @name Modes for buf_page_get_known_nowait */ /* @{ */ #define BUF_MAKE_YOUNG 51 /*!< Move the block to the start of the LRU list if there is a danger that the block would drift out of the buffer pool*/ #define BUF_KEEP_OLD 52 /*!< Preserve the current LRU position of the block. */ /* @} */ #define MAX_BUFFER_POOLS 64 /*!< The maximum number of buffer pools that can be defined */ #define BUF_POOL_WATCH_SIZE 1 /*!< Maximum number of concurrent buffer pool watches */ extern buf_pool_t* buf_pool_ptr[MAX_BUFFER_POOLS]; /*!< The buffer pools of the database */ #ifdef UNIV_DEBUG extern ibool buf_debug_prints;/*!< If this is set TRUE, the program prints info whenever read or flush occurs */ #endif /* UNIV_DEBUG */ #else /* !UNIV_HOTBACKUP */ extern buf_block_t* back_block1; /*!< first block, for --apply-log */ extern buf_block_t* back_block2; /*!< second block, for page reorganize */ #endif /* !UNIV_HOTBACKUP */ /** Magic value to use instead of checksums when they are disabled */ #define BUF_NO_CHECKSUM_MAGIC 0xDEADBEEFUL /** @brief States of a control block @see buf_page_struct The enumeration values must be 0..7. */ enum buf_page_state { BUF_BLOCK_ZIP_FREE = 0, /*!< contains a free compressed page */ BUF_BLOCK_POOL_WATCH = 0, /*!< a sentinel for the buffer pool watch, element of buf_pool_watch[] */ BUF_BLOCK_ZIP_PAGE, /*!< contains a clean compressed page */ BUF_BLOCK_ZIP_DIRTY, /*!< contains a compressed page that is in the buf_pool->flush_list */ BUF_BLOCK_NOT_USED, /*!< is in the free list; must be after the BUF_BLOCK_ZIP_ constants for compressed-only pages @see buf_block_state_valid() */ BUF_BLOCK_READY_FOR_USE, /*!< when buf_LRU_get_free_block returns a block, it is in this state */ BUF_BLOCK_FILE_PAGE, /*!< contains a buffered file page */ BUF_BLOCK_MEMORY, /*!< contains some main memory object */ BUF_BLOCK_REMOVE_HASH /*!< hash index should be removed before putting to the free list */ }; #ifndef UNIV_HOTBACKUP /********************************************************************//** Acquire mutex on all buffer pool instances */ UNIV_INLINE void buf_pool_mutex_enter_all(void); /*===========================*/ /********************************************************************//** Release mutex on all buffer pool instances */ UNIV_INLINE void buf_pool_mutex_exit_all(void); /*==========================*/ /********************************************************************//** Creates the buffer pool. @return own: buf_pool object, NULL if not enough memory or error */ UNIV_INTERN ulint buf_pool_init( /*=========*/ ulint size, /*!< in: Size of the total pool in bytes */ ulint n_instances); /*!< in: Number of instances */ /********************************************************************//** Frees the buffer pool at shutdown. This must not be invoked before freeing all mutexes. */ UNIV_INTERN void buf_pool_free( /*==========*/ ulint n_instances); /*!< in: numbere of instances to free */ /********************************************************************//** Drops the adaptive hash index. To prevent a livelock, this function is only to be called while holding btr_search_latch and while btr_search_enabled == FALSE. */ UNIV_INTERN void buf_pool_drop_hash_index(void); /*==========================*/ /********************************************************************//** Relocate a buffer control block. Relocates the block on the LRU list and in buf_pool->page_hash. Does not relocate bpage->list. The caller must take care of relocating bpage->list. */ UNIV_INTERN void buf_relocate( /*=========*/ buf_page_t* bpage, /*!< in/out: control block being relocated; buf_page_get_state(bpage) must be BUF_BLOCK_ZIP_DIRTY or BUF_BLOCK_ZIP_PAGE */ buf_page_t* dpage) /*!< in/out: destination control block */ __attribute__((nonnull)); /********************************************************************//** Resizes the buffer pool. */ UNIV_INTERN void buf_pool_resize(void); /*=================*/ /*********************************************************************//** Gets the current size of buffer buf_pool in bytes. @return size in bytes */ UNIV_INLINE ulint buf_pool_get_curr_size(void); /*========================*/ /*********************************************************************//** Gets the current size of buffer buf_pool in frames. @return size in pages */ UNIV_INLINE ulint buf_pool_get_n_pages(void); /*=======================*/ /********************************************************************//** Gets the smallest oldest_modification lsn for any page in the pool. Returns zero if all modified pages have been flushed to disk. @return oldest modification in pool, zero if none */ UNIV_INTERN ib_uint64_t buf_pool_get_oldest_modification(void); /*==================================*/ /********************************************************************//** Allocates a buffer block. @return own: the allocated block, in state BUF_BLOCK_MEMORY */ UNIV_INTERN buf_block_t* buf_block_alloc( /*============*/ buf_pool_t* buf_pool, /*!< buffer pool instance */ ulint zip_size); /*!< in: compressed page size in bytes, or 0 if uncompressed tablespace */ /********************************************************************//** Frees a buffer block which does not contain a file page. */ UNIV_INLINE void buf_block_free( /*===========*/ buf_block_t* block); /*!< in, own: block to be freed */ #endif /* !UNIV_HOTBACKUP */ /*********************************************************************//** Copies contents of a buffer frame to a given buffer. @return buf */ UNIV_INLINE byte* buf_frame_copy( /*===========*/ byte* buf, /*!< in: buffer to copy to */ const buf_frame_t* frame); /*!< in: buffer frame */ #ifndef UNIV_HOTBACKUP /**************************************************************//** NOTE! The following macros should be used instead of buf_page_get_gen, to improve debugging. Only values RW_S_LATCH and RW_X_LATCH are allowed in LA! */ #define buf_page_get(SP, ZS, OF, LA, MTR) buf_page_get_gen(\ SP, ZS, OF, LA, NULL,\ BUF_GET, __FILE__, __LINE__, MTR) /**************************************************************//** Use these macros to bufferfix a page with no latching. Remember not to read the contents of the page unless you know it is safe. Do not modify the contents of the page! We have separated this case, because it is error-prone programming not to set a latch, and it should be used with care. */ #define buf_page_get_with_no_latch(SP, ZS, OF, MTR) buf_page_get_gen(\ SP, ZS, OF, RW_NO_LATCH, NULL,\ BUF_GET_NO_LATCH, __FILE__, __LINE__, MTR) /********************************************************************//** This is the general function used to get optimistic access to a database page. @return TRUE if success */ UNIV_INTERN ibool buf_page_optimistic_get( /*====================*/ ulint rw_latch,/*!< in: RW_S_LATCH, RW_X_LATCH */ buf_block_t* block, /*!< in: guessed block */ ib_uint64_t modify_clock,/*!< in: modify clock value if mode is ..._GUESS_ON_CLOCK */ const char* file, /*!< in: file name */ ulint line, /*!< in: line where called */ mtr_t* mtr); /*!< in: mini-transaction */ /********************************************************************//** This is used to get access to a known database page, when no waiting can be done. @return TRUE if success */ UNIV_INTERN ibool buf_page_get_known_nowait( /*======================*/ ulint rw_latch,/*!< in: RW_S_LATCH, RW_X_LATCH */ buf_block_t* block, /*!< in: the known page */ ulint mode, /*!< in: BUF_MAKE_YOUNG or BUF_KEEP_OLD */ const char* file, /*!< in: file name */ ulint line, /*!< in: line where called */ mtr_t* mtr); /*!< in: mini-transaction */ /*******************************************************************//** Given a tablespace id and page number tries to get that page. If the page is not in the buffer pool it is not loaded and NULL is returned. Suitable for using when holding the kernel mutex. */ UNIV_INTERN const buf_block_t* buf_page_try_get_func( /*==================*/ ulint space_id,/*!< in: tablespace id */ ulint page_no,/*!< in: page number */ const char* file, /*!< in: file name */ ulint line, /*!< in: line where called */ mtr_t* mtr); /*!< in: mini-transaction */ /** Tries to get a page. If the page is not in the buffer pool it is not loaded. Suitable for using when holding the kernel mutex. @param space_id in: tablespace id @param page_no in: page number @param mtr in: mini-transaction @return the page if in buffer pool, NULL if not */ #define buf_page_try_get(space_id, page_no, mtr) \ buf_page_try_get_func(space_id, page_no, __FILE__, __LINE__, mtr); /********************************************************************//** Get read access to a compressed page (usually of type FIL_PAGE_TYPE_ZBLOB or FIL_PAGE_TYPE_ZBLOB2). The page must be released with buf_page_release_zip(). NOTE: the page is not protected by any latch. Mutual exclusion has to be implemented at a higher level. In other words, all possible accesses to a given page through this function must be protected by the same set of mutexes or latches. @return pointer to the block, or NULL if not compressed */ UNIV_INTERN buf_page_t* buf_page_get_zip( /*=============*/ ulint space, /*!< in: space id */ ulint zip_size,/*!< in: compressed page size */ ulint offset);/*!< in: page number */ /********************************************************************//** This is the general function used to get access to a database page. @return pointer to the block or NULL */ UNIV_INTERN buf_block_t* buf_page_get_gen( /*=============*/ ulint space, /*!< in: space id */ ulint zip_size,/*!< in: compressed page size in bytes or 0 for uncompressed pages */ ulint offset, /*!< in: page number */ ulint rw_latch,/*!< in: RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */ buf_block_t* guess, /*!< in: guessed block or NULL */ ulint mode, /*!< in: BUF_GET, BUF_GET_IF_IN_POOL, BUF_GET_NO_LATCH or BUF_GET_IF_IN_POOL_OR_WATCH */ const char* file, /*!< in: file name */ ulint line, /*!< in: line where called */ mtr_t* mtr); /*!< in: mini-transaction */ /********************************************************************//** Initializes a page to the buffer buf_pool. The page is usually not read from a file even if it cannot be found in the buffer buf_pool. This is one of the functions which perform to a block a state transition NOT_USED => FILE_PAGE (the other is buf_page_get_gen). @return pointer to the block, page bufferfixed */ UNIV_INTERN buf_block_t* buf_page_create( /*============*/ ulint space, /*!< in: space id */ ulint offset, /*!< in: offset of the page within space in units of a page */ ulint zip_size,/*!< in: compressed page size, or 0 */ mtr_t* mtr); /*!< in: mini-transaction handle */ #else /* !UNIV_HOTBACKUP */ /********************************************************************//** Inits a page to the buffer buf_pool, for use in ibbackup --restore. */ UNIV_INTERN void buf_page_init_for_backup_restore( /*=============================*/ ulint space, /*!< in: space id */ ulint offset, /*!< in: offset of the page within space in units of a page */ ulint zip_size,/*!< in: compressed page size in bytes or 0 for uncompressed pages */ buf_block_t* block); /*!< in: block to init */ #endif /* !UNIV_HOTBACKUP */ #ifndef UNIV_HOTBACKUP /********************************************************************//** Releases a compressed-only page acquired with buf_page_get_zip(). */ UNIV_INLINE void buf_page_release_zip( /*=================*/ buf_page_t* bpage); /*!< in: buffer block */ /********************************************************************//** Decrements the bufferfix count of a buffer control block and releases a latch, if specified. */ UNIV_INLINE void buf_page_release( /*=============*/ buf_block_t* block, /*!< in: buffer block */ ulint rw_latch); /*!< in: RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */ /********************************************************************//** Moves a page to the start of the buffer pool LRU list. This high-level function can be used to prevent an important page from slipping out of the buffer pool. */ UNIV_INTERN void buf_page_make_young( /*================*/ buf_page_t* bpage); /*!< in: buffer block of a file page */ /********************************************************************//** Returns TRUE if the page can be found in the buffer pool hash table. NOTE that it is possible that the page is not yet read from disk, though. @return TRUE if found in the page hash table */ UNIV_INLINE ibool buf_page_peek( /*==========*/ ulint space, /*!< in: space id */ ulint offset);/*!< in: page number */ /********************************************************************//** Resets the check_index_page_at_flush field of a page if found in the buffer pool. */ UNIV_INTERN void buf_reset_check_index_page_at_flush( /*================================*/ ulint space, /*!< in: space id */ ulint offset);/*!< in: page number */ #ifdef UNIV_DEBUG_FILE_ACCESSES /********************************************************************//** Sets file_page_was_freed TRUE if the page is found in the buffer pool. This function should be called when we free a file page and want the debug version to check that it is not accessed any more unless reallocated. @return control block if found in page hash table, otherwise NULL */ UNIV_INTERN buf_page_t* buf_page_set_file_page_was_freed( /*=============================*/ ulint space, /*!< in: space id */ ulint offset);/*!< in: page number */ /********************************************************************//** Sets file_page_was_freed FALSE if the page is found in the buffer pool. This function should be called when we free a file page and want the debug version to check that it is not accessed any more unless reallocated. @return control block if found in page hash table, otherwise NULL */ UNIV_INTERN buf_page_t* buf_page_reset_file_page_was_freed( /*===============================*/ ulint space, /*!< in: space id */ ulint offset); /*!< in: page number */ #endif /* UNIV_DEBUG_FILE_ACCESSES */ /********************************************************************//** Reads the freed_page_clock of a buffer block. @return freed_page_clock */ UNIV_INLINE ulint buf_page_get_freed_page_clock( /*==========================*/ const buf_page_t* bpage) /*!< in: block */ __attribute__((pure)); /********************************************************************//** Reads the freed_page_clock of a buffer block. @return freed_page_clock */ UNIV_INLINE ulint buf_block_get_freed_page_clock( /*===========================*/ const buf_block_t* block) /*!< in: block */ __attribute__((pure)); /********************************************************************//** Recommends a move of a block to the start of the LRU list if there is danger of dropping from the buffer pool. NOTE: does not reserve the buffer pool mutex. @return TRUE if should be made younger */ UNIV_INLINE ibool buf_page_peek_if_too_old( /*=====================*/ const buf_page_t* bpage); /*!< in: block to make younger */ /********************************************************************//** Returns the current state of is_hashed of a page. FALSE if the page is not in the pool. NOTE that this operation does not fix the page in the pool if it is found there. @return TRUE if page hash index is built in search system */ UNIV_INTERN ibool buf_page_peek_if_search_hashed( /*===========================*/ ulint space, /*!< in: space id */ ulint offset);/*!< in: page number */ /********************************************************************//** Gets the youngest modification log sequence number for a frame. Returns zero if not file page or no modification occurred yet. @return newest modification to page */ UNIV_INLINE ib_uint64_t buf_page_get_newest_modification( /*=============================*/ const buf_page_t* bpage); /*!< in: block containing the page frame */ /********************************************************************//** Increments the modify clock of a frame by 1. The caller must (1) own the buf_pool->mutex and block bufferfix count has to be zero, (2) or own an x-lock on the block. */ UNIV_INLINE void buf_block_modify_clock_inc( /*=======================*/ buf_block_t* block); /*!< in: block */ /********************************************************************//** Returns the value of the modify clock. The caller must have an s-lock or x-lock on the block. @return value */ UNIV_INLINE ib_uint64_t buf_block_get_modify_clock( /*=======================*/ buf_block_t* block); /*!< in: block */ #else /* !UNIV_HOTBACKUP */ # define buf_block_modify_clock_inc(block) ((void) 0) #endif /* !UNIV_HOTBACKUP */ /********************************************************************//** Calculates a page checksum which is stored to the page when it is written to a file. Note that we must be careful to calculate the same value on 32-bit and 64-bit architectures. @return checksum */ UNIV_INTERN ulint buf_calc_page_new_checksum( /*=======================*/ const byte* page); /*!< in: buffer page */ /********************************************************************//** In versions < 4.0.14 and < 4.1.1 there was a bug that the checksum only looked at the first few bytes of the page. This calculates that old checksum. NOTE: we must first store the new formula checksum to FIL_PAGE_SPACE_OR_CHKSUM before calculating and storing this old checksum because this takes that field as an input! @return checksum */ UNIV_INTERN ulint buf_calc_page_old_checksum( /*=======================*/ const byte* page); /*!< in: buffer page */ /********************************************************************//** Checks if a page is corrupt. @return TRUE if corrupted */ UNIV_INTERN ibool buf_page_is_corrupted( /*==================*/ const byte* read_buf, /*!< in: a database page */ ulint zip_size); /*!< in: size of compressed page; 0 for uncompressed pages */ #ifndef UNIV_HOTBACKUP /**********************************************************************//** Gets the space id, page offset, and byte offset within page of a pointer pointing to a buffer frame containing a file page. */ UNIV_INLINE void buf_ptr_get_fsp_addr( /*=================*/ const void* ptr, /*!< in: pointer to a buffer frame */ ulint* space, /*!< out: space id */ fil_addr_t* addr); /*!< out: page offset and byte offset */ /**********************************************************************//** Gets the hash value of a block. This can be used in searches in the lock hash table. @return lock hash value */ UNIV_INLINE ulint buf_block_get_lock_hash_val( /*========================*/ const buf_block_t* block) /*!< in: block */ __attribute__((pure)); #ifdef UNIV_DEBUG /*********************************************************************//** Finds a block in the buffer pool that points to a given compressed page. @return buffer block pointing to the compressed page, or NULL */ UNIV_INTERN buf_block_t* buf_pool_contains_zip( /*==================*/ buf_pool_t* buf_pool, /*!< in: buffer pool instance */ const void* data); /*!< in: pointer to compressed page */ #endif /* UNIV_DEBUG */ #if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG /*********************************************************************//** Validates the buffer pool data structure. @return TRUE */ UNIV_INTERN ibool buf_validate(void); /*==============*/ #endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */ #if defined UNIV_DEBUG_PRINT || defined UNIV_DEBUG || defined UNIV_BUF_DEBUG /*********************************************************************//** Prints info of the buffer pool data structure. */ UNIV_INTERN void buf_print(void); /*============*/ #endif /* UNIV_DEBUG_PRINT || UNIV_DEBUG || UNIV_BUF_DEBUG */ #endif /* !UNIV_HOTBACKUP */ /********************************************************************//** Prints a page to stderr. */ UNIV_INTERN void buf_page_print( /*===========*/ const byte* read_buf, /*!< in: a database page */ ulint zip_size); /*!< in: compressed page size, or 0 for uncompressed pages */ /********************************************************************//** Decompress a block. @return TRUE if successful */ UNIV_INTERN ibool buf_zip_decompress( /*===============*/ buf_block_t* block, /*!< in/out: block */ ibool check); /*!< in: TRUE=verify the page checksum */ #ifndef UNIV_HOTBACKUP #ifdef UNIV_DEBUG /*********************************************************************//** Returns the number of latched pages in the buffer pool. @return number of latched pages */ UNIV_INTERN ulint buf_get_latched_pages_number(void); /*==============================*/ #endif /* UNIV_DEBUG */ /*********************************************************************//** Returns the number of pending buf pool ios. @return number of pending I/O operations */ UNIV_INTERN ulint buf_get_n_pending_ios(void); /*=======================*/ /*********************************************************************//** Prints info of the buffer i/o. */ UNIV_INTERN void buf_print_io( /*=========*/ FILE* file); /*!< in: file where to print */ /*********************************************************************//** Returns the ratio in percents of modified pages in the buffer pool / database pages in the buffer pool. @return modified page percentage ratio */ UNIV_INTERN ulint buf_get_modified_ratio_pct(void); /*============================*/ /**********************************************************************//** Refreshes the statistics used to print per-second averages. */ UNIV_INTERN void buf_refresh_io_stats( /*=================*/ buf_pool_t* buf_pool); /*!< buffer pool instance */ /**********************************************************************//** Refreshes the statistics used to print per-second averages. */ UNIV_INTERN void buf_refresh_io_stats_all(void); /*=================*/ /*********************************************************************//** Asserts that all file pages in the buffer are in a replaceable state. @return TRUE */ UNIV_INTERN ibool buf_all_freed(void); /*===============*/ /*********************************************************************//** Checks that there currently are no pending i/o-operations for the buffer pool. @return TRUE if there is no pending i/o */ UNIV_INTERN ibool buf_pool_check_no_pending_io(void); /*==============================*/ /*********************************************************************//** Invalidates the file pages in the buffer pool when an archive recovery is completed. All the file pages buffered must be in a replaceable state when this function is called: not latched and not modified. */ UNIV_INTERN void buf_pool_invalidate(void); /*=====================*/ #endif /* !UNIV_HOTBACKUP */ /*======================================================================== --------------------------- LOWER LEVEL ROUTINES ------------------------- =========================================================================*/ #ifdef UNIV_SYNC_DEBUG /*********************************************************************//** Adds latch level info for the rw-lock protecting the buffer frame. This should be called in the debug version after a successful latching of a page if we know the latching order level of the acquired latch. */ UNIV_INLINE void buf_block_dbg_add_level( /*====================*/ buf_block_t* block, /*!< in: buffer page where we have acquired latch */ ulint level); /*!< in: latching order level */ #else /* UNIV_SYNC_DEBUG */ # define buf_block_dbg_add_level(block, level) /* nothing */ #endif /* UNIV_SYNC_DEBUG */ /*********************************************************************//** Gets the state of a block. @return state */ UNIV_INLINE enum buf_page_state buf_page_get_state( /*===============*/ const buf_page_t* bpage); /*!< in: pointer to the control block */ /*********************************************************************//** Gets the state of a block. @return state */ UNIV_INLINE enum buf_page_state buf_block_get_state( /*================*/ const buf_block_t* block) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Sets the state of a block. */ UNIV_INLINE void buf_page_set_state( /*===============*/ buf_page_t* bpage, /*!< in/out: pointer to control block */ enum buf_page_state state); /*!< in: state */ /*********************************************************************//** Sets the state of a block. */ UNIV_INLINE void buf_block_set_state( /*================*/ buf_block_t* block, /*!< in/out: pointer to control block */ enum buf_page_state state); /*!< in: state */ /*********************************************************************//** Determines if a block is mapped to a tablespace. @return TRUE if mapped */ UNIV_INLINE ibool buf_page_in_file( /*=============*/ const buf_page_t* bpage) /*!< in: pointer to control block */ __attribute__((pure)); #ifndef UNIV_HOTBACKUP /*********************************************************************//** Determines if a block should be on unzip_LRU list. @return TRUE if block belongs to unzip_LRU */ UNIV_INLINE ibool buf_page_belongs_to_unzip_LRU( /*==========================*/ const buf_page_t* bpage) /*!< in: pointer to control block */ __attribute__((pure)); /*********************************************************************//** Gets the mutex of a block. @return pointer to mutex protecting bpage */ UNIV_INLINE mutex_t* buf_page_get_mutex( /*===============*/ const buf_page_t* bpage) /*!< in: pointer to control block */ __attribute__((pure)); /*********************************************************************//** Get the flush type of a page. @return flush type */ UNIV_INLINE enum buf_flush buf_page_get_flush_type( /*====================*/ const buf_page_t* bpage) /*!< in: buffer page */ __attribute__((pure)); /*********************************************************************//** Set the flush type of a page. */ UNIV_INLINE void buf_page_set_flush_type( /*====================*/ buf_page_t* bpage, /*!< in: buffer page */ enum buf_flush flush_type); /*!< in: flush type */ /*********************************************************************//** Map a block to a file page. */ UNIV_INLINE void buf_block_set_file_page( /*====================*/ buf_block_t* block, /*!< in/out: pointer to control block */ ulint space, /*!< in: tablespace id */ ulint page_no);/*!< in: page number */ /*********************************************************************//** Gets the io_fix state of a block. @return io_fix state */ UNIV_INLINE enum buf_io_fix buf_page_get_io_fix( /*================*/ const buf_page_t* bpage) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the io_fix state of a block. @return io_fix state */ UNIV_INLINE enum buf_io_fix buf_block_get_io_fix( /*================*/ const buf_block_t* block) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Sets the io_fix state of a block. */ UNIV_INLINE void buf_page_set_io_fix( /*================*/ buf_page_t* bpage, /*!< in/out: control block */ enum buf_io_fix io_fix);/*!< in: io_fix state */ /*********************************************************************//** Sets the io_fix state of a block. */ UNIV_INLINE void buf_block_set_io_fix( /*=================*/ buf_block_t* block, /*!< in/out: control block */ enum buf_io_fix io_fix);/*!< in: io_fix state */ /********************************************************************//** Determine if a buffer block can be relocated in memory. The block can be dirty, but it must not be I/O-fixed or bufferfixed. */ UNIV_INLINE ibool buf_page_can_relocate( /*==================*/ const buf_page_t* bpage) /*!< control block being relocated */ __attribute__((pure)); /*********************************************************************//** Determine if a block has been flagged old. @return TRUE if old */ UNIV_INLINE ibool buf_page_is_old( /*============*/ const buf_page_t* bpage) /*!< in: control block */ __attribute__((pure)); /*********************************************************************//** Flag a block old. */ UNIV_INLINE void buf_page_set_old( /*=============*/ buf_page_t* bpage, /*!< in/out: control block */ ibool old); /*!< in: old */ /*********************************************************************//** Determine the time of first access of a block in the buffer pool. @return ut_time_ms() at the time of first access, 0 if not accessed */ UNIV_INLINE unsigned buf_page_is_accessed( /*=================*/ const buf_page_t* bpage) /*!< in: control block */ __attribute__((nonnull, pure)); /*********************************************************************//** Flag a block accessed. */ UNIV_INLINE void buf_page_set_accessed( /*==================*/ buf_page_t* bpage, /*!< in/out: control block */ ulint time_ms) /*!< in: ut_time_ms() */ __attribute__((nonnull)); /*********************************************************************//** Gets the buf_block_t handle of a buffered file block if an uncompressed page frame exists, or NULL. @return control block, or NULL */ UNIV_INLINE buf_block_t* buf_page_get_block( /*===============*/ buf_page_t* bpage) /*!< in: control block, or NULL */ __attribute__((pure)); #endif /* !UNIV_HOTBACKUP */ #ifdef UNIV_DEBUG /*********************************************************************//** Gets a pointer to the memory frame of a block. @return pointer to the frame */ UNIV_INLINE buf_frame_t* buf_block_get_frame( /*================*/ const buf_block_t* block) /*!< in: pointer to the control block */ __attribute__((pure)); #else /* UNIV_DEBUG */ # define buf_block_get_frame(block) (block)->frame #endif /* UNIV_DEBUG */ /*********************************************************************//** Gets the space id of a block. @return space id */ UNIV_INLINE ulint buf_page_get_space( /*===============*/ const buf_page_t* bpage) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the space id of a block. @return space id */ UNIV_INLINE ulint buf_block_get_space( /*================*/ const buf_block_t* block) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the page number of a block. @return page number */ UNIV_INLINE ulint buf_page_get_page_no( /*=================*/ const buf_page_t* bpage) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the page number of a block. @return page number */ UNIV_INLINE ulint buf_block_get_page_no( /*==================*/ const buf_block_t* block) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the compressed page size of a block. @return compressed page size, or 0 */ UNIV_INLINE ulint buf_page_get_zip_size( /*==================*/ const buf_page_t* bpage) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the compressed page size of a block. @return compressed page size, or 0 */ UNIV_INLINE ulint buf_block_get_zip_size( /*===================*/ const buf_block_t* block) /*!< in: pointer to the control block */ __attribute__((pure)); /*********************************************************************//** Gets the compressed page descriptor corresponding to an uncompressed page if applicable. */ #define buf_block_get_page_zip(block) \ (UNIV_LIKELY_NULL((block)->page.zip.data) ? &(block)->page.zip : NULL) #ifndef UNIV_HOTBACKUP /*******************************************************************//** Gets the block to whose frame the pointer is pointing to. @return pointer to block, never NULL */ UNIV_INTERN buf_block_t* buf_block_align( /*============*/ const byte* ptr); /*!< in: pointer to a frame */ /********************************************************************//** Find out if a pointer belongs to a buf_block_t. It can be a pointer to the buf_block_t itself or a member of it @return TRUE if ptr belongs to a buf_block_t struct */ UNIV_INTERN ibool buf_pointer_is_block_field( /*=======================*/ const void* ptr); /*!< in: pointer not dereferenced */ /** Find out if a pointer corresponds to a buf_block_t::mutex. @param m in: mutex candidate @return TRUE if m is a buf_block_t::mutex */ #define buf_pool_is_block_mutex(m) \ buf_pointer_is_block_field((const void*)(m)) /** Find out if a pointer corresponds to a buf_block_t::lock. @param l in: rw-lock candidate @return TRUE if l is a buf_block_t::lock */ #define buf_pool_is_block_lock(l) \ buf_pointer_is_block_field((const void*)(l)) #if defined UNIV_DEBUG || defined UNIV_ZIP_DEBUG /*********************************************************************//** Gets the compressed page descriptor corresponding to an uncompressed page if applicable. @return compressed page descriptor, or NULL */ UNIV_INLINE const page_zip_des_t* buf_frame_get_page_zip( /*===================*/ const byte* ptr); /*!< in: pointer to the page */ #endif /* UNIV_DEBUG || UNIV_ZIP_DEBUG */ /********************************************************************//** Function which inits a page for read to the buffer buf_pool. If the page is (1) already in buf_pool, or (2) if we specify to read only ibuf pages and the page is not an ibuf page, or (3) if the space is deleted or being deleted, then this function does nothing. Sets the io_fix flag to BUF_IO_READ and sets a non-recursive exclusive lock on the buffer frame. The io-handler must take care that the flag is cleared and the lock released later. @return pointer to the block or NULL */ UNIV_INTERN buf_page_t* buf_page_init_for_read( /*===================*/ ulint* err, /*!< out: DB_SUCCESS or DB_TABLESPACE_DELETED */ ulint mode, /*!< in: BUF_READ_IBUF_PAGES_ONLY, ... */ ulint space, /*!< in: space id */ ulint zip_size,/*!< in: compressed page size, or 0 */ ibool unzip, /*!< in: TRUE=request uncompressed page */ ib_int64_t tablespace_version,/*!< in: prevents reading from a wrong version of the tablespace in case we have done DISCARD + IMPORT */ ulint offset);/*!< in: page number */ /********************************************************************//** Completes an asynchronous read or write request of a file page to or from the buffer pool. */ UNIV_INTERN void buf_page_io_complete( /*=================*/ buf_page_t* bpage); /*!< in: pointer to the block in question */ /********************************************************************//** Calculates a folded value of a file page address to use in the page hash table. @return the folded value */ UNIV_INLINE ulint buf_page_address_fold( /*==================*/ ulint space, /*!< in: space id */ ulint offset) /*!< in: offset of the page within space */ __attribute__((const)); /******************************************************************//** Returns the buffer pool instance given a page instance @return buf_pool */ UNIV_INLINE buf_pool_t* buf_pool_from_bpage( /*================*/ const buf_page_t* bpage); /*!< in: buffer pool page */ /******************************************************************//** Returns the buffer pool instance given a block instance @return buf_pool */ UNIV_INLINE buf_pool_t* buf_pool_from_block( /*================*/ const buf_block_t* block); /*!< in: block */ /******************************************************************//** Returns the buffer pool instance given space and offset of page @return buffer pool */ UNIV_INLINE buf_pool_t* buf_pool_get( /*==========*/ ulint space, /*!< in: space id */ ulint offset);/*!< in: offset of the page within space */ /******************************************************************//** Returns the buffer pool instance given its array index @return buffer pool */ UNIV_INLINE buf_pool_t* buf_pool_from_array( /*====================*/ ulint index); /*!< in: array index to get buffer pool instance from */ /******************************************************************//** Returns the control block of a file page, NULL if not found. @return block, NULL if not found */ UNIV_INLINE buf_page_t* buf_page_hash_get_low( /*==================*/ buf_pool_t* buf_pool, /*!< buffer pool instance */ ulint space, /*!< in: space id */ ulint offset, /*!< in: offset of the page within space */ ulint fold); /*!< in: buf_page_address_fold( space, offset) */ /******************************************************************//** Returns the control block of a file page, NULL if not found. @return block, NULL if not found or not a real control block */ UNIV_INLINE buf_page_t* buf_page_hash_get( /*==============*/ buf_pool_t* buf_pool, /*!< in: buffer pool instance */ ulint space, /*!< in: space id */ ulint offset); /*!< in: offset of the page within space */ /******************************************************************//** Returns the control block of a file page, NULL if not found or an uncompressed page frame does not exist. @return block, NULL if not found */ UNIV_INLINE buf_block_t* buf_block_hash_get( /*===============*/ buf_pool_t* buf_pool, /*!< in: buffer pool instance */ ulint space, /*!< in: space id */ ulint offset); /*!< in: offset of the page within space */ /*********************************************************************//** Gets the current length of the free list of buffer blocks. @return length of the free list */ UNIV_INTERN ulint buf_get_free_list_len(void); /*=======================*/ /******************************************************************** Determine if a block is a sentinel for a buffer pool watch. @return TRUE if a sentinel for a buffer pool watch, FALSE if not */ UNIV_INTERN ibool buf_pool_watch_is_sentinel( /*=======================*/ buf_pool_t* buf_pool, /*!< buffer pool instance */ const buf_page_t* bpage) /*!< in: block */ __attribute__((nonnull, warn_unused_result)); /****************************************************************//** Add watch for the given page to be read in. Caller must have the buffer pool @return NULL if watch set, block if the page is in the buffer pool */ UNIV_INTERN buf_page_t* buf_pool_watch_set( /*===============*/ ulint space, /*!< in: space id */ ulint offset, /*!< in: page number */ ulint fold) /*!< in: buf_page_address_fold(space, offset) */ __attribute__((warn_unused_result)); /****************************************************************//** Stop watching if the page has been read in. buf_pool_watch_set(space,offset) must have returned NULL before. */ UNIV_INTERN void buf_pool_watch_unset( /*=================*/ ulint space, /*!< in: space id */ ulint offset);/*!< in: page number */ /****************************************************************//** Check if the page has been read in. This may only be called after buf_pool_watch_set(space,offset) has returned NULL and before invoking buf_pool_watch_unset(space,offset). @return FALSE if the given page was not read in, TRUE if it was */ UNIV_INTERN ibool buf_pool_watch_occurred( /*====================*/ ulint space, /*!< in: space id */ ulint offset) /*!< in: page number */ __attribute__((warn_unused_result)); /********************************************************************//** Get total buffer pool statistics. */ UNIV_INTERN void buf_get_total_list_len( /*===================*/ ulint* LRU_len, /*!< out: length of all LRU lists */ ulint* free_len, /*!< out: length of all free lists */ ulint* flush_list_len);/*!< out: length of all flush lists */ /********************************************************************//** Get total buffer pool statistics. */ UNIV_INTERN void buf_get_total_stat( /*===============*/ buf_pool_stat_t*tot_stat); /*!< out: buffer pool stats */ #endif /* !UNIV_HOTBACKUP */ /** The common buffer control block structure for compressed and uncompressed frames */ struct buf_page_struct{ /** @name General fields None of these bit-fields must be modified without holding buf_page_get_mutex() [buf_block_struct::mutex or buf_pool->zip_mutex], since they can be stored in the same machine word. Some of these fields are additionally protected by buf_pool->mutex. */ /* @{ */ unsigned space:32; /*!< tablespace id; also protected by buf_pool->mutex. */ unsigned offset:32; /*!< page number; also protected by buf_pool->mutex. */ unsigned state:3; /*!< state of the control block; also protected by buf_pool->mutex. State transitions from BUF_BLOCK_READY_FOR_USE to BUF_BLOCK_MEMORY need not be protected by buf_page_get_mutex(). @see enum buf_page_state */ #ifndef UNIV_HOTBACKUP unsigned flush_type:2; /*!< if this block is currently being flushed to disk, this tells the flush_type. @see enum buf_flush */ unsigned io_fix:2; /*!< type of pending I/O operation; also protected by buf_pool->mutex @see enum buf_io_fix */ unsigned buf_fix_count:25;/*!< count of how manyfold this block is currently bufferfixed */ /* @} */ #endif /* !UNIV_HOTBACKUP */ page_zip_des_t zip; /*!< compressed page; zip.data (but not the data it points to) is also protected by buf_pool_mutex; state == BUF_BLOCK_ZIP_PAGE and zip.data == NULL means an active buf_pool_watch */ #ifndef UNIV_HOTBACKUP buf_page_t* hash; /*!< node used in chaining to buf_pool->page_hash or buf_pool->zip_hash */ #ifdef UNIV_DEBUG ibool in_page_hash; /*!< TRUE if in buf_pool->page_hash */ ibool in_zip_hash; /*!< TRUE if in buf_pool->zip_hash */ #endif /* UNIV_DEBUG */ /** @name Page flushing fields All these are protected by buf_pool_mutex. */ /* @{ */ UT_LIST_NODE_T(buf_page_t) list; /*!< based on state, this is a list node, protected either by buf_pool_mutex or by flush_list_mutex, in one of the following lists in buf_pool: - BUF_BLOCK_NOT_USED: free - BUF_BLOCK_FILE_PAGE: flush_list - BUF_BLOCK_ZIP_DIRTY: flush_list - BUF_BLOCK_ZIP_PAGE: zip_clean - BUF_BLOCK_ZIP_FREE: zip_free[] If bpage is part of flush_list then the node pointers are covered by flush_list_mutex. Otherwise these pointers are protected by buf_pool_mutex. The contents of the list node is undefined if !in_flush_list && state == BUF_BLOCK_FILE_PAGE, or if state is one of BUF_BLOCK_MEMORY, BUF_BLOCK_REMOVE_HASH or BUF_BLOCK_READY_IN_USE. */ #ifdef UNIV_DEBUG ibool in_flush_list; /*!< TRUE if in buf_pool->flush_list; when flush_list_mutex is free, the following should hold: in_flush_list == (state == BUF_BLOCK_FILE_PAGE || state == BUF_BLOCK_ZIP_DIRTY) Writes to this field must be covered by both block->mutex and flush_list_mutex. Hence reads can happen while holding any one of the two mutexes */ ibool in_free_list; /*!< TRUE if in buf_pool->free; when buf_pool_mutex is free, the following should hold: in_free_list == (state == BUF_BLOCK_NOT_USED) */ #endif /* UNIV_DEBUG */ ib_uint64_t newest_modification; /*!< log sequence number of the youngest modification to this block, zero if not modified. Protected by block mutex */ ib_uint64_t oldest_modification; /*!< log sequence number of the START of the log entry written of the oldest modification to this block which has not yet been flushed on disk; zero if all modifications are on disk. Writes to this field must be covered by both block->mutex and flush_list_mutex. Hence reads can happen while holding any one of the two mutexes */ /* @} */ /** @name LRU replacement algorithm fields These fields are protected by buf_pool->mutex only (not buf_pool->zip_mutex or buf_block_struct::mutex). */ /* @{ */ UT_LIST_NODE_T(buf_page_t) LRU; /*!< node of the LRU list */ #ifdef UNIV_DEBUG ibool in_LRU_list; /*!< TRUE if the page is in the LRU list; used in debugging */ #endif /* UNIV_DEBUG */ unsigned old:1; /*!< TRUE if the block is in the old blocks in buf_pool->LRU_old */ unsigned freed_page_clock:31;/*!< the value of buf_pool->freed_page_clock when this block was the last time put to the head of the LRU list; a thread is allowed to read this for heuristic purposes without holding any mutex or latch */ unsigned access_time:32; /*!< time of first access, or 0 if the block was never accessed in the buffer pool */ /* @} */ # ifdef UNIV_DEBUG_FILE_ACCESSES ibool file_page_was_freed; /*!< this is set to TRUE when fsp frees a page in buffer pool */ # endif /* UNIV_DEBUG_FILE_ACCESSES */ #endif /* !UNIV_HOTBACKUP */ buf_pool_t* buf_pool; /*!< buffer pool instance this page belongs to */ }; /** The buffer control block structure */ struct buf_block_struct{ /** @name General fields */ /* @{ */ buf_page_t page; /*!< page information; this must be the first field, so that buf_pool->page_hash can point to buf_page_t or buf_block_t */ byte* frame; /*!< pointer to buffer frame which is of size UNIV_PAGE_SIZE, and aligned to an address divisible by UNIV_PAGE_SIZE */ #ifndef UNIV_HOTBACKUP UT_LIST_NODE_T(buf_block_t) unzip_LRU; /*!< node of the decompressed LRU list; a block is in the unzip_LRU list if page.state == BUF_BLOCK_FILE_PAGE and page.zip.data != NULL */ #ifdef UNIV_DEBUG ibool in_unzip_LRU_list;/*!< TRUE if the page is in the decompressed LRU list; used in debugging */ #endif /* UNIV_DEBUG */ mutex_t mutex; /*!< mutex protecting this block: state (also protected by the buffer pool mutex), io_fix, buf_fix_count, and accessed; we introduce this new mutex in InnoDB-5.1 to relieve contention on the buffer pool mutex */ rw_lock_t lock; /*!< read-write lock of the buffer frame */ unsigned lock_hash_val:32;/*!< hashed value of the page address in the record lock hash table; protected by buf_block_t::lock (or buf_block_t::mutex, buf_pool->mutex in buf_page_get_gen(), buf_page_init_for_read() and buf_page_create()) */ ibool check_index_page_at_flush; /*!< TRUE if we know that this is an index page, and want the database to check its consistency before flush; note that there may be pages in the buffer pool which are index pages, but this flag is not set because we do not keep track of all pages; NOT protected by any mutex */ /* @} */ /** @name Optimistic search field */ /* @{ */ ib_uint64_t modify_clock; /*!< this clock is incremented every time a pointer to a record on the page may become obsolete; this is used in the optimistic cursor positioning: if the modify clock has not changed, we know that the pointer is still valid; this field may be changed if the thread (1) owns the pool mutex and the page is not bufferfixed, or (2) the thread has an x-latch on the block */ /* @} */ /** @name Hash search fields (unprotected) NOTE that these fields are NOT protected by any semaphore! */ /* @{ */ ulint n_hash_helps; /*!< counter which controls building of a new hash index for the page */ ulint n_fields; /*!< recommended prefix length for hash search: number of full fields */ ulint n_bytes; /*!< recommended prefix: number of bytes in an incomplete field */ ibool left_side; /*!< TRUE or FALSE, depending on whether the leftmost record of several records with the same prefix should be indexed in the hash index */ /* @} */ /** @name Hash search fields These 6 fields may only be modified when we have an x-latch on btr_search_latch AND - we are holding an s-latch or x-latch on buf_block_struct::lock or - we know that buf_block_struct::buf_fix_count == 0. An exception to this is when we init or create a page in the buffer pool in buf0buf.c. */ /* @{ */ #if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG ulint n_pointers; /*!< used in debugging: the number of pointers in the adaptive hash index pointing to this frame */ #endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */ unsigned is_hashed:1; /*!< TRUE if hash index has already been built on this page; note that it does not guarantee that the index is complete, though: there may have been hash collisions, record deletions, etc. */ unsigned curr_n_fields:10;/*!< prefix length for hash indexing: number of full fields */ unsigned curr_n_bytes:15;/*!< number of bytes in hash indexing */ unsigned curr_left_side:1;/*!< TRUE or FALSE in hash indexing */ dict_index_t* index; /*!< Index for which the adaptive hash index has been created. */ /* @} */ # ifdef UNIV_SYNC_DEBUG /** @name Debug fields */ /* @{ */ rw_lock_t debug_latch; /*!< in the debug version, each thread which bufferfixes the block acquires an s-latch here; so we can use the debug utilities in sync0rw */ /* @} */ # endif #endif /* !UNIV_HOTBACKUP */ }; /** Check if a buf_block_t object is in a valid state @param block buffer block @return TRUE if valid */ #define buf_block_state_valid(block) \ (buf_block_get_state(block) >= BUF_BLOCK_NOT_USED \ && (buf_block_get_state(block) <= BUF_BLOCK_REMOVE_HASH)) #ifndef UNIV_HOTBACKUP /**********************************************************************//** Compute the hash fold value for blocks in buf_pool->zip_hash. */ /* @{ */ #define BUF_POOL_ZIP_FOLD_PTR(ptr) ((ulint) (ptr) / UNIV_PAGE_SIZE) #define BUF_POOL_ZIP_FOLD(b) BUF_POOL_ZIP_FOLD_PTR((b)->frame) #define BUF_POOL_ZIP_FOLD_BPAGE(b) BUF_POOL_ZIP_FOLD((buf_block_t*) (b)) /* @} */ /** @brief The buffer pool statistics structure. */ struct buf_pool_stat_struct{ ulint n_page_gets; /*!< number of page gets performed; also successful searches through the adaptive hash index are counted as page gets; this field is NOT protected by the buffer pool mutex */ ulint n_pages_read; /*!< number read operations */ ulint n_pages_written;/*!< number write operations */ ulint n_pages_created;/*!< number of pages created in the pool with no read */ ulint n_ra_pages_read;/*!< number of pages read in as part of read ahead */ ulint n_ra_pages_evicted;/*!< number of read ahead pages that are evicted without being accessed */ ulint n_pages_made_young; /*!< number of pages made young, in calls to buf_LRU_make_block_young() */ ulint n_pages_not_made_young; /*!< number of pages not made young because the first access was not long enough ago, in buf_page_peek_if_too_old() */ }; /** Statistics of buddy blocks of a given size. */ struct buf_buddy_stat_struct { /** Number of blocks allocated from the buddy system. */ ulint used; /** Number of blocks relocated by the buddy system. */ ib_uint64_t relocated; /** Total duration of block relocations, in microseconds. */ ib_uint64_t relocated_usec; }; /** @brief The buffer pool structure. NOTE! The definition appears here only for other modules of this directory (buf) to see it. Do not use from outside! */ struct buf_pool_struct{ /** @name General fields */ /* @{ */ mutex_t mutex; /*!< Buffer pool mutex of this instance */ mutex_t zip_mutex; /*!< Zip mutex of this buffer pool instance, protects compressed only pages (of type buf_page_t, not buf_block_t */ ulint instance_no; /*!< Array index of this buffer pool instance */ ulint old_pool_size; /*!< Old pool size in bytes */ ulint curr_pool_size; /*!< Current pool size in bytes */ ulint LRU_old_ratio; /*!< Reserve this much of the buffer pool for "old" blocks */ #ifdef UNIV_DEBUG ulint buddy_n_frames; /*!< Number of frames allocated from the buffer pool to the buddy system */ #endif #if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG ulint mutex_exit_forbidden; /*!< Forbid release mutex */ #endif ulint n_chunks; /*!< number of buffer pool chunks */ buf_chunk_t* chunks; /*!< buffer pool chunks */ ulint curr_size; /*!< current pool size in pages */ hash_table_t* page_hash; /*!< hash table of buf_page_t or buf_block_t file pages, buf_page_in_file() == TRUE, indexed by (space_id, offset) */ hash_table_t* zip_hash; /*!< hash table of buf_block_t blocks whose frames are allocated to the zip buddy system, indexed by block->frame */ ulint n_pend_reads; /*!< number of pending read operations */ ulint n_pend_unzip; /*!< number of pending decompressions */ time_t last_printout_time; /*!< when buf_print_io was last time called */ buf_buddy_stat_t buddy_stat[BUF_BUDDY_SIZES + 1]; /*!< Statistics of buddy system, indexed by block size */ buf_pool_stat_t stat; /*!< current statistics */ buf_pool_stat_t old_stat; /*!< old statistics */ /* @} */ /** @name Page flushing algorithm fields */ /* @{ */ mutex_t flush_list_mutex;/*!< mutex protecting the flush list access. This mutex protects flush_list, flush_rbt and bpage::list pointers when the bpage is on flush_list. It also protects writes to bpage::oldest_modification */ UT_LIST_BASE_NODE_T(buf_page_t) flush_list; /*!< base node of the modified block list */ ibool init_flush[BUF_FLUSH_N_TYPES]; /*!< this is TRUE when a flush of the given type is being initialized */ ulint n_flush[BUF_FLUSH_N_TYPES]; /*!< this is the number of pending writes in the given flush type */ os_event_t no_flush[BUF_FLUSH_N_TYPES]; /*!< this is in the set state when there is no flush batch of the given type running */ ib_rbt_t* flush_rbt; /*!< a red-black tree is used exclusively during recovery to speed up insertions in the flush_list. This tree contains blocks in order of oldest_modification LSN and is kept in sync with the flush_list. Each member of the tree MUST also be on the flush_list. This tree is relevant only in recovery and is set to NULL once the recovery is over. Protected by flush_list_mutex */ ulint freed_page_clock;/*!< a sequence number used to count the number of buffer blocks removed from the end of the LRU list; NOTE that this counter may wrap around at 4 billion! A thread is allowed to read this for heuristic purposes without holding any mutex or latch */ ulint LRU_flush_ended;/*!< when an LRU flush ends for a page, this is incremented by one; this is set to zero when a buffer block is allocated */ /* @} */ /** @name LRU replacement algorithm fields */ /* @{ */ UT_LIST_BASE_NODE_T(buf_page_t) free; /*!< base node of the free block list */ UT_LIST_BASE_NODE_T(buf_page_t) LRU; /*!< base node of the LRU list */ buf_page_t* LRU_old; /*!< pointer to the about buf_LRU_old_ratio/BUF_LRU_OLD_RATIO_DIV oldest blocks in the LRU list; NULL if LRU length less than BUF_LRU_OLD_MIN_LEN; NOTE: when LRU_old != NULL, its length should always equal LRU_old_len */ ulint LRU_old_len; /*!< length of the LRU list from the block to which LRU_old points onward, including that block; see buf0lru.c for the restrictions on this value; 0 if LRU_old == NULL; NOTE: LRU_old_len must be adjusted whenever LRU_old shrinks or grows! */ UT_LIST_BASE_NODE_T(buf_block_t) unzip_LRU; /*!< base node of the unzip_LRU list */ /* @} */ /** @name Buddy allocator fields The buddy allocator is used for allocating compressed page frames and buf_page_t descriptors of blocks that exist in the buffer pool only in compressed form. */ /* @{ */ UT_LIST_BASE_NODE_T(buf_page_t) zip_clean; /*!< unmodified compressed pages */ UT_LIST_BASE_NODE_T(buf_page_t) zip_free[BUF_BUDDY_SIZES]; /*!< buddy free lists */ buf_page_t watch[BUF_POOL_WATCH_SIZE]; /*!< Sentinel records for buffer pool watches. Protected by buf_pool->mutex. */ #if BUF_BUDDY_HIGH != UNIV_PAGE_SIZE # error "BUF_BUDDY_HIGH != UNIV_PAGE_SIZE" #endif #if BUF_BUDDY_LOW > PAGE_ZIP_MIN_SIZE # error "BUF_BUDDY_LOW > PAGE_ZIP_MIN_SIZE" #endif /* @} */ }; /** mutex protecting the buffer pool struct and control blocks, except the read-write lock in them */ extern mutex_t buf_pool_mutex; /** mutex protecting the control blocks of compressed-only pages (of type buf_page_t, not buf_block_t) */ extern mutex_t buf_pool_zip_mutex; /** @name Accessors for buf_pool_mutex. Use these instead of accessing buf_pool_mutex directly. */ /* @{ */ /** Test if buf_pool_mutex is owned. */ #define buf_pool_mutex_own(b) mutex_own(&b->mutex) /** Acquire the buffer pool mutex. */ #define buf_pool_mutex_enter(b) do { \ ut_ad(!mutex_own(&b->zip_mutex)); \ mutex_enter(&b->mutex); \ } while (0) /** Test if flush list mutex is owned. */ #define buf_flush_list_mutex_own(b) mutex_own(&b->flush_list_mutex) /** Acquire the flush list mutex. */ #define buf_flush_list_mutex_enter(b) do { \ mutex_enter(&b->flush_list_mutex); \ } while (0) /** Release the flush list mutex. */ # define buf_flush_list_mutex_exit(b) do { \ mutex_exit(&b->flush_list_mutex); \ } while (0) #if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG /** Forbid the release of the buffer pool mutex. */ # define buf_pool_mutex_exit_forbid(b) do { \ ut_ad(buf_pool_mutex_own(b)); \ b->mutex_exit_forbidden++; \ } while (0) /** Allow the release of the buffer pool mutex. */ # define buf_pool_mutex_exit_allow(b) do { \ ut_ad(buf_pool_mutex_own(b)); \ ut_a(b->mutex_exit_forbidden); \ b->mutex_exit_forbidden--; \ } while (0) /** Release the buffer pool mutex. */ # define buf_pool_mutex_exit(b) do { \ ut_a(!b->mutex_exit_forbidden); \ mutex_exit(&b->mutex); \ } while (0) #else /** Forbid the release of the buffer pool mutex. */ # define buf_pool_mutex_exit_forbid(b) ((void) 0) /** Allow the release of the buffer pool mutex. */ # define buf_pool_mutex_exit_allow(b) ((void) 0) /** Release the buffer pool mutex. */ # define buf_pool_mutex_exit(b) mutex_exit(&b->mutex) #endif #endif /* !UNIV_HOTBACKUP */ /* @} */ /********************************************************************** Let us list the consistency conditions for different control block states. NOT_USED: is in free list, not in LRU list, not in flush list, nor page hash table READY_FOR_USE: is not in free list, LRU list, or flush list, nor page hash table MEMORY: is not in free list, LRU list, or flush list, nor page hash table FILE_PAGE: space and offset are defined, is in page hash table if io_fix == BUF_IO_WRITE, pool: no_flush[flush_type] is in reset state, pool: n_flush[flush_type] > 0 (1) if buf_fix_count == 0, then is in LRU list, not in free list is in flush list, if and only if oldest_modification > 0 is x-locked, if and only if io_fix == BUF_IO_READ is s-locked, if and only if io_fix == BUF_IO_WRITE (2) if buf_fix_count > 0, then is not in LRU list, not in free list is in flush list, if and only if oldest_modification > 0 if io_fix == BUF_IO_READ, is x-locked if io_fix == BUF_IO_WRITE, is s-locked State transitions: NOT_USED => READY_FOR_USE READY_FOR_USE => MEMORY READY_FOR_USE => FILE_PAGE MEMORY => NOT_USED FILE_PAGE => NOT_USED NOTE: This transition is allowed if and only if (1) buf_fix_count == 0, (2) oldest_modification == 0, and (3) io_fix == 0. */ #ifndef UNIV_NONINL #include "buf0buf.ic" #endif #endif