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by brian
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/* Innobase relational database engine; Copyright (C) 2001 Innobase Oy
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License 2
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as published by the Free Software Foundation in June 1991.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License 2
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along with this program (in file COPYING); if not, write to the Free
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Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/******************************************************
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The database buffer pool high-level routines
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(c) 1995 Innobase Oy
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Created 11/5/1995 Heikki Tuuri
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*******************************************************/
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#ifndef buf0buf_h
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#define buf0buf_h
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#include "univ.i" |
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#include "fil0fil.h" |
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#include "mtr0types.h" |
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#include "buf0types.h" |
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#include "sync0rw.h" |
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#include "hash0hash.h" |
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#include "ut0byte.h" |
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#include "os0proc.h" |
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/* Flags for flush types */
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#define BUF_FLUSH_LRU 1
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#define BUF_FLUSH_SINGLE_PAGE 2
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#define BUF_FLUSH_LIST 3 /* An array in the pool struct |
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has size BUF_FLUSH_LIST + 1: if you
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add more flush types, put them in
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the middle! */
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/* Modes for buf_page_get_gen */
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#define BUF_GET 10 /* get always */ |
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#define BUF_GET_IF_IN_POOL 11 /* get if in pool */ |
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#define BUF_GET_NOWAIT 12 /* get if can set the latch without |
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waiting */
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#define BUF_GET_NO_LATCH 14 /* get and bufferfix, but set no latch; |
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we have separated this case, because
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it is error-prone programming not to
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set a latch, and it should be used
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with care */
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/* Modes for buf_page_get_known_nowait */
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#define BUF_MAKE_YOUNG 51
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#define BUF_KEEP_OLD 52
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/* Magic value to use instead of checksums when they are disabled */
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#define BUF_NO_CHECKSUM_MAGIC 0xDEADBEEFUL
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extern buf_pool_t* buf_pool; /* The buffer pool of the database */ |
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#ifdef UNIV_DEBUG
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extern ibool buf_debug_prints;/* If this is set TRUE, the program |
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prints info whenever read or flush
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occurs */
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#endif /* UNIV_DEBUG */ |
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extern ulint srv_buf_pool_write_requests; /* variable to count write request |
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issued */
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/************************************************************************
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Creates the buffer pool. */
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buf_pool_t* |
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buf_pool_init( |
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/*==========*/
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/* out, own: buf_pool object, NULL if not
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enough memory or error */
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ulint max_size, /* in: maximum size of the buf_pool in |
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blocks */
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ulint curr_size, /* in: current size to use, must be <= |
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max_size, currently must be equal to
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max_size */
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ulint n_frames); /* in: number of frames; if AWE is used, |
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this is the size of the address space window
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where physical memory pages are mapped; if
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AWE is not used then this must be the same
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as max_size */
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/*************************************************************************
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Gets the current size of buffer buf_pool in bytes. In the case of AWE, the
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size of AWE window (= the frames). */
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UNIV_INLINE
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ulint
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buf_pool_get_curr_size(void); |
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/*========================*/
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/* out: size in bytes */
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/*************************************************************************
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Gets the maximum size of buffer pool in bytes. In the case of AWE, the
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size of AWE window (= the frames). */
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UNIV_INLINE
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ulint
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buf_pool_get_max_size(void); |
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/*=======================*/
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/* out: size in bytes */
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/************************************************************************
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Gets the smallest oldest_modification lsn for any page in the pool. Returns
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ut_dulint_zero if all modified pages have been flushed to disk. */
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UNIV_INLINE
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dulint
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buf_pool_get_oldest_modification(void); |
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/*==================================*/
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/* out: oldest modification in pool,
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ut_dulint_zero if none */
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/*************************************************************************
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Allocates a buffer frame. */
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buf_frame_t* |
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buf_frame_alloc(void); |
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/*==================*/
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/* out: buffer frame */
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/*************************************************************************
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Frees a buffer frame which does not contain a file page. */
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void
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buf_frame_free( |
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/*===========*/
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buf_frame_t* frame); /* in: buffer frame */ |
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/*************************************************************************
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Copies contents of a buffer frame to a given buffer. */
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UNIV_INLINE
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byte* |
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buf_frame_copy( |
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/*===========*/
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/* out: buf */
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byte* buf, /* in: buffer to copy to */ |
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buf_frame_t* frame); /* in: buffer frame */ |
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/******************************************************************
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NOTE! The following macros should be used instead of buf_page_get_gen,
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to improve debugging. Only values RW_S_LATCH and RW_X_LATCH are allowed
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in LA! */
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#define buf_page_get(SP, OF, LA, MTR) buf_page_get_gen(\
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SP, OF, LA, NULL,\
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BUF_GET, __FILE__, __LINE__, MTR)
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/******************************************************************
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Use these macros to bufferfix a page with no latching. Remember not to
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read the contents of the page unless you know it is safe. Do not modify
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the contents of the page! We have separated this case, because it is
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error-prone programming not to set a latch, and it should be used
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with care. */
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#define buf_page_get_with_no_latch(SP, OF, MTR) buf_page_get_gen(\
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SP, OF, RW_NO_LATCH, NULL,\
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BUF_GET_NO_LATCH, __FILE__, __LINE__, MTR)
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/******************************************************************
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NOTE! The following macros should be used instead of buf_page_get_gen, to
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improve debugging. Only values RW_S_LATCH and RW_X_LATCH are allowed as LA! */
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#define buf_page_get_nowait(SP, OF, LA, MTR) buf_page_get_gen(\
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SP, OF, LA, NULL,\
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BUF_GET_NOWAIT, __FILE__, __LINE__, MTR)
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/******************************************************************
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NOTE! The following macros should be used instead of
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buf_page_optimistic_get_func, to improve debugging. Only values RW_S_LATCH and
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RW_X_LATCH are allowed as LA! */
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#define buf_page_optimistic_get(LA, BL, G, MC, MTR) \
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buf_page_optimistic_get_func(LA, BL, G, MC, __FILE__, __LINE__, MTR)
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/************************************************************************
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This is the general function used to get optimistic access to a database
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page. */
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ibool
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buf_page_optimistic_get_func( |
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/*=========================*/
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/* out: TRUE if success */
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ulint rw_latch,/* in: RW_S_LATCH, RW_X_LATCH */ |
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buf_block_t* block, /* in: guessed block */ |
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buf_frame_t* guess, /* in: guessed frame; note that AWE may move |
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frames */
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dulint modify_clock,/* in: modify clock value if mode is |
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..._GUESS_ON_CLOCK */
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const char* file, /* in: file name */ |
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ulint line, /* in: line where called */ |
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mtr_t* mtr); /* in: mini-transaction */ |
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/************************************************************************
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Tries to get the page, but if file io is required, releases all latches
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in mtr down to the given savepoint. If io is required, this function
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retrieves the page to buffer buf_pool, but does not bufferfix it or latch
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it. */
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UNIV_INLINE
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buf_frame_t* |
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buf_page_get_release_on_io( |
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/*=======================*/
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/* out: pointer to the frame, or NULL
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if not in buffer buf_pool */
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ulint space, /* in: space id */ |
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ulint offset, /* in: offset of the page within space |
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in units of a page */
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buf_frame_t* guess, /* in: guessed frame or NULL */ |
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ulint rw_latch, /* in: RW_X_LATCH, RW_S_LATCH, |
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or RW_NO_LATCH */
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ulint savepoint, /* in: mtr savepoint */ |
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mtr_t* mtr); /* in: mtr */ |
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/************************************************************************
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This is used to get access to a known database page, when no waiting can be
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done. */
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ibool
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buf_page_get_known_nowait( |
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/*======================*/
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/* out: TRUE if success */
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ulint rw_latch,/* in: RW_S_LATCH, RW_X_LATCH */ |
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buf_frame_t* guess, /* in: the known page frame */ |
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ulint mode, /* in: BUF_MAKE_YOUNG or BUF_KEEP_OLD */ |
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const char* file, /* in: file name */ |
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ulint line, /* in: line where called */ |
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mtr_t* mtr); /* in: mini-transaction */ |
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/************************************************************************
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This is the general function used to get access to a database page. */
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buf_frame_t* |
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buf_page_get_gen( |
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/*=============*/
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/* out: pointer to the frame or NULL */
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ulint space, /* in: space id */ |
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ulint offset, /* in: page number */ |
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ulint rw_latch,/* in: RW_S_LATCH, RW_X_LATCH, RW_NO_LATCH */ |
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buf_frame_t* guess, /* in: guessed frame or NULL */ |
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ulint mode, /* in: BUF_GET, BUF_GET_IF_IN_POOL, |
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BUF_GET_NO_LATCH */
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const char* file, /* in: file name */ |
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ulint line, /* in: line where called */ |
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mtr_t* mtr); /* in: mini-transaction */ |
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/************************************************************************
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Initializes a page to the buffer buf_pool. The page is usually not read
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from a file even if it cannot be found in the buffer buf_pool. This is one
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of the functions which perform to a block a state transition NOT_USED =>
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FILE_PAGE (the other is buf_page_init_for_read above). */
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buf_frame_t* |
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buf_page_create( |
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/*============*/
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/* out: pointer to the frame, page bufferfixed */
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ulint space, /* in: space id */ |
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ulint offset, /* in: offset of the page within space in units of |
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a page */
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mtr_t* mtr); /* in: mini-transaction handle */ |
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/************************************************************************
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Inits a page to the buffer buf_pool, for use in ibbackup --restore. */
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void
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buf_page_init_for_backup_restore( |
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/*=============================*/
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ulint space, /* in: space id */ |
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ulint offset, /* in: offset of the page within space |
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in units of a page */
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buf_block_t* block); /* in: block to init */ |
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/************************************************************************
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Decrements the bufferfix count of a buffer control block and releases
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a latch, if specified. */
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UNIV_INLINE
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void
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buf_page_release( |
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/*=============*/
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buf_block_t* block, /* in: buffer block */ |
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ulint rw_latch, /* in: RW_S_LATCH, RW_X_LATCH, |
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RW_NO_LATCH */
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mtr_t* mtr); /* in: mtr */ |
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/************************************************************************
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Moves a page to the start of the buffer pool LRU list. This high-level
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function can be used to prevent an important page from from slipping out of
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the buffer pool. */
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void
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buf_page_make_young( |
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/*================*/
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buf_frame_t* frame); /* in: buffer frame of a file page */ |
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/************************************************************************
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Returns TRUE if the page can be found in the buffer pool hash table. NOTE
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that it is possible that the page is not yet read from disk, though. */
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ibool
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buf_page_peek( |
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/*==========*/
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/* out: TRUE if found from page hash table,
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NOTE that the page is not necessarily yet read
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from disk! */
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ulint space, /* in: space id */ |
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ulint offset);/* in: page number */ |
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/************************************************************************
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Returns the buffer control block if the page can be found in the buffer
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pool. NOTE that it is possible that the page is not yet read
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from disk, though. This is a very low-level function: use with care! */
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buf_block_t* |
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buf_page_peek_block( |
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/*================*/
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/* out: control block if found from page hash table,
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otherwise NULL; NOTE that the page is not necessarily
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yet read from disk! */
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ulint space, /* in: space id */ |
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ulint offset);/* in: page number */ |
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/************************************************************************
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Resets the check_index_page_at_flush field of a page if found in the buffer
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pool. */
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void
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buf_reset_check_index_page_at_flush( |
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/*================================*/
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ulint space, /* in: space id */ |
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ulint offset);/* in: page number */ |
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/************************************************************************
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Sets file_page_was_freed TRUE if the page is found in the buffer pool.
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This function should be called when we free a file page and want the
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debug version to check that it is not accessed any more unless
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reallocated. */
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buf_block_t* |
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buf_page_set_file_page_was_freed( |
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/*=============================*/
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/* out: control block if found from page hash table,
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otherwise NULL */
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ulint space, /* in: space id */ |
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ulint offset); /* in: page number */ |
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/************************************************************************
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Sets file_page_was_freed FALSE if the page is found in the buffer pool.
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This function should be called when we free a file page and want the
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debug version to check that it is not accessed any more unless
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reallocated. */
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buf_block_t* |
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buf_page_reset_file_page_was_freed( |
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/*===============================*/
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/* out: control block if found from page hash table,
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otherwise NULL */
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ulint space, /* in: space id */ |
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ulint offset); /* in: page number */ |
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/************************************************************************
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Recommends a move of a block to the start of the LRU list if there is danger
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of dropping from the buffer pool. NOTE: does not reserve the buffer pool
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mutex. */
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UNIV_INLINE
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ibool
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buf_block_peek_if_too_old( |
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/*======================*/
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/* out: TRUE if should be made younger */
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buf_block_t* block); /* in: block to make younger */ |
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/************************************************************************
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Returns the current state of is_hashed of a page. FALSE if the page is
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not in the pool. NOTE that this operation does not fix the page in the
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pool if it is found there. */
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ibool
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buf_page_peek_if_search_hashed( |
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/*===========================*/
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/* out: TRUE if page hash index is built in search
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system */
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ulint space, /* in: space id */ |
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ulint offset);/* in: page number */ |
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/************************************************************************
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Gets the youngest modification log sequence number for a frame.
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Returns zero if not file page or no modification occurred yet. */
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UNIV_INLINE
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dulint
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358 |
buf_frame_get_newest_modification( |
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359 |
/*==============================*/
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360 |
/* out: newest modification to page */
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buf_frame_t* frame); /* in: pointer to a frame */ |
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362 |
/************************************************************************
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363 |
Increments the modify clock of a frame by 1. The caller must (1) own the
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364 |
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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366 |
UNIV_INLINE
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367 |
dulint
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368 |
buf_frame_modify_clock_inc( |
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369 |
/*=======================*/
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370 |
/* out: new value */
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371 |
buf_frame_t* frame); /* in: pointer to a frame */ |
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372 |
/************************************************************************
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373 |
Increments the modify clock of a frame by 1. The caller must (1) own the
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374 |
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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376 |
UNIV_INLINE
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377 |
dulint
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378 |
buf_block_modify_clock_inc( |
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379 |
/*=======================*/
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380 |
/* out: new value */
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381 |
buf_block_t* block); /* in: block */ |
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382 |
/************************************************************************
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383 |
Returns the value of the modify clock. The caller must have an s-lock
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384 |
or x-lock on the block. */
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385 |
UNIV_INLINE
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386 |
dulint
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387 |
buf_block_get_modify_clock( |
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388 |
/*=======================*/
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389 |
/* out: value */
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390 |
buf_block_t* block); /* in: block */ |
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391 |
/************************************************************************
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392 |
Calculates a page checksum which is stored to the page when it is written
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393 |
to a file. Note that we must be careful to calculate the same value
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394 |
on 32-bit and 64-bit architectures. */
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395 |
||
396 |
ulint
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397 |
buf_calc_page_new_checksum( |
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398 |
/*=======================*/
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399 |
/* out: checksum */
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400 |
byte* page); /* in: buffer page */ |
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401 |
/************************************************************************
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|
402 |
In versions < 4.0.14 and < 4.1.1 there was a bug that the checksum only
|
|
403 |
looked at the first few bytes of the page. This calculates that old
|
|
404 |
checksum.
|
|
405 |
NOTE: we must first store the new formula checksum to
|
|
406 |
FIL_PAGE_SPACE_OR_CHKSUM before calculating and storing this old checksum
|
|
407 |
because this takes that field as an input! */
|
|
408 |
||
409 |
ulint
|
|
410 |
buf_calc_page_old_checksum( |
|
411 |
/*=======================*/
|
|
412 |
/* out: checksum */
|
|
413 |
byte* page); /* in: buffer page */ |
|
414 |
/************************************************************************
|
|
415 |
Checks if a page is corrupt. */
|
|
416 |
||
417 |
ibool
|
|
418 |
buf_page_is_corrupted( |
|
419 |
/*==================*/
|
|
420 |
/* out: TRUE if corrupted */
|
|
421 |
byte* read_buf); /* in: a database page */ |
|
422 |
/**************************************************************************
|
|
423 |
Gets the page number of a pointer pointing within a buffer frame containing
|
|
424 |
a file page. */
|
|
425 |
UNIV_INLINE
|
|
426 |
ulint
|
|
427 |
buf_frame_get_page_no( |
|
428 |
/*==================*/
|
|
429 |
/* out: page number */
|
|
430 |
byte* ptr); /* in: pointer to within a buffer frame */ |
|
431 |
/**************************************************************************
|
|
432 |
Gets the space id of a pointer pointing within a buffer frame containing a
|
|
433 |
file page. */
|
|
434 |
UNIV_INLINE
|
|
435 |
ulint
|
|
436 |
buf_frame_get_space_id( |
|
437 |
/*===================*/
|
|
438 |
/* out: space id */
|
|
439 |
byte* ptr); /* in: pointer to within a buffer frame */ |
|
440 |
/**************************************************************************
|
|
441 |
Gets the space id, page offset, and byte offset within page of a
|
|
442 |
pointer pointing to a buffer frame containing a file page. */
|
|
443 |
UNIV_INLINE
|
|
444 |
void
|
|
445 |
buf_ptr_get_fsp_addr( |
|
446 |
/*=================*/
|
|
447 |
byte* ptr, /* in: pointer to a buffer frame */ |
|
448 |
ulint* space, /* out: space id */ |
|
449 |
fil_addr_t* addr); /* out: page offset and byte offset */ |
|
450 |
/**************************************************************************
|
|
451 |
Gets the hash value of the page the pointer is pointing to. This can be used
|
|
452 |
in searches in the lock hash table. */
|
|
453 |
UNIV_INLINE
|
|
454 |
ulint
|
|
455 |
buf_frame_get_lock_hash_val( |
|
456 |
/*========================*/
|
|
457 |
/* out: lock hash value */
|
|
458 |
byte* ptr); /* in: pointer to within a buffer frame */ |
|
459 |
/**************************************************************************
|
|
460 |
Gets the mutex number protecting the page record lock hash chain in the lock
|
|
461 |
table. */
|
|
462 |
UNIV_INLINE
|
|
463 |
mutex_t* |
|
464 |
buf_frame_get_mutex( |
|
465 |
/*================*/
|
|
466 |
/* out: mutex */
|
|
467 |
byte* ptr); /* in: pointer to within a buffer frame */ |
|
468 |
/***********************************************************************
|
|
469 |
Gets the frame the pointer is pointing to. */
|
|
470 |
UNIV_INLINE
|
|
471 |
buf_frame_t* |
|
472 |
buf_frame_align( |
|
473 |
/*============*/
|
|
474 |
/* out: pointer to frame */
|
|
475 |
byte* ptr); /* in: pointer to a frame */ |
|
476 |
/***********************************************************************
|
|
477 |
Checks if a pointer points to the block array of the buffer pool (blocks, not
|
|
478 |
the frames). */
|
|
479 |
UNIV_INLINE
|
|
480 |
ibool
|
|
481 |
buf_pool_is_block( |
|
482 |
/*==============*/
|
|
483 |
/* out: TRUE if pointer to block */
|
|
484 |
void* ptr); /* in: pointer to memory */ |
|
485 |
#ifdef UNIV_DEBUG
|
|
486 |
/*************************************************************************
|
|
487 |
Validates the buffer pool data structure. */
|
|
488 |
||
489 |
ibool
|
|
490 |
buf_validate(void); |
|
491 |
/*==============*/
|
|
492 |
/*************************************************************************
|
|
493 |
Prints info of the buffer pool data structure. */
|
|
494 |
||
495 |
void
|
|
496 |
buf_print(void); |
|
497 |
/*============*/
|
|
498 |
#endif /* UNIV_DEBUG */ |
|
499 |
/************************************************************************
|
|
500 |
Prints a page to stderr. */
|
|
501 |
||
502 |
void
|
|
503 |
buf_page_print( |
|
504 |
/*===========*/
|
|
505 |
byte* read_buf); /* in: a database page */ |
|
506 |
/*************************************************************************
|
|
507 |
Returns the number of latched pages in the buffer pool. */
|
|
508 |
||
509 |
ulint
|
|
510 |
buf_get_latched_pages_number(void); |
|
511 |
/*==============================*/
|
|
512 |
/*************************************************************************
|
|
513 |
Returns the number of pending buf pool ios. */
|
|
514 |
||
515 |
ulint
|
|
516 |
buf_get_n_pending_ios(void); |
|
517 |
/*=======================*/
|
|
518 |
/*************************************************************************
|
|
519 |
Prints info of the buffer i/o. */
|
|
520 |
||
521 |
void
|
|
522 |
buf_print_io( |
|
523 |
/*=========*/
|
|
524 |
FILE* file); /* in: file where to print */ |
|
525 |
/*************************************************************************
|
|
526 |
Returns the ratio in percents of modified pages in the buffer pool /
|
|
527 |
database pages in the buffer pool. */
|
|
528 |
||
529 |
ulint
|
|
530 |
buf_get_modified_ratio_pct(void); |
|
531 |
/*============================*/
|
|
532 |
/**************************************************************************
|
|
533 |
Refreshes the statistics used to print per-second averages. */
|
|
534 |
||
535 |
void
|
|
536 |
buf_refresh_io_stats(void); |
|
537 |
/*======================*/
|
|
538 |
/*************************************************************************
|
|
539 |
Checks that all file pages in the buffer are in a replaceable state. */
|
|
540 |
||
541 |
ibool
|
|
542 |
buf_all_freed(void); |
|
543 |
/*===============*/
|
|
544 |
/*************************************************************************
|
|
545 |
Checks that there currently are no pending i/o-operations for the buffer
|
|
546 |
pool. */
|
|
547 |
||
548 |
ibool
|
|
549 |
buf_pool_check_no_pending_io(void); |
|
550 |
/*==============================*/
|
|
551 |
/* out: TRUE if there is no pending i/o */
|
|
552 |
/*************************************************************************
|
|
553 |
Invalidates the file pages in the buffer pool when an archive recovery is
|
|
554 |
completed. All the file pages buffered must be in a replaceable state when
|
|
555 |
this function is called: not latched and not modified. */
|
|
556 |
||
557 |
void
|
|
558 |
buf_pool_invalidate(void); |
|
559 |
/*=====================*/
|
|
560 |
||
561 |
/*========================================================================
|
|
562 |
--------------------------- LOWER LEVEL ROUTINES -------------------------
|
|
563 |
=========================================================================*/
|
|
564 |
||
565 |
/************************************************************************
|
|
566 |
Maps the page of block to a frame, if not mapped yet. Unmaps some page
|
|
567 |
from the end of the awe_LRU_free_mapped. */
|
|
568 |
||
569 |
void
|
|
570 |
buf_awe_map_page_to_frame( |
|
571 |
/*======================*/
|
|
572 |
buf_block_t* block, /* in: block whose page should be |
|
573 |
mapped to a frame */
|
|
574 |
ibool add_to_mapped_list);/* in: TRUE if we in the case |
|
575 |
we need to map the page should also
|
|
576 |
add the block to the
|
|
577 |
awe_LRU_free_mapped list */
|
|
578 |
#ifdef UNIV_SYNC_DEBUG
|
|
579 |
/*************************************************************************
|
|
580 |
Adds latch level info for the rw-lock protecting the buffer frame. This
|
|
581 |
should be called in the debug version after a successful latching of a
|
|
582 |
page if we know the latching order level of the acquired latch. */
|
|
583 |
UNIV_INLINE
|
|
584 |
void
|
|
585 |
buf_page_dbg_add_level( |
|
586 |
/*===================*/
|
|
587 |
buf_frame_t* frame, /* in: buffer page where we have acquired |
|
588 |
a latch */
|
|
589 |
ulint level); /* in: latching order level */ |
|
590 |
#endif /* UNIV_SYNC_DEBUG */ |
|
591 |
/*************************************************************************
|
|
592 |
Gets a pointer to the memory frame of a block. */
|
|
593 |
UNIV_INLINE
|
|
594 |
buf_frame_t* |
|
595 |
buf_block_get_frame( |
|
596 |
/*================*/
|
|
597 |
/* out: pointer to the frame */
|
|
598 |
buf_block_t* block); /* in: pointer to the control block */ |
|
599 |
/*************************************************************************
|
|
600 |
Gets the space id of a block. */
|
|
601 |
UNIV_INLINE
|
|
602 |
ulint
|
|
603 |
buf_block_get_space( |
|
604 |
/*================*/
|
|
605 |
/* out: space id */
|
|
606 |
buf_block_t* block); /* in: pointer to the control block */ |
|
607 |
/*************************************************************************
|
|
608 |
Gets the page number of a block. */
|
|
609 |
UNIV_INLINE
|
|
610 |
ulint
|
|
611 |
buf_block_get_page_no( |
|
612 |
/*==================*/
|
|
613 |
/* out: page number */
|
|
614 |
buf_block_t* block); /* in: pointer to the control block */ |
|
615 |
/***********************************************************************
|
|
616 |
Gets the block to whose frame the pointer is pointing to. */
|
|
617 |
UNIV_INLINE
|
|
618 |
buf_block_t* |
|
619 |
buf_block_align( |
|
620 |
/*============*/
|
|
621 |
/* out: pointer to block */
|
|
622 |
byte* ptr); /* in: pointer to a frame */ |
|
623 |
/************************************************************************
|
|
624 |
This function is used to get info if there is an io operation
|
|
625 |
going on on a buffer page. */
|
|
626 |
UNIV_INLINE
|
|
627 |
ibool
|
|
628 |
buf_page_io_query( |
|
629 |
/*==============*/
|
|
630 |
/* out: TRUE if io going on */
|
|
631 |
buf_block_t* block); /* in: pool block, must be bufferfixed */ |
|
632 |
/***********************************************************************
|
|
633 |
Accessor function for block array. */
|
|
634 |
UNIV_INLINE
|
|
635 |
buf_block_t* |
|
636 |
buf_pool_get_nth_block( |
|
637 |
/*===================*/
|
|
638 |
/* out: pointer to block */
|
|
639 |
buf_pool_t* pool, /* in: pool */ |
|
640 |
ulint i); /* in: index of the block */ |
|
641 |
/************************************************************************
|
|
642 |
Function which inits a page for read to the buffer buf_pool. If the page is
|
|
643 |
(1) already in buf_pool, or
|
|
644 |
(2) if we specify to read only ibuf pages and the page is not an ibuf page, or
|
|
645 |
(3) if the space is deleted or being deleted,
|
|
646 |
then this function does nothing.
|
|
647 |
Sets the io_fix flag to BUF_IO_READ and sets a non-recursive exclusive lock
|
|
648 |
on the buffer frame. The io-handler must take care that the flag is cleared
|
|
649 |
and the lock released later. This is one of the functions which perform the
|
|
650 |
state transition NOT_USED => FILE_PAGE to a block (the other is
|
|
651 |
buf_page_create). */
|
|
652 |
||
653 |
buf_block_t* |
|
654 |
buf_page_init_for_read( |
|
655 |
/*===================*/
|
|
656 |
/* out: pointer to the block or NULL */
|
|
657 |
ulint* err, /* out: DB_SUCCESS or DB_TABLESPACE_DELETED */ |
|
658 |
ulint mode, /* in: BUF_READ_IBUF_PAGES_ONLY, ... */ |
|
659 |
ulint space, /* in: space id */ |
|
660 |
ib_longlong tablespace_version,/* in: prevents reading from a wrong |
|
661 |
version of the tablespace in case we have done
|
|
662 |
DISCARD + IMPORT */
|
|
663 |
ulint offset);/* in: page number */ |
|
664 |
/************************************************************************
|
|
665 |
Completes an asynchronous read or write request of a file page to or from
|
|
666 |
the buffer pool. */
|
|
667 |
||
668 |
void
|
|
669 |
buf_page_io_complete( |
|
670 |
/*=================*/
|
|
671 |
buf_block_t* block); /* in: pointer to the block in question */ |
|
672 |
/************************************************************************
|
|
673 |
Calculates a folded value of a file page address to use in the page hash
|
|
674 |
table. */
|
|
675 |
UNIV_INLINE
|
|
676 |
ulint
|
|
677 |
buf_page_address_fold( |
|
678 |
/*==================*/
|
|
679 |
/* out: the folded value */
|
|
680 |
ulint space, /* in: space id */ |
|
681 |
ulint offset);/* in: offset of the page within space */ |
|
682 |
/**********************************************************************
|
|
683 |
Returns the control block of a file page, NULL if not found. */
|
|
684 |
UNIV_INLINE
|
|
685 |
buf_block_t* |
|
686 |
buf_page_hash_get( |
|
687 |
/*==============*/
|
|
688 |
/* out: block, NULL if not found */
|
|
689 |
ulint space, /* in: space id */ |
|
690 |
ulint offset);/* in: offset of the page within space */ |
|
691 |
/***********************************************************************
|
|
692 |
Increments the pool clock by one and returns its new value. Remember that
|
|
693 |
in the 32 bit version the clock wraps around at 4 billion! */
|
|
694 |
UNIV_INLINE
|
|
695 |
ulint
|
|
696 |
buf_pool_clock_tic(void); |
|
697 |
/*====================*/
|
|
698 |
/* out: new clock value */
|
|
699 |
/*************************************************************************
|
|
700 |
Gets the current length of the free list of buffer blocks. */
|
|
701 |
||
702 |
ulint
|
|
703 |
buf_get_free_list_len(void); |
|
704 |
/*=======================*/
|
|
705 |
||
706 |
||
707 |
||
708 |
/* The buffer control block structure */
|
|
709 |
||
710 |
struct buf_block_struct{ |
|
711 |
||
712 |
/* 1. General fields */
|
|
713 |
||
714 |
ulint magic_n; /* magic number to check */ |
|
715 |
ulint state; /* state of the control block: |
|
716 |
BUF_BLOCK_NOT_USED, ...; changing
|
|
717 |
this is only allowed when a thread
|
|
718 |
has BOTH the buffer pool mutex AND
|
|
719 |
block->mutex locked */
|
|
720 |
byte* frame; /* pointer to buffer frame which |
|
721 |
is of size UNIV_PAGE_SIZE, and
|
|
722 |
aligned to an address divisible by
|
|
723 |
UNIV_PAGE_SIZE; if AWE is used, this
|
|
724 |
will be NULL for the pages which are
|
|
725 |
currently not mapped into the virtual
|
|
726 |
address space window of the buffer
|
|
727 |
pool */
|
|
728 |
os_awe_t* awe_info; /* if AWE is used, then an array of |
|
729 |
awe page infos for
|
|
730 |
UNIV_PAGE_SIZE / OS_AWE_X86_PAGE_SIZE
|
|
731 |
(normally = 4) physical memory
|
|
732 |
pages; otherwise NULL */
|
|
733 |
ulint space; /* space id of the page */ |
|
734 |
ulint offset; /* page number within the space */ |
|
735 |
ulint lock_hash_val; /* hashed value of the page address |
|
736 |
in the record lock hash table */
|
|
737 |
mutex_t mutex; /* mutex protecting this block: |
|
738 |
state (also protected by the buffer
|
|
739 |
pool mutex), io_fix, buf_fix_count,
|
|
740 |
and accessed; we introduce this new
|
|
741 |
mutex in InnoDB-5.1 to relieve
|
|
742 |
contention on the buffer pool mutex */
|
|
743 |
rw_lock_t lock; /* read-write lock of the buffer |
|
744 |
frame */
|
|
745 |
buf_block_t* hash; /* node used in chaining to the page |
|
746 |
hash table */
|
|
747 |
ibool check_index_page_at_flush; |
|
748 |
/* TRUE if we know that this is
|
|
749 |
an index page, and want the database
|
|
750 |
to check its consistency before flush;
|
|
751 |
note that there may be pages in the
|
|
752 |
buffer pool which are index pages,
|
|
753 |
but this flag is not set because
|
|
754 |
we do not keep track of all pages */
|
|
755 |
/* 2. Page flushing fields */
|
|
756 |
||
757 |
UT_LIST_NODE_T(buf_block_t) flush_list; |
|
758 |
/* node of the modified, not yet
|
|
759 |
flushed blocks list */
|
|
760 |
dulint newest_modification; |
|
761 |
/* log sequence number of the youngest
|
|
762 |
modification to this block, zero if
|
|
763 |
not modified */
|
|
764 |
dulint oldest_modification; |
|
765 |
/* log sequence number of the START of
|
|
766 |
the log entry written of the oldest
|
|
767 |
modification to this block which has
|
|
768 |
not yet been flushed on disk; zero if
|
|
769 |
all modifications are on disk */
|
|
770 |
ulint flush_type; /* if this block is currently being |
|
771 |
flushed to disk, this tells the
|
|
772 |
flush_type: BUF_FLUSH_LRU or
|
|
773 |
BUF_FLUSH_LIST */
|
|
774 |
||
775 |
/* 3. LRU replacement algorithm fields */
|
|
776 |
||
777 |
UT_LIST_NODE_T(buf_block_t) free; |
|
778 |
/* node of the free block list */
|
|
779 |
ibool in_free_list; /* TRUE if in the free list; used in |
|
780 |
debugging */
|
|
781 |
UT_LIST_NODE_T(buf_block_t) LRU; |
|
782 |
/* node of the LRU list */
|
|
783 |
UT_LIST_NODE_T(buf_block_t) awe_LRU_free_mapped; |
|
784 |
/* in the AWE version node in the
|
|
785 |
list of free and LRU blocks which are
|
|
786 |
mapped to a frame */
|
|
787 |
ibool in_LRU_list; /* TRUE of the page is in the LRU list; |
|
788 |
used in debugging */
|
|
789 |
ulint LRU_position; /* value which monotonically |
|
790 |
decreases (or may stay constant if
|
|
791 |
the block is in the old blocks) toward
|
|
792 |
the end of the LRU list, if the pool
|
|
793 |
ulint_clock has not wrapped around:
|
|
794 |
NOTE that this value can only be used
|
|
795 |
in heuristic algorithms, because of
|
|
796 |
the possibility of a wrap-around! */
|
|
797 |
ulint freed_page_clock;/* the value of freed_page_clock |
|
798 |
of the buffer pool when this block was
|
|
799 |
the last time put to the head of the
|
|
800 |
LRU list; a thread is allowed to
|
|
801 |
read this for heuristic purposes
|
|
802 |
without holding any mutex or latch */
|
|
803 |
ibool old; /* TRUE if the block is in the old |
|
804 |
blocks in the LRU list */
|
|
805 |
ibool accessed; /* TRUE if the page has been accessed |
|
806 |
while in the buffer pool: read-ahead
|
|
807 |
may read in pages which have not been
|
|
808 |
accessed yet; this is protected by
|
|
809 |
block->mutex; a thread is allowed to
|
|
810 |
read this for heuristic purposes
|
|
811 |
without holding any mutex or latch */
|
|
812 |
ulint buf_fix_count; /* count of how manyfold this block |
|
813 |
is currently bufferfixed; this is
|
|
814 |
protected by block->mutex */
|
|
815 |
ulint io_fix; /* if a read is pending to the frame, |
|
816 |
io_fix is BUF_IO_READ, in the case
|
|
817 |
of a write BUF_IO_WRITE, otherwise 0;
|
|
818 |
this is protected by block->mutex */
|
|
819 |
/* 4. Optimistic search field */
|
|
820 |
||
821 |
dulint modify_clock; /* this clock is incremented every |
|
822 |
time a pointer to a record on the
|
|
823 |
page may become obsolete; this is
|
|
824 |
used in the optimistic cursor
|
|
825 |
positioning: if the modify clock has
|
|
826 |
not changed, we know that the pointer
|
|
827 |
is still valid; this field may be
|
|
828 |
changed if the thread (1) owns the
|
|
829 |
pool mutex and the page is not
|
|
830 |
bufferfixed, or (2) the thread has an
|
|
831 |
x-latch on the block */
|
|
832 |
||
833 |
/* 5. Hash search fields: NOTE that the first 4 fields are NOT
|
|
834 |
protected by any semaphore! */
|
|
835 |
||
836 |
ulint n_hash_helps; /* counter which controls building |
|
837 |
of a new hash index for the page */
|
|
838 |
ulint n_fields; /* recommended prefix length for hash |
|
839 |
search: number of full fields */
|
|
840 |
ulint n_bytes; /* recommended prefix: number of bytes |
|
841 |
in an incomplete field */
|
|
842 |
ibool left_side; /* TRUE or FALSE, depending on |
|
843 |
whether the leftmost record of several
|
|
844 |
records with the same prefix should be
|
|
845 |
indexed in the hash index */
|
|
846 |
||
847 |
/* These 6 fields may only be modified when we have
|
|
848 |
an x-latch on btr_search_latch AND
|
|
849 |
a) we are holding an s-latch or x-latch on block->lock or
|
|
850 |
b) we know that block->buf_fix_count == 0.
|
|
851 |
||
852 |
An exception to this is when we init or create a page
|
|
853 |
in the buffer pool in buf0buf.c. */
|
|
854 |
||
855 |
ibool is_hashed; /* TRUE if hash index has already been |
|
856 |
built on this page; note that it does
|
|
857 |
not guarantee that the index is
|
|
858 |
complete, though: there may have been
|
|
859 |
hash collisions, record deletions,
|
|
860 |
etc. */
|
|
861 |
ulint n_pointers; /* used in debugging: the number of |
|
862 |
pointers in the adaptive hash index
|
|
863 |
pointing to this frame */
|
|
864 |
ulint curr_n_fields; /* prefix length for hash indexing: |
|
865 |
number of full fields */
|
|
866 |
ulint curr_n_bytes; /* number of bytes in hash indexing */ |
|
867 |
ibool curr_left_side; /* TRUE or FALSE in hash indexing */ |
|
868 |
dict_index_t* index; /* Index for which the adaptive |
|
869 |
hash index has been created. */
|
|
870 |
/* 6. Debug fields */
|
|
871 |
#ifdef UNIV_SYNC_DEBUG
|
|
872 |
rw_lock_t debug_latch; /* in the debug version, each thread |
|
873 |
which bufferfixes the block acquires
|
|
874 |
an s-latch here; so we can use the
|
|
875 |
debug utilities in sync0rw */
|
|
876 |
#endif
|
|
877 |
ibool file_page_was_freed; |
|
878 |
/* this is set to TRUE when fsp
|
|
879 |
frees a page in buffer pool */
|
|
880 |
};
|
|
881 |
||
882 |
#define BUF_BLOCK_MAGIC_N 41526563
|
|
883 |
||
884 |
/* The buffer pool structure. NOTE! The definition appears here only for
|
|
885 |
other modules of this directory (buf) to see it. Do not use from outside! */
|
|
886 |
||
887 |
struct buf_pool_struct{ |
|
888 |
||
889 |
/* 1. General fields */
|
|
890 |
||
891 |
mutex_t mutex; /* mutex protecting the buffer pool |
|
892 |
struct and control blocks, except the
|
|
893 |
read-write lock in them */
|
|
894 |
byte* frame_mem; /* pointer to the memory area which |
|
895 |
was allocated for the frames; in AWE
|
|
896 |
this is the virtual address space
|
|
897 |
window where we map pages stored
|
|
898 |
in physical memory */
|
|
899 |
byte* frame_zero; /* pointer to the first buffer frame: |
|
900 |
this may differ from frame_mem, because
|
|
901 |
this is aligned by the frame size */
|
|
902 |
byte* high_end; /* pointer to the end of the buffer |
|
903 |
frames */
|
|
904 |
ulint n_frames; /* number of frames */ |
|
905 |
buf_block_t* blocks; /* array of buffer control blocks */ |
|
906 |
buf_block_t** blocks_of_frames;/* inverse mapping which can be used |
|
907 |
to retrieve the buffer control block
|
|
908 |
of a frame; this is an array which
|
|
909 |
lists the blocks of frames in the
|
|
910 |
order frame_zero,
|
|
911 |
frame_zero + UNIV_PAGE_SIZE, ...
|
|
912 |
a control block is always assigned
|
|
913 |
for each frame, even if the frame does
|
|
914 |
not contain any data; note that in AWE
|
|
915 |
there are more control blocks than
|
|
916 |
buffer frames */
|
|
917 |
os_awe_t* awe_info; /* if AWE is used, AWE info for the |
|
918 |
physical 4 kB memory pages associated
|
|
919 |
with buffer frames */
|
|
920 |
ulint max_size; /* number of control blocks == |
|
921 |
maximum pool size in pages */
|
|
922 |
ulint curr_size; /* current pool size in pages; |
|
923 |
currently always the same as
|
|
924 |
max_size */
|
|
925 |
hash_table_t* page_hash; /* hash table of the file pages */ |
|
926 |
||
927 |
ulint n_pend_reads; /* number of pending read operations */ |
|
928 |
||
929 |
time_t last_printout_time; /* when buf_print was last time |
|
930 |
called */
|
|
931 |
ulint n_pages_read; /* number read operations */ |
|
932 |
ulint n_pages_written;/* number write operations */ |
|
933 |
ulint n_pages_created;/* number of pages created in the pool |
|
934 |
with no read */
|
|
935 |
ulint n_page_gets; /* number of page gets performed; |
|
936 |
also successful searches through
|
|
937 |
the adaptive hash index are
|
|
938 |
counted as page gets; this field
|
|
939 |
is NOT protected by the buffer
|
|
940 |
pool mutex */
|
|
941 |
ulint n_pages_awe_remapped; /* if AWE is enabled, the |
|
942 |
number of remaps of blocks to
|
|
943 |
buffer frames */
|
|
944 |
ulint n_page_gets_old;/* n_page_gets when buf_print was |
|
945 |
last time called: used to calculate
|
|
946 |
hit rate */
|
|
947 |
ulint n_pages_read_old;/* n_pages_read when buf_print was |
|
948 |
last time called */
|
|
949 |
ulint n_pages_written_old;/* number write operations */ |
|
950 |
ulint n_pages_created_old;/* number of pages created in |
|
951 |
the pool with no read */
|
|
952 |
ulint n_pages_awe_remapped_old; |
|
953 |
/* 2. Page flushing algorithm fields */
|
|
954 |
||
955 |
UT_LIST_BASE_NODE_T(buf_block_t) flush_list; |
|
956 |
/* base node of the modified block
|
|
957 |
list */
|
|
958 |
ibool init_flush[BUF_FLUSH_LIST + 1]; |
|
959 |
/* this is TRUE when a flush of the
|
|
960 |
given type is being initialized */
|
|
961 |
ulint n_flush[BUF_FLUSH_LIST + 1]; |
|
962 |
/* this is the number of pending
|
|
963 |
writes in the given flush type */
|
|
964 |
os_event_t no_flush[BUF_FLUSH_LIST + 1]; |
|
965 |
/* this is in the set state when there
|
|
966 |
is no flush batch of the given type
|
|
967 |
running */
|
|
968 |
ulint ulint_clock; /* a sequence number used to count |
|
969 |
time. NOTE! This counter wraps
|
|
970 |
around at 4 billion (if ulint ==
|
|
971 |
32 bits)! */
|
|
972 |
ulint freed_page_clock;/* a sequence number used to count the |
|
973 |
number of buffer blocks removed from
|
|
974 |
the end of the LRU list; NOTE that
|
|
975 |
this counter may wrap around at 4
|
|
976 |
billion! A thread is allowed to
|
|
977 |
read this for heuristic purposes
|
|
978 |
without holding any mutex or latch */
|
|
979 |
ulint LRU_flush_ended;/* when an LRU flush ends for a page, |
|
980 |
this is incremented by one; this is
|
|
981 |
set to zero when a buffer block is
|
|
982 |
allocated */
|
|
983 |
||
984 |
/* 3. LRU replacement algorithm fields */
|
|
985 |
||
986 |
UT_LIST_BASE_NODE_T(buf_block_t) free; |
|
987 |
/* base node of the free block list;
|
|
988 |
in the case of AWE, at the start are
|
|
989 |
always free blocks for which the
|
|
990 |
physical memory is mapped to a frame */
|
|
991 |
UT_LIST_BASE_NODE_T(buf_block_t) LRU; |
|
992 |
/* base node of the LRU list */
|
|
993 |
buf_block_t* LRU_old; /* pointer to the about 3/8 oldest |
|
994 |
blocks in the LRU list; NULL if LRU
|
|
995 |
length less than BUF_LRU_OLD_MIN_LEN */
|
|
996 |
ulint LRU_old_len; /* length of the LRU list from |
|
997 |
the block to which LRU_old points
|
|
998 |
onward, including that block;
|
|
999 |
see buf0lru.c for the restrictions
|
|
1000 |
on this value; not defined if
|
|
1001 |
LRU_old == NULL */
|
|
1002 |
UT_LIST_BASE_NODE_T(buf_block_t) awe_LRU_free_mapped; |
|
1003 |
/* list of those blocks which are
|
|
1004 |
in the LRU list or the free list, and
|
|
1005 |
where the page is mapped to a frame;
|
|
1006 |
thus, frames allocated, e.g., to the
|
|
1007 |
locki table, are not in this list */
|
|
1008 |
};
|
|
1009 |
||
1010 |
/* States of a control block */
|
|
1011 |
#define BUF_BLOCK_NOT_USED 211 /* is in the free list */ |
|
1012 |
#define BUF_BLOCK_READY_FOR_USE 212 /* when buf_get_free_block returns |
|
1013 |
a block, it is in this state */
|
|
1014 |
#define BUF_BLOCK_FILE_PAGE 213 /* contains a buffered file page */ |
|
1015 |
#define BUF_BLOCK_MEMORY 214 /* contains some main memory object */ |
|
1016 |
#define BUF_BLOCK_REMOVE_HASH 215 /* hash index should be removed |
|
1017 |
before putting to the free list */
|
|
1018 |
||
1019 |
/* Io_fix states of a control block; these must be != 0 */
|
|
1020 |
#define BUF_IO_READ 561
|
|
1021 |
#define BUF_IO_WRITE 562
|
|
1022 |
||
1023 |
/************************************************************************
|
|
1024 |
Let us list the consistency conditions for different control block states.
|
|
1025 |
||
1026 |
NOT_USED: is in free list, not in LRU list, not in flush list, nor
|
|
1027 |
page hash table
|
|
1028 |
READY_FOR_USE: is not in free list, LRU list, or flush list, nor page
|
|
1029 |
hash table
|
|
1030 |
MEMORY: is not in free list, LRU list, or flush list, nor page
|
|
1031 |
hash table
|
|
1032 |
FILE_PAGE: space and offset are defined, is in page hash table
|
|
1033 |
if io_fix == BUF_IO_WRITE,
|
|
1034 |
pool: no_flush[block->flush_type] is in reset state,
|
|
1035 |
pool: n_flush[block->flush_type] > 0
|
|
1036 |
||
1037 |
(1) if buf_fix_count == 0, then
|
|
1038 |
is in LRU list, not in free list
|
|
1039 |
is in flush list,
|
|
1040 |
if and only if oldest_modification > 0
|
|
1041 |
is x-locked,
|
|
1042 |
if and only if io_fix == BUF_IO_READ
|
|
1043 |
is s-locked,
|
|
1044 |
if and only if io_fix == BUF_IO_WRITE
|
|
1045 |
||
1046 |
(2) if buf_fix_count > 0, then
|
|
1047 |
is not in LRU list, not in free list
|
|
1048 |
is in flush list,
|
|
1049 |
if and only if oldest_modification > 0
|
|
1050 |
if io_fix == BUF_IO_READ,
|
|
1051 |
is x-locked
|
|
1052 |
if io_fix == BUF_IO_WRITE,
|
|
1053 |
is s-locked
|
|
1054 |
||
1055 |
State transitions:
|
|
1056 |
||
1057 |
NOT_USED => READY_FOR_USE
|
|
1058 |
READY_FOR_USE => MEMORY
|
|
1059 |
READY_FOR_USE => FILE_PAGE
|
|
1060 |
MEMORY => NOT_USED
|
|
1061 |
FILE_PAGE => NOT_USED NOTE: This transition is allowed if and only if
|
|
1062 |
(1) buf_fix_count == 0,
|
|
1063 |
(2) oldest_modification == 0, and
|
|
1064 |
(3) io_fix == 0.
|
|
1065 |
*/
|
|
1066 |
||
1067 |
#ifndef UNIV_NONINL
|
|
1068 |
#include "buf0buf.ic" |
|
1069 |
#endif
|
|
1070 |
||
1071 |
#endif
|