211 lines
6.5 KiB
C++
211 lines
6.5 KiB
C++
/* Copyright (c) 2018, 2021, Alibaba and/or its affiliates. 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, version 2.0,
|
|
as published by the Free Software Foundation.
|
|
This program is also distributed with certain software (including
|
|
but not limited to OpenSSL) that is licensed under separate terms,
|
|
as designated in a particular file or component or in included license
|
|
documentation. The authors of MySQL/PolarDB-X Engine hereby grant you an
|
|
additional permission to link the program and your derivative works with the
|
|
separately licensed software that they have included with
|
|
MySQL/PolarDB-X Engine.
|
|
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, version 2.0, 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/lizard0sys.h
|
|
Lizard system implementation.
|
|
|
|
Created 2020-03-23 by Jianwei.zhao
|
|
*******************************************************/
|
|
#ifndef lizard0sys_h
|
|
#define lizard0sys_h
|
|
|
|
#include "fsp0types.h"
|
|
#include "lizard0scn.h"
|
|
#include "trx0types.h"
|
|
#include "trx0sys.h"
|
|
|
|
struct mtr_t;
|
|
|
|
/** Lizard system file segment header */
|
|
typedef byte lizard_sys_fseg_t;
|
|
|
|
/** Lizard system header:
|
|
it begins from LIZARD_SYS, and includes file segment header. */
|
|
typedef byte lizard_sysf_t;
|
|
|
|
/** Lizard system header */
|
|
/**-----------------------------------------------------------------------*/
|
|
|
|
/** The offset of lizard system header on the file segment page */
|
|
#define LIZARD_SYS FSEG_PAGE_DATA
|
|
|
|
/** The scn number which is stored here, it occupied 8 bytes */
|
|
#define LIZARD_SYS_SCN 0
|
|
|
|
/** The global commit number which is stored here. */
|
|
#define LIZARD_SYS_GCN (LIZARD_SYS_SCN + 8)
|
|
|
|
/** The purge scn number which is stored here, it occupied 8 bytes */
|
|
#define LIZARD_SYS_PURGE_SCN (LIZARD_SYS_GCN + 8)
|
|
|
|
/** The offset of file segment header */
|
|
#define LIZARD_SYS_FSEG_HEADER (LIZARD_SYS_PURGE_SCN + 8)
|
|
|
|
/**
|
|
Revision history:
|
|
------------------------------------------------------
|
|
1. Add purged_gcn
|
|
*/
|
|
|
|
#define LIZARD_SYS_PURGE_GCN (LIZARD_SYS_FSEG_HEADER + FSEG_HEADER_SIZE)
|
|
|
|
/** The start of not used */
|
|
#define LIZARD_SYS_NOT_USED (LIZARD_SYS_PURGE_GCN + 8)
|
|
/**-----------------------------------------------------------------------*/
|
|
|
|
/** The page number of lizard system header in lizard tablespace */
|
|
#define LIZARD_SYS_PAGE_NO 3
|
|
|
|
/** Initial value of min_active_trx_id */
|
|
#define LIZARD_SYS_MTX_ID_NULL 0
|
|
|
|
#ifdef UNIV_PFS_MUTEX
|
|
/* min active trx_id mutex PFS key */
|
|
extern mysql_pfs_key_t lizard_sys_mtx_id_mutex_key;
|
|
#endif
|
|
|
|
namespace lizard {
|
|
|
|
/** The memory structure of lizard system */
|
|
struct lizard_sys_t {
|
|
/** The global scn number which is total order. */
|
|
SCN scn;
|
|
|
|
/** The min active trx id */
|
|
std::atomic<trx_id_t> min_active_trx_id;
|
|
|
|
/** min_active_trx has been inited */
|
|
bool mtx_inited;
|
|
|
|
/** Length of txn undo log segment free list */
|
|
ulint txn_undo_log_free_list_len;
|
|
|
|
/** Count of txn undo log which is cached */
|
|
ulint txn_undo_log_cached;
|
|
|
|
/** A min safe SCN, only used for purge */
|
|
std::atomic<scn_t> min_safe_scn;
|
|
|
|
/*!< Ordered on commited scn of trx_t of all the
|
|
currenrtly active RW transactions */
|
|
trx_ut_list_t serialisation_list_scn;
|
|
};
|
|
|
|
/** Create lizard system structure. */
|
|
void lizard_sys_create();
|
|
|
|
/** Close lizard system structure. */
|
|
void lizard_sys_close();
|
|
|
|
/** Init the elements of lizard system */
|
|
void lizard_sys_init();
|
|
|
|
/** Get the address of lizard system header */
|
|
extern lizard_sysf_t *lizard_sysf_get(mtr_t *mtr);
|
|
|
|
/** Create lizard system pages within lizard tablespace */
|
|
extern void lizard_create_sys_pages();
|
|
|
|
/** GLobal lizard system */
|
|
extern lizard_sys_t *lizard_sys;
|
|
|
|
/** Get current SCN number */
|
|
extern scn_t lizard_sys_get_scn();
|
|
|
|
/** Get current persisted GCN number */
|
|
extern gcn_t lizard_sys_get_gcn();
|
|
|
|
/** Get max snapshot GCN number */
|
|
extern gcn_t lizard_sys_get_snapshot_gcn();
|
|
|
|
/**
|
|
Modify the min active trx id
|
|
|
|
@param[in] the add/removed trx */
|
|
void lizard_sys_mod_min_active_trx_id(trx_t *trx);
|
|
|
|
/**
|
|
Get the min active trx id
|
|
|
|
@retval the min active id in trx_sys. */
|
|
trx_id_t lizard_sys_get_min_active_trx_id();
|
|
|
|
/**
|
|
In MySQL 8.0:
|
|
* Hold trx_sys::mutex, generate trx->no, add trx to trx_sys->serialisation_list
|
|
* Hold purge_sys::pq_mutex, add undo rseg to purge_queue. All undo records are ordered.
|
|
* Erase above mutexs, commit in undo header
|
|
* Hold trx_sys::mutex, erase serialisation_list, rw_trx_ids, rw_trx_list,
|
|
the modifications from the committed trx can be seen.
|
|
|
|
In Lizard:
|
|
* Hold trx_sys::mutex, generate trx->txn_desc.scn
|
|
* Hold SCN::mutex, add trx to trx_sys->serialisation_list_scn
|
|
* Erase trx_sys::mutex, hold purge_sys::pq_mutex and rseg::mutex, and add
|
|
undo rseg to purge_queue. So undo records in the same rseg are ordered, but
|
|
undo records from different rsegs are not ordered in purge_heap.
|
|
* Erase above mutexs, commit in undo header
|
|
* Hold SCN::mutex, remove trx in trx_sys->serialisation_list_scn,
|
|
and update min_safe_scn.
|
|
|
|
To ensure purge_sys purge in order, min_safe_scn is used for purge sys.
|
|
min_safe_scn is the current smallest scn of committing transactions (both
|
|
prepared state and committed in memory state).
|
|
|
|
This function might be used in the following scenarios:
|
|
* purge sys should get a safe scn for purging
|
|
* clone
|
|
* PolarDB
|
|
|
|
@retval the min safe commited scn in current lizard sys
|
|
*/
|
|
scn_t lizard_sys_get_min_safe_scn();
|
|
|
|
/** Erase trx in serialisation_list_scn, and update min_safe_scn
|
|
@param[in] trx trx to be removed */
|
|
void lizard_sys_erase_lists(trx_t *trx);
|
|
|
|
#if defined UNIV_DEBUG || defined LIZARD_DEBUG
|
|
/** Check if min_safe_scn is valid */
|
|
void min_safe_scn_valid();
|
|
#endif /* UNIV_DEBUG || LIZARD_DEBUG */
|
|
|
|
/**
|
|
Get the max gcn between snapshot gcn and m_gcn
|
|
|
|
@retval the valid gcn. */
|
|
gcn_t lizard_sys_acquire_gcn();
|
|
|
|
} // namespace lizard
|
|
|
|
#if defined UNIV_DEBUG || defined LIZARD_DEBUG
|
|
#define assert_lizard_min_safe_scn_valid() \
|
|
do { \
|
|
lizard::min_safe_scn_valid(); \
|
|
} while (0)
|
|
|
|
#else
|
|
|
|
#define assert_lizard_min_safe_scn_valid()
|
|
|
|
#endif /* UNIV_DEBUG || LIZARD_DEBUG */
|
|
|
|
#endif // lizard0sys_h define
|