mirror of
https://github.com/MariaDB/server.git
synced 2025-01-19 21:42:35 +01:00
fce131ccee
and clarifies the invariant in dict_table_get_on_id(). In Mar 2007 Marko observed a crash during recovery, the crash resulted from an UNDO operation on a system table. His solution was to acquire an X lock on the data dictionary, this in hindsight was an overkill. It is unclear what caused the crash, current hypothesis is that it was a memory corruption. The X lock results in performance issues by when undoing changes due to rollback during normal operation on regular tables. Why the change is safe: ====================== The InnoDB code has changed since the original X lock change was made. In the new code we always lock the data dictionary in X mode during startup when UNDOing operations on the system tables (this is a given). This ensures that the crash Marko observed cannot happen as long as all transactions that update the system tables follow the standard rules by setting the appropriate DICT_OP flag when writing the log records when they make the changes. If transactions violate the above mentioned rule then during recovery (at startup) the rollback code (see trx0roll.c) will not acquire the X lock and we will see the crash again. This will however be a different bug.
779 lines
27 KiB
C
779 lines
27 KiB
C
/*****************************************************************************
|
|
|
|
Copyright (c) 1995, 2010, Innobase Oy. All Rights Reserved.
|
|
Copyright (c) 2008, Google Inc.
|
|
|
|
Portions of this file contain modifications contributed and copyrighted by
|
|
Google, Inc. Those modifications are gratefully acknowledged and are described
|
|
briefly in the InnoDB documentation. The contributions by Google are
|
|
incorporated with their permission, and subject to the conditions contained in
|
|
the file COPYING.Google.
|
|
|
|
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., 59 Temple
|
|
Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
*****************************************************************************/
|
|
|
|
/**************************************************//**
|
|
@file include/sync0sync.h
|
|
Mutex, the basic synchronization primitive
|
|
|
|
Created 9/5/1995 Heikki Tuuri
|
|
*******************************************************/
|
|
|
|
#ifndef sync0sync_h
|
|
#define sync0sync_h
|
|
|
|
#include "univ.i"
|
|
#include "sync0types.h"
|
|
#include "ut0lst.h"
|
|
#include "ut0mem.h"
|
|
#include "os0thread.h"
|
|
#include "os0sync.h"
|
|
#include "sync0arr.h"
|
|
|
|
#if defined(UNIV_DEBUG) && !defined(UNIV_HOTBACKUP)
|
|
extern my_bool timed_mutexes;
|
|
#endif /* UNIV_DEBUG && !UNIV_HOTBACKUP */
|
|
|
|
#ifdef HAVE_WINDOWS_ATOMICS
|
|
typedef LONG lock_word_t; /*!< On Windows, InterlockedExchange operates
|
|
on LONG variable */
|
|
#else
|
|
typedef byte lock_word_t;
|
|
#endif
|
|
|
|
#if defined UNIV_PFS_MUTEX || defined UNIV_PFS_RWLOCK
|
|
/* There are mutexes/rwlocks that we want to exclude from
|
|
instrumentation even if their corresponding performance schema
|
|
define is set. And this PFS_NOT_INSTRUMENTED is used
|
|
as the key value to dentify those objects that would
|
|
be excluded from instrumentation. */
|
|
# define PFS_NOT_INSTRUMENTED ULINT32_UNDEFINED
|
|
|
|
# define PFS_IS_INSTRUMENTED(key) ((key) != PFS_NOT_INSTRUMENTED)
|
|
|
|
/* By default, buffer mutexes and rwlocks will be excluded from
|
|
instrumentation due to their large number of instances. */
|
|
# define PFS_SKIP_BUFFER_MUTEX_RWLOCK
|
|
|
|
#endif /* UNIV_PFS_MUTEX || UNIV_PFS_RWLOCK */
|
|
|
|
#ifdef UNIV_PFS_MUTEX
|
|
/* Key defines to register InnoDB mutexes with performance schema */
|
|
extern mysql_pfs_key_t autoinc_mutex_key;
|
|
extern mysql_pfs_key_t btr_search_enabled_mutex_key;
|
|
extern mysql_pfs_key_t buffer_block_mutex_key;
|
|
extern mysql_pfs_key_t buf_pool_mutex_key;
|
|
extern mysql_pfs_key_t buf_pool_zip_mutex_key;
|
|
extern mysql_pfs_key_t cache_last_read_mutex_key;
|
|
extern mysql_pfs_key_t dict_foreign_err_mutex_key;
|
|
extern mysql_pfs_key_t dict_sys_mutex_key;
|
|
extern mysql_pfs_key_t file_format_max_mutex_key;
|
|
extern mysql_pfs_key_t fil_system_mutex_key;
|
|
extern mysql_pfs_key_t flush_list_mutex_key;
|
|
extern mysql_pfs_key_t hash_table_mutex_key;
|
|
extern mysql_pfs_key_t ibuf_bitmap_mutex_key;
|
|
extern mysql_pfs_key_t ibuf_mutex_key;
|
|
extern mysql_pfs_key_t ibuf_pessimistic_insert_mutex_key;
|
|
extern mysql_pfs_key_t ios_mutex_key;
|
|
extern mysql_pfs_key_t log_sys_mutex_key;
|
|
extern mysql_pfs_key_t log_flush_order_mutex_key;
|
|
extern mysql_pfs_key_t kernel_mutex_key;
|
|
# ifdef UNIV_MEM_DEBUG
|
|
extern mysql_pfs_key_t mem_hash_mutex_key;
|
|
# endif /* UNIV_MEM_DEBUG */
|
|
extern mysql_pfs_key_t mem_pool_mutex_key;
|
|
extern mysql_pfs_key_t mutex_list_mutex_key;
|
|
extern mysql_pfs_key_t purge_sys_mutex_key;
|
|
extern mysql_pfs_key_t recv_sys_mutex_key;
|
|
extern mysql_pfs_key_t rseg_mutex_key;
|
|
# ifdef UNIV_SYNC_DEBUG
|
|
extern mysql_pfs_key_t rw_lock_debug_mutex_key;
|
|
# endif /* UNIV_SYNC_DEBUG */
|
|
extern mysql_pfs_key_t rw_lock_list_mutex_key;
|
|
extern mysql_pfs_key_t rw_lock_mutex_key;
|
|
extern mysql_pfs_key_t srv_dict_tmpfile_mutex_key;
|
|
extern mysql_pfs_key_t srv_innodb_monitor_mutex_key;
|
|
extern mysql_pfs_key_t srv_misc_tmpfile_mutex_key;
|
|
extern mysql_pfs_key_t srv_monitor_file_mutex_key;
|
|
extern mysql_pfs_key_t syn_arr_mutex_key;
|
|
# ifdef UNIV_SYNC_DEBUG
|
|
extern mysql_pfs_key_t sync_thread_mutex_key;
|
|
# endif /* UNIV_SYNC_DEBUG */
|
|
extern mysql_pfs_key_t trx_doublewrite_mutex_key;
|
|
extern mysql_pfs_key_t thr_local_mutex_key;
|
|
extern mysql_pfs_key_t trx_undo_mutex_key;
|
|
#endif /* UNIV_PFS_MUTEX */
|
|
|
|
/******************************************************************//**
|
|
Initializes the synchronization data structures. */
|
|
UNIV_INTERN
|
|
void
|
|
sync_init(void);
|
|
/*===========*/
|
|
/******************************************************************//**
|
|
Frees the resources in synchronization data structures. */
|
|
UNIV_INTERN
|
|
void
|
|
sync_close(void);
|
|
/*===========*/
|
|
|
|
#undef mutex_free /* Fix for MacOS X */
|
|
|
|
#ifdef UNIV_PFS_MUTEX
|
|
/**********************************************************************
|
|
Following mutex APIs would be performance schema instrumented
|
|
if "UNIV_PFS_MUTEX" is defined:
|
|
|
|
mutex_create
|
|
mutex_enter
|
|
mutex_exit
|
|
mutex_enter_nowait
|
|
mutex_free
|
|
|
|
These mutex APIs will point to corresponding wrapper functions that contain
|
|
the performance schema instrumentation if "UNIV_PFS_MUTEX" is defined.
|
|
The instrumented wrapper functions have the prefix of "innodb_".
|
|
|
|
NOTE! The following macro should be used in mutex operation, not the
|
|
corresponding function. */
|
|
|
|
/******************************************************************//**
|
|
Creates, or rather, initializes a mutex object to a specified memory
|
|
location (which must be appropriately aligned). The mutex is initialized
|
|
in the reset state. Explicit freeing of the mutex with mutex_free is
|
|
necessary only if the memory block containing it is freed. */
|
|
# ifdef UNIV_DEBUG
|
|
# ifdef UNIV_SYNC_DEBUG
|
|
# define mutex_create(K, M, level) \
|
|
pfs_mutex_create_func((K), (M), #M, (level), __FILE__, __LINE__)
|
|
# else
|
|
# define mutex_create(K, M, level) \
|
|
pfs_mutex_create_func((K), (M), #M, __FILE__, __LINE__)
|
|
# endif/* UNIV_SYNC_DEBUG */
|
|
# else
|
|
# define mutex_create(K, M, level) \
|
|
pfs_mutex_create_func((K), (M), __FILE__, __LINE__)
|
|
# endif /* UNIV_DEBUG */
|
|
|
|
# define mutex_enter(M) \
|
|
pfs_mutex_enter_func((M), __FILE__, __LINE__)
|
|
|
|
# define mutex_enter_nowait(M) \
|
|
pfs_mutex_enter_nowait_func((M), __FILE__, __LINE__)
|
|
|
|
# define mutex_exit(M) pfs_mutex_exit_func(M)
|
|
|
|
# define mutex_free(M) pfs_mutex_free_func(M)
|
|
|
|
#else /* UNIV_PFS_MUTEX */
|
|
|
|
/* If "UNIV_PFS_MUTEX" is not defined, the mutex APIs point to
|
|
original non-instrumented functions */
|
|
# ifdef UNIV_DEBUG
|
|
# ifdef UNIV_SYNC_DEBUG
|
|
# define mutex_create(K, M, level) \
|
|
mutex_create_func((M), #M, (level), __FILE__, __LINE__)
|
|
# else /* UNIV_SYNC_DEBUG */
|
|
# define mutex_create(K, M, level) \
|
|
mutex_create_func((M), #M, __FILE__, __LINE__)
|
|
# endif /* UNIV_SYNC_DEBUG */
|
|
# else /* UNIV_DEBUG */
|
|
# define mutex_create(K, M, level) \
|
|
mutex_create_func((M), __FILE__, __LINE__)
|
|
# endif /* UNIV_DEBUG */
|
|
|
|
# define mutex_enter(M) mutex_enter_func((M), __FILE__, __LINE__)
|
|
|
|
# define mutex_enter_nowait(M) \
|
|
mutex_enter_nowait_func((M), __FILE__, __LINE__)
|
|
|
|
# define mutex_exit(M) mutex_exit_func(M)
|
|
|
|
# define mutex_free(M) mutex_free_func(M)
|
|
|
|
#endif /* UNIV_PFS_MUTEX */
|
|
|
|
/******************************************************************//**
|
|
Creates, or rather, initializes a mutex object in a specified memory
|
|
location (which must be appropriately aligned). The mutex is initialized
|
|
in the reset state. Explicit freeing of the mutex with mutex_free is
|
|
necessary only if the memory block containing it is freed. */
|
|
UNIV_INTERN
|
|
void
|
|
mutex_create_func(
|
|
/*==============*/
|
|
mutex_t* mutex, /*!< in: pointer to memory */
|
|
#ifdef UNIV_DEBUG
|
|
const char* cmutex_name, /*!< in: mutex name */
|
|
# ifdef UNIV_SYNC_DEBUG
|
|
ulint level, /*!< in: level */
|
|
# endif /* UNIV_SYNC_DEBUG */
|
|
#endif /* UNIV_DEBUG */
|
|
const char* cfile_name, /*!< in: file name where created */
|
|
ulint cline); /*!< in: file line where created */
|
|
|
|
/******************************************************************//**
|
|
NOTE! Use the corresponding macro mutex_free(), not directly this function!
|
|
Calling this function is obligatory only if the memory buffer containing
|
|
the mutex is freed. Removes a mutex object from the mutex list. The mutex
|
|
is checked to be in the reset state. */
|
|
UNIV_INTERN
|
|
void
|
|
mutex_free_func(
|
|
/*============*/
|
|
mutex_t* mutex); /*!< in: mutex */
|
|
/**************************************************************//**
|
|
NOTE! The following macro should be used in mutex locking, not the
|
|
corresponding function. */
|
|
|
|
/* NOTE! currently same as mutex_enter! */
|
|
|
|
#define mutex_enter_fast(M) mutex_enter_func((M), __FILE__, __LINE__)
|
|
/******************************************************************//**
|
|
NOTE! Use the corresponding macro in the header file, not this function
|
|
directly. Locks a mutex for the current thread. If the mutex is reserved
|
|
the function spins a preset time (controlled by SYNC_SPIN_ROUNDS) waiting
|
|
for the mutex before suspending the thread. */
|
|
UNIV_INLINE
|
|
void
|
|
mutex_enter_func(
|
|
/*=============*/
|
|
mutex_t* mutex, /*!< in: pointer to mutex */
|
|
const char* file_name, /*!< in: file name where locked */
|
|
ulint line); /*!< in: line where locked */
|
|
/********************************************************************//**
|
|
NOTE! Use the corresponding macro in the header file, not this function
|
|
directly. Tries to lock the mutex for the current thread. If the lock is not
|
|
acquired immediately, returns with return value 1.
|
|
@return 0 if succeed, 1 if not */
|
|
UNIV_INTERN
|
|
ulint
|
|
mutex_enter_nowait_func(
|
|
/*====================*/
|
|
mutex_t* mutex, /*!< in: pointer to mutex */
|
|
const char* file_name, /*!< in: file name where mutex
|
|
requested */
|
|
ulint line); /*!< in: line where requested */
|
|
/******************************************************************//**
|
|
NOTE! Use the corresponding macro mutex_exit(), not directly this function!
|
|
Unlocks a mutex owned by the current thread. */
|
|
UNIV_INLINE
|
|
void
|
|
mutex_exit_func(
|
|
/*============*/
|
|
mutex_t* mutex); /*!< in: pointer to mutex */
|
|
|
|
|
|
#ifdef UNIV_PFS_MUTEX
|
|
/******************************************************************//**
|
|
NOTE! Please use the corresponding macro mutex_create(), not directly
|
|
this function!
|
|
A wrapper function for mutex_create_func(), registers the mutex
|
|
with peformance schema if "UNIV_PFS_MUTEX" is defined when
|
|
creating the mutex */
|
|
UNIV_INLINE
|
|
void
|
|
pfs_mutex_create_func(
|
|
/*==================*/
|
|
PSI_mutex_key key, /*!< in: Performance Schema key */
|
|
mutex_t* mutex, /*!< in: pointer to memory */
|
|
# ifdef UNIV_DEBUG
|
|
const char* cmutex_name, /*!< in: mutex name */
|
|
# ifdef UNIV_SYNC_DEBUG
|
|
ulint level, /*!< in: level */
|
|
# endif /* UNIV_SYNC_DEBUG */
|
|
# endif /* UNIV_DEBUG */
|
|
const char* cfile_name, /*!< in: file name where created */
|
|
ulint cline); /*!< in: file line where created */
|
|
/******************************************************************//**
|
|
NOTE! Please use the corresponding macro mutex_enter(), not directly
|
|
this function!
|
|
This is a performance schema instrumented wrapper function for
|
|
mutex_enter_func(). */
|
|
UNIV_INLINE
|
|
void
|
|
pfs_mutex_enter_func(
|
|
/*=================*/
|
|
mutex_t* mutex, /*!< in: pointer to mutex */
|
|
const char* file_name, /*!< in: file name where locked */
|
|
ulint line); /*!< in: line where locked */
|
|
/********************************************************************//**
|
|
NOTE! Please use the corresponding macro mutex_enter_nowait(), not directly
|
|
this function!
|
|
This is a performance schema instrumented wrapper function for
|
|
mutex_enter_nowait_func.
|
|
@return 0 if succeed, 1 if not */
|
|
UNIV_INLINE
|
|
ulint
|
|
pfs_mutex_enter_nowait_func(
|
|
/*========================*/
|
|
mutex_t* mutex, /*!< in: pointer to mutex */
|
|
const char* file_name, /*!< in: file name where mutex
|
|
requested */
|
|
ulint line); /*!< in: line where requested */
|
|
/******************************************************************//**
|
|
NOTE! Please use the corresponding macro mutex_exit(), not directly
|
|
this function!
|
|
A wrap function of mutex_exit_func() with peformance schema instrumentation.
|
|
Unlocks a mutex owned by the current thread. */
|
|
UNIV_INLINE
|
|
void
|
|
pfs_mutex_exit_func(
|
|
/*================*/
|
|
mutex_t* mutex); /*!< in: pointer to mutex */
|
|
|
|
/******************************************************************//**
|
|
NOTE! Please use the corresponding macro mutex_free(), not directly
|
|
this function!
|
|
Wrapper function for mutex_free_func(). Also destroys the performance
|
|
schema probes when freeing the mutex */
|
|
UNIV_INLINE
|
|
void
|
|
pfs_mutex_free_func(
|
|
/*================*/
|
|
mutex_t* mutex); /*!< in: mutex */
|
|
|
|
#endif /* UNIV_PFS_MUTEX */
|
|
|
|
#ifdef UNIV_SYNC_DEBUG
|
|
/******************************************************************//**
|
|
Returns TRUE if no mutex or rw-lock is currently locked.
|
|
Works only in the debug version.
|
|
@return TRUE if no mutexes and rw-locks reserved */
|
|
UNIV_INTERN
|
|
ibool
|
|
sync_all_freed(void);
|
|
/*================*/
|
|
#endif /* UNIV_SYNC_DEBUG */
|
|
/*#####################################################################
|
|
FUNCTION PROTOTYPES FOR DEBUGGING */
|
|
/*******************************************************************//**
|
|
Prints wait info of the sync system. */
|
|
UNIV_INTERN
|
|
void
|
|
sync_print_wait_info(
|
|
/*=================*/
|
|
FILE* file); /*!< in: file where to print */
|
|
/*******************************************************************//**
|
|
Prints info of the sync system. */
|
|
UNIV_INTERN
|
|
void
|
|
sync_print(
|
|
/*=======*/
|
|
FILE* file); /*!< in: file where to print */
|
|
#ifdef UNIV_DEBUG
|
|
/******************************************************************//**
|
|
Checks that the mutex has been initialized.
|
|
@return TRUE */
|
|
UNIV_INTERN
|
|
ibool
|
|
mutex_validate(
|
|
/*===========*/
|
|
const mutex_t* mutex); /*!< in: mutex */
|
|
/******************************************************************//**
|
|
Checks that the current thread owns the mutex. Works only
|
|
in the debug version.
|
|
@return TRUE if owns */
|
|
UNIV_INTERN
|
|
ibool
|
|
mutex_own(
|
|
/*======*/
|
|
const mutex_t* mutex) /*!< in: mutex */
|
|
__attribute__((warn_unused_result));
|
|
#endif /* UNIV_DEBUG */
|
|
#ifdef UNIV_SYNC_DEBUG
|
|
/******************************************************************//**
|
|
Adds a latch and its level in the thread level array. Allocates the memory
|
|
for the array if called first time for this OS thread. Makes the checks
|
|
against other latch levels stored in the array for this thread. */
|
|
UNIV_INTERN
|
|
void
|
|
sync_thread_add_level(
|
|
/*==================*/
|
|
void* latch, /*!< in: pointer to a mutex or an rw-lock */
|
|
ulint level); /*!< in: level in the latching order; if
|
|
SYNC_LEVEL_VARYING, nothing is done */
|
|
/******************************************************************//**
|
|
Removes a latch from the thread level array if it is found there.
|
|
@return TRUE if found in the array; it is no error if the latch is
|
|
not found, as we presently are not able to determine the level for
|
|
every latch reservation the program does */
|
|
UNIV_INTERN
|
|
ibool
|
|
sync_thread_reset_level(
|
|
/*====================*/
|
|
void* latch); /*!< in: pointer to a mutex or an rw-lock */
|
|
/******************************************************************//**
|
|
Checks that the level array for the current thread is empty.
|
|
@return TRUE if empty */
|
|
UNIV_INTERN
|
|
ibool
|
|
sync_thread_levels_empty(void);
|
|
/*==========================*/
|
|
/******************************************************************//**
|
|
Checks if the level array for the current thread contains a
|
|
mutex or rw-latch at the specified level.
|
|
@return a matching latch, or NULL if not found */
|
|
UNIV_INTERN
|
|
void*
|
|
sync_thread_levels_contains(
|
|
/*========================*/
|
|
ulint level); /*!< in: latching order level
|
|
(SYNC_DICT, ...)*/
|
|
/******************************************************************//**
|
|
Checks if the level array for the current thread is empty.
|
|
@return a latch, or NULL if empty except the exceptions specified below */
|
|
UNIV_INTERN
|
|
void*
|
|
sync_thread_levels_nonempty_gen(
|
|
/*============================*/
|
|
ibool dict_mutex_allowed); /*!< in: TRUE if dictionary mutex is
|
|
allowed to be owned by the thread,
|
|
also purge_is_running mutex is
|
|
allowed */
|
|
#define sync_thread_levels_empty_gen(d) (!sync_thread_levels_nonempty_gen(d))
|
|
/******************************************************************//**
|
|
Gets the debug information for a reserved mutex. */
|
|
UNIV_INTERN
|
|
void
|
|
mutex_get_debug_info(
|
|
/*=================*/
|
|
mutex_t* mutex, /*!< in: mutex */
|
|
const char** file_name, /*!< out: file where requested */
|
|
ulint* line, /*!< out: line where requested */
|
|
os_thread_id_t* thread_id); /*!< out: id of the thread which owns
|
|
the mutex */
|
|
/******************************************************************//**
|
|
Counts currently reserved mutexes. Works only in the debug version.
|
|
@return number of reserved mutexes */
|
|
UNIV_INTERN
|
|
ulint
|
|
mutex_n_reserved(void);
|
|
/*==================*/
|
|
#endif /* UNIV_SYNC_DEBUG */
|
|
/******************************************************************//**
|
|
NOT to be used outside this module except in debugging! Gets the value
|
|
of the lock word. */
|
|
UNIV_INLINE
|
|
lock_word_t
|
|
mutex_get_lock_word(
|
|
/*================*/
|
|
const mutex_t* mutex); /*!< in: mutex */
|
|
#ifdef UNIV_SYNC_DEBUG
|
|
/******************************************************************//**
|
|
NOT to be used outside this module except in debugging! Gets the waiters
|
|
field in a mutex.
|
|
@return value to set */
|
|
UNIV_INLINE
|
|
ulint
|
|
mutex_get_waiters(
|
|
/*==============*/
|
|
const mutex_t* mutex); /*!< in: mutex */
|
|
#endif /* UNIV_SYNC_DEBUG */
|
|
|
|
/*
|
|
LATCHING ORDER WITHIN THE DATABASE
|
|
==================================
|
|
|
|
The mutex or latch in the central memory object, for instance, a rollback
|
|
segment object, must be acquired before acquiring the latch or latches to
|
|
the corresponding file data structure. In the latching order below, these
|
|
file page object latches are placed immediately below the corresponding
|
|
central memory object latch or mutex.
|
|
|
|
Synchronization object Notes
|
|
---------------------- -----
|
|
|
|
Dictionary mutex If we have a pointer to a dictionary
|
|
| object, e.g., a table, it can be
|
|
| accessed without reserving the
|
|
| dictionary mutex. We must have a
|
|
| reservation, a memoryfix, to the
|
|
| appropriate table object in this case,
|
|
| and the table must be explicitly
|
|
| released later.
|
|
V
|
|
Dictionary header
|
|
|
|
|
V
|
|
Secondary index tree latch The tree latch protects also all
|
|
| the B-tree non-leaf pages. These
|
|
V can be read with the page only
|
|
Secondary index non-leaf bufferfixed to save CPU time,
|
|
| no s-latch is needed on the page.
|
|
| Modification of a page requires an
|
|
| x-latch on the page, however. If a
|
|
| thread owns an x-latch to the tree,
|
|
| it is allowed to latch non-leaf pages
|
|
| even after it has acquired the fsp
|
|
| latch.
|
|
V
|
|
Secondary index leaf The latch on the secondary index leaf
|
|
| can be kept while accessing the
|
|
| clustered index, to save CPU time.
|
|
V
|
|
Clustered index tree latch To increase concurrency, the tree
|
|
| latch is usually released when the
|
|
| leaf page latch has been acquired.
|
|
V
|
|
Clustered index non-leaf
|
|
|
|
|
V
|
|
Clustered index leaf
|
|
|
|
|
V
|
|
Transaction system header
|
|
|
|
|
V
|
|
Transaction undo mutex The undo log entry must be written
|
|
| before any index page is modified.
|
|
| Transaction undo mutex is for the undo
|
|
| logs the analogue of the tree latch
|
|
| for a B-tree. If a thread has the
|
|
| trx undo mutex reserved, it is allowed
|
|
| to latch the undo log pages in any
|
|
| order, and also after it has acquired
|
|
| the fsp latch.
|
|
V
|
|
Rollback segment mutex The rollback segment mutex must be
|
|
| reserved, if, e.g., a new page must
|
|
| be added to an undo log. The rollback
|
|
| segment and the undo logs in its
|
|
| history list can be seen as an
|
|
| analogue of a B-tree, and the latches
|
|
| reserved similarly, using a version of
|
|
| lock-coupling. If an undo log must be
|
|
| extended by a page when inserting an
|
|
| undo log record, this corresponds to
|
|
| a pessimistic insert in a B-tree.
|
|
V
|
|
Rollback segment header
|
|
|
|
|
V
|
|
Purge system latch
|
|
|
|
|
V
|
|
Undo log pages If a thread owns the trx undo mutex,
|
|
| or for a log in the history list, the
|
|
| rseg mutex, it is allowed to latch
|
|
| undo log pages in any order, and even
|
|
| after it has acquired the fsp latch.
|
|
| If a thread does not have the
|
|
| appropriate mutex, it is allowed to
|
|
| latch only a single undo log page in
|
|
| a mini-transaction.
|
|
V
|
|
File space management latch If a mini-transaction must allocate
|
|
| several file pages, it can do that,
|
|
| because it keeps the x-latch to the
|
|
| file space management in its memo.
|
|
V
|
|
File system pages
|
|
|
|
|
V
|
|
Kernel mutex If a kernel operation needs a file
|
|
| page allocation, it must reserve the
|
|
| fsp x-latch before acquiring the kernel
|
|
| mutex.
|
|
V
|
|
Search system mutex
|
|
|
|
|
V
|
|
Buffer pool mutex
|
|
|
|
|
V
|
|
Log mutex
|
|
|
|
|
Any other latch
|
|
|
|
|
V
|
|
Memory pool mutex */
|
|
|
|
/* Latching order levels */
|
|
|
|
/* User transaction locks are higher than any of the latch levels below:
|
|
no latches are allowed when a thread goes to wait for a normal table
|
|
or row lock! */
|
|
#define SYNC_USER_TRX_LOCK 9999
|
|
#define SYNC_NO_ORDER_CHECK 3000 /* this can be used to suppress
|
|
latching order checking */
|
|
#define SYNC_LEVEL_VARYING 2000 /* Level is varying. Only used with
|
|
buffer pool page locks, which do not
|
|
have a fixed level, but instead have
|
|
their level set after the page is
|
|
locked; see e.g.
|
|
ibuf_bitmap_get_map_page(). */
|
|
#define SYNC_TRX_I_S_RWLOCK 1910 /* Used for
|
|
trx_i_s_cache_t::rw_lock */
|
|
#define SYNC_TRX_I_S_LAST_READ 1900 /* Used for
|
|
trx_i_s_cache_t::last_read_mutex */
|
|
#define SYNC_FILE_FORMAT_TAG 1200 /* Used to serialize access to the
|
|
file format tag */
|
|
#define SYNC_DICT_OPERATION 1001 /* table create, drop, etc. reserve
|
|
this in X-mode; implicit or backround
|
|
operations purge, rollback, foreign
|
|
key checks reserve this in S-mode */
|
|
#define SYNC_DICT 1000
|
|
#define SYNC_DICT_AUTOINC_MUTEX 999
|
|
#define SYNC_DICT_HEADER 995
|
|
#define SYNC_IBUF_HEADER 914
|
|
#define SYNC_IBUF_PESS_INSERT_MUTEX 912
|
|
#define SYNC_IBUF_MUTEX 910 /* ibuf mutex is really below
|
|
SYNC_FSP_PAGE: we assign a value this
|
|
high only to make the program to pass
|
|
the debug checks */
|
|
/*-------------------------------*/
|
|
#define SYNC_INDEX_TREE 900
|
|
#define SYNC_TREE_NODE_NEW 892
|
|
#define SYNC_TREE_NODE_FROM_HASH 891
|
|
#define SYNC_TREE_NODE 890
|
|
#define SYNC_PURGE_SYS 810
|
|
#define SYNC_PURGE_LATCH 800
|
|
#define SYNC_TRX_UNDO 700
|
|
#define SYNC_RSEG 600
|
|
#define SYNC_RSEG_HEADER_NEW 591
|
|
#define SYNC_RSEG_HEADER 590
|
|
#define SYNC_TRX_UNDO_PAGE 570
|
|
#define SYNC_EXTERN_STORAGE 500
|
|
#define SYNC_FSP 400
|
|
#define SYNC_FSP_PAGE 395
|
|
/*------------------------------------- Insert buffer headers */
|
|
/*------------------------------------- ibuf_mutex */
|
|
/*------------------------------------- Insert buffer tree */
|
|
#define SYNC_IBUF_BITMAP_MUTEX 351
|
|
#define SYNC_IBUF_BITMAP 350
|
|
/*------------------------------------- MySQL query cache mutex */
|
|
/*------------------------------------- MySQL binlog mutex */
|
|
/*-------------------------------*/
|
|
#define SYNC_KERNEL 300
|
|
#define SYNC_REC_LOCK 299
|
|
#define SYNC_TRX_LOCK_HEAP 298
|
|
#define SYNC_TRX_SYS_HEADER 290
|
|
#define SYNC_LOG 170
|
|
#define SYNC_LOG_FLUSH_ORDER 147
|
|
#define SYNC_RECV 168
|
|
#define SYNC_WORK_QUEUE 162
|
|
#define SYNC_SEARCH_SYS_CONF 161 /* for assigning btr_search_enabled */
|
|
#define SYNC_SEARCH_SYS 160 /* NOTE that if we have a memory
|
|
heap that can be extended to the
|
|
buffer pool, its logical level is
|
|
SYNC_SEARCH_SYS, as memory allocation
|
|
can call routines there! Otherwise
|
|
the level is SYNC_MEM_HASH. */
|
|
#define SYNC_BUF_POOL 150 /* Buffer pool mutex */
|
|
#define SYNC_BUF_BLOCK 146 /* Block mutex */
|
|
#define SYNC_BUF_FLUSH_LIST 145 /* Buffer flush list mutex */
|
|
#define SYNC_DOUBLEWRITE 140
|
|
#define SYNC_ANY_LATCH 135
|
|
#define SYNC_THR_LOCAL 133
|
|
#define SYNC_MEM_HASH 131
|
|
#define SYNC_MEM_POOL 130
|
|
|
|
/* Codes used to designate lock operations */
|
|
#define RW_LOCK_NOT_LOCKED 350
|
|
#define RW_LOCK_EX 351
|
|
#define RW_LOCK_EXCLUSIVE 351
|
|
#define RW_LOCK_SHARED 352
|
|
#define RW_LOCK_WAIT_EX 353
|
|
#define SYNC_MUTEX 354
|
|
|
|
/* NOTE! The structure appears here only for the compiler to know its size.
|
|
Do not use its fields directly! The structure used in the spin lock
|
|
implementation of a mutual exclusion semaphore. */
|
|
|
|
/** InnoDB mutex */
|
|
struct mutex_struct {
|
|
os_event_t event; /*!< Used by sync0arr.c for the wait queue */
|
|
volatile lock_word_t lock_word; /*!< lock_word is the target
|
|
of the atomic test-and-set instruction when
|
|
atomic operations are enabled. */
|
|
|
|
#if !defined(HAVE_ATOMIC_BUILTINS)
|
|
os_fast_mutex_t
|
|
os_fast_mutex; /*!< We use this OS mutex in place of lock_word
|
|
when atomic operations are not enabled */
|
|
#endif
|
|
ulint waiters; /*!< This ulint is set to 1 if there are (or
|
|
may be) threads waiting in the global wait
|
|
array for this mutex to be released.
|
|
Otherwise, this is 0. */
|
|
UT_LIST_NODE_T(mutex_t) list; /*!< All allocated mutexes are put into
|
|
a list. Pointers to the next and prev. */
|
|
#ifdef UNIV_SYNC_DEBUG
|
|
const char* file_name; /*!< File where the mutex was locked */
|
|
ulint line; /*!< Line where the mutex was locked */
|
|
ulint level; /*!< Level in the global latching order */
|
|
#endif /* UNIV_SYNC_DEBUG */
|
|
const char* cfile_name;/*!< File name where mutex created */
|
|
ulint cline; /*!< Line where created */
|
|
#ifdef UNIV_DEBUG
|
|
os_thread_id_t thread_id; /*!< The thread id of the thread
|
|
which locked the mutex. */
|
|
ulint magic_n; /*!< MUTEX_MAGIC_N */
|
|
/** Value of mutex_struct::magic_n */
|
|
# define MUTEX_MAGIC_N (ulint)979585
|
|
#endif /* UNIV_DEBUG */
|
|
ulong count_os_wait; /*!< count of os_wait */
|
|
#ifdef UNIV_DEBUG
|
|
ulong count_using; /*!< count of times mutex used */
|
|
ulong count_spin_loop; /*!< count of spin loops */
|
|
ulong count_spin_rounds;/*!< count of spin rounds */
|
|
ulong count_os_yield; /*!< count of os_wait */
|
|
ulonglong lspent_time; /*!< mutex os_wait timer msec */
|
|
ulonglong lmax_spent_time;/*!< mutex os_wait timer msec */
|
|
const char* cmutex_name; /*!< mutex name */
|
|
ulint mutex_type; /*!< 0=usual mutex, 1=rw_lock mutex */
|
|
#endif /* UNIV_DEBUG */
|
|
#ifdef UNIV_PFS_MUTEX
|
|
struct PSI_mutex* pfs_psi; /*!< The performance schema
|
|
instrumentation hook */
|
|
#endif
|
|
};
|
|
|
|
/** The global array of wait cells for implementation of the databases own
|
|
mutexes and read-write locks. */
|
|
extern sync_array_t* sync_primary_wait_array;/* Appears here for
|
|
debugging purposes only! */
|
|
|
|
/** Constant determining how long spin wait is continued before suspending
|
|
the thread. A value 600 rounds on a 1995 100 MHz Pentium seems to correspond
|
|
to 20 microseconds. */
|
|
|
|
#define SYNC_SPIN_ROUNDS srv_n_spin_wait_rounds
|
|
|
|
/** The number of mutex_exit calls. Intended for performance monitoring. */
|
|
extern ib_int64_t mutex_exit_count;
|
|
|
|
#ifdef UNIV_SYNC_DEBUG
|
|
/** Latching order checks start when this is set TRUE */
|
|
extern ibool sync_order_checks_on;
|
|
#endif /* UNIV_SYNC_DEBUG */
|
|
|
|
/** This variable is set to TRUE when sync_init is called */
|
|
extern ibool sync_initialized;
|
|
|
|
/** Global list of database mutexes (not OS mutexes) created. */
|
|
typedef UT_LIST_BASE_NODE_T(mutex_t) ut_list_base_node_t;
|
|
/** Global list of database mutexes (not OS mutexes) created. */
|
|
extern ut_list_base_node_t mutex_list;
|
|
|
|
/** Mutex protecting the mutex_list variable */
|
|
extern mutex_t mutex_list_mutex;
|
|
|
|
|
|
#ifndef UNIV_NONINL
|
|
#include "sync0sync.ic"
|
|
#endif
|
|
|
|
#endif
|