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mariadb/storage/innobase/include/trx0trx.h
Marko Mäkelä 50faeda4d6 Remove trx_t::has_search_latch and simplify debug code 
When the btr_search_latch was split into an array of latches
in MySQL 5.7.8 as part of the Oracle Bug#20985298 fix, the "caching"
of the latch across storage engine API calls was removed, and
the field trx->has_search_latch would only be set during a short
time frame in the execution of row_search_mvcc(), which was
formerly called row_search_for_mysql().

This means that the column
INFORMATION_SCHEMA.INNODB_TRX.TRX_ADAPTIVE_HASH_LATCHED will always
report 0. That column cannot be removed in MariaDB 10.2, but it
can be removed in future releases.

trx_t::has_search_latch: Remove.

trx_assert_no_search_latch(): Remove.

row_sel_try_search_shortcut_for_mysql(): Remove a redundant condition
on trx->has_search_latch (it was always true).

sync_check_iterate(): Make the parameter const.

sync_check_functor_t: Make the operator() const, and remove result()
and the virtual destructor. There is no need to have mutable state
in the functors.

sync_checker<bool>: Replaces dict_sync_check and btrsea_sync_check.

sync_check: Replaces btrsea_sync_check.

dict_sync_check: Instantiated from sync_checker.

sync_allowed_latches: Use std::find() directly on the array.
Remove the std::vector.

TrxInInnoDB::enter(), TrxInInnoDB::exit(): Remove obviously redundant
debug assertions on trx->in_depth, and use equality comparison against 0
because it could be more efficient on some architectures.
2017-06-16 13:17:05 +03:00

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/*****************************************************************************
Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2015, 2017, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/trx0trx.h
The transaction
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#ifndef trx0trx_h
#define trx0trx_h
#include <set>
#include <list>
#include "ha_prototypes.h"
#include "dict0types.h"
#include "trx0types.h"
#include "ut0new.h"
#include "lock0types.h"
#include "log0log.h"
#include "usr0types.h"
#include "que0types.h"
#include "mem0mem.h"
#include "trx0xa.h"
#include "ut0vec.h"
#include "fts0fts.h"
#include "srv0srv.h"
// Forward declaration
struct mtr_t;
// Forward declaration
class ReadView;
// Forward declaration
class FlushObserver;
/** Dummy session used currently in MySQL interface */
extern sess_t* trx_dummy_sess;
/** Set flush observer for the transaction
@param[in/out] trx transaction struct
@param[in] observer flush observer */
void
trx_set_flush_observer(
trx_t* trx,
FlushObserver* observer);
/******************************************************************//**
Set detailed error message for the transaction. */
void
trx_set_detailed_error(
/*===================*/
trx_t* trx, /*!< in: transaction struct */
const char* msg); /*!< in: detailed error message */
/*************************************************************//**
Set detailed error message for the transaction from a file. Note that the
file is rewinded before reading from it. */
void
trx_set_detailed_error_from_file(
/*=============================*/
trx_t* trx, /*!< in: transaction struct */
FILE* file); /*!< in: file to read message from */
/****************************************************************//**
Retrieves the error_info field from a trx.
@return the error info */
UNIV_INLINE
const dict_index_t*
trx_get_error_info(
/*===============*/
const trx_t* trx); /*!< in: trx object */
/********************************************************************//**
Creates a transaction object for MySQL.
@return own: transaction object */
trx_t*
trx_allocate_for_mysql(void);
/*========================*/
/********************************************************************//**
Creates a transaction object for background operations by the master thread.
@return own: transaction object */
trx_t*
trx_allocate_for_background(void);
/*=============================*/
/** Frees and initialize a transaction object instantinated during recovery.
@param trx trx object to free and initialize during recovery */
void
trx_free_resurrected(trx_t* trx);
/** Free a transaction that was allocated by background or user threads.
@param trx trx object to free */
void
trx_free_for_background(trx_t* trx);
/********************************************************************//**
At shutdown, frees a transaction object that is in the PREPARED state. */
void
trx_free_prepared(
/*==============*/
trx_t* trx); /*!< in, own: trx object */
/** Free a transaction object for MySQL.
@param[in,out] trx transaction */
void
trx_free_for_mysql(trx_t* trx);
/** Disconnect a transaction from MySQL.
@param[in,out] trx transaction */
void
trx_disconnect_plain(trx_t* trx);
/** Disconnect a prepared transaction from MySQL.
@param[in,out] trx transaction */
void
trx_disconnect_prepared(trx_t* trx);
/** Initialize (resurrect) transactions at startup. */
void
trx_lists_init_at_db_start();
/*************************************************************//**
Starts the transaction if it is not yet started. */
void
trx_start_if_not_started_xa_low(
/*============================*/
trx_t* trx, /*!< in/out: transaction */
bool read_write); /*!< in: true if read write transaction */
/*************************************************************//**
Starts the transaction if it is not yet started. */
void
trx_start_if_not_started_low(
/*=========================*/
trx_t* trx, /*!< in/out: transaction */
bool read_write); /*!< in: true if read write transaction */
/*************************************************************//**
Starts a transaction for internal processing. */
void
trx_start_internal_low(
/*===================*/
trx_t* trx); /*!< in/out: transaction */
/** Starts a read-only transaction for internal processing.
@param[in,out] trx transaction to be started */
void
trx_start_internal_read_only_low(
trx_t* trx);
#ifdef UNIV_DEBUG
#define trx_start_if_not_started_xa(t, rw) \
do { \
(t)->start_line = __LINE__; \
(t)->start_file = __FILE__; \
trx_start_if_not_started_xa_low((t), rw); \
} while (false)
#define trx_start_if_not_started(t, rw) \
do { \
(t)->start_line = __LINE__; \
(t)->start_file = __FILE__; \
trx_start_if_not_started_low((t), rw); \
} while (false)
#define trx_start_internal(t) \
do { \
(t)->start_line = __LINE__; \
(t)->start_file = __FILE__; \
trx_start_internal_low((t)); \
} while (false)
#define trx_start_internal_read_only(t) \
do { \
(t)->start_line = __LINE__; \
(t)->start_file = __FILE__; \
trx_start_internal_read_only_low(t); \
} while (false)
#else
#define trx_start_if_not_started(t, rw) \
trx_start_if_not_started_low((t), rw)
#define trx_start_internal(t) \
trx_start_internal_low((t))
#define trx_start_internal_read_only(t) \
trx_start_internal_read_only_low(t)
#define trx_start_if_not_started_xa(t, rw) \
trx_start_if_not_started_xa_low((t), (rw))
#endif /* UNIV_DEBUG */
/*************************************************************//**
Starts the transaction for a DDL operation. */
void
trx_start_for_ddl_low(
/*==================*/
trx_t* trx, /*!< in/out: transaction */
trx_dict_op_t op); /*!< in: dictionary operation type */
#ifdef UNIV_DEBUG
#define trx_start_for_ddl(t, o) \
do { \
ut_ad((t)->start_file == 0); \
(t)->start_line = __LINE__; \
(t)->start_file = __FILE__; \
trx_start_for_ddl_low((t), (o)); \
} while (0)
#else
#define trx_start_for_ddl(t, o) \
trx_start_for_ddl_low((t), (o))
#endif /* UNIV_DEBUG */
/****************************************************************//**
Commits a transaction. */
void
trx_commit(
/*=======*/
trx_t* trx); /*!< in/out: transaction */
/****************************************************************//**
Commits a transaction and a mini-transaction. */
void
trx_commit_low(
/*===========*/
trx_t* trx, /*!< in/out: transaction */
mtr_t* mtr); /*!< in/out: mini-transaction (will be committed),
or NULL if trx made no modifications */
/****************************************************************//**
Cleans up a transaction at database startup. The cleanup is needed if
the transaction already got to the middle of a commit when the database
crashed, and we cannot roll it back. */
void
trx_cleanup_at_db_startup(
/*======================*/
trx_t* trx); /*!< in: transaction */
/**********************************************************************//**
Does the transaction commit for MySQL.
@return DB_SUCCESS or error number */
dberr_t
trx_commit_for_mysql(
/*=================*/
trx_t* trx); /*!< in/out: transaction */
/**
Does the transaction prepare for MySQL.
@param[in, out] trx Transaction instance to prepare */
dberr_t
trx_prepare_for_mysql(trx_t* trx);
/**********************************************************************//**
This function is used to find number of prepared transactions and
their transaction objects for a recovery.
@return number of prepared transactions */
int
trx_recover_for_mysql(
/*==================*/
XID* xid_list, /*!< in/out: prepared transactions */
ulint len); /*!< in: number of slots in xid_list */
/*******************************************************************//**
This function is used to find one X/Open XA distributed transaction
which is in the prepared state
@return trx or NULL; on match, the trx->xid will be invalidated;
note that the trx may have been committed, unless the caller is
holding lock_sys->mutex */
trx_t *
trx_get_trx_by_xid(
/*===============*/
XID* xid); /*!< in: X/Open XA transaction identifier */
/**********************************************************************//**
If required, flushes the log to disk if we called trx_commit_for_mysql()
with trx->flush_log_later == TRUE. */
void
trx_commit_complete_for_mysql(
/*==========================*/
trx_t* trx); /*!< in/out: transaction */
/**********************************************************************//**
Marks the latest SQL statement ended. */
void
trx_mark_sql_stat_end(
/*==================*/
trx_t* trx); /*!< in: trx handle */
/********************************************************************//**
Assigns a read view for a consistent read query. All the consistent reads
within the same transaction will get the same read view, which is created
when this function is first called for a new started transaction. */
ReadView*
trx_assign_read_view(
/*=================*/
trx_t* trx); /*!< in: active transaction */
/****************************************************************//**
@return the transaction's read view or NULL if one not assigned. */
UNIV_INLINE
ReadView*
trx_get_read_view(
/*==============*/
trx_t* trx);
/****************************************************************//**
@return the transaction's read view or NULL if one not assigned. */
UNIV_INLINE
const ReadView*
trx_get_read_view(
/*==============*/
const trx_t* trx);
/****************************************************************//**
Prepares a transaction for commit/rollback. */
void
trx_commit_or_rollback_prepare(
/*===========================*/
trx_t* trx); /*!< in/out: transaction */
/*********************************************************************//**
Creates a commit command node struct.
@return own: commit node struct */
commit_node_t*
trx_commit_node_create(
/*===================*/
mem_heap_t* heap); /*!< in: mem heap where created */
/***********************************************************//**
Performs an execution step for a commit type node in a query graph.
@return query thread to run next, or NULL */
que_thr_t*
trx_commit_step(
/*============*/
que_thr_t* thr); /*!< in: query thread */
/**********************************************************************//**
Prints info about a transaction.
Caller must hold trx_sys->mutex. */
void
trx_print_low(
/*==========*/
FILE* f,
/*!< in: output stream */
const trx_t* trx,
/*!< in: transaction */
ulint max_query_len,
/*!< in: max query length to print,
or 0 to use the default max length */
ulint n_rec_locks,
/*!< in: lock_number_of_rows_locked(&trx->lock) */
ulint n_trx_locks,
/*!< in: length of trx->lock.trx_locks */
ulint heap_size);
/*!< in: mem_heap_get_size(trx->lock.lock_heap) */
/**********************************************************************//**
Prints info about a transaction.
The caller must hold lock_sys->mutex and trx_sys->mutex.
When possible, use trx_print() instead. */
void
trx_print_latched(
/*==============*/
FILE* f, /*!< in: output stream */
const trx_t* trx, /*!< in: transaction */
ulint max_query_len); /*!< in: max query length to print,
or 0 to use the default max length */
#ifdef WITH_WSREP
/**********************************************************************//**
Prints info about a transaction.
Transaction information may be retrieved without having trx_sys->mutex acquired
so it may not be completely accurate. The caller must own lock_sys->mutex
and the trx must have some locks to make sure that it does not escape
without locking lock_sys->mutex. */
UNIV_INTERN
void
wsrep_trx_print_locking(
FILE* f, /*!< in: output stream */
const trx_t* trx, /*!< in: transaction */
ulint max_query_len) /*!< in: max query length to print,
or 0 to use the default max length */
MY_ATTRIBUTE((nonnull));
#endif /* WITH_WSREP */
/**********************************************************************//**
Prints info about a transaction.
Acquires and releases lock_sys->mutex and trx_sys->mutex. */
void
trx_print(
/*======*/
FILE* f, /*!< in: output stream */
const trx_t* trx, /*!< in: transaction */
ulint max_query_len); /*!< in: max query length to print,
or 0 to use the default max length */
/**********************************************************************//**
Determine if a transaction is a dictionary operation.
@return dictionary operation mode */
UNIV_INLINE
enum trx_dict_op_t
trx_get_dict_operation(
/*===================*/
const trx_t* trx) /*!< in: transaction */
MY_ATTRIBUTE((warn_unused_result));
/**********************************************************************//**
Flag a transaction a dictionary operation. */
UNIV_INLINE
void
trx_set_dict_operation(
/*===================*/
trx_t* trx, /*!< in/out: transaction */
enum trx_dict_op_t op); /*!< in: operation, not
TRX_DICT_OP_NONE */
/**********************************************************************//**
Determines if a transaction is in the given state.
The caller must hold trx_sys->mutex, or it must be the thread
that is serving a running transaction.
A running RW transaction must be in trx_sys->rw_trx_list.
@return TRUE if trx->state == state */
UNIV_INLINE
bool
trx_state_eq(
/*=========*/
const trx_t* trx, /*!< in: transaction */
trx_state_t state, /*!< in: state;
if state != TRX_STATE_NOT_STARTED
asserts that
trx->state != TRX_STATE_NOT_STARTED */
bool relaxed = false)
/*!< in: whether to allow
trx->state == TRX_STATE_NOT_STARTED
after an error has been reported */
MY_ATTRIBUTE((nonnull, warn_unused_result));
# ifdef UNIV_DEBUG
/**********************************************************************//**
Asserts that a transaction has been started.
The caller must hold trx_sys->mutex.
@return TRUE if started */
ibool
trx_assert_started(
/*===============*/
const trx_t* trx) /*!< in: transaction */
MY_ATTRIBUTE((warn_unused_result));
# endif /* UNIV_DEBUG */
/**********************************************************************//**
Determines if the currently running transaction has been interrupted.
@return TRUE if interrupted */
ibool
trx_is_interrupted(
/*===============*/
const trx_t* trx); /*!< in: transaction */
/**********************************************************************//**
Determines if the currently running transaction is in strict mode.
@return TRUE if strict */
ibool
trx_is_strict(
/*==========*/
trx_t* trx); /*!< in: transaction */
/*******************************************************************//**
Calculates the "weight" of a transaction. The weight of one transaction
is estimated as the number of altered rows + the number of locked rows.
@param t transaction
@return transaction weight */
#define TRX_WEIGHT(t) ((t)->undo_no + UT_LIST_GET_LEN((t)->lock.trx_locks))
/*******************************************************************//**
Compares the "weight" (or size) of two transactions. Transactions that
have edited non-transactional tables are considered heavier than ones
that have not.
@return true if weight(a) >= weight(b) */
bool
trx_weight_ge(
/*==========*/
const trx_t* a, /*!< in: the transaction to be compared */
const trx_t* b); /*!< in: the transaction to be compared */
/* Maximum length of a string that can be returned by
trx_get_que_state_str(). */
#define TRX_QUE_STATE_STR_MAX_LEN 12 /* "ROLLING BACK" */
/*******************************************************************//**
Retrieves transaction's que state in a human readable string. The string
should not be free()'d or modified.
@return string in the data segment */
UNIV_INLINE
const char*
trx_get_que_state_str(
/*==================*/
const trx_t* trx); /*!< in: transaction */
/** Retreieves the transaction ID.
In a given point in time it is guaranteed that IDs of the running
transactions are unique. The values returned by this function for readonly
transactions may be reused, so a subsequent RO transaction may get the same ID
as a RO transaction that existed in the past. The values returned by this
function should be used for printing purposes only.
@param[in] trx transaction whose id to retrieve
@return transaction id */
UNIV_INLINE
trx_id_t
trx_get_id_for_print(
const trx_t* trx);
/** Create the trx_t pool */
void
trx_pool_init();
/** Destroy the trx_t pool */
void
trx_pool_close();
/**
Set the transaction as a read-write transaction if it is not already
tagged as such.
@param[in,out] trx Transaction that needs to be "upgraded" to RW from RO */
void
trx_set_rw_mode(
trx_t* trx);
/**
Increase the reference count. If the transaction is in state
TRX_STATE_COMMITTED_IN_MEMORY then the transaction is considered
committed and the reference count is not incremented.
@param trx Transaction that is being referenced
@param do_ref_count Increment the reference iff this is true
@return transaction instance if it is not committed */
UNIV_INLINE
trx_t*
trx_reference(
trx_t* trx,
bool do_ref_count);
/**
Release the transaction. Decrease the reference count.
@param trx Transaction that is being released */
UNIV_INLINE
void
trx_release_reference(
trx_t* trx);
/**
Check if the transaction is being referenced. */
#define trx_is_referenced(t) ((t)->n_ref > 0)
/**
@param[in] requestor Transaction requesting the lock
@param[in] holder Transaction holding the lock
@return the transaction that will be rolled back, null don't care */
UNIV_INLINE
const trx_t*
trx_arbitrate(const trx_t* requestor, const trx_t* holder);
/**
@param[in] trx Transaction to check
@return true if the transaction is a high priority transaction.*/
UNIV_INLINE
bool
trx_is_high_priority(const trx_t* trx);
/**
Kill all transactions that are blocking this transaction from acquiring locks.
@param[in,out] trx High priority transaction */
void
trx_kill_blocking(trx_t* trx);
/**
Transactions that aren't started by the MySQL server don't set
the trx_t::mysql_thd field. For such transactions we set the lock
wait timeout to 0 instead of the user configured value that comes
from innodb_lock_wait_timeout via trx_t::mysql_thd.
@param trx transaction
@return lock wait timeout in seconds */
#define trx_lock_wait_timeout_get(t) \
((t)->mysql_thd != NULL \
? thd_lock_wait_timeout((t)->mysql_thd) \
: 0)
/**
Determine if the transaction is a non-locking autocommit select
(implied read-only).
@param t transaction
@return true if non-locking autocommit select transaction. */
#define trx_is_autocommit_non_locking(t) \
((t)->auto_commit && (t)->will_lock == 0)
/**
Determine if the transaction is a non-locking autocommit select
with an explicit check for the read-only status.
@param t transaction
@return true if non-locking autocommit read-only transaction. */
#define trx_is_ac_nl_ro(t) \
((t)->read_only && trx_is_autocommit_non_locking((t)))
/**
Assert that the transaction is in the trx_sys_t::rw_trx_list */
#define assert_trx_in_rw_list(t) do { \
ut_ad(!(t)->read_only); \
ut_ad((t)->in_rw_trx_list \
== !((t)->read_only || !(t)->rsegs.m_redo.rseg)); \
check_trx_state(t); \
} while (0)
/**
Check transaction state */
#define check_trx_state(t) do { \
ut_ad(!trx_is_autocommit_non_locking((t))); \
switch ((t)->state) { \
case TRX_STATE_PREPARED: \
/* fall through */ \
case TRX_STATE_ACTIVE: \
case TRX_STATE_COMMITTED_IN_MEMORY: \
continue; \
case TRX_STATE_NOT_STARTED: \
case TRX_STATE_FORCED_ROLLBACK: \
break; \
} \
ut_error; \
} while (0)
/** Check if transaction is free so that it can be re-initialized.
@param t transaction handle */
#define assert_trx_is_free(t) do { \
ut_ad(trx_state_eq((t), TRX_STATE_NOT_STARTED) \
|| trx_state_eq((t), TRX_STATE_FORCED_ROLLBACK)); \
ut_ad(!trx->has_logged()); \
ut_ad(!MVCC::is_view_active((t)->read_view)); \
ut_ad((t)->lock.wait_thr == NULL); \
ut_ad(UT_LIST_GET_LEN((t)->lock.trx_locks) == 0); \
ut_ad((t)->dict_operation == TRX_DICT_OP_NONE); \
} while(0)
/** Check if transaction is in-active so that it can be freed and put back to
transaction pool.
@param t transaction handle */
#define assert_trx_is_inactive(t) do { \
assert_trx_is_free((t)); \
ut_ad((t)->dict_operation_lock_mode == 0); \
} while(0)
#ifdef UNIV_DEBUG
/*******************************************************************//**
Assert that an autocommit non-locking select cannot be in the
rw_trx_list and that it is a read-only transaction.
The tranasction must be in the mysql_trx_list. */
# define assert_trx_nonlocking_or_in_list(t) \
do { \
if (trx_is_autocommit_non_locking(t)) { \
trx_state_t t_state = (t)->state; \
ut_ad((t)->read_only); \
ut_ad(!(t)->is_recovered); \
ut_ad(!(t)->in_rw_trx_list); \
ut_ad((t)->in_mysql_trx_list); \
ut_ad(t_state == TRX_STATE_NOT_STARTED \
|| t_state == TRX_STATE_FORCED_ROLLBACK \
|| t_state == TRX_STATE_ACTIVE); \
} else { \
check_trx_state(t); \
} \
} while (0)
#else /* UNIV_DEBUG */
/*******************************************************************//**
Assert that an autocommit non-locking slect cannot be in the
rw_trx_list and that it is a read-only transaction.
The tranasction must be in the mysql_trx_list. */
# define assert_trx_nonlocking_or_in_list(trx) ((void)0)
#endif /* UNIV_DEBUG */
typedef std::vector<ib_lock_t*, ut_allocator<ib_lock_t*> > lock_pool_t;
/*******************************************************************//**
Latching protocol for trx_lock_t::que_state. trx_lock_t::que_state
captures the state of the query thread during the execution of a query.
This is different from a transaction state. The query state of a transaction
can be updated asynchronously by other threads. The other threads can be
system threads, like the timeout monitor thread or user threads executing
other queries. Another thing to be mindful of is that there is a delay between
when a query thread is put into LOCK_WAIT state and before it actually starts
waiting. Between these two events it is possible that the query thread is
granted the lock it was waiting for, which implies that the state can be changed
asynchronously.
All these operations take place within the context of locking. Therefore state
changes within the locking code must acquire both the lock mutex and the
trx->mutex when changing trx->lock.que_state to TRX_QUE_LOCK_WAIT or
trx->lock.wait_lock to non-NULL but when the lock wait ends it is sufficient
to only acquire the trx->mutex.
To query the state either of the mutexes is sufficient within the locking
code and no mutex is required when the query thread is no longer waiting. */
/** The locks and state of an active transaction. Protected by
lock_sys->mutex, trx->mutex or both. */
struct trx_lock_t {
ulint n_active_thrs; /*!< number of active query threads */
trx_que_t que_state; /*!< valid when trx->state
== TRX_STATE_ACTIVE: TRX_QUE_RUNNING,
TRX_QUE_LOCK_WAIT, ... */
lock_t* wait_lock; /*!< if trx execution state is
TRX_QUE_LOCK_WAIT, this points to
the lock request, otherwise this is
NULL; set to non-NULL when holding
both trx->mutex and lock_sys->mutex;
set to NULL when holding
lock_sys->mutex; readers should
hold lock_sys->mutex, except when
they are holding trx->mutex and
wait_lock==NULL */
ib_uint64_t deadlock_mark; /*!< A mark field that is initialized
to and checked against lock_mark_counter
by lock_deadlock_recursive(). */
bool was_chosen_as_deadlock_victim;
/*!< when the transaction decides to
wait for a lock, it sets this to false;
if another transaction chooses this
transaction as a victim in deadlock
resolution, it sets this to true.
Protected by trx->mutex. */
time_t wait_started; /*!< lock wait started at this time,
protected only by lock_sys->mutex */
que_thr_t* wait_thr; /*!< query thread belonging to this
trx that is in QUE_THR_LOCK_WAIT
state. For threads suspended in a
lock wait, this is protected by
lock_sys->mutex. Otherwise, this may
only be modified by the thread that is
serving the running transaction. */
lock_pool_t rec_pool; /*!< Pre-allocated record locks */
lock_pool_t table_pool; /*!< Pre-allocated table locks */
ulint rec_cached; /*!< Next free rec lock in pool */
ulint table_cached; /*!< Next free table lock in pool */
mem_heap_t* lock_heap; /*!< memory heap for trx_locks;
protected by lock_sys->mutex */
trx_lock_list_t trx_locks; /*!< locks requested by the transaction;
insertions are protected by trx->mutex
and lock_sys->mutex; removals are
protected by lock_sys->mutex */
lock_pool_t table_locks; /*!< All table locks requested by this
transaction, including AUTOINC locks */
bool cancel; /*!< true if the transaction is being
rolled back either via deadlock
detection or due to lock timeout. The
caller has to acquire the trx_t::mutex
in order to cancel the locks. In
lock_trx_table_locks_remove() we
check for this cancel of a transaction's
locks and avoid reacquiring the trx
mutex to prevent recursive deadlocks.
Protected by both the lock sys mutex
and the trx_t::mutex. */
ulint n_rec_locks; /*!< number of rec locks in this trx */
/** The transaction called ha_innobase::start_stmt() to
lock a table. Most likely a temporary table. */
bool start_stmt;
};
/** Type used to store the list of tables that are modified by a given
transaction. We store pointers to the table objects in memory because
we know that a table object will not be destroyed while a transaction
that modified it is running. */
typedef std::set<
dict_table_t*,
std::less<dict_table_t*>,
ut_allocator<dict_table_t*> > trx_mod_tables_t;
/** The transaction handle
Normally, there is a 1:1 relationship between a transaction handle
(trx) and a session (client connection). One session is associated
with exactly one user transaction. There are some exceptions to this:
* For DDL operations, a subtransaction is allocated that modifies the
data dictionary tables. Lock waits and deadlocks are prevented by
acquiring the dict_operation_lock before starting the subtransaction
and releasing it after committing the subtransaction.
* The purge system uses a special transaction that is not associated
with any session.
* If the system crashed or it was quickly shut down while there were
transactions in the ACTIVE or PREPARED state, these transactions would
no longer be associated with a session when the server is restarted.
A session may be served by at most one thread at a time. The serving
thread of a session might change in some MySQL implementations.
Therefore we do not have os_thread_get_curr_id() assertions in the code.
Normally, only the thread that is currently associated with a running
transaction may access (read and modify) the trx object, and it may do
so without holding any mutex. The following are exceptions to this:
* trx_rollback_resurrected() may access resurrected (connectionless)
transactions while the system is already processing new user
transactions. The trx_sys->mutex prevents a race condition between it
and lock_trx_release_locks() [invoked by trx_commit()].
* trx_print_low() may access transactions not associated with the current
thread. The caller must be holding trx_sys->mutex and lock_sys->mutex.
* When a transaction handle is in the trx_sys->mysql_trx_list or
trx_sys->trx_list, some of its fields must not be modified without
holding trx_sys->mutex exclusively.
* The locking code (in particular, lock_deadlock_recursive() and
lock_rec_convert_impl_to_expl()) will access transactions associated
to other connections. The locks of transactions are protected by
lock_sys->mutex and sometimes by trx->mutex. */
typedef enum {
TRX_SERVER_ABORT = 0,
TRX_WSREP_ABORT = 1
} trx_abort_t;
/** Represents an instance of rollback segment along with its state variables.*/
struct trx_undo_ptr_t {
trx_rseg_t* rseg; /*!< rollback segment assigned to the
transaction, or NULL if not assigned
yet */
trx_undo_t* insert_undo; /*!< pointer to the insert undo log, or
NULL if no inserts performed yet */
trx_undo_t* update_undo; /*!< pointer to the update undo log, or
NULL if no update performed yet */
};
/** An instance of temporary rollback segment. */
struct trx_temp_undo_t {
/** temporary rollback segment, or NULL if not assigned yet */
trx_rseg_t* rseg;
/** pointer to the undo log, or NULL if nothing logged yet */
trx_undo_t* undo;
};
/** Rollback segments assigned to a transaction for undo logging. */
struct trx_rsegs_t {
/** undo log ptr holding reference to a rollback segment that resides in
system/undo tablespace used for undo logging of tables that needs
to be recovered on crash. */
trx_undo_ptr_t m_redo;
/** undo log for temporary tables; discarded immediately after
transaction commit/rollback */
trx_temp_undo_t m_noredo;
};
struct TrxVersion {
TrxVersion(trx_t* trx);
/**
@return true if the trx_t instance is the same */
bool operator==(const TrxVersion& rhs) const
{
return(rhs.m_trx == m_trx);
}
trx_t* m_trx;
ulint m_version;
};
typedef std::list<TrxVersion, ut_allocator<TrxVersion> > hit_list_t;
struct trx_t {
TrxMutex mutex; /*!< Mutex protecting the fields
state and lock (except some fields
of lock, which are protected by
lock_sys->mutex) */
/* Note: in_depth was split from in_innodb for fixing a RO
performance issue. Acquiring the trx_t::mutex for each row
costs ~3% in performance. It is not required for correctness.
Therefore we increment/decrement in_depth without holding any
mutex. The assumption is that the Server will only ever call
the handler from one thread. This is not true for kill_connection.
Therefore in innobase_kill_connection. We don't increment this
counter via TrxInInnoDB. */
ib_uint32_t in_depth; /*!< Track nested TrxInInnoDB
count */
ib_uint32_t in_innodb; /*!< if the thread is executing
in the InnoDB context count > 0. */
bool abort; /*!< if this flag is set then
this transaction must abort when
it can */
trx_id_t id; /*!< transaction id */
trx_id_t no; /*!< transaction serialization number:
max trx id shortly before the
transaction is moved to
COMMITTED_IN_MEMORY state.
Protected by trx_sys_t::mutex
when trx->in_rw_trx_list. Initially
set to TRX_ID_MAX. */
/** State of the trx from the point of view of concurrency control
and the valid state transitions.
Possible states:
TRX_STATE_NOT_STARTED
TRX_STATE_FORCED_ROLLBACK
TRX_STATE_ACTIVE
TRX_STATE_PREPARED
TRX_STATE_COMMITTED_IN_MEMORY (alias below COMMITTED)
Valid state transitions are:
Regular transactions:
* NOT_STARTED -> ACTIVE -> COMMITTED -> NOT_STARTED
Auto-commit non-locking read-only:
* NOT_STARTED -> ACTIVE -> NOT_STARTED
XA (2PC):
* NOT_STARTED -> ACTIVE -> PREPARED -> COMMITTED -> NOT_STARTED
Recovered XA:
* NOT_STARTED -> PREPARED -> COMMITTED -> (freed)
XA (2PC) (shutdown or disconnect before ROLLBACK or COMMIT):
* NOT_STARTED -> PREPARED -> (freed)
Disconnected XA can become recovered:
* ... -> ACTIVE -> PREPARED (connected) -> PREPARED (disconnected)
Disconnected means from mysql e.g due to the mysql client disconnection.
Latching and various transaction lists membership rules:
XA (2PC) transactions are always treated as non-autocommit.
Transitions to ACTIVE or NOT_STARTED occur when
!in_rw_trx_list (no trx_sys->mutex needed).
Autocommit non-locking read-only transactions move between states
without holding any mutex. They are !in_rw_trx_list.
All transactions, unless they are determined to be ac-nl-ro,
explicitly tagged as read-only or read-write, will first be put
on the read-only transaction list. Only when a !read-only transaction
in the read-only list tries to acquire an X or IX lock on a table
do we remove it from the read-only list and put it on the read-write
list. During this switch we assign it a rollback segment.
When a transaction is NOT_STARTED, it can be in_mysql_trx_list if
it is a user transaction. It cannot be in rw_trx_list.
ACTIVE->PREPARED->COMMITTED is only possible when trx->in_rw_trx_list.
The transition ACTIVE->PREPARED is protected by trx_sys->mutex.
ACTIVE->COMMITTED is possible when the transaction is in
rw_trx_list.
Transitions to COMMITTED are protected by both lock_sys->mutex
and trx->mutex.
NOTE: Some of these state change constraints are an overkill,
currently only required for a consistent view for printing stats.
This unnecessarily adds a huge cost for the general case. */
trx_state_t state;
ReadView* read_view; /*!< consistent read view used in the
transaction, or NULL if not yet set */
UT_LIST_NODE_T(trx_t)
trx_list; /*!< list of transactions;
protected by trx_sys->mutex. */
UT_LIST_NODE_T(trx_t)
no_list; /*!< Required during view creation
to check for the view limit for
transactions that are committing */
trx_lock_t lock; /*!< Information about the transaction
locks and state. Protected by
trx->mutex or lock_sys->mutex
or both */
bool is_recovered; /*!< 0=normal transaction,
1=recovered, must be rolled back,
protected by trx_sys->mutex when
trx->in_rw_trx_list holds */
hit_list_t hit_list; /*!< List of transactions to kill,
when a high priority transaction
is blocked on a lock wait. */
os_thread_id_t killed_by; /*!< The thread ID that wants to
kill this transaction asynchronously.
This is required because we recursively
enter the handlerton methods and need
to distinguish between the kill thread
and the transaction thread.
Note: We need to be careful w.r.t the
Thread Pool. The thread doing the kill
should not leave InnoDB between the
mark and the actual async kill because
the running thread can change. */
/* These fields are not protected by any mutex. */
const char* op_info; /*!< English text describing the
current operation, or an empty
string */
ulint isolation_level;/*!< TRX_ISO_REPEATABLE_READ, ... */
bool check_foreigns; /*!< normally TRUE, but if the user
wants to suppress foreign key checks,
(in table imports, for example) we
set this FALSE */
/*------------------------------*/
/* MySQL has a transaction coordinator to coordinate two phase
commit between multiple storage engines and the binary log. When
an engine participates in a transaction, it's responsible for
registering itself using the trans_register_ha() API. */
bool is_registered; /* This flag is set to true after the
transaction has been registered with
the coordinator using the XA API, and
is set to false after commit or
rollback. */
unsigned active_commit_ordered:1;/* 1 if owns prepare mutex */
/*------------------------------*/
bool check_unique_secondary;
/*!< normally TRUE, but if the user
wants to speed up inserts by
suppressing unique key checks
for secondary indexes when we decide
if we can use the insert buffer for
them, we set this FALSE */
bool flush_log_later;/* In 2PC, we hold the
prepare_commit mutex across
both phases. In that case, we
defer flush of the logs to disk
until after we release the
mutex. */
bool must_flush_log_later;/*!< this flag is set to TRUE in
trx_commit() if flush_log_later was
TRUE, and there were modifications by
the transaction; in that case we must
flush the log in
trx_commit_complete_for_mysql() */
ulint duplicates; /*!< TRX_DUP_IGNORE | TRX_DUP_REPLACE */
trx_dict_op_t dict_operation; /**< @see enum trx_dict_op_t */
/* Fields protected by the srv_conc_mutex. */
bool declared_to_be_inside_innodb;
/*!< this is TRUE if we have declared
this transaction in
srv_conc_enter_innodb to be inside the
InnoDB engine */
ib_uint32_t n_tickets_to_enter_innodb;
/*!< this can be > 0 only when
declared_to_... is TRUE; when we come
to srv_conc_innodb_enter, if the value
here is > 0, we decrement this by 1 */
ib_uint32_t dict_operation_lock_mode;
/*!< 0, RW_S_LATCH, or RW_X_LATCH:
the latch mode trx currently holds
on dict_operation_lock. Protected
by dict_operation_lock. */
time_t start_time; /*!< time the state last time became
TRX_STATE_ACTIVE */
ib_uint64_t start_time_micro; /*!< start time of transaction in
microseconds */
lsn_t commit_lsn; /*!< lsn at the time of the commit */
table_id_t table_id; /*!< Table to drop iff dict_operation
== TRX_DICT_OP_TABLE, or 0. */
/*------------------------------*/
THD* mysql_thd; /*!< MySQL thread handle corresponding
to this trx, or NULL */
trx_abort_t abort_type; /*!< Transaction abort type*/
const char* mysql_log_file_name;
/*!< if MySQL binlog is used, this field
contains a pointer to the latest file
name; this is NULL if binlog is not
used */
int64_t mysql_log_offset;
/*!< if MySQL binlog is used, this
field contains the end offset of the
binlog entry */
/*------------------------------*/
ib_uint32_t n_mysql_tables_in_use; /*!< number of Innobase tables
used in the processing of the current
SQL statement in MySQL */
ib_uint32_t mysql_n_tables_locked;
/*!< how many tables the current SQL
statement uses, except those
in consistent read */
/*------------------------------*/
#ifdef UNIV_DEBUG
/** The following two fields are mutually exclusive. */
/* @{ */
bool in_rw_trx_list; /*!< true if in trx_sys->rw_trx_list */
/* @} */
#endif /* UNIV_DEBUG */
UT_LIST_NODE_T(trx_t)
mysql_trx_list; /*!< list of transactions created for
MySQL; protected by trx_sys->mutex */
#ifdef UNIV_DEBUG
bool in_mysql_trx_list;
/*!< true if in
trx_sys->mysql_trx_list */
#endif /* UNIV_DEBUG */
/*------------------------------*/
dberr_t error_state; /*!< 0 if no error, otherwise error
number; NOTE That ONLY the thread
doing the transaction is allowed to
set this field: this is NOT protected
by any mutex */
const dict_index_t*error_info; /*!< if the error number indicates a
duplicate key error, a pointer to
the problematic index is stored here */
ulint error_key_num; /*!< if the index creation fails to a
duplicate key error, a mysql key
number of that index is stored here */
sess_t* sess; /*!< session of the trx, NULL if none */
que_t* graph; /*!< query currently run in the session,
or NULL if none; NOTE that the query
belongs to the session, and it can
survive over a transaction commit, if
it is a stored procedure with a COMMIT
WORK statement, for instance */
/*------------------------------*/
UT_LIST_BASE_NODE_T(trx_named_savept_t)
trx_savepoints; /*!< savepoints set with SAVEPOINT ...,
oldest first */
/*------------------------------*/
UndoMutex undo_mutex; /*!< mutex protecting the fields in this
section (down to undo_no_arr), EXCEPT
last_sql_stat_start, which can be
accessed only when we know that there
cannot be any activity in the undo
logs! */
undo_no_t undo_no; /*!< next undo log record number to
assign; since the undo log is
private for a transaction, this
is a simple ascending sequence
with no gaps; thus it represents
the number of modified/inserted
rows in a transaction */
ulint undo_rseg_space;
/*!< space id where last undo record
was written */
trx_savept_t last_sql_stat_start;
/*!< undo_no when the last sql statement
was started: in case of an error, trx
is rolled back down to this undo
number; see note at undo_mutex! */
trx_rsegs_t rsegs; /* rollback segments for undo logging */
undo_no_t roll_limit; /*!< least undo number to undo during
a partial rollback; 0 otherwise */
#ifdef UNIV_DEBUG
bool in_rollback; /*!< true when the transaction is
executing a partial or full rollback */
#endif /* UNIV_DEBUG */
ulint pages_undone; /*!< number of undo log pages undone
since the last undo log truncation */
/*------------------------------*/
ulint n_autoinc_rows; /*!< no. of AUTO-INC rows required for
an SQL statement. This is useful for
multi-row INSERTs */
ib_vector_t* autoinc_locks; /* AUTOINC locks held by this
transaction. Note that these are
also in the lock list trx_locks. This
vector needs to be freed explicitly
when the trx instance is destroyed.
Protected by lock_sys->mutex. */
/*------------------------------*/
bool read_only; /*!< true if transaction is flagged
as a READ-ONLY transaction.
if auto_commit && will_lock == 0
then it will be handled as a
AC-NL-RO-SELECT (Auto Commit Non-Locking
Read Only Select). A read only
transaction will not be assigned an
UNDO log. */
bool auto_commit; /*!< true if it is an autocommit */
ib_uint32_t will_lock; /*!< Will acquire some locks. Increment
each time we determine that a lock will
be acquired by the MySQL layer. */
/*------------------------------*/
fts_trx_t* fts_trx; /*!< FTS information, or NULL if
transaction hasn't modified tables
with FTS indexes (yet). */
doc_id_t fts_next_doc_id;/* The document id used for updates */
/*------------------------------*/
ib_uint32_t flush_tables; /*!< if "covering" the FLUSH TABLES",
count of tables being flushed. */
/*------------------------------*/
bool ddl; /*!< true if it is an internal
transaction for DDL */
bool internal; /*!< true if it is a system/internal
transaction background task. This
includes DDL transactions too. Such
transactions are always treated as
read-write. */
/*------------------------------*/
#ifdef UNIV_DEBUG
unsigned start_line; /*!< Track where it was started from */
const char* start_file; /*!< Filename where it was started */
#endif /* UNIV_DEBUG */
lint n_ref; /*!< Count of references, protected
by trx_t::mutex. We can't release the
locks nor commit the transaction until
this reference is 0. We can change
the state to COMMITTED_IN_MEMORY to
signify that it is no longer
"active". */
/** Version of this instance. It is incremented each time the
instance is re-used in trx_start_low(). It is used to track
whether a transaction has been restarted since it was tagged
for asynchronous rollback. */
ulint version;
XID* xid; /*!< X/Open XA transaction
identification to identify a
transaction branch */
trx_mod_tables_t mod_tables; /*!< List of tables that were modified
by this transaction */
/*------------------------------*/
char* detailed_error; /*!< detailed error message for last
error, or empty. */
FlushObserver* flush_observer; /*!< flush observer */
/* Lock wait statistics */
ulint n_rec_lock_waits;
/*!< Number of record lock waits,
might not be exactly correct. */
ulint n_table_lock_waits;
/*!< Number of table lock waits,
might not be exactly correct. */
ulint total_rec_lock_wait_time;
/*!< Total rec lock wait time up
to this moment. */
ulint total_table_lock_wait_time;
/*!< Total table lock wait time
up to this moment. */
#ifdef WITH_WSREP
os_event_t wsrep_event; /* event waited for in srv_conc_slot */
#endif /* WITH_WSREP */
ulint magic_n;
/** @return whether any persistent undo log has been generated */
bool has_logged_persistent() const
{
return(rsegs.m_redo.insert_undo || rsegs.m_redo.update_undo);
}
/** @return whether any undo log has been generated */
bool has_logged() const
{
return(has_logged_persistent() || rsegs.m_noredo.undo);
}
/** @return rollback segment for modifying temporary tables */
trx_rseg_t* get_temp_rseg()
{
if (trx_rseg_t* rseg = rsegs.m_noredo.rseg) {
ut_ad(id != 0);
return(rseg);
}
return(assign_temp_rseg());
}
private:
/** Assign a rollback segment for modifying temporary tables.
@return the assigned rollback segment */
trx_rseg_t* assign_temp_rseg();
};
/**
Check if transaction is started.
@param[in] trx Transaction whose state we need to check
@reutrn true if transaction is in state started */
inline
bool
trx_is_started(
const trx_t* trx)
{
return(trx->state != TRX_STATE_NOT_STARTED
&& trx->state != TRX_STATE_FORCED_ROLLBACK);
}
/* Transaction isolation levels (trx->isolation_level) */
#define TRX_ISO_READ_UNCOMMITTED 0 /* dirty read: non-locking
SELECTs are performed so that
we do not look at a possible
earlier version of a record;
thus they are not 'consistent'
reads under this isolation
level; otherwise like level
2 */
#define TRX_ISO_READ_COMMITTED 1 /* somewhat Oracle-like
isolation, except that in
range UPDATE and DELETE we
must block phantom rows
with next-key locks;
SELECT ... FOR UPDATE and ...
LOCK IN SHARE MODE only lock
the index records, NOT the
gaps before them, and thus
allow free inserting;
each consistent read reads its
own snapshot */
#define TRX_ISO_REPEATABLE_READ 2 /* this is the default;
all consistent reads in the
same trx read the same
snapshot;
full next-key locking used
in locking reads to block
insertions into gaps */
#define TRX_ISO_SERIALIZABLE 3 /* all plain SELECTs are
converted to LOCK IN SHARE
MODE reads */
/* Treatment of duplicate values (trx->duplicates; for example, in inserts).
Multiple flags can be combined with bitwise OR. */
#define TRX_DUP_IGNORE 1U /* duplicate rows are to be updated */
#define TRX_DUP_REPLACE 2U /* duplicate rows are to be replaced */
/** Commit node states */
enum commit_node_state {
COMMIT_NODE_SEND = 1, /*!< about to send a commit signal to
the transaction */
COMMIT_NODE_WAIT /*!< commit signal sent to the transaction,
waiting for completion */
};
/** Commit command node in a query graph */
struct commit_node_t{
que_common_t common; /*!< node type: QUE_NODE_COMMIT */
enum commit_node_state
state; /*!< node execution state */
};
/** Test if trx->mutex is owned. */
#define trx_mutex_own(t) mutex_own(&t->mutex)
/** Acquire the trx->mutex. */
#define trx_mutex_enter(t) do { \
mutex_enter(&t->mutex); \
} while (0)
/** Release the trx->mutex. */
#define trx_mutex_exit(t) do { \
mutex_exit(&t->mutex); \
} while (0)
/** Track if a transaction is executing inside InnoDB code. It acts
like a gate between the Server and InnoDB. */
class TrxInInnoDB {
public:
/**
@param[in,out] trx Transaction entering InnoDB via the handler
@param[in] disable true if called from COMMIT/ROLLBACK method */
TrxInInnoDB(trx_t* trx, bool disable = false)
:
m_trx(trx)
{
enter(trx, disable);
}
/**
Destructor */
~TrxInInnoDB()
{
exit(m_trx);
}
/**
@return true if the transaction has been marked for asynchronous
rollback */
bool is_aborted() const
{
return(is_aborted(m_trx));
}
/**
@return true if the transaction can't be rolled back asynchronously */
bool is_rollback_disabled() const
{
return((m_trx->in_innodb & TRX_FORCE_ROLLBACK_DISABLE) > 0);
}
/**
@return true if the transaction has been marked for asynchronous
rollback */
static bool is_aborted(const trx_t* trx)
{
if (trx->state == TRX_STATE_NOT_STARTED) {
return(false);
}
ut_ad(srv_read_only_mode || trx->in_depth > 0);
ut_ad(srv_read_only_mode || trx->in_innodb > 0);
return(trx->abort
|| trx->state == TRX_STATE_FORCED_ROLLBACK);
}
/**
Start statement requested for transaction.
@param[in, out] trx Transaction at the start of a SQL statement */
static void begin_stmt(trx_t* trx)
{
enter(trx, false);
}
/**
Note an end statement for transaction
@param[in, out] trx Transaction at end of a SQL statement */
static void end_stmt(trx_t* trx)
{
exit(trx);
}
/**
@return true if the rollback is being initiated by the thread that
marked the transaction for asynchronous rollback */
static bool is_async_rollback(const trx_t* trx)
{
return(trx->killed_by == os_thread_get_curr_id());
}
private:
/**
Note that we have crossed into InnoDB code.
@param[in] disable true if called from COMMIT/ROLLBACK method */
static void enter(trx_t* trx, bool disable)
{
if (srv_read_only_mode) {
return;
}
ut_ad(!is_async_rollback(trx));
/* If it hasn't already been marked for async rollback.
and it will be committed/rolled back. */
if (disable) {
trx_mutex_enter(trx);
if (!is_forced_rollback(trx)
&& is_started(trx)
&& !trx_is_autocommit_non_locking(trx)) {
ut_ad(trx->killed_by == 0);
/* This transaction has crossed the point of
no return and cannot be rolled back
asynchronously now. It must commit or rollback
synhronously. */
trx->in_innodb |= TRX_FORCE_ROLLBACK_DISABLE;
}
trx_mutex_exit(trx);
}
/* Avoid excessive mutex acquire/release */
if (trx->in_depth++) {
/* The transaction is already inside InnoDB. */
return;
}
trx_mutex_enter(trx);
wait(trx);
ut_ad((trx->in_innodb & TRX_FORCE_ROLLBACK_MASK) == 0);
++trx->in_innodb;
trx_mutex_exit(trx);
}
/**
Note that we are exiting InnoDB code */
static void exit(trx_t* trx)
{
if (srv_read_only_mode) {
return;
}
/* Avoid excessive mutex acquire/release */
ut_ad(trx->in_depth > 0);
if (--trx->in_depth) {
return;
}
trx_mutex_enter(trx);
ut_ad((trx->in_innodb & TRX_FORCE_ROLLBACK_MASK) > 0);
--trx->in_innodb;
trx_mutex_exit(trx);
}
/*
@return true if it is a forced rollback, asynchronously */
static bool is_forced_rollback(const trx_t* trx)
{
ut_ad(trx_mutex_own(trx));
return((trx->in_innodb & TRX_FORCE_ROLLBACK)) > 0;
}
/**
Wait for the asynchronous rollback to complete, if it is in progress */
static void wait(trx_t* trx)
{
ut_ad(trx_mutex_own(trx));
ulint loop_count = 0;
/* start with optimistic sleep time - 20 micro seconds. */
ulint sleep_time = 20;
while (is_forced_rollback(trx)) {
/* Wait for the async rollback to complete */
trx_mutex_exit(trx);
loop_count++;
/* If the wait is long, don't hog the cpu. */
if (loop_count < 100) {
/* 20 microseconds */
sleep_time = 20;
} else if (loop_count < 1000) {
/* 1 millisecond */
sleep_time = 1000;
} else {
/* 100 milliseconds */
sleep_time = 100000;
}
os_thread_sleep(sleep_time);
trx_mutex_enter(trx);
}
}
/**
@return true if transaction is started */
static bool is_started(const trx_t* trx)
{
ut_ad(trx_mutex_own(trx));
return(trx_is_started(trx));
}
private:
/**
Transaction instance crossing the handler boundary from the Server. */
trx_t* m_trx;
};
#include "trx0trx.ic"
#endif
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