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用于EagleEye3.0 规则集漏报和误报测试的示例项目，项目收集于github和gitee
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test-example-projects/c++_projects/280w-mysql-8.0.18/sql/xa.cc

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/* Copyright (c) 2013, 2019, Oracle 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 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.
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 */
#include "sql/xa.h"
#include <memory>
#include <new>
#include <string>
#include <unordered_map>
#include <utility>
#include "m_ctype.h"
#include "m_string.h"
#include "map_helpers.h"
#include "my_dbug.h"
#include "my_loglevel.h"
#include "my_macros.h"
#include "my_psi_config.h"
#include "my_sys.h"
#include "mysql/components/services/log_builtins.h"
#include "mysql/components/services/mysql_mutex_bits.h"
#include "mysql/components/services/psi_mutex_bits.h"
#include "mysql/plugin.h" // MYSQL_XIDDATASIZE
#include "mysql/psi/mysql_mutex.h"
#include "mysql/psi/mysql_transaction.h"
#include "mysql/psi/psi_base.h"
#include "mysql/service_mysql_alloc.h"
#include "mysql_com.h"
#include "mysqld_error.h"
#include "sql/auth/sql_security_ctx.h"
#include "sql/binlog.h" // is_transaction_empty
#include "sql/clone_handler.h"
#include "sql/debug_sync.h" // DEBUG_SYNC
#include "sql/handler.h" // handlerton
#include "sql/item.h"
#include "sql/log.h"
#include "sql/mdl.h"
#include "sql/mdl_context_backup.h" // MDL_context_backup_manager
#include "sql/mysqld.h" // server_id
#include "sql/protocol.h"
#include "sql/psi_memory_key.h" // key_memory_XID
#include "sql/query_options.h"
#include "sql/rpl_context.h"
#include "sql/rpl_gtid.h"
#include "sql/sql_class.h" // THD
#include "sql/sql_const.h"
#include "sql/sql_error.h"
#include "sql/sql_list.h"
#include "sql/sql_plugin.h" // plugin_foreach
#include "sql/sql_table.h" // filename_to_tablename
#include "sql/system_variables.h"
#include "sql/tc_log.h" // tc_log
#include "sql/transaction.h" // trans_begin, trans_rollback
#include "sql/transaction_info.h"
#include "sql_string.h"
#include "template_utils.h"
#include "thr_mutex.h"
const char *XID_STATE::xa_state_names[] = {"NON-EXISTING", "ACTIVE", "IDLE",
"PREPARED", "ROLLBACK ONLY"};
/* for recover() handlerton call */
static const int MIN_XID_LIST_SIZE = 128;
static const int MAX_XID_LIST_SIZE = 1024 * 128;
struct transaction_free_hash {
void operator()(Transaction_ctx *) const;
};
static bool inited = false;
static mysql_mutex_t LOCK_transaction_cache;
static malloc_unordered_map<std::string, std::shared_ptr<Transaction_ctx>>
transaction_cache{key_memory_XID};
static const uint MYSQL_XID_PREFIX_LEN = 8; // must be a multiple of 8
static const uint MYSQL_XID_OFFSET = MYSQL_XID_PREFIX_LEN + sizeof(server_id);
static const uint MYSQL_XID_GTRID_LEN = MYSQL_XID_OFFSET + sizeof(my_xid);
static void attach_native_trx(THD *thd);
static std::shared_ptr<Transaction_ctx> transaction_cache_search(XID *xid);
static bool transaction_cache_insert(XID *xid, Transaction_ctx *transaction);
static bool transaction_cache_insert_recovery(XID *xid);
my_xid xid_t::get_my_xid() const {
static_assert(XIDDATASIZE == MYSQL_XIDDATASIZE,
"Our #define needs to match the one in plugin.h.");
if (gtrid_length == static_cast<long>(MYSQL_XID_GTRID_LEN) &&
bqual_length == 0 &&
!memcmp(data, MYSQL_XID_PREFIX, MYSQL_XID_PREFIX_LEN)) {
my_xid tmp;
memcpy(&tmp, data + MYSQL_XID_OFFSET, sizeof(tmp));
return tmp;
}
return 0;
}
void xid_t::set(my_xid xid) {
formatID = 1;
memcpy(data, MYSQL_XID_PREFIX, MYSQL_XID_PREFIX_LEN);
memcpy(data + MYSQL_XID_PREFIX_LEN, &server_id, sizeof(server_id));
memcpy(data + MYSQL_XID_OFFSET, &xid, sizeof(xid));
gtrid_length = MYSQL_XID_GTRID_LEN;
bqual_length = 0;
}
static bool xacommit_handlerton(THD *, plugin_ref plugin, void *arg) {
handlerton *hton = plugin_data<handlerton *>(plugin);
if (hton->state == SHOW_OPTION_YES && hton->recover) {
xa_status_code ret = hton->commit_by_xid(hton, (XID *)arg);
/*
Consider XAER_NOTA as success since not every storage should be
involved into XA transaction, therefore absence of transaction
specified by xid in storage engine doesn't mean that a real error
happened. To illustrate it, lets consider the corner case
when no one storage engine is involved into XA transaction:
XA START 'xid1';
XA END 'xid1';
XA PREPARE 'xid1';
XA COMMIT 'xid1';
For this use case, handing of the statement XA COMMIT leads to
returning XAER_NOTA by ha_innodb::commit_by_xid because there isn't
a real transaction managed by innodb. So, there is no XA transaction
with specified xid in resource manager represented by InnoDB storage
engine although such transaction exists in transaction manager
represented by mysql server runtime.
*/
if (ret != XA_OK && ret != XAER_NOTA) {
my_error(ER_XAER_RMERR, MYF(0));
return true;
}
return false;
}
return false;
}
static bool xarollback_handlerton(THD *, plugin_ref plugin, void *arg) {
handlerton *hton = plugin_data<handlerton *>(plugin);
if (hton->state == SHOW_OPTION_YES && hton->recover) {
xa_status_code ret = hton->rollback_by_xid(hton, (XID *)arg);
/*
Consider XAER_NOTA as success since not every storage should be
involved into XA transaction, therefore absence of transaction
specified by xid in storage engine doesn't mean that a real error
happened. To illustrate it, lets consider the corner case
when no one storage engine is involved into XA transaction:
XA START 'xid1';
XA END 'xid1';
XA PREPARE 'xid1';
XA COMMIT 'xid1';
For this use case, handing of the statement XA COMMIT leads to
returning XAER_NOTA by ha_innodb::commit_by_xid because there isn't
a real transaction managed by innodb. So, there is no XA transaction
with specified xid in resource manager represented by InnoDB storage
engine although such transaction exists in transaction manager
represented by mysql server runtime.
*/
if (ret != XA_OK && ret != XAER_NOTA) {
my_error(ER_XAER_RMERR, MYF(0));
return true;
}
return false;
}
return false;
}
static bool ha_commit_or_rollback_by_xid(THD *, XID *xid, bool commit) {
return plugin_foreach(nullptr,
commit ? xacommit_handlerton : xarollback_handlerton,
MYSQL_STORAGE_ENGINE_PLUGIN, xid);
}
Recovered_xa_transactions *Recovered_xa_transactions::m_instance = nullptr;
Recovered_xa_transactions::Recovered_xa_transactions()
: m_prepared_xa_trans(Malloc_allocator<XA_recover_txn *>(
key_memory_Recovered_xa_transactions)),
m_mem_root_inited(false) {}
Recovered_xa_transactions &Recovered_xa_transactions::instance() {
return *m_instance;
}
bool Recovered_xa_transactions::init() {
m_instance = new (std::nothrow) Recovered_xa_transactions();
return m_instance == nullptr;
}
void Recovered_xa_transactions::destroy() {
delete m_instance;
m_instance = nullptr;
}
bool Recovered_xa_transactions::add_prepared_xa_transaction(
XA_recover_txn *prepared_xa_trn_arg) {
XA_recover_txn *prepared_xa_trn = new (&m_mem_root) XA_recover_txn();
if (prepared_xa_trn == nullptr) {
LogErr(ERROR_LEVEL, ER_SERVER_OUTOFMEMORY,
static_cast<int>(sizeof(XA_recover_txn)));
return true;
}
prepared_xa_trn->id = prepared_xa_trn_arg->id;
prepared_xa_trn->mod_tables = prepared_xa_trn_arg->mod_tables;
m_prepared_xa_trans.push_back(prepared_xa_trn);
return false;
}
MEM_ROOT *Recovered_xa_transactions::get_allocated_memroot() {
if (!m_mem_root_inited) {
init_sql_alloc(key_memory_XID, &m_mem_root, TABLE_ALLOC_BLOCK_SIZE, 0);
m_mem_root_inited = true;
}
return &m_mem_root;
}
struct xarecover_st {
int len, found_foreign_xids, found_my_xids;
XA_recover_txn *list;
const memroot_unordered_set<my_xid> *commit_list;
bool dry_run;
};
static bool xarecover_create_mdl_backup(XA_recover_txn &txn,
MEM_ROOT *mem_root) {
MDL_request_list mdl_requests;
List_iterator<st_handler_tablename> table_list_it(*txn.mod_tables);
st_handler_tablename *tbl_name;
while ((tbl_name = table_list_it++)) {
MDL_request *table_mdl_request = new (mem_root) MDL_request;
if (table_mdl_request == nullptr) {
/* Out of memory: Abort() */
return true;
}
char db_buff[NAME_CHAR_LEN * FILENAME_CHARSET_MBMAXLEN + 1];
int len = filename_to_tablename(tbl_name->db, db_buff, sizeof(db_buff));
db_buff[len] = '\0';
char name_buff[NAME_CHAR_LEN * FILENAME_CHARSET_MBMAXLEN + 1];
len = filename_to_tablename(tbl_name->tablename, name_buff,
sizeof(name_buff));
name_buff[len] = '\0';
/*
We do not have information about the actual lock taken
during the transaction. Hence we are going with a strong
lock to be safe.
*/
MDL_REQUEST_INIT(table_mdl_request, MDL_key::TABLE, db_buff, name_buff,
MDL_SHARED_WRITE, MDL_TRANSACTION);
mdl_requests.push_front(table_mdl_request);
}
return MDL_context_backup_manager::instance().create_backup(
&mdl_requests, txn.id.key(), txn.id.key_length());
}
bool Recovered_xa_transactions::recover_prepared_xa_transactions() {
bool ret = false;
if (m_mem_root_inited) {
while (!m_prepared_xa_trans.empty()) {
auto prepared_xa_trn = m_prepared_xa_trans.front();
transaction_cache_insert_recovery(&prepared_xa_trn->id);
if (xarecover_create_mdl_backup(*prepared_xa_trn, &m_mem_root)) {
ret = true;
break;
}
m_prepared_xa_trans.pop_front();
}
free_root(&m_mem_root, MYF(0));
m_mem_root_inited = false;
}
return ret;
}
static bool xarecover_handlerton(THD *, plugin_ref plugin, void *arg) {
handlerton *hton = plugin_data<handlerton *>(plugin);
xarecover_st *info = (struct xarecover_st *)arg;
int got;
if (hton->state == SHOW_OPTION_YES && hton->recover) {
while (
(got = hton->recover(
hton, info->list, info->len,
Recovered_xa_transactions::instance().get_allocated_memroot())) >
0) {
LogErr(INFORMATION_LEVEL, ER_XA_RECOVER_FOUND_TRX_IN_SE, got,
ha_resolve_storage_engine_name(hton));
for (int i = 0; i < got; i++) {
my_xid x = info->list[i].id.get_my_xid();
if (!x) // not "mine" - that is generated by external TM
{
#ifndef DBUG_OFF
char buf[XIDDATASIZE * 4 + 6]; // see xid_to_str
XID *xid = &info->list[i].id;
LogErr(INFORMATION_LEVEL, ER_XA_IGNORING_XID, xid->xid_to_str(buf));
#endif
if (Recovered_xa_transactions::instance().add_prepared_xa_transaction(
&info->list[i])) {
return true;
}
info->found_foreign_xids++;
continue;
}
if (info->dry_run) {
info->found_my_xids++;
continue;
}
// recovery mode
if (info->commit_list
? info->commit_list->count(x) != 0
: tc_heuristic_recover == TC_HEURISTIC_RECOVER_COMMIT) {
#ifndef DBUG_OFF
char buf[XIDDATASIZE * 4 + 6]; // see xid_to_str
XID *xid = &info->list[i].id;
LogErr(INFORMATION_LEVEL, ER_XA_COMMITTING_XID, xid->xid_to_str(buf));
#endif
hton->commit_by_xid(hton, &info->list[i].id);
} else {
#ifndef DBUG_OFF
char buf[XIDDATASIZE * 4 + 6]; // see xid_to_str
XID *xid = &info->list[i].id;
LogErr(INFORMATION_LEVEL, ER_XA_ROLLING_BACK_XID,
xid->xid_to_str(buf));
#endif
hton->rollback_by_xid(hton, &info->list[i].id);
}
}
if (got < info->len) break;
}
}
return false;
}
int ha_recover(const memroot_unordered_set<my_xid> *commit_list) {
xarecover_st info;
DBUG_TRACE;
info.found_foreign_xids = info.found_my_xids = 0;
info.commit_list = commit_list;
info.dry_run =
(info.commit_list == 0 && tc_heuristic_recover == TC_HEURISTIC_NOT_USED);
info.list = NULL;
/* commit_list and tc_heuristic_recover cannot be set both */
DBUG_ASSERT(info.commit_list == 0 ||
tc_heuristic_recover == TC_HEURISTIC_NOT_USED);
/* if either is set, total_ha_2pc must be set too */
DBUG_ASSERT(info.dry_run || total_ha_2pc > (ulong)opt_bin_log);
if (total_ha_2pc <= (ulong)opt_bin_log) return 0;
if (info.commit_list) LogErr(SYSTEM_LEVEL, ER_XA_STARTING_RECOVERY);
if (total_ha_2pc > (ulong)opt_bin_log + 1) {
if (tc_heuristic_recover == TC_HEURISTIC_RECOVER_ROLLBACK) {
LogErr(ERROR_LEVEL, ER_XA_NO_MULTI_2PC_HEURISTIC_RECOVER);
return 1;
}
} else {
/*
If there is only one 2pc capable storage engine it is always safe
to rollback. This setting will be ignored if we are in automatic
recovery mode.
*/
tc_heuristic_recover = TC_HEURISTIC_RECOVER_ROLLBACK; // forcing ROLLBACK
info.dry_run = false;
}
for (info.len = MAX_XID_LIST_SIZE;
info.list == 0 && info.len > MIN_XID_LIST_SIZE; info.len /= 2) {
info.list = new (std::nothrow) XA_recover_txn[info.len];
}
if (!info.list) {
LogErr(ERROR_LEVEL, ER_SERVER_OUTOFMEMORY,
static_cast<int>(info.len * sizeof(XID)));
return 1;
}
if (plugin_foreach(nullptr, xarecover_handlerton, MYSQL_STORAGE_ENGINE_PLUGIN,
&info)) {
return 1;
}
delete[] info.list;
if (info.found_foreign_xids)
LogErr(WARNING_LEVEL, ER_XA_RECOVER_FOUND_XA_TRX, info.found_foreign_xids);
if (info.dry_run && info.found_my_xids) {
LogErr(ERROR_LEVEL, ER_XA_RECOVER_EXPLANATION, info.found_my_xids,
opt_tc_log_file);
return 1;
}
if (info.commit_list) LogErr(SYSTEM_LEVEL, ER_XA_RECOVERY_DONE);
return 0;
}
bool xa_trans_force_rollback(THD *thd) {
/*
We must reset rm_error before calling ha_rollback(),
so thd->transaction.xid structure gets reset
by ha_rollback()/THD::transaction::cleanup().
*/
thd->get_transaction()->xid_state()->reset_error();
if (ha_rollback_trans(thd, true)) {
my_error(ER_XAER_RMERR, MYF(0));
return true;
}
return false;
}
void cleanup_trans_state(THD *thd) {
thd->variables.option_bits &= ~OPTION_BEGIN;
thd->server_status &=
~(SERVER_STATUS_IN_TRANS | SERVER_STATUS_IN_TRANS_READONLY);
thd->get_transaction()->reset_unsafe_rollback_flags(Transaction_ctx::SESSION);
DBUG_PRINT("info", ("clearing SERVER_STATUS_IN_TRANS"));
transaction_cache_delete(thd->get_transaction());
}
/**
Find XA transaction in cache by its xid value.
@param thd Thread context
@param xid_for_trn_in_recover xid value to look for in transaction cache
@param xid_state State of XA transaction in current session
@return Pointer to an instance of Transaction_ctx corresponding to a
xid in argument. If XA transaction not found returns nullptr and
sets an error in DA to specify a reason of search failure.
*/
static std::shared_ptr<Transaction_ctx>
find_trn_for_recover_and_check_its_state(THD *thd,
xid_t *xid_for_trn_in_recover,
XID_STATE *xid_state) {
if (!xid_state->has_state(XID_STATE::XA_NOTR)) {
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
return nullptr;
}
/*
Note, that there is no race condition here between
transaction_cache_search and transaction_cache_delete,
since we always delete our own XID
(m_xid == thd->transaction().xid_state().m_xid).
The only case when m_xid != thd->transaction.xid_state.m_xid
and xid_state->in_thd == 0 is in the function
transaction_cache_insert_recovery(XID), which is called before starting
client connections, and thus is always single-threaded.
*/
std::shared_ptr<Transaction_ctx> transaction =
transaction_cache_search(xid_for_trn_in_recover);
XID_STATE *xs = (transaction ? transaction->xid_state() : nullptr);
if (!xs || !xs->is_in_recovery()) {
my_error(ER_XAER_NOTA, MYF(0));
return nullptr;
} else if (thd->in_active_multi_stmt_transaction()) {
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
return nullptr;
}
DBUG_ASSERT(xs->is_in_recovery());
return transaction;
}
/**
Commit and terminate a XA transaction.
@param thd Current thread
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_commit::trans_xa_commit(THD *thd) {
XID_STATE *xid_state = thd->get_transaction()->xid_state();
bool res = true;
DBUG_ASSERT(!thd->slave_thread || xid_state->get_xid()->is_null() ||
m_xa_opt == XA_ONE_PHASE);
/* Inform clone handler of XA operation. */
Clone_handler::XA_Operation xa_guard(thd);
if (!xid_state->has_same_xid(m_xid)) {
res = process_external_xa_commit(thd, m_xid, xid_state);
} else {
res = process_internal_xa_commit(thd, xid_state);
}
return (res);
}
/**
Acquire Commit metadata lock and all locks acquired by a prepared XA
transaction before server was shutdown or terminated.
@param thd Thread context
@param external_xid XID value specified by XA COMMIT or XA ROLLBACK that
corresponds to a XA transaction generated outside
current session context.
@retval false Success
@retval true Failure
*/
static bool acquire_mandatory_metadata_locks(THD *thd, xid_t *external_xid) {
/*
Acquire metadata lock which will ensure that XA ROLLBACK is blocked
by active FLUSH TABLES WITH READ LOCK (and vice versa ROLLBACK in
progress blocks FTWRL). This is to avoid binlog and redo entries
while a backup is in progress.
*/
MDL_request mdl_request;
MDL_REQUEST_INIT(&mdl_request, MDL_key::COMMIT, "", "",
MDL_INTENTION_EXCLUSIVE, MDL_STATEMENT);
if (thd->mdl_context.acquire_lock(&mdl_request,
thd->variables.lock_wait_timeout)) {
return true;
}
/*
Like in the commit case a failure to store gtid is regarded
as the resource manager issue.
*/
if (MDL_context_backup_manager::instance().restore_backup(
&thd->mdl_context, external_xid->key(), external_xid->key_length())) {
return true;
}
return false;
}
/**
Handle the statement XA COMMIT for the case when xid corresponds to
an external XA transaction, that it a transaction generated outside
current session context.
@param thd Thread context
@param external_xid XID value specified by XA COMMIT that corresponds to
a XA transaction generated outside current session
context. In fact, it means that XA COMMIT is run
against a XA transaction recovered after server restart.
@param xid_state State of XA transaction corresponding to the current
session that expected to have the value
XID_STATE::XA_NOTR
@return operation result
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_commit::process_external_xa_commit(THD *thd,
xid_t *external_xid,
XID_STATE *xid_state) {
std::shared_ptr<Transaction_ctx> transaction =
find_trn_for_recover_and_check_its_state(thd, external_xid, xid_state);
if (!transaction) return true;
XID_STATE *xs = transaction->xid_state();
DBUG_ASSERT(xs->get_xid()->eq(external_xid));
/*
Resumed transaction XA-commit.
The case deals with the "external" XA-commit by either a slave applier
or a different than XA-prepared transaction session.
*/
bool res = xs->xa_trans_rolled_back();
DEBUG_SYNC(thd, "external_xa_commit_before_acquire_xa_lock");
/*
Acquire XID_STATE::m_xa_lock to prevent concurrent running of two
XA COMMIT/XA ROLLBACK statements. Without acquiring this lock an attempt
to run two XA COMMIT/XA ROLLBACK statement for the same xid value may lead
to writing two events for the same xid into the binlog (e.g. twice
XA COMMIT event, that is an event for XA COMMIT some_xid_value
followed by an another event XA COMMIT with the same xid value).
As a consequences, presence of two XA COMMIT/XA ROLLACK statements for
the same xid value in binlog would break replication.
*/
std::lock_guard<std::mutex> lk(xs->get_xa_lock());
/*
Double check that the XA transaction still does exist since the transaction
could be removed from the cache by another XA COMMIT/XA ROLLBACK statement
being executed concurrently from parallel session with the same xid value.
*/
if (!find_trn_for_recover_and_check_its_state(thd, external_xid, xid_state))
return true;
if (acquire_mandatory_metadata_locks(thd, external_xid)) {
/*
We can't rollback an XA transaction on lock failure due to
Innodb redo log and bin log update is involved in rollback.
Return error to user for a retry.
*/
my_error(ER_XA_RETRY, MYF(0));
return true;
}
DEBUG_SYNC(thd, "external_xa_commit_after_acquire_commit_lock");
/* Do not execute gtid wrapper whenever 'res' is true (rm error) */
bool need_clear_owned_gtid = false;
bool gtid_error = commit_owned_gtids(thd, true, &need_clear_owned_gtid);
if (gtid_error) my_error(ER_XA_RBROLLBACK, MYF(0));
res = res || gtid_error;
/*
xs' is_binlogged() is passed through xid_state's member to low-level
logging routines for deciding how to log. The same applies to
Rollback case.
*/
if (xs->is_binlogged())
xid_state->set_binlogged();
else
xid_state->unset_binlogged();
res = ha_commit_or_rollback_by_xid(thd, external_xid, !res) || res;
xid_state->unset_binlogged();
MDL_context_backup_manager::instance().delete_backup(
external_xid->key(), external_xid->key_length());
transaction_cache_delete(transaction.get());
gtid_state_commit_or_rollback(thd, need_clear_owned_gtid, !gtid_error);
return res;
}
/**
Handle the statement XA COMMIT for the case when xid corresponds to
an internal XA transaction, that is a transaction generated by
current session context.
@param thd Thread context
@param xid_state State of XA transaction corresponding to the current
session.
@return operation result
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_commit::process_internal_xa_commit(THD *thd,
XID_STATE *xid_state) {
DBUG_TRACE;
bool res = false;
bool gtid_error = false, need_clear_owned_gtid = false;
if (xid_state->xa_trans_rolled_back()) {
xa_trans_force_rollback(thd);
res = thd->is_error();
} else if (xid_state->has_state(XID_STATE::XA_IDLE) &&
m_xa_opt == XA_ONE_PHASE) {
int r = ha_commit_trans(thd, true);
if ((res = r)) my_error(r == 1 ? ER_XA_RBROLLBACK : ER_XAER_RMERR, MYF(0));
} else if (xid_state->has_state(XID_STATE::XA_PREPARED) &&
m_xa_opt == XA_NONE) {
MDL_request mdl_request;
/*
Acquire metadata lock which will ensure that COMMIT is blocked
by active FLUSH TABLES WITH READ LOCK (and vice versa COMMIT in
progress blocks FTWRL).
We allow FLUSHer to COMMIT; we assume FLUSHer knows what it does.
*/
MDL_REQUEST_INIT(&mdl_request, MDL_key::COMMIT, "", "",
MDL_INTENTION_EXCLUSIVE, MDL_STATEMENT);
if (thd->mdl_context.acquire_lock(&mdl_request,
thd->variables.lock_wait_timeout)) {
/*
We can't rollback an XA transaction on lock failure due to
Innodb redo log and bin log update are involved in rollback.
Return error to user for a retry.
*/
my_error(ER_XA_RETRY, MYF(0));
return true;
}
gtid_error = commit_owned_gtids(thd, true, &need_clear_owned_gtid);
if (gtid_error) {
res = true;
/*
Failure to store gtid is regarded as a unilateral one of the
resource manager therefore the transaction is to be rolled back.
The specified error is the same as @c xa_trans_force_rollback.
The prepared XA will be rolled back along and so will do Gtid state,
see ha_rollback_trans().
Todo/fixme: fix binlogging, "XA rollback" event could be missed out.
Todo/fixme: as to XAER_RMERR, should not it be XA_RBROLLBACK?
Rationale: there's no consistency concern after rollback,
unlike what XAER_RMERR suggests.
*/
ha_rollback_trans(thd, true);
my_error(ER_XAER_RMERR, MYF(0));
} else {
DBUG_EXECUTE_IF("simulate_crash_on_commit_xa_trx", DBUG_SUICIDE(););
DEBUG_SYNC(thd, "trans_xa_commit_after_acquire_commit_lock");
if (tc_log)
res = tc_log->commit(thd, /* all */ true);
else
res = ha_commit_low(thd, /* all */ true);
DBUG_EXECUTE_IF("simulate_xa_commit_log_failure", { res = true; });
if (res)
my_error(ER_XAER_RMERR, MYF(0)); // todo/fixme: consider to rollback it
#ifdef HAVE_PSI_TRANSACTION_INTERFACE
else {
/*
Since we don't call ha_commit_trans() for prepared transactions,
we need to explicitly mark the transaction as committed.
*/
MYSQL_COMMIT_TRANSACTION(thd->m_transaction_psi);
}
thd->m_transaction_psi = nullptr;
#endif
}
} else {
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
return true;
}
gtid_state_commit_or_rollback(thd, need_clear_owned_gtid, !gtid_error);
cleanup_trans_state(thd);
xid_state->set_state(XID_STATE::XA_NOTR);
xid_state->unset_binlogged();
trans_track_end_trx(thd);
/* The transaction should be marked as complete in P_S. */
DBUG_ASSERT(thd->m_transaction_psi == nullptr || res);
return res;
}
bool Sql_cmd_xa_commit::execute(THD *thd) {
bool st = trans_xa_commit(thd);
if (!st) {
thd->mdl_context.release_transactional_locks();
/*
We've just done a commit, reset transaction
isolation level and access mode to the session default.
*/
trans_reset_one_shot_chistics(thd);
my_ok(thd);
}
return st;
}
/**
Roll back and terminate a XA transaction.
@param thd Current thread
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_rollback::trans_xa_rollback(THD *thd) {
XID_STATE *xid_state = thd->get_transaction()->xid_state();
bool res = true;
/* Inform clone handler of XA operation. */
Clone_handler::XA_Operation xa_guard(thd);
if (!xid_state->has_same_xid(m_xid)) {
res = process_external_xa_rollback(thd, m_xid, xid_state);
} else {
res = process_internal_xa_rollback(thd, xid_state);
}
return (res);
}
/**
Handle the statement XA ROLLBACK for the case when xid corresponds to
an external XA transaction, that it a transaction generated outside
current session context.
@param thd Thread context
@param external_xid XID value specified by XA ROLLBACK that corresponds to
a XA transaction generated outside current session
context. In fact, it means that XA ROLLBACK is run
against a XA transaction recovered after server restart.
@param xid_state State of XA transaction corresponding to the current
session that expected to have the value
XID_STATE::XA_NOTR
@return operation result
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_rollback::process_external_xa_rollback(THD *thd,
xid_t *external_xid,
XID_STATE *xid_state) {
DBUG_TRACE;
std::shared_ptr<Transaction_ctx> transaction =
find_trn_for_recover_and_check_its_state(thd, external_xid, xid_state);
if (!transaction) return true;
XID_STATE *xs = transaction->xid_state();
DBUG_ASSERT(xs->get_xid()->eq(external_xid));
/*
Acquire XID_STATE::m_xa_lock to prevent concurrent running of two
XA COMMIT/XA ROLLBACK statements. Without acquiring this lock an attempt
to run two XA COMMIT/XA ROLLBACK statement for the same xid value may lead
to writing two events for the same xid into the binlog (e.g. twice
XA ROLLBACK event, that is an event for XA ROLLBACK some_xid_value
followed by an another event XA ROLLBACK with the same xid value).
As a consequences, presence of two XA COMMIT/XA ROLLACK statements for
the same xid value in binlog would break replication.
*/
std::lock_guard<std::mutex> lk(xs->get_xa_lock());
/*
Double check that the XA transaction still does exist since the transaction
could be removed from the cache by another XA COMMIT/XA ROLLBACK statement
being executed concurrently from parallel session with the same xid value.
*/
if (!find_trn_for_recover_and_check_its_state(thd, external_xid, xid_state))
return true;
if (acquire_mandatory_metadata_locks(thd, external_xid)) {
/*
We can't rollback an XA transaction on lock failure due to
Innodb redo log and bin log update is involved in rollback.
Return error to user for a retry.
*/
my_error(ER_XAER_RMERR, MYF(0));
return true;
}
bool need_clear_owned_gtid = false;
bool gtid_error = commit_owned_gtids(thd, true, &need_clear_owned_gtid);
if (gtid_error) my_error(ER_XA_RBROLLBACK, MYF(0));
bool res = xs->xa_trans_rolled_back();
if (xs->is_binlogged())
xid_state->set_binlogged();
else
xid_state->unset_binlogged();
res = ha_commit_or_rollback_by_xid(thd, external_xid, false) || res;
xid_state->unset_binlogged();
MDL_context_backup_manager::instance().delete_backup(
external_xid->key(), external_xid->key_length());
transaction_cache_delete(transaction.get());
gtid_state_commit_or_rollback(thd, need_clear_owned_gtid, !gtid_error);
return res || gtid_error;
}
/**
Handle the statement XA ROLLBACK for the case when xid corresponds to
an internal XA transaction, that is a transaction generated by
current session context.
@param thd Thread context
@param xid_state State of XA transaction corresponding to the current
session.
@return operation result
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_rollback::process_internal_xa_rollback(THD *thd,
XID_STATE *xid_state) {
DBUG_TRACE;
if (xid_state->has_state(XID_STATE::XA_NOTR) ||
xid_state->has_state(XID_STATE::XA_ACTIVE)) {
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
return true;
}
/*
Acquire metadata lock which will ensure that XA ROLLBACK is blocked
by active FLUSH TABLES WITH READ LOCK (and vice versa ROLLBACK in
progress blocks FTWRL). This is to avoid binlog and redo entries
while a backup is in progress.
*/
MDL_request mdl_request;
MDL_REQUEST_INIT(&mdl_request, MDL_key::COMMIT, "", "",
MDL_INTENTION_EXCLUSIVE, MDL_STATEMENT);
if (thd->mdl_context.acquire_lock(&mdl_request,
thd->variables.lock_wait_timeout)) {
/*
We can't rollback an XA transaction on lock failure due to
Innodb redo log and bin log update is involved in rollback.
Return error to user for a retry.
*/
my_error(ER_XAER_RMERR, MYF(0));
return true;
}
bool need_clear_owned_gtid = false;
bool gtid_error = commit_owned_gtids(thd, true, &need_clear_owned_gtid);
bool res = xa_trans_force_rollback(thd) || gtid_error;
gtid_state_commit_or_rollback(thd, need_clear_owned_gtid, !gtid_error);
// todo: report a bug in that the raised rm_error in this branch
// is masked unlike the "external" rollback branch above.
DBUG_EXECUTE_IF("simulate_xa_rm_error", {
my_error(ER_XA_RBROLLBACK, MYF(0));
res = true;
});
cleanup_trans_state(thd);
xid_state->set_state(XID_STATE::XA_NOTR);
xid_state->unset_binlogged();
trans_track_end_trx(thd);
/* The transaction should be marked as complete in P_S. */
DBUG_ASSERT(thd->m_transaction_psi == nullptr);
return res;
}
bool Sql_cmd_xa_rollback::execute(THD *thd) {
bool st = trans_xa_rollback(thd);
if (!st) {
thd->mdl_context.release_transactional_locks();
/*
We've just done a rollback, reset transaction
isolation level and access mode to the session default.
*/
trans_reset_one_shot_chistics(thd);
my_ok(thd);
}
DBUG_EXECUTE_IF("crash_after_xa_rollback", DBUG_SUICIDE(););
return st;
}
/**
Start a XA transaction with the given xid value.
@param thd Current thread
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_start::trans_xa_start(THD *thd) {
XID_STATE *xid_state = thd->get_transaction()->xid_state();
DBUG_TRACE;
if (xid_state->has_state(XID_STATE::XA_IDLE) && m_xa_opt == XA_RESUME) {
bool not_equal = !xid_state->has_same_xid(m_xid);
if (not_equal)
my_error(ER_XAER_NOTA, MYF(0));
else {
xid_state->set_state(XID_STATE::XA_ACTIVE);
MYSQL_SET_TRANSACTION_XA_STATE(
thd->m_transaction_psi,
(int)thd->get_transaction()->xid_state()->get_state());
}
return not_equal;
}
/* TODO: JOIN is not supported yet. */
if (m_xa_opt != XA_NONE)
my_error(ER_XAER_INVAL, MYF(0));
else if (!xid_state->has_state(XID_STATE::XA_NOTR))
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
else if (thd->locked_tables_mode || thd->in_active_multi_stmt_transaction())
my_error(ER_XAER_OUTSIDE, MYF(0));
else if (!trans_begin(thd)) {
xid_state->start_normal_xa(m_xid);
MYSQL_SET_TRANSACTION_XID(thd->m_transaction_psi,
(const void *)xid_state->get_xid(),
(int)xid_state->get_state());
if (transaction_cache_insert(m_xid, thd->get_transaction())) {
xid_state->reset();
trans_rollback(thd);
}
}
return thd->is_error() || !xid_state->has_state(XID_STATE::XA_ACTIVE);
}
bool Sql_cmd_xa_start::execute(THD *thd) {
bool st = trans_xa_start(thd);
if (!st) {
thd->rpl_detach_engine_ha_data();
my_ok(thd);
}
return st;
}
/**
Put a XA transaction in the IDLE state.
@param thd Current thread
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_end::trans_xa_end(THD *thd) {
XID_STATE *xid_state = thd->get_transaction()->xid_state();
DBUG_TRACE;
/* TODO: SUSPEND and FOR MIGRATE are not supported yet. */
if (m_xa_opt != XA_NONE)
my_error(ER_XAER_INVAL, MYF(0));
else if (!xid_state->has_state(XID_STATE::XA_ACTIVE))
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
else if (!xid_state->has_same_xid(m_xid))
my_error(ER_XAER_NOTA, MYF(0));
else if (!xid_state->xa_trans_rolled_back()) {
xid_state->set_state(XID_STATE::XA_IDLE);
MYSQL_SET_TRANSACTION_XA_STATE(thd->m_transaction_psi,
(int)xid_state->get_state());
} else {
MYSQL_SET_TRANSACTION_XA_STATE(thd->m_transaction_psi,
(int)xid_state->get_state());
}
return thd->is_error() || !xid_state->has_state(XID_STATE::XA_IDLE);
}
bool Sql_cmd_xa_end::execute(THD *thd) {
bool st = trans_xa_end(thd);
if (!st) my_ok(thd);
return st;
}
/**
Put a XA transaction in the PREPARED state.
@param thd Current thread
@retval false Success
@retval true Failure
*/
bool Sql_cmd_xa_prepare::trans_xa_prepare(THD *thd) {
XID_STATE *xid_state = thd->get_transaction()->xid_state();
DBUG_TRACE;
if (!xid_state->has_state(XID_STATE::XA_IDLE))
my_error(ER_XAER_RMFAIL, MYF(0), xid_state->state_name());
else if (!xid_state->has_same_xid(m_xid))
my_error(ER_XAER_NOTA, MYF(0));
else if (thd->slave_thread &&
is_transaction_empty(
thd)) // No changes in none of the storage engine
// means, filtered statements in the slave
my_error(ER_XA_REPLICATION_FILTERS,
MYF(0)); // Empty XA transactions not allowed
else {
/*
Acquire metadata lock which will ensure that XA PREPARE is blocked
by active FLUSH TABLES WITH READ LOCK (and vice versa PREPARE in
progress blocks FTWRL). This is to avoid binlog and redo entries
while a backup is in progress.
*/
MDL_request mdl_request;
MDL_REQUEST_INIT(&mdl_request, MDL_key::COMMIT, "", "",
MDL_INTENTION_EXCLUSIVE, MDL_STATEMENT);
if (thd->mdl_context.acquire_lock(&mdl_request,
thd->variables.lock_wait_timeout) ||
ha_prepare(thd)) {
/*
Rollback the transaction if lock failed. For ha_prepare() failure
scenarios, transaction is already rolled back by ha_prepare().
*/
if (!mdl_request.ticket) ha_rollback_trans(thd, true);
#ifdef HAVE_PSI_TRANSACTION_INTERFACE
DBUG_ASSERT(thd->m_transaction_psi == NULL);
#endif
/*
Reset rm_error in case ha_prepare() returned error,
so thd->transaction.xid structure gets reset
by THD::transaction::cleanup().
*/
thd->get_transaction()->xid_state()->reset_error();
cleanup_trans_state(thd);
xid_state->set_state(XID_STATE::XA_NOTR);
thd->get_transaction()->cleanup();
my_error(ER_XA_RBROLLBACK, MYF(0));
} else {
xid_state->set_state(XID_STATE::XA_PREPARED);
MYSQL_SET_TRANSACTION_XA_STATE(thd->m_transaction_psi,
(int)xid_state->get_state());
if (thd->rpl_thd_ctx.session_gtids_ctx().notify_after_xa_prepare(thd))
LogErr(WARNING_LEVEL, ER_TRX_GTID_COLLECT_REJECT);
}
}
return thd->is_error() || !xid_state->has_state(XID_STATE::XA_PREPARED);
}
bool Sql_cmd_xa_prepare::execute(THD *thd) {
bool st = trans_xa_prepare(thd);
if (!st) {
if (!thd->rpl_unflag_detached_engine_ha_data() ||
!(st = applier_reset_xa_trans(thd)))
my_ok(thd);
}
return st;
}
/**
Return the list of XID's to a client, the same way SHOW commands do.
@param thd Current thread
@retval false Success
@retval true Failure
@note
I didn't find in XA specs that an RM cannot return the same XID twice,
so trans_xa_recover does not filter XID's to ensure uniqueness.
It can be easily fixed later, if necessary.
*/
bool Sql_cmd_xa_recover::trans_xa_recover(THD *thd) {
List<Item> field_list;
Protocol *protocol = thd->get_protocol();
DBUG_TRACE;
field_list.push_back(
new Item_int(NAME_STRING("formatID"), 0, MY_INT32_NUM_DECIMAL_DIGITS));
field_list.push_back(new Item_int(NAME_STRING("gtrid_length"), 0,
MY_INT32_NUM_DECIMAL_DIGITS));
field_list.push_back(new Item_int(NAME_STRING("bqual_length"), 0,
MY_INT32_NUM_DECIMAL_DIGITS));
field_list.push_back(new Item_empty_string("data", XIDDATASIZE * 2 + 2));
if (thd->send_result_metadata(&field_list,
Protocol::SEND_NUM_ROWS | Protocol::SEND_EOF))
return true;
mysql_mutex_lock(&LOCK_transaction_cache);
for (const auto &key_and_value : transaction_cache) {
Transaction_ctx *transaction = key_and_value.second.get();
XID_STATE *xs = transaction->xid_state();
if (xs->has_state(XID_STATE::XA_PREPARED)) {
protocol->start_row();
xs->store_xid_info(protocol, m_print_xid_as_hex);
if (protocol->end_row()) {
mysql_mutex_unlock(&LOCK_transaction_cache);
return true;
}
}
}
mysql_mutex_unlock(&LOCK_transaction_cache);
my_eof(thd);
return false;
}
/**
Check if the current user has a privilege to perform XA RECOVER.
@param thd Current thread
@retval false A user has a privilege to perform XA RECOVER
@retval true A user doesn't have a privilege to perform XA RECOVER
*/
bool Sql_cmd_xa_recover::check_xa_recover_privilege(THD *thd) const {
Security_context *sctx = thd->security_context();
if (!sctx->has_global_grant(STRING_WITH_LEN("XA_RECOVER_ADMIN")).first) {
/*
Report an error ER_XAER_RMERR. A supplementary error
ER_SPECIFIC_ACCESS_DENIED_ERROR is also reported when
SHOW WARNINGS is issued. This provides more information
about the reason for failure.
*/
my_error(ER_XAER_RMERR, MYF(0));
my_error(ER_SPECIFIC_ACCESS_DENIED_ERROR, MYF(0), "XA_RECOVER_ADMIN");
return true;
}
return false;
}
bool Sql_cmd_xa_recover::execute(THD *thd) {
bool st = check_xa_recover_privilege(thd) || trans_xa_recover(thd);
DBUG_EXECUTE_IF("crash_after_xa_recover", { DBUG_SUICIDE(); });
return st;
}
bool XID_STATE::xa_trans_rolled_back() {
DBUG_EXECUTE_IF("simulate_xa_rm_error", rm_error = true;);
if (rm_error) {
switch (rm_error) {
case ER_LOCK_WAIT_TIMEOUT:
my_error(ER_XA_RBTIMEOUT, MYF(0));
break;
case ER_LOCK_DEADLOCK:
my_error(ER_XA_RBDEADLOCK, MYF(0));
break;
default:
my_error(ER_XA_RBROLLBACK, MYF(0));
}
xa_state = XID_STATE::XA_ROLLBACK_ONLY;
}
return (xa_state == XID_STATE::XA_ROLLBACK_ONLY);
}
bool XID_STATE::check_xa_idle_or_prepared(bool report_error) const {
if (xa_state == XA_IDLE || xa_state == XA_PREPARED) {
if (report_error)
my_error(ER_XAER_RMFAIL, MYF(0), xa_state_names[xa_state]);
return true;
}
return false;
}
bool XID_STATE::check_has_uncommitted_xa() const {
if (xa_state == XA_IDLE || xa_state == XA_PREPARED ||
xa_state == XA_ROLLBACK_ONLY) {
my_error(ER_XAER_RMFAIL, MYF(0), xa_state_names[xa_state]);
return true;
}
return false;
}
bool XID_STATE::check_in_xa(bool report_error) const {
if (xa_state != XA_NOTR) {
if (report_error)
my_error(ER_XAER_RMFAIL, MYF(0), xa_state_names[xa_state]);
return true;
}
return false;
}
void XID_STATE::set_error(THD *thd) {
if (xa_state != XA_NOTR) rm_error = thd->get_stmt_da()->mysql_errno();
}
void XID_STATE::store_xid_info(Protocol *protocol,
bool print_xid_as_hex) const {
protocol->store_longlong(static_cast<longlong>(m_xid.formatID), false);
protocol->store_longlong(static_cast<longlong>(m_xid.gtrid_length), false);
protocol->store_longlong(static_cast<longlong>(m_xid.bqual_length), false);
if (print_xid_as_hex) {
/*
xid_buf contains enough space for 0x followed by HEX representation
of the binary XID data and one null termination character.
*/
char xid_buf[XIDDATASIZE * 2 + 2 + 1];
xid_buf[0] = '0';
xid_buf[1] = 'x';
size_t xid_str_len =
bin_to_hex_str(xid_buf + 2, sizeof(xid_buf) - 2, m_xid.data,
m_xid.gtrid_length + m_xid.bqual_length) +
2;
protocol->store_string(xid_buf, xid_str_len, &my_charset_bin);
} else {
protocol->store_string(m_xid.data, m_xid.gtrid_length + m_xid.bqual_length,
&my_charset_bin);
}
}
#ifndef DBUG_OFF
char *XID::xid_to_str(char *buf) const {
char *s = buf;
*s++ = '\'';
for (int i = 0; i < gtrid_length + bqual_length; i++) {
/* is_next_dig is set if next character is a number */
bool is_next_dig = false;
if (i < XIDDATASIZE) {
char ch = data[i + 1];
is_next_dig = (ch >= '0' && ch <= '9');
}
if (i == gtrid_length) {
*s++ = '\'';
if (bqual_length) {
*s++ = '.';
*s++ = '\'';
}
}
uchar c = static_cast<uchar>(data[i]);
if (c < 32 || c > 126) {
*s++ = '\\';
/*
If next character is a number, write current character with
3 octal numbers to ensure that the next number is not seen
as part of the octal number
*/
if (c > 077 || is_next_dig) *s++ = _dig_vec_lower[c >> 6];
if (c > 007 || is_next_dig) *s++ = _dig_vec_lower[(c >> 3) & 7];
*s++ = _dig_vec_lower[c & 7];
} else {
if (c == '\'' || c == '\\') *s++ = '\\';
*s++ = c;
}
}
*s++ = '\'';
*s = 0;
return buf;
}
#endif
static inline std::string to_string(const XID &xid) {
return std::string(pointer_cast<const char *>(xid.key()), xid.key_length());
}
/**
Callback that is called to do cleanup.
@param transaction pointer to free
*/
void transaction_free_hash::operator()(Transaction_ctx *transaction) const {
// Only time it's allocated is during recovery process.
if (transaction->xid_state()->is_in_recovery()) delete transaction;
}
#ifdef HAVE_PSI_INTERFACE
static PSI_mutex_key key_LOCK_transaction_cache;
static PSI_mutex_info transaction_cache_mutexes[] = {
{&key_LOCK_transaction_cache, "LOCK_transaction_cache", PSI_FLAG_SINGLETON,
0, PSI_DOCUMENT_ME}};
static void init_transaction_cache_psi_keys(void) {
const char *category = "sql";
int count;
count = static_cast<int>(array_elements(transaction_cache_mutexes));
mysql_mutex_register(category, transaction_cache_mutexes, count);
}
#endif /* HAVE_PSI_INTERFACE */
bool transaction_cache_init() {
#ifdef HAVE_PSI_INTERFACE
init_transaction_cache_psi_keys();
#endif
mysql_mutex_init(key_LOCK_transaction_cache, &LOCK_transaction_cache,
MY_MUTEX_INIT_FAST);
inited = true;
return false;
}
void transaction_cache_free() {
if (inited) {
transaction_cache.clear();
mysql_mutex_destroy(&LOCK_transaction_cache);
}
}
/**
Search information about XA transaction by a XID value.
@param xid Pointer to a XID structure that identifies a XA transaction.
@return pointer to a Transaction_ctx that describes the whole transaction
including XA-specific information (XID_STATE).
@retval NULL failure
@retval != NULL success
*/
static std::shared_ptr<Transaction_ctx> transaction_cache_search(XID *xid) {
std::shared_ptr<Transaction_ctx> res{nullptr};
mysql_mutex_lock(&LOCK_transaction_cache);
const auto it = transaction_cache.find(to_string(*xid));
if (it != transaction_cache.end()) res = it->second;
mysql_mutex_unlock(&LOCK_transaction_cache);
return res;
}
/**
Insert information about XA transaction into a cache indexed by XID.
@param xid Pointer to a XID structure that identifies a XA transaction.
@param transaction
Pointer to Transaction object that is inserted.
@return operation result
@retval false success or a cache already contains XID_STATE
for this XID value
@retval true failure
*/
bool transaction_cache_insert(XID *xid, Transaction_ctx *transaction) {
mysql_mutex_lock(&LOCK_transaction_cache);
std::shared_ptr<Transaction_ctx> ptr(transaction, transaction_free_hash());
bool res = !transaction_cache.emplace(to_string(*xid), std::move(ptr)).second;
mysql_mutex_unlock(&LOCK_transaction_cache);
if (res) {
my_error(ER_XAER_DUPID, MYF(0));
}
return res;
}
inline bool create_and_insert_new_transaction(XID *xid, bool is_binlogged_arg) {
Transaction_ctx *transaction = new (std::nothrow) Transaction_ctx();
XID_STATE *xs;
if (!transaction) {
my_error(ER_OUTOFMEMORY, MYF(ME_FATALERROR), sizeof(Transaction_ctx));
return true;
}
xs = transaction->xid_state();
xs->start_recovery_xa(xid, is_binlogged_arg);
return !transaction_cache
.emplace(to_string(*xs->get_xid()),
std::shared_ptr<Transaction_ctx>(
transaction, transaction_free_hash()))
.second;
}
bool transaction_cache_detach(Transaction_ctx *transaction) {
bool res = false;
XID_STATE *xs = transaction->xid_state();
XID xid = *(xs->get_xid());
bool was_logged = xs->is_binlogged();
DBUG_ASSERT(xs->has_state(XID_STATE::XA_PREPARED));
mysql_mutex_lock(&LOCK_transaction_cache);
DBUG_ASSERT(transaction_cache.count(to_string(xid)) != 0);
transaction_cache.erase(to_string(xid));
res = create_and_insert_new_transaction(&xid, was_logged);
mysql_mutex_unlock(&LOCK_transaction_cache);
return res;
}
/**
Insert information about XA transaction being recovered into a cache
indexed by XID.
@param xid Pointer to a XID structure that identifies a XA transaction.
@return operation result
@retval false success or a cache already contains Transaction_ctx
for this XID value
@retval true failure
*/
bool transaction_cache_insert_recovery(XID *xid) {
mysql_mutex_lock(&LOCK_transaction_cache);
if (transaction_cache.count(to_string(*xid))) {
mysql_mutex_unlock(&LOCK_transaction_cache);
return false;
}
/*
It's assumed that XA transaction was binlogged before the server
shutdown. If --log-bin has changed since that from OFF to ON, XA
COMMIT or XA ROLLBACK of this transaction may be logged alone into
the binary log.
*/
bool res = create_and_insert_new_transaction(xid, true);
mysql_mutex_unlock(&LOCK_transaction_cache);
return res;
}
void transaction_cache_delete(Transaction_ctx *transaction) {
mysql_mutex_lock(&LOCK_transaction_cache);
const auto it =
transaction_cache.find(to_string(*transaction->xid_state()->get_xid()));
if (it != transaction_cache.end() && it->second.get() == transaction)
transaction_cache.erase(it);
mysql_mutex_unlock(&LOCK_transaction_cache);
}
/**
The function restores previously saved storage engine transaction context.
@param thd Thread context
*/
static void attach_native_trx(THD *thd) {
Ha_trx_info *ha_info =
thd->get_transaction()->ha_trx_info(Transaction_ctx::SESSION);
Ha_trx_info *ha_info_next;
if (ha_info) {
for (; ha_info; ha_info = ha_info_next) {
handlerton *hton = ha_info->ht();
reattach_engine_ha_data_to_thd(thd, hton);
ha_info_next = ha_info->next();
ha_info->reset();
}
} else {
/*
Although the current `Ha_trx_info` object is null, we need to make sure
that the data engine plugins have the oportunity to attach their internal
transactions and clean up the session.
*/
thd->rpl_reattach_engine_ha_data();
}
}
/**
This is a specific to "slave" applier collection of standard cleanup
actions to reset XA transaction states at the end of XA prepare rather than
to do it at the transaction commit, see @c ha_commit_one_phase.
THD of the slave applier is dissociated from a transaction object in engine
that continues to exist there.
@param thd current thread
@return the value of is_error()
*/
bool applier_reset_xa_trans(THD *thd) {
DBUG_TRACE;
Transaction_ctx *trn_ctx = thd->get_transaction();
XID_STATE *xid_state = trn_ctx->xid_state();
/*
Return error is not an option as XA is in prepared state and
connection is gone. Log the error and continue.
*/
if (MDL_context_backup_manager::instance().create_backup(
&thd->mdl_context, xid_state->get_xid()->key(),
xid_state->get_xid()->key_length())) {
LogErr(ERROR_LEVEL, ER_XA_CANT_CREATE_MDL_BACKUP);
}
/*
In the following the server transaction state gets reset for
a slave applier thread similarly to xa_commit logics
except commit does not run.
*/
thd->variables.option_bits &= ~OPTION_BEGIN;
trn_ctx->reset_unsafe_rollback_flags(Transaction_ctx::STMT);
thd->server_status &= ~SERVER_STATUS_IN_TRANS;
/* Server transaction ctx is detached from THD */
transaction_cache_detach(trn_ctx);
xid_state->reset();
/*
The current engine transactions is detached from THD, and
previously saved is restored.
*/
attach_native_trx(thd);
trn_ctx->set_ha_trx_info(Transaction_ctx::SESSION, NULL);
trn_ctx->set_no_2pc(Transaction_ctx::SESSION, false);
trn_ctx->cleanup();
#ifdef HAVE_PSI_TRANSACTION_INTERFACE
thd->m_transaction_psi = NULL;
#endif
thd->mdl_context.release_transactional_locks();
/*
On client sessions a XA PREPARE will always be followed by a XA COMMIT
or a XA ROLLBACK, and both statements will reset the tx isolation level
and access mode when the statement is finishing a transaction.
For replicated workload it is possible to have other transactions between
the XA PREPARE and the XA [COMMIT|ROLLBACK].
So, if the slave applier changed the current transaction isolation level,
it needs to be restored to the session default value after having the
XA transaction prepared.
*/
trans_reset_one_shot_chistics(thd);
return thd->is_error();
}
/**
The function detaches existing storage engines transaction
context from thd. Backup area to save it is provided to low level
storage engine function.
is invoked by plugin_foreach() after
trans_xa_start() for each storage engine.
@param[in,out] thd Thread context
@param plugin Reference to handlerton
@return false on success, true otherwise.
*/
bool detach_native_trx(THD *thd, plugin_ref plugin, void *) {
DBUG_TRACE;
handlerton *hton = plugin_data<handlerton *>(plugin);
if (hton->replace_native_transaction_in_thd) {
/* Ensure any active backup engine ha_data won't be overwritten */
DBUG_ASSERT(!thd->get_ha_data(hton->slot)->ha_ptr_backup);
hton->replace_native_transaction_in_thd(
thd, NULL, &thd->get_ha_data(hton->slot)->ha_ptr_backup);
}
return false;
}
bool reattach_native_trx(THD *thd, plugin_ref plugin, void *) {
DBUG_TRACE;
handlerton *hton = plugin_data<handlerton *>(plugin);
if (hton->replace_native_transaction_in_thd) {
/* restore the saved original engine transaction's link with thd */
void **trx_backup = &thd->get_ha_data(hton->slot)->ha_ptr_backup;
hton->replace_native_transaction_in_thd(thd, *trx_backup, NULL);
*trx_backup = NULL;
}
return false;
}