MWL#116: After-review fixes.

include/my_sys.h

@@ -554,6 +554,8 @@ typedef int (*qsort2_cmp)(const void *, const void *, const void *);
 
 #define my_b_tell(info) ((info)->pos_in_file + \
 			 (size_t) (*(info)->current_pos - (info)->request_pos))
+#define my_b_write_tell(info) ((info)->pos_in_file + \
+			 ((info)->write_pos - (info)->write_buffer))
 
 #define my_b_get_buffer_start(info) (info)->request_pos 
 #define my_b_get_bytes_in_buffer(info) (char*) (info)->read_end -   \

mysql-test/r/xa_binlog.result

+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
+SET binlog_format= mixed;
+RESET MASTER;
+XA START 'xatest';
+INSERT INTO t1 VALUES (1);
+XA END 'xatest';
+XA PREPARE 'xatest';
+XA COMMIT 'xatest';
+XA START 'xatest';
+INSERT INTO t1 VALUES (2);
+XA END 'xatest';
+XA COMMIT 'xatest' ONE PHASE;
+BEGIN;
+INSERT INTO t1 VALUES (3);
+COMMIT;
+SELECT * FROM t1 ORDER BY a;
+a
+1
+2
+3
+SHOW BINLOG EVENTS LIMIT 1,9;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+master-bin.000001	#	Query	1	#	BEGIN
+master-bin.000001	#	Query	1	#	use `test`; INSERT INTO t1 VALUES (1)
+master-bin.000001	#	Query	1	#	COMMIT
+master-bin.000001	#	Query	1	#	BEGIN
+master-bin.000001	#	Query	1	#	use `test`; INSERT INTO t1 VALUES (2)
+master-bin.000001	#	Query	1	#	COMMIT
+master-bin.000001	#	Query	1	#	BEGIN
+master-bin.000001	#	Query	1	#	use `test`; INSERT INTO t1 VALUES (3)
+master-bin.000001	#	Xid	1	#	COMMIT /* xid=XX */
+DROP TABLE t1;

mysql-test/suite/binlog/t/binlog_ioerr.test

@@ -21,7 +21,8 @@ SELECT * FROM t1;
 # Actually the output from this currently shows a bug.
 # The injected IO error leaves partially written transactions in the binlog in
 # the form of stray "BEGIN" events.
-# These should disappear from the output if binlog error handling is improved.
+# These should disappear from the output if binlog error handling is improved
+# (see MySQL Bug#37148 and WL#1790).
 --replace_regex /\/\* xid=.* \*\//\/* XID *\// /Server ver: .*, Binlog ver: .*/Server ver: #, Binlog ver: #/ /table_id: [0-9]+/table_id: #/
 --replace_column 1 BINLOG 2 POS 5 ENDPOS
 SHOW BINLOG EVENTS;

mysql-test/suite/pbxt/r/pbxt_xa_binlog.result

@@ -16,6 +16,7 @@ select * from t2;
 b
 2
 SET sql_log_bin = 0;
+BEGIN;
 INSERT INTO t1 VALUES (3);
 INSERT INTO t2 VALUES (4);
 COMMIT;

mysql-test/suite/pbxt/t/pbxt_xa_binlog.test

@@ -20,6 +20,7 @@ select * from t2;
 
 # Test 2-phase commit when we disable binlogging.
 SET sql_log_bin = 0;
+BEGIN;
 INSERT INTO t1 VALUES (3);
 INSERT INTO t2 VALUES (4);
 COMMIT;

mysql-test/t/group_commit_binlog_pos.test

@@ -8,6 +8,10 @@
 # Don't test this under valgrind, memory leaks will occur as we crash
 --source include/not_valgrind.inc
 
+# The test case currently uses grep and tail, which may be unavailable on
+# some windows systems. But see MWL#191 for how to remove the need for grep.
+--source include/not_windows.inc
+
 # XtraDB stores the binlog position corresponding to the last commit, and
 # prints it during crash recovery.
 # Test that we get the correct position when we group commit several

mysql-test/t/xa_binlog.test

+--source include/have_innodb.inc
+--source include/have_log_bin.inc
+
+CREATE TABLE t1 (a INT PRIMARY KEY) ENGINE=InnoDB;
+
+# Fix binlog format (otherwise SHOW BINLOG EVENTS will fluctuate).
+SET binlog_format= mixed;
+
+RESET MASTER;
+
+XA START 'xatest';
+INSERT INTO t1 VALUES (1);
+XA END 'xatest';
+XA PREPARE 'xatest';
+XA COMMIT 'xatest';
+
+XA START 'xatest';
+INSERT INTO t1 VALUES (2);
+XA END 'xatest';
+XA COMMIT 'xatest' ONE PHASE;
+
+BEGIN;
+INSERT INTO t1 VALUES (3);
+COMMIT;
+
+SELECT * FROM t1 ORDER BY a;
+
+--replace_column 2 # 5 #
+--replace_regex /xid=[0-9]+/xid=XX/
+SHOW BINLOG EVENTS LIMIT 1,9;
+
+DROP TABLE t1;

sql/handler.cc

@@ -1186,17 +1186,16 @@ int ha_commit_trans(THD *thd, bool all)
       Sic: we know that prepare() is not NULL since otherwise
       trans->no_2pc would have been set.
     */
-    if ((err= ht->prepare(ht, thd, all)))
-      my_error(ER_ERROR_DURING_COMMIT, MYF(0), err);
+    err= ht->prepare(ht, thd, all);
     status_var_increment(thd->status_var.ha_prepare_count);
+    if (err)
+      my_error(ER_ERROR_DURING_COMMIT, MYF(0), err);
 
     if (err)
       goto err;
 
-    if (ht->prepare_ordered)
-      need_prepare_ordered= TRUE;
-    if (ht->commit_ordered)
-      need_commit_ordered= TRUE;
+    need_prepare_ordered|= (ht->prepare_ordered != NULL);
+    need_commit_ordered|= (ht->commit_ordered != NULL);
   }
   DBUG_EXECUTE_IF("crash_commit_after_prepare", DBUG_ABORT(););
 
@@ -1225,8 +1224,7 @@ int ha_commit_trans(THD *thd, bool all)
 
   /* Come here if error and we need to rollback. */
 err:
-  if (!error)
-    error= 1;
+  error= 1;                                  /* Transaction was rolled back */
   ha_rollback_trans(thd, all);
 
 end:
@@ -1877,8 +1875,11 @@ int ha_start_consistent_snapshot(THD *thd)
   bool warn= true;
 
   /*
-    Holding the LOCK_commit_ordered mutex ensures that for any transaction
-    we either see it committed in all engines, or in none.
+    Holding the LOCK_commit_ordered mutex ensures that we get the same
+    snapshot for all engines (including the binary log).  This allows us
+    among other things to do backups with
+    START TRANSACTION WITH CONSISTENT SNAPSHOT and
+    have a consistent binlog position.
   */
   pthread_mutex_lock(&LOCK_commit_ordered);
   plugin_foreach(thd, snapshot_handlerton, MYSQL_STORAGE_ENGINE_PLUGIN, &warn);

sql/handler.h

@@ -670,7 +670,7 @@ struct handlerton
      Not that like prepare(), commit_ordered() is only called when 2-phase
      commit takes place. Ie. when no binary log and only a single engine
      participates in a transaction, one commit() is called, no
-     commit_orderd(). So engines must be prepared for this.
+     commit_ordered(). So engines must be prepared for this.
 
      The calls to commit_ordered() in multiple parallel transactions is
      guaranteed to happen in the same order in every participating
@@ -683,7 +683,7 @@ struct handlerton
      transaction visible to other transactions, thereby making the order of
      transaction commits be defined by the order of commit_ordered() calls.
 
-     The intension is that commit_ordered() should do the minimal amount of
+     The intention is that commit_ordered() should do the minimal amount of
      work that needs to happen in consistent commit order among handlers. To
      preserve ordering, calls need to be serialised on a global mutex, so
      doing any time-consuming or blocking operations in commit_ordered() will
@@ -727,7 +727,7 @@ struct handlerton
      order transactions will be eventually committed.
 
      Like commit_ordered(), prepare_ordered() calls are serialised to maintain
-     ordering, so the intension is that they should execute fast, with only
+     ordering, so the intention is that they should execute fast, with only
      the minimal amount of work needed to define commit order. Handlers can
      rely on this serialisation, and do not need to do any extra locking to
      avoid two prepare_ordered() calls running in parallel.
@@ -747,8 +747,7 @@ struct handlerton
      require blocking all other commits for an indefinite time).
 
      When 2-phase commit is not used (eg. only one engine (and no binlog) in
-     transaction), prepare() is not called and in such cases prepare_ordered()
-     also is not called.
+     transaction), neither prepare() nor prepare_ordered() is called.
    */
    void (*prepare_ordered)(handlerton *hton, THD *thd, bool all);
    int  (*recover)(handlerton *hton, XID *xid_list, uint len);

sql/log.cc

@@ -63,6 +63,30 @@ static int binlog_commit(handlerton *hton, THD *thd, bool all);
 static int binlog_rollback(handlerton *hton, THD *thd, bool all);
 static int binlog_prepare(handlerton *hton, THD *thd, bool all);
 
+static LEX_STRING const write_error_msg=
+    { C_STRING_WITH_LEN("error writing to the binary log") };
+
+#ifndef DBUG_OFF
+static ulong opt_binlog_dbug_fsync_sleep= 0;
+#endif
+
+static my_bool mutexes_inited;
+pthread_mutex_t LOCK_prepare_ordered;
+pthread_mutex_t LOCK_commit_ordered;
+
+static ulonglong binlog_status_var_num_commits;
+static ulonglong binlog_status_var_num_group_commits;
+
+static SHOW_VAR binlog_status_vars_detail[]=
+{
+  {"commits",
+    (char *)&binlog_status_var_num_commits, SHOW_LONGLONG},
+  {"group_commits",
+    (char *)&binlog_status_var_num_group_commits, SHOW_LONGLONG},
+  {NullS, NullS, SHOW_LONG}
+};
+
+
 /**
   Silence all errors and warnings reported when performing a write
   to a log table.
@@ -113,41 +137,6 @@ char *make_default_log_name(char *buff,const char* log_ext)
                    MYF(MY_UNPACK_FILENAME|MY_REPLACE_EXT));
 }
 
-/*
-  Helper class to hold a mutex for the duration of the
-  block.
-
-  Eliminates the need for explicit unlocking of mutexes on, e.g.,
-  error returns.  On passing a null pointer, the sentry will not do
-  anything.
- */
-class Mutex_sentry
-{
-public:
-  Mutex_sentry(pthread_mutex_t *mutex)
-    : m_mutex(mutex)
-  {
-    if (m_mutex)
-      pthread_mutex_lock(mutex);
-  }
-
-  ~Mutex_sentry()
-  {
-    if (m_mutex)
-      pthread_mutex_unlock(m_mutex);
-#ifndef DBUG_OFF
-    m_mutex= 0;
-#endif
-  }
-
-private:
-  pthread_mutex_t *m_mutex;
-
-  // It's not allowed to copy this object in any way
-  Mutex_sentry(Mutex_sentry const&);
-  void operator=(Mutex_sentry const&);
-};
-
 /*
   Helper class to store binary log transaction data.
 */
@@ -155,7 +144,8 @@ class binlog_trx_data {
 public:
   binlog_trx_data()
     : at_least_one_stmt_committed(0), incident(FALSE), m_pending(0),
-    before_stmt_pos(MY_OFF_T_UNDEF), commit_bin_log_file_pos(0), using_xa(0)
+    before_stmt_pos(MY_OFF_T_UNDEF), commit_bin_log_file_pos(0),
+      using_xa(FALSE), xa_xid(0)
   {
     trans_log.end_of_file= max_binlog_cache_size;
   }
@@ -271,6 +261,7 @@ public:
     XA, false if not.
   */
   bool using_xa;
+  my_xid xa_xid;
 };
 
 handlerton *binlog_hton;
@@ -1415,6 +1406,8 @@ static int binlog_close_connection(handlerton *hton, THD *thd)
 
     thd      The thread whose transaction should be ended
     trx_data Pointer to the transaction data to use
+    all      True if the entire transaction should be ended, false if
+             only the statement transaction should be ended.
     end_ev   The end event to use (COMMIT, ROLLBACK, or commit XID)
 
   DESCRIPTION
@@ -1523,9 +1516,6 @@ binlog_truncate_trx_cache(THD *thd, binlog_trx_data *trx_data, bool all)
   DBUG_RETURN(error);
 }
 
-static LEX_STRING const write_error_msg=
-    { C_STRING_WITH_LEN("error writing to the binary log") };
-
 static int binlog_prepare(handlerton *hton, THD *thd, bool all)
 {
   /*
@@ -3989,10 +3979,6 @@ err:
 }
 
 
-#ifndef DBUG_OFF
-static ulong opt_binlog_dbug_fsync_sleep= 0;
-#endif
-
 bool MYSQL_BIN_LOG::flush_and_sync()
 {
   int err=0, fd=log_file.file;
@@ -4004,9 +3990,8 @@ bool MYSQL_BIN_LOG::flush_and_sync()
     sync_binlog_counter= 0;
     err=my_sync(fd, MYF(MY_WME));
 #ifndef DBUG_OFF
-    ulong usec_sleep= opt_binlog_dbug_fsync_sleep;
-    if (usec_sleep > 0)
-      my_sleep(usec_sleep);
+    if (opt_binlog_dbug_fsync_sleep > 0)
+      my_sleep(opt_binlog_dbug_fsync_sleep);
 #endif
   }
   return err;
@@ -4444,7 +4429,19 @@ bool MYSQL_BIN_LOG::write(Log_event *event_info)
 #endif /* USING_TRANSACTIONS */
     DBUG_PRINT("info",("event type: %d",event_info->get_type_code()));
     if (file == &log_file)
+    {
       pthread_mutex_lock(&LOCK_log);
+      /*
+        We did not want to take LOCK_log unless really necessary.
+        However, now that we hold LOCK_log, we must check is_open() again, lest
+        the log was closed just before.
+      */
+      if (unlikely(!is_open()))
+      {
+        pthread_mutex_unlock(&LOCK_log);
+        DBUG_RETURN(error);
+      }
+    }
 
     /*
       No check for auto events flag here - this write method should
@@ -4662,6 +4659,7 @@ uint MYSQL_BIN_LOG::next_file_id()
 
 int MYSQL_BIN_LOG::write_cache(IO_CACHE *cache)
 {
+  safe_mutex_assert_owner(&LOCK_log);
   if (reinit_io_cache(cache, READ_CACHE, 0, 0, 0))
     return ER_ERROR_ON_WRITE;
   uint length= my_b_bytes_in_cache(cache), group, carry, hdr_offs;
@@ -4821,12 +4819,15 @@ bool MYSQL_BIN_LOG::write_incident(THD *thd)
   Incident_log_event ev(thd, incident, write_error_msg);
 
   pthread_mutex_lock(&LOCK_log);
+  if (likely(is_open()))
+  {
     error= ev.write(&log_file);
     if (!error && !(error= flush_and_sync()))
     {
       signal_update();
       rotate_and_purge(RP_LOCK_LOG_IS_ALREADY_LOCKED);
     }
+  }
   pthread_mutex_unlock(&LOCK_log);
 
   DBUG_RETURN(error);
@@ -4869,6 +4870,9 @@ MYSQL_BIN_LOG::write_transaction_to_binlog(THD *thd, binlog_trx_data *trx_data,
   entry.all= all;
 
   /*
+    Log "BEGIN" at the beginning of every transaction.  Here, a transaction is
+    either a BEGIN..COMMIT block or a single statement in autocommit mode.
+
     Create the necessary events here, where we have the correct THD (and
     thread context).
 
@@ -4925,7 +4929,7 @@ MYSQL_BIN_LOG::write_transaction_to_binlog_events(group_commit_entry *entry)
   else
     trx_group_commit_leader(entry);
 
-  if (!entry->error)
+  if (likely(!entry->error))
     return 0;
 
   switch (entry->error)
@@ -4953,7 +4957,7 @@ MYSQL_BIN_LOG::write_transaction_to_binlog_events(group_commit_entry *entry)
     we need to mark it as not needed for recovery (unlog() is not called
     for a transaction if log_xid() fails).
   */
-  if (entry->trx_data->using_xa)
+  if (entry->trx_data->using_xa && entry->trx_data->xa_xid)
     mark_xid_done();
 
   return 1;
@@ -5018,26 +5022,20 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader)
       binlog_trx_data *trx_data= current->trx_data;
       IO_CACHE *cache= &trx_data->trans_log;
 
-      /* Skip log_xid for transactions without xid, marked by NULL end_event. */
-      if (!current->end_event)
-        continue;
-
       /*
         We only bother to write to the binary log if there is anything
         to write.
       */
       if (my_b_tell(cache) > 0)
       {
-        current->error= write_transaction(current);
-        if (current->error)
+        if ((current->error= write_transaction(current)))
           current->commit_errno= errno;
 
         write_count++;
       }
 
-      trx_data->commit_bin_log_file_pos=
-        log_file.pos_in_file + (log_file.write_pos - log_file.write_buffer);
-      if (trx_data->using_xa)
+      trx_data->commit_bin_log_file_pos= my_b_write_tell(&log_file);
+      if (trx_data->using_xa && trx_data->xa_xid)
         xid_count++;
     }
 
@@ -5095,6 +5093,8 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader)
   current= queue;
   while (current != NULL)
   {
+    group_commit_entry *next;
+
     DEBUG_SYNC(leader->thd, "commit_loop_entry_commit_ordered");
     ++num_commits;
     if (current->trx_data->using_xa && !current->error)
@@ -5104,7 +5104,7 @@ MYSQL_BIN_LOG::trx_group_commit_leader(group_commit_entry *leader)
       Careful not to access current->next after waking up the other thread! As
       it may change immediately after wakeup.
     */
-    group_commit_entry *next= current->next;
+    next= current->next;
     if (current != leader)                      // Don't wake up ourself
       current->thd->signal_wakeup_ready();
     current= next;
@@ -5120,19 +5120,7 @@ MYSQL_BIN_LOG::write_transaction(group_commit_entry *entry)
 {
   binlog_trx_data *trx_data= entry->trx_data;
   IO_CACHE *cache= &trx_data->trans_log;
-  /*
-    Log "BEGIN" at the beginning of every transaction.  Here, a transaction is
-    either a BEGIN..COMMIT block or a single statement in autocommit mode. The
-    event was constructed in write_transaction_to_binlog(), in the thread
-    running the transaction.
-
-    Now this Query_log_event has artificial log_pos 0. It must be
-    adjusted to reflect the real position in the log. Not doing it
-    would confuse the slave: it would prevent this one from
-    knowing where he is in the master's binlog, which would result
-    in wrong positions being shown to the user, MASTER_POS_WAIT
-    undue waiting etc.
-  */
+
   if (entry->begin_event->write(&log_file))
     return ER_ERROR_ON_WRITE;
 
@@ -5579,10 +5567,6 @@ void sql_print_information(const char *format, ...)
 }
 
 
-static my_bool mutexes_inited;
-pthread_mutex_t LOCK_prepare_ordered;
-pthread_mutex_t LOCK_commit_ordered;
-
 void
 TC_init()
 {
@@ -5593,6 +5577,7 @@ TC_init()
   mutexes_inited= TRUE;
 }
 
+
 void
 TC_destroy()
 {
@@ -5604,39 +5589,42 @@ TC_destroy()
   }
 }
 
+
 void
 TC_LOG::run_prepare_ordered(THD *thd, bool all)
 {
   Ha_trx_info *ha_info=
     all ? thd->transaction.all.ha_list : thd->transaction.stmt.ha_list;
 
+  safe_mutex_assert_owner(&LOCK_prepare_ordered);
   for (; ha_info; ha_info= ha_info->next())
   {
     handlerton *ht= ha_info->ht();
     if (!ht->prepare_ordered)
       continue;
-    safe_mutex_assert_owner(&LOCK_prepare_ordered);
     ht->prepare_ordered(ht, thd, all);
   }
 }
 
+
 void
 TC_LOG::run_commit_ordered(THD *thd, bool all)
 {
   Ha_trx_info *ha_info=
     all ? thd->transaction.all.ha_list : thd->transaction.stmt.ha_list;
 
+  safe_mutex_assert_owner(&LOCK_commit_ordered);
   for (; ha_info; ha_info= ha_info->next())
   {
     handlerton *ht= ha_info->ht();
     if (!ht->commit_ordered)
       continue;
-    safe_mutex_assert_owner(&LOCK_commit_ordered);
     ht->commit_ordered(ht, thd, all);
     DEBUG_SYNC(thd, "commit_after_run_commit_ordered");
   }
 }
 
+
 int TC_LOG_MMAP::log_and_order(THD *thd, my_xid xid, bool all,
                                bool need_prepare_ordered,
                                bool need_commit_ordered)
@@ -5666,10 +5654,9 @@ int TC_LOG_MMAP::log_and_order(THD *thd, my_xid xid, bool all,
     pthread_mutex_unlock(&LOCK_prepare_ordered);
   }
 
+  cookie= 0;
   if (xid)
     cookie= log_one_transaction(xid);
-  else
-    cookie= 0;
 
   if (need_commit_ordered)
   {
@@ -6391,13 +6378,23 @@ TC_LOG_BINLOG::log_and_order(THD *thd, my_xid xid, bool all,
     (binlog_trx_data*) thd_get_ha_data(thd, binlog_hton);
 
   trx_data->using_xa= TRUE;
+  trx_data->xa_xid= xid;
   if (xid)
   {
     Xid_log_event xid_event(thd, xid);
     err= binlog_flush_trx_cache(thd, trx_data, &xid_event, all);
   }
   else
-    err= binlog_flush_trx_cache(thd, trx_data, NULL, all);
+  {
+    /*
+      Empty xid occurs in XA COMMIT ... ONE PHASE.
+      In this case, we do not have a MySQL xid for the transaction, and the
+      external XA transaction coordinator will have to handle recovery if
+      needed. So we end the transaction with a plain COMMIT query event.
+    */
+    Query_log_event end_event(thd, STRING_WITH_LEN("COMMIT"), TRUE, TRUE, 0);
+    err= binlog_flush_trx_cache(thd, trx_data, &end_event, all);
+  }
 
   DBUG_RETURN(!err);
 }
@@ -6434,14 +6431,17 @@ TC_LOG_BINLOG::mark_xids_active(uint xid_count)
 void
 TC_LOG_BINLOG::mark_xid_done()
 {
+  my_bool send_signal;
+
   DBUG_ENTER("TC_LOG_BINLOG::mark_xid_done");
   pthread_mutex_lock(&LOCK_prep_xids);
   DBUG_ASSERT(prepared_xids > 0);
-  if (--prepared_xids == 0) {
+  send_signal= !--prepared_xids;
+  pthread_mutex_unlock(&LOCK_prep_xids);
+  if (send_signal) {
     DBUG_PRINT("info", ("prepared_xids=%lu", prepared_xids));
     pthread_cond_signal(&COND_prep_xids);
   }
-  pthread_mutex_unlock(&LOCK_prep_xids);
   DBUG_VOID_RETURN;
 }
 
@@ -6553,18 +6553,6 @@ mysql_bin_log_commit_pos(THD *thd, ulonglong *out_pos, const char **out_file)
 #endif /* INNODB_COMPATIBILITY_HOOKS */
 
 
-static ulonglong binlog_status_var_num_commits;
-static ulonglong binlog_status_var_num_group_commits;
-
-static SHOW_VAR binlog_status_vars_detail[]=
-{
-  {"commits",
-    (char *)&binlog_status_var_num_commits, SHOW_LONGLONG},
-  {"group_commits",
-    (char *)&binlog_status_var_num_group_commits, SHOW_LONGLONG},
-  {NullS, NullS, SHOW_LONG}
-};
-
 static int show_binlog_vars(THD *thd, SHOW_VAR *var, char *buff)
 {
   mysql_bin_log.set_status_variables();
@@ -6608,15 +6596,10 @@ static struct st_mysql_sys_var *binlog_sys_vars[]=
 void
 TC_LOG_BINLOG::set_status_variables()
 {
-  ulonglong num_commits, num_group_commits;
-
   pthread_mutex_lock(&LOCK_commit_ordered);
-  num_commits= this->num_commits;
-  num_group_commits= this->num_group_commits;
+  binlog_status_var_num_commits= this->num_commits;
+  binlog_status_var_num_group_commits= this->num_group_commits;
   pthread_mutex_unlock(&LOCK_commit_ordered);
-
-  binlog_status_var_num_commits= num_commits;
-  binlog_status_var_num_group_commits= num_group_commits;
 }
 
 struct st_mysql_storage_engine binlog_storage_engine=

sql/sql_class.cc

@@ -4023,8 +4023,8 @@ THD::signal_wakeup_ready()
 {
   pthread_mutex_lock(&LOCK_wakeup_ready);
   wakeup_ready= true;
-  pthread_cond_signal(&COND_wakeup_ready);
   pthread_mutex_unlock(&LOCK_wakeup_ready);
+  pthread_cond_signal(&COND_wakeup_ready);
 }
 
 

storage/xtradb/handler/ha_innodb.cc

@@ -11643,6 +11643,12 @@ static MYSQL_SYSVAR_ENUM(adaptive_checkpoint, srv_adaptive_checkpoint,
   "Enable/Disable flushing along modified age. (none, reflex, [estimate])",
   NULL, innodb_adaptive_checkpoint_update, 2, &adaptive_checkpoint_typelib);
 
+static MYSQL_SYSVAR_ULONG(enable_unsafe_group_commit, srv_deprecated_enable_unsafe_group_commit,
+  PLUGIN_VAR_RQCMDARG,
+  "Enable/Disable unsafe group commit when support_xa=OFF and use with binlog or other XA storage engine. "
+  "(Deprecated, and does nothing, group commit is always enabled in a safe way)",
+  NULL, NULL, 0, 0, 1, 0);
+
 static MYSQL_SYSVAR_ULONG(expand_import, srv_expand_import,
   PLUGIN_VAR_RQCMDARG,
   "Enable/Disable converting automatically *.ibd files when import tablespace.",
@@ -11748,6 +11754,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(read_ahead),
   MYSQL_SYSVAR(adaptive_checkpoint),
   MYSQL_SYSVAR(flush_log_at_trx_commit_session),
+  MYSQL_SYSVAR(enable_unsafe_group_commit),
   MYSQL_SYSVAR(expand_import),
   MYSQL_SYSVAR(extra_rsegments),
   MYSQL_SYSVAR(dict_size_limit),

storage/xtradb/include/srv0srv.h

@@ -230,7 +230,7 @@ extern ulong	srv_ibuf_active_contract;
 extern ulong	srv_ibuf_accel_rate;
 extern ulint	srv_checkpoint_age_target;
 extern ulong	srv_flush_neighbor_pages;
-extern ulong	srv_enable_unsafe_group_commit;
+extern ulong	srv_deprecated_enable_unsafe_group_commit;
 extern ulong	srv_read_ahead;
 extern ulong	srv_adaptive_checkpoint;
 

storage/xtradb/srv/srv0srv.c

@@ -407,7 +407,7 @@ UNIV_INTERN ulong	srv_ibuf_accel_rate = 100;
 UNIV_INTERN ulint	srv_checkpoint_age_target = 0;
 UNIV_INTERN ulong	srv_flush_neighbor_pages = 1; /* 0:disable 1:enable */
 
-UNIV_INTERN ulong	srv_enable_unsafe_group_commit = 0; /* 0:disable 1:enable */
+UNIV_INTERN ulong	srv_deprecated_enable_unsafe_group_commit = 0;
 UNIV_INTERN ulong	srv_read_ahead = 3; /* 1: random  2: linear  3: Both */
 UNIV_INTERN ulong	srv_adaptive_checkpoint = 0; /* 0: none  1: reflex  2: estimate */