BUG#23171 (Illegal slave restart group position):

Second patch to fix skipping code. Moving relay and binary log 
position changing code from do_apply_event [old exec_event()] into
do_update_pos() and doing other changes necessary to support that.

Fixing a bug that can cause deadlock if rotating binary log when committing
a changes to a transactional table that is not inside a transaction and
cause a rotate log.


sql/log.cc:
  Changing condition in binlog_commit() to skip calling
  binlog_end_trans() twice to match condition in binlog_end_trans().
sql/log_event.cc:
  Name change: apply_event_impl() -> do_apply_event()
  Name change: advance_coord_impl() -> do_update_pos()
  
  do_apply_event() now uses pointer to constant RELAY_LOG_INFO to prevent
  inadvertandly changing the position in the code. Doing this would make
  the skipping code loose track of where it is. All position changing code
  shall now be in do_update_pos().
  
  Factoring out relay and binary log position updating code from
  do_apply_event() [previously exec_event()] into do_update_pos().
  Using a safe approach to make it work: will refine the refactoring
  when the skipping code is implemented.
  
  Adding const casts where needed.
  
  Changing signature to use pointers to constant objects where needed.
sql/rpl_rli.cc:
  Making cached_charset_compare() const to work with constant instances of RELAY_LOG_INFO.
  
  Debriding code.
sql/rpl_rli.h:
  Making cached_charset_compare() const to work with constant instances of RELAY_LOG_INFO.
  
  Debriding code.
sql/rpl_utility.cc:
  Using pointer to const RELAY_LOG_INFO to make it work with other code.
sql/rpl_utility.h:
  Using pointer to const RELAY_LOG_INFO to make it work with other code.
sql/slave.cc:
  Using pointer to const RELAY_LOG_INFO to make it work with other code.
  
  Adding const cast where necessary.
sql/slave.h:
  Using pointer to const RELAY_LOG_INFO to make it work with other code.

1 files changed, 186 insertions, 154 deletions

diff --git a/sql/log_event.cc b/sql/log_event.cc
index 3b8a953539b..3bdc6412dc6 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -531,23 +531,19 @@ Log_event::Log_event(const char* buf,
 #ifndef MYSQL_CLIENT
 #ifdef HAVE_REPLICATION
 
-/*
-  Log_event::apply_event_impl()
-*/
-
-int Log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Log_event::do_update_pos(RELAY_LOG_INFO *rli)
 {
-  DBUG_ENTER("Log_event::apply_event_impl");
-
   /*
     rli is null when (as far as I (Guilhem) know) the caller is
-    Load_log_event::apply_event_impl *and* that one is called from
-    Execute_load_log_event::apply_event_impl.  In this case, we don't
-    do anything here ; Execute_load_log_event::apply_event_impl will
-    call Log_event::apply_event_impl again later with the proper rli.
+    Load_log_event::do_apply_event *and* that one is called from
+    Execute_load_log_event::do_apply_event.  In this case, we don't
+    do anything here ; Execute_load_log_event::do_apply_event will
+    call Log_event::do_apply_event again later with the proper rli.
     Strictly speaking, if we were sure that rli is null only in the
     case discussed above, 'if (rli)' is useless here.  But as we are
     not 100% sure, keep it for now.
+
+    Matz: I don't think we will need this check with this refactoring.
   */
   if (rli)
   {
@@ -583,7 +579,7 @@ int Log_event::apply_event_impl(RELAY_LOG_INFO* rli)
       rli->inc_group_relay_log_pos(log_pos);
       flush_relay_log_info(rli);
       /*
-         Note that Rotate_log_event::apply_event_impl() does not call
+         Note that Rotate_log_event::do_apply_event() does not call
          this function, so there is no chance that a fake rotate event
          resets last_master_timestamp.  Note that we update without
          mutex (probably ok - except in some very rare cases, only
@@ -593,9 +589,9 @@ int Log_event::apply_event_impl(RELAY_LOG_INFO* rli)
       rli->last_master_timestamp= when;
     }
   }
-  DBUG_RETURN(0);
-}
 
+  return 0;                                   // Cannot fail currently
+}
 
 /*
   Log_event::pack_info()
@@ -1819,18 +1815,18 @@ void Query_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
 
 
 /*
-  Query_log_event::apply_event_impl()
+  Query_log_event::do_apply_event()
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
 
-int Query_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Query_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
-  return apply_event_impl(rli, query, q_len);
+  return do_apply_event(rli, query, q_len);
 }
 
 
-int Query_log_event::apply_event_impl(RELAY_LOG_INFO* rli,
+int Query_log_event::do_apply_event(RELAY_LOG_INFO const *rli,
                                       const char *query_arg, uint32 q_len_arg)
 {
   LEX_STRING new_db;
@@ -1839,7 +1835,7 @@ int Query_log_event::apply_event_impl(RELAY_LOG_INFO* rli,
     Colleagues: please never free(thd->catalog) in MySQL. This would
     lead to bugs as here thd->catalog is a part of an alloced block,
     not an entire alloced block (see
-    Query_log_event::apply_event_impl()). Same for thd->db.  Thank
+    Query_log_event::do_apply_event()). Same for thd->db.  Thank
     you.
   */
   thd->catalog= catalog_len ? (char *) catalog : (char *)"";
@@ -1859,11 +1855,11 @@ int Query_log_event::apply_event_impl(RELAY_LOG_INFO* rli,
     END of the current log event (COMMIT). We save it in rli so that InnoDB can
     access it.
   */
-  rli->future_group_master_log_pos= log_pos;
+  const_cast<RELAY_LOG_INFO*>(rli)->future_group_master_log_pos= log_pos;
   DBUG_PRINT("info", ("log_pos: %lu", (ulong) log_pos));
 
-  clear_all_errors(thd, rli);
-  rli->clear_tables_to_lock();
+  clear_all_errors(thd, const_cast<RELAY_LOG_INFO*>(rli));
+  const_cast<RELAY_LOG_INFO*>(rli)->clear_tables_to_lock();
 
   /*
     Note:   We do not need to execute reset_one_shot_variables() if this
@@ -1872,7 +1868,7 @@ int Query_log_event::apply_event_impl(RELAY_LOG_INFO* rli,
             its companion query.  If the SET is ignored because of
             db_ok(), the companion query will also be ignored, and if
             the companion query is ignored in the db_ok() test of
-            ::apply_event_impl(), then the companion SET also have so
+            ::do_apply_event(), then the companion SET also have so
             we don't need to reset_one_shot_variables().
   */
   if (rpl_filter->db_ok(thd->db))
@@ -1962,7 +1958,7 @@ int Query_log_event::apply_event_impl(RELAY_LOG_INFO* rli,
         to check/fix it.
       */
       if (mysql_test_parse_for_slave(thd, thd->query, thd->query_length))
-        clear_all_errors(thd, rli);        /* Can ignore query */
+        clear_all_errors(thd, const_cast<RELAY_LOG_INFO*>(rli)); /* Can ignore query */
       else
       {
         slave_print_msg(ERROR_LEVEL, rli, expected_error, 
@@ -2013,7 +2009,7 @@ Default database: '%s'. Query: '%s'",
  	     ignored_error_code(actual_error))
     {
       DBUG_PRINT("info",("error ignored"));
-      clear_all_errors(thd, rli);
+      clear_all_errors(thd, const_cast<RELAY_LOG_INFO*>(rli));
     }
     /*
       Other cases: mostly we expected no error and get one.
@@ -2080,16 +2076,26 @@ end:
   thd->first_successful_insert_id_in_prev_stmt= 0;
   thd->stmt_depends_on_first_successful_insert_id_in_prev_stmt= 0;
   free_root(thd->mem_root,MYF(MY_KEEP_PREALLOC));
+  return thd->query_error;
+}
+
+int Query_log_event::do_update_pos(RELAY_LOG_INFO *rli)
+{
   /*
-    If there was an error we stop. Otherwise we increment positions. Note that
-    we will not increment group* positions if we are just after a SET
-    ONE_SHOT, because SET ONE_SHOT should not be separated from its following
-    updating query.
+    Note that we will not increment group* positions if we are just
+    after a SET ONE_SHOT, because SET ONE_SHOT should not be separated
+    from its following updating query.
   */
-  return (thd->query_error ? thd->query_error : 
-          (thd->one_shot_set ? (rli->inc_event_relay_log_pos(),0) :
-           Log_event::apply_event_impl(rli))); 
+  if (thd->one_shot_set)
+  {
+    rli->inc_event_relay_log_pos();
+    return 0;
+  }
+  else
+    return Log_event::do_update_pos(rli);
 }
+
+
 #endif
 
 
@@ -2216,7 +2222,7 @@ bool Start_log_event_v3::write(IO_CACHE* file)
 
 
 /*
-  Start_log_event_v3::apply_event_impl()
+  Start_log_event_v3::do_apply_event()
 
   The master started
 
@@ -2235,9 +2241,9 @@ bool Start_log_event_v3::write(IO_CACHE* file)
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Start_log_event_v3::apply_event_impl(RELAY_LOG_INFO* rli)
+int Start_log_event_v3::do_apply_event(RELAY_LOG_INFO const *rli)
 {
-  DBUG_ENTER("Start_log_event_v3::apply_event_impl");
+  DBUG_ENTER("Start_log_event_v3::do_apply_event");
   switch (binlog_version)
   {
   case 3:
@@ -2279,7 +2285,7 @@ int Start_log_event_v3::apply_event_impl(RELAY_LOG_INFO* rli)
     /* this case is impossible */
     DBUG_RETURN(1);
   }
-  DBUG_RETURN(Log_event::apply_event_impl(rli));
+  DBUG_RETURN(0);
 }
 #endif /* defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT) */
 
@@ -2468,22 +2474,18 @@ bool Format_description_log_event::write(IO_CACHE* file)
 
 /*
   SYNOPSIS
-    Format_description_log_event::apply_event_impl()
+    Format_description_log_event::do_apply_event()
 
   IMPLEMENTATION
     Save the information which describes the binlog's format, to be
     able to read all coming events.  Call
-    Start_log_event_v3::apply_event_impl().
+    Start_log_event_v3::do_apply_event().
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Format_description_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Format_description_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
-  DBUG_ENTER("Format_description_log_event::apply_event_impl");
-
-  /* save the information describing this binlog */
-  delete rli->relay_log.description_event_for_exec;
-  rli->relay_log.description_event_for_exec= this;
+  DBUG_ENTER("Format_description_log_event::do_apply_event");
 
 #ifdef USING_TRANSACTIONS
   /*
@@ -2505,14 +2507,36 @@ int Format_description_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
                     "or ROLLBACK in relay log). A probable cause is that "
                     "the master died while writing the transaction to "
                     "its binary log, thus rolled back too."); 
-    rli->cleanup_context(thd, 1);
+    const_cast<RELAY_LOG_INFO*>(rli)->cleanup_context(thd, 1);
   }
 #endif
   /*
     If this event comes from ourselves, there is no cleaning task to
-    perform, we don't call Start_log_event_v3::apply_event_impl()
+    perform, we don't call Start_log_event_v3::do_apply_event()
     (this was just to update the log's description event).
   */
+  if (server_id != (uint32) ::server_id)
+  {
+    /*
+      If the event was not requested by the slave i.e. the master sent
+      it while the slave asked for a position >4, the event will make
+      rli->group_master_log_pos advance. Say that the slave asked for
+      position 1000, and the Format_desc event's end is 96. Then in
+      the beginning of replication rli->group_master_log_pos will be
+      0, then 96, then jump to first really asked event (which is
+      >96). So this is ok.
+    */
+    DBUG_RETURN(Start_log_event_v3::do_apply_event(rli));
+  }
+  DBUG_RETURN(0);
+}
+
+int Format_description_log_event::do_update_pos(RELAY_LOG_INFO *rli)
+{
+  /* save the information describing this binlog */
+  delete rli->relay_log.description_event_for_exec;
+  rli->relay_log.description_event_for_exec= this;
+
   if (server_id == (uint32) ::server_id)
   {
     /*
@@ -2529,19 +2553,14 @@ int Format_description_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
       the Intvar_log_event respectively.
      */
     rli->inc_event_relay_log_pos();
-    DBUG_RETURN(0);
+    return 0;
+  }
+  else
+  {
+    return Log_event::do_update_pos(rli);
   }
-
-  /*
-    If the event was not requested by the slave i.e. the master sent it while
-    the slave asked for a position >4, the event will make
-    rli->group_master_log_pos advance. Say that the slave asked for position
-    1000, and the Format_desc event's end is 96. Then in the beginning of
-    replication rli->group_master_log_pos will be 0, then 96, then jump to
-    first really asked event (which is >96). So this is ok.
-  */
-  DBUG_RETURN(Start_log_event_v3::apply_event_impl(rli));
 }
+
 #endif
 
   /**************************************************************************
@@ -3023,18 +3042,18 @@ void Load_log_event::set_fields(const char* affected_db,
   Does the data loading job when executing a LOAD DATA on the slave
 
   SYNOPSIS
-    Load_log_event::apply_event_impl
+    Load_log_event::do_apply_event
       net
       rli
       use_rli_only_for_errors	  - if set to 1, rli is provided to
-                                  Load_log_event::apply_event_impl
+                                  Load_log_event::do_apply_event
                                   only for this function to have
                                   RPL_LOG_NAME and
                                   rli->last_slave_error, both being
                                   used by error reports. rli's
                                   position advancing is skipped (done
                                   by the caller which is
-                                  Execute_load_log_event::apply_event_impl).
+                                  Execute_load_log_event::do_apply_event).
                                   - if set to 0, rli is provided for
                                   full use, i.e. for error reports and
                                   position advancing.
@@ -3047,8 +3066,8 @@ void Load_log_event::set_fields(const char* affected_db,
     1    	Failure
 */
 
-int Load_log_event::apply_event_impl(NET* net, RELAY_LOG_INFO* rli, 
-			       bool use_rli_only_for_errors)
+int Load_log_event::do_apply_event(NET* net, RELAY_LOG_INFO const *rli,
+                                     bool use_rli_only_for_errors)
 {
   LEX_STRING new_db;
   new_db.length= db_len;
@@ -3057,9 +3076,9 @@ int Load_log_event::apply_event_impl(NET* net, RELAY_LOG_INFO* rli,
   DBUG_ASSERT(thd->query == 0);
   thd->query_length= 0;                         // Should not be needed
   thd->query_error= 0;
-  clear_all_errors(thd, rli);
+  clear_all_errors(thd, const_cast<RELAY_LOG_INFO*>(rli));
 
-  /* see Query_log_event::apply_event_impl() and BUG#13360 */
+  /* see Query_log_event::do_apply_event() and BUG#13360 */
   DBUG_ASSERT(!rli->m_table_map.count());
   /*
     Usually mysql_init_query() is called by mysql_parse(), but we need it here
@@ -3070,9 +3089,9 @@ int Load_log_event::apply_event_impl(NET* net, RELAY_LOG_INFO* rli,
   {
     /*
       Saved for InnoDB, see comment in
-      Query_log_event::apply_event_impl()
+      Query_log_event::do_apply_event()
     */
-    rli->future_group_master_log_pos= log_pos;
+    const_cast<RELAY_LOG_INFO*>(rli)->future_group_master_log_pos= log_pos;
     DBUG_PRINT("info", ("log_pos: %lu", (ulong) log_pos));
   }
  
@@ -3084,7 +3103,7 @@ int Load_log_event::apply_event_impl(NET* net, RELAY_LOG_INFO* rli,
     still consume a lot of space on the slave (space in the relay log
     + space of temp files: twice the space of the file to load...)
     even if it will finally be ignored.  TODO: fix this; this can be
-    done by testing rules in Create_file_log_event::apply_event_impl()
+    done by testing rules in Create_file_log_event::do_apply_event()
     and then discarding Append_block and al. Another way is do the
     filtering in the I/O thread (more efficient: no disk writes at
     all).
@@ -3096,7 +3115,7 @@ int Load_log_event::apply_event_impl(NET* net, RELAY_LOG_INFO* rli,
             its companion query.  If the SET is ignored because of
             db_ok(), the companion query will also be ignored, and if
             the companion query is ignored in the db_ok() test of
-            ::apply_event_impl(), then the companion SET also have so
+            ::do_apply_event(), then the companion SET also have so
             we don't need to reset_one_shot_variables().
   */
   if (rpl_filter->db_ok(thd->db))
@@ -3293,7 +3312,7 @@ Fatal error running LOAD DATA INFILE on table '%s'. Default database: '%s'",
     return 1;
   }
 
-  return ( use_rli_only_for_errors ? 0 : Log_event::apply_event_impl(rli) ); 
+  return ( use_rli_only_for_errors ? 0 : Log_event::do_apply_event(rli) ); 
 }
 #endif
 
@@ -3407,7 +3426,7 @@ bool Rotate_log_event::write(IO_CACHE* file)
 #endif
 
 /*
-  Rotate_log_event::apply_event_impl()
+  Rotate_log_event::do_apply_event()
 
   Got a rotate log event from the master
 
@@ -3424,10 +3443,9 @@ bool Rotate_log_event::write(IO_CACHE* file)
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Rotate_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Rotate_log_event::do_update_pos(RELAY_LOG_INFO *rli)
 {
-  DBUG_ENTER("Rotate_log_event::apply_event_impl");
-
+  DBUG_ENTER("Rotate_log_event::do_update_pos");
   pthread_mutex_lock(&rli->data_lock);
   rli->event_relay_log_pos= my_b_tell(rli->cur_log);
   /*
@@ -3470,8 +3488,10 @@ int Rotate_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
   pthread_mutex_unlock(&rli->data_lock);
   pthread_cond_broadcast(&rli->data_cond);
   flush_relay_log_info(rli);
+
   DBUG_RETURN(0);
 }
+
 #endif
 
 
@@ -3577,11 +3597,11 @@ void Intvar_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
 
 
 /*
-  Intvar_log_event::apply_event_impl()
+  Intvar_log_event::do_apply_event()
 */
 
 #if defined(HAVE_REPLICATION)&& !defined(MYSQL_CLIENT)
-int Intvar_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Intvar_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   switch (type) {
   case LAST_INSERT_ID_EVENT:
@@ -3592,6 +3612,11 @@ int Intvar_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
     thd->force_one_auto_inc_interval(val);
     break;
   }
+  return 0;
+}
+
+int Intvar_log_event::do_update_pos(RELAY_LOG_INFO *rli)
+{
   rli->inc_event_relay_log_pos();
   return 0;
 }
@@ -3656,13 +3681,19 @@ void Rand_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
 
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Rand_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Rand_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   thd->rand.seed1= (ulong) seed1;
   thd->rand.seed2= (ulong) seed2;
+  return 0;
+}
+
+int Rand_log_event::do_update_pos(RELAY_LOG_INFO *rli)
+{
   rli->inc_event_relay_log_pos();
   return 0;
 }
+
 #endif /* !MYSQL_CLIENT */
 
 
@@ -3729,12 +3760,12 @@ void Xid_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
 
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Xid_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Xid_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   /* For a slave Xid_log_event is COMMIT */
   general_log_print(thd, COM_QUERY,
                     "COMMIT /* implicit, from Xid_log_event */");
-  return end_trans(thd, COMMIT) || Log_event::apply_event_impl(rli);
+  return end_trans(thd, COMMIT);
 }
 #endif /* !MYSQL_CLIENT */
 
@@ -4010,11 +4041,11 @@ void User_var_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
 
 
 /*
-  User_var_log_event::apply_event_impl()
+  User_var_log_event::do_apply_event()
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int User_var_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int User_var_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   Item *it= 0;
   CHARSET_INFO *charset;
@@ -4076,9 +4107,15 @@ int User_var_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
   e.update_hash(val, val_len, type, charset, DERIVATION_IMPLICIT, 0);
   free_root(thd->mem_root,0);
 
+  return 0;
+}
+
+int User_var_log_event::do_update_pos(RELAY_LOG_INFO *rli)
+{
   rli->inc_event_relay_log_pos();
   return 0;
 }
+
 #endif /* !MYSQL_CLIENT */
 
 
@@ -4228,11 +4265,11 @@ Slave_log_event::Slave_log_event(const char* buf, uint event_len)
 
 
 #ifndef MYSQL_CLIENT
-int Slave_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Slave_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   if (mysql_bin_log.is_open())
     mysql_bin_log.write(this);
-  return Log_event::apply_event_impl(rli);
+  return 0;
 }
 #endif /* !MYSQL_CLIENT */
 
@@ -4261,7 +4298,7 @@ void Stop_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
 
 
 /*
-  Stop_log_event::apply_event_impl()
+  Stop_log_event::do_apply_event()
 
   The master stopped.  We used to clean up all temporary tables but
   this is useless as, as the master has shut down properly, it has
@@ -4270,12 +4307,12 @@ void Stop_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
   slave_load_tmpdir, but this is useless as it has been cleared at the
   end of LOAD DATA INFILE.  So we have nothing to do here.  The place
   were we must do this cleaning is in
-  Start_log_event_v3::apply_event_impl(), not here. Because if we come
+  Start_log_event_v3::do_apply_event(), not here. Because if we come
   here, the master was sane.
 */
 
 #ifndef MYSQL_CLIENT
-int Stop_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Stop_log_event::do_update_pos(RELAY_LOG_INFO *rli)
 {
   /*
     We do not want to update master_log pos because we get a rotate event
@@ -4293,6 +4330,7 @@ int Stop_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
   }
   return 0;
 }
+
 #endif /* !MYSQL_CLIENT */
 #endif /* HAVE_REPLICATION */
 
@@ -4483,11 +4521,11 @@ void Create_file_log_event::pack_info(Protocol *protocol)
 
 
 /*
-  Create_file_log_event::apply_event_impl()
+  Create_file_log_event::do_apply_event()
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Create_file_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Create_file_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   char proc_info[17+FN_REFLEN+10], *fname_buf;
   char *ext;
@@ -4549,7 +4587,7 @@ err:
   if (fd >= 0)
     my_close(fd, MYF(0));
   thd->proc_info= 0;
-  return error ? 1 : Log_event::apply_event_impl(rli);
+  return error == 0;
 }
 #endif /* defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT) */
 
@@ -4657,15 +4695,15 @@ int Append_block_log_event::get_create_or_append() const
 }
 
 /*
-  Append_block_log_event::apply_event_impl()
+  Append_block_log_event::do_apply_event()
 */
 
-int Append_block_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Append_block_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   char proc_info[17+FN_REFLEN+10], *fname= proc_info+17;
   int fd;
   int error = 1;
-  DBUG_ENTER("Append_block_log_event::apply_event_impl");
+  DBUG_ENTER("Append_block_log_event::do_apply_event");
 
   fname= strmov(proc_info, "Making temp file ");
   slave_load_file_stem(fname, file_id, server_id, ".data");
@@ -4704,7 +4742,7 @@ err:
   if (fd >= 0)
     my_close(fd, MYF(0));
   thd->proc_info= 0;
-  DBUG_RETURN(error ? error : Log_event::apply_event_impl(rli));
+  DBUG_RETURN(error);
 }
 #endif
 
@@ -4788,18 +4826,18 @@ void Delete_file_log_event::pack_info(Protocol *protocol)
 #endif
 
 /*
-  Delete_file_log_event::apply_event_impl()
+  Delete_file_log_event::do_apply_event()
 */
 
 #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
-int Delete_file_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Delete_file_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   char fname[FN_REFLEN+10];
   char *ext= slave_load_file_stem(fname, file_id, server_id, ".data");
   (void) my_delete(fname, MYF(MY_WME));
   strmov(ext, ".info");
   (void) my_delete(fname, MYF(MY_WME));
-  return Log_event::apply_event_impl(rli);
+  return 0;
 }
 #endif /* defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT) */
 
@@ -4885,10 +4923,10 @@ void Execute_load_log_event::pack_info(Protocol *protocol)
 
 
 /*
-  Execute_load_log_event::apply_event_impl()
+  Execute_load_log_event::do_apply_event()
 */
 
-int Execute_load_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+int Execute_load_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   char fname[FN_REFLEN+10];
   char *ext;
@@ -4919,15 +4957,15 @@ int Execute_load_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
 
   lev->thd = thd;
   /*
-    lev->apply_event_impl should use rli only for errors i.e. should
+    lev->do_apply_event should use rli only for errors i.e. should
     not advance rli's position.
 
-    lev->apply_event_impl is the place where the table is loaded (it
+    lev->do_apply_event is the place where the table is loaded (it
     calls mysql_load()).
   */
 
-  rli->future_group_master_log_pos= log_pos;
-  if (lev->apply_event_impl(0,rli,1)) 
+  const_cast<RELAY_LOG_INFO*>(rli)->future_group_master_log_pos= log_pos;
+  if (lev->do_apply_event(0,rli,1)) 
   {
     /*
       We want to indicate the name of the file that could not be loaded
@@ -4970,7 +5008,7 @@ err:
     my_close(fd, MYF(0));
     end_io_cache(&file);
   }
-  return error ? error : Log_event::apply_event_impl(rli);
+  return error;
 }
 
 #endif /* defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT) */
@@ -5138,7 +5176,7 @@ void Execute_load_query_log_event::pack_info(Protocol *protocol)
 
 
 int
-Execute_load_query_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
+Execute_load_query_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
   char *p;
   char *buf;
@@ -5175,7 +5213,7 @@ Execute_load_query_log_event::apply_event_impl(RELAY_LOG_INFO* rli)
   p= strmake(p, STRING_WITH_LEN(" INTO"));
   p= strmake(p, query+fn_pos_end, q_len-fn_pos_end);
 
-  error= Query_log_event::apply_event_impl(rli, buf, p-buf);
+  error= Query_log_event::do_apply_event(rli, buf, p-buf);
 
   /* Forging file name for deletion in same buffer */
   *fname_end= 0;
@@ -5488,7 +5526,7 @@ int Rows_log_event::do_add_row_data(byte *const row_data,
         the master does not have a default value (and isn't nullable)
  */
 static int
-unpack_row(RELAY_LOG_INFO *rli,
+unpack_row(RELAY_LOG_INFO const *rli,
            TABLE *table, uint const colcnt, byte *record,
            char const *row, MY_BITMAP const *cols,
            char const **row_end, ulong *master_reclength,
@@ -5590,17 +5628,17 @@ unpack_row(RELAY_LOG_INFO *rli,
   return error;
 }
 
-int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
+int Rows_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
-  DBUG_ENTER("Rows_log_event::apply_event_impl(st_relay_log_info*)");
+  DBUG_ENTER("Rows_log_event::do_apply_event(st_relay_log_info*)");
   int error= 0;
   char const *row_start= (char const *)m_rows_buf;
 
   /*
-    If m_table_id == ~0UL, then we have a dummy event that does
-    not contain any data.  In that case, we just remove all tables in
-    the tables_to_lock list, close the thread tables, step the relay
-    log position, and return with success.
+    If m_table_id == ~0UL, then we have a dummy event that does not
+    contain any data.  In that case, we just remove all tables in the
+    tables_to_lock list, close the thread tables, and return with
+    success.  The relay log position will be stepped in 
    */
   if (m_table_id == ~0UL)
   {
@@ -5610,16 +5648,15 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
      */
     DBUG_ASSERT(get_flags(STMT_END_F));
 
-    rli->clear_tables_to_lock();
+    const_cast<RELAY_LOG_INFO*>(rli)->clear_tables_to_lock();
     close_thread_tables(thd);
     thd->clear_error();
-    rli->inc_event_relay_log_pos();
     DBUG_RETURN(0);
   }
 
   /*
     'thd' has been set by exec_relay_log_event(), just before calling
-    apply_event_impl(). We still check here to prevent future coding
+    do_apply_event(). We still check here to prevent future coding
     errors.
   */
   DBUG_ASSERT(rli->sql_thd == thd);
@@ -5637,7 +5674,7 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
     /*
       lock_tables() reads the contents of thd->lex, so they must be
       initialized. Contrary to in
-      Table_map_log_event::apply_event_impl() we don't call
+      Table_map_log_event::do_apply_event() we don't call
       mysql_init_query() as that may reset the binlog format.
     */
     lex_start(thd, NULL, 0);
@@ -5650,7 +5687,7 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
         slave_print_msg(ERROR_LEVEL, rli, error,
                         "Error in %s event: when locking tables",
                         get_type_str());
-        rli->clear_tables_to_lock();
+        const_cast<RELAY_LOG_INFO*>(rli)->clear_tables_to_lock();
         DBUG_RETURN(error);
       }
 
@@ -5668,10 +5705,12 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
         need to add code to assert that is the case.
        */
       thd->binlog_flush_pending_rows_event(false);
-      close_tables_for_reopen(thd, &rli->tables_to_lock);
+      close_tables_for_reopen(thd, &const_cast<RELAY_LOG_INFO*>(rli)->tables_to_lock);
 
-      if ((error= open_tables(thd, &rli->tables_to_lock,
-                              &rli->tables_to_lock_count, 0)))
+      if ((error= open_tables(thd,
+                              &const_cast<RELAY_LOG_INFO*>(rli)->tables_to_lock,
+                              &const_cast<RELAY_LOG_INFO*>(rli)->tables_to_lock_count,
+                              0)))
       {
         if (thd->query_error || thd->is_fatal_error)
         {
@@ -5686,7 +5725,7 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
                            "unexpected success or fatal error"));
           thd->query_error= 1;
         }
-        rli->clear_tables_to_lock();
+        const_cast<RELAY_LOG_INFO*>(rli)->clear_tables_to_lock();
         DBUG_RETURN(error);
       }
     }
@@ -5701,23 +5740,23 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
     TABLE_LIST *ptr;
     for (ptr= rli->tables_to_lock ; ptr ; ptr= ptr->next_global)
     {
-      rli->m_table_map.set_table(ptr->table_id, ptr->table);
+      const_cast<RELAY_LOG_INFO*>(rli)->m_table_map.set_table(ptr->table_id, ptr->table);
     }
 #ifdef HAVE_QUERY_CACHE
     query_cache.invalidate_locked_for_write(rli->tables_to_lock);
 #endif
-    rli->clear_tables_to_lock();
+    const_cast<RELAY_LOG_INFO*>(rli)->clear_tables_to_lock();
   }
 
   DBUG_ASSERT(rli->tables_to_lock == NULL && rli->tables_to_lock_count == 0);
 
-  TABLE* table= rli->m_table_map.get_table(m_table_id);
+  TABLE* table= const_cast<RELAY_LOG_INFO*>(rli)->m_table_map.get_table(m_table_id);
 
   if (table)
   {
     /*
       table == NULL means that this table should not be replicated
-      (this was set up by Table_map_log_event::apply_event_impl()
+      (this was set up by Table_map_log_event::do_apply_event()
       which tested replicate-* rules).
     */
 
@@ -5785,7 +5824,7 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
       row_start= row_end;
     }
     DBUG_EXECUTE_IF("STOP_SLAVE_after_first_Rows_event",
-                    rli->abort_slave=1;);
+                    const_cast<RELAY_LOG_INFO*>(rli)->abort_slave= 1;);
     error= do_after_row_operations(table, error);
     if (!cache_stmt)
     {
@@ -5812,7 +5851,7 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
       thread is certainly going to stop.
     */
     thd->reset_current_stmt_binlog_row_based();
-    rli->cleanup_context(thd, 1);
+    const_cast<RELAY_LOG_INFO*>(rli)->cleanup_context(thd, 1);
     thd->query_error= 1;
     DBUG_RETURN(error);
   }
@@ -5856,8 +5895,7 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
     */
 
     thd->reset_current_stmt_binlog_row_based();
-    rli->cleanup_context(thd, 0);
-    rli->transaction_end(thd);
+    const_cast<RELAY_LOG_INFO*>(rli)->cleanup_context(thd, 0);
 
     if (error == 0)
     {
@@ -5870,7 +5908,6 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
         do not become visible. We still prefer to wipe them out.
       */
       thd->clear_error();
-      error= Log_event::apply_event_impl(rli);
     }
     else
       slave_print_msg(ERROR_LEVEL, rli, error,
@@ -5899,15 +5936,15 @@ int Rows_log_event::apply_event_impl(st_relay_log_info *rli)
       problem.  When WL#2975 is implemented, just remove the member
       st_relay_log_info::unsafe_to_stop_at and all its occurences.
     */
-    rli->unsafe_to_stop_at= time(0);
+    const_cast<RELAY_LOG_INFO*>(rli)->unsafe_to_stop_at= time(0);
   }
 
   DBUG_ASSERT(error == 0);
   thd->clear_error();
-  rli->inc_event_relay_log_pos();
-  
+
   DBUG_RETURN(0);
 }
+
 #endif /* !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION) */
 
 #ifndef MYSQL_CLIENT
@@ -6081,15 +6118,15 @@ Table_map_log_event::Table_map_log_event(const char *buf, uint event_len,
   const char *const vpart= buf + common_header_len + post_header_len;
 
   /* Extract the length of the various parts from the buffer */
-  byte const* const ptr_dblen= (byte const*)vpart + 0;
+  byte const *const ptr_dblen= (byte const*)vpart + 0;
   m_dblen= *(uchar*) ptr_dblen;
 
   /* Length of database name + counter + terminating null */
-  byte const* const ptr_tbllen= ptr_dblen + m_dblen + 2;
+  byte const *const ptr_tbllen= ptr_dblen + m_dblen + 2;
   m_tbllen= *(uchar*) ptr_tbllen;
 
   /* Length of table name + counter + terminating null */
-  byte const* const ptr_colcnt= ptr_tbllen + m_tbllen + 2;
+  byte const *const ptr_colcnt= ptr_tbllen + m_tbllen + 2;
   uchar *ptr_after_colcnt= (uchar*) ptr_colcnt;
   m_colcnt= net_field_length(&ptr_after_colcnt);
 
@@ -6134,9 +6171,9 @@ Table_map_log_event::~Table_map_log_event()
  */
 
 #if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
-int Table_map_log_event::apply_event_impl(st_relay_log_info *rli)
+int Table_map_log_event::do_apply_event(RELAY_LOG_INFO const *rli)
 {
-  DBUG_ENTER("Table_map_log_event::apply_event_impl(st_relay_log_info*)");
+  DBUG_ENTER("Table_map_log_event::do_apply_event(st_relay_log_info*)");
 
   DBUG_ASSERT(rli->sql_thd == thd);
 
@@ -6240,29 +6277,24 @@ int Table_map_log_event::apply_event_impl(st_relay_log_info *rli)
       locked by linking the table into the list of tables to lock.
     */
     table_list->next_global= table_list->next_local= rli->tables_to_lock;
-    rli->tables_to_lock= table_list;
-    rli->tables_to_lock_count++;
+    const_cast<RELAY_LOG_INFO*>(rli)->tables_to_lock= table_list;
+    const_cast<RELAY_LOG_INFO*>(rli)->tables_to_lock_count++;
     /* 'memory' is freed in clear_tables_to_lock */
   }
 
-  /*
-    We explicitly do not call Log_event::apply_event_impl() here since
-    we do not want the relay log position to be flushed to disk. The
-    flushing will be done by the last Rows_log_event that either ends
-    a statement (outside a transaction) or a transaction.
-
-    A table map event can *never* end a transaction or a statement, so we
-    just step the relay log position.
-  */
-
-  if (likely(!error))
-    rli->inc_event_relay_log_pos();
   DBUG_RETURN(error);
 
 err:
   my_free((gptr) memory, MYF(MY_WME));
   DBUG_RETURN(error);
 }
+
+int Table_map_log_event::do_update_pos(RELAY_LOG_INFO *rli)
+{
+  rli->inc_event_relay_log_pos();
+  return 0;
+}
+
 #endif /* !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION) */
 
 #ifndef MYSQL_CLIENT
@@ -6427,7 +6459,7 @@ int Write_rows_log_event::do_after_row_operations(TABLE *table, int error)
   return error;
 }
 
-int Write_rows_log_event::do_prepare_row(THD *thd, RELAY_LOG_INFO *rli,
+int Write_rows_log_event::do_prepare_row(THD *thd, RELAY_LOG_INFO const *rli,
                                          TABLE *table,
                                          char const *row_start,
                                          char const **row_end)
@@ -6973,7 +7005,7 @@ int Delete_rows_log_event::do_after_row_operations(TABLE *table, int error)
   return error;
 }
 
-int Delete_rows_log_event::do_prepare_row(THD *thd, RELAY_LOG_INFO *rli,
+int Delete_rows_log_event::do_prepare_row(THD *thd, RELAY_LOG_INFO const *rli,
                                           TABLE *table,
                                           char const *row_start,
                                           char const **row_end)
@@ -7110,7 +7142,7 @@ int Update_rows_log_event::do_after_row_operations(TABLE *table, int error)
   return error;
 }
 
-int Update_rows_log_event::do_prepare_row(THD *thd, RELAY_LOG_INFO *rli,
+int Update_rows_log_event::do_prepare_row(THD *thd, RELAY_LOG_INFO const *rli,
                                           TABLE *table,
                                           char const *row_start,
                                           char const **row_end)