removed init_count from IO_CACHE.

Added missing mutex_unlock to slave replication code.

1 files changed, 366 insertions, 307 deletions

diff --git a/sql/slave.cc b/sql/slave.cc
index 93e711f2e14..66837436a09 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -42,12 +42,16 @@ bool do_table_inited = 0, ignore_table_inited = 0;
 bool wild_do_table_inited = 0, wild_ignore_table_inited = 0;
 bool table_rules_on = 0;
 static TABLE* save_temporary_tables = 0;
-ulong relay_log_space_limit = 0; /* TODO: fix variables to access ulonglong
-				    values and make it ulonglong */
-// when slave thread exits, we need to remember the temporary tables so we
-// can re-use them on slave start
+/* TODO: fix variables to access ulonglong values and make it ulonglong */
+ulong relay_log_space_limit = 0;
+
+/*
+  When slave thread exits, we need to remember the temporary tables so we
+  can re-use them on slave start.
+
+  TODO: move the vars below under MASTER_INFO
+*/
 
-// TODO: move the vars below under MASTER_INFO
 int disconnect_slave_event_count = 0, abort_slave_event_count = 0;
 static int events_till_disconnect = -1;
 int events_till_abort = -1;
@@ -83,9 +87,10 @@ void init_thread_mask(int* mask,MASTER_INFO* mi,bool inverse)
   bool set_io = mi->slave_running, set_sql = mi->rli.slave_running;
   if (inverse)
   {
-    /* This makes me think of the Russian idiom "I am not I, and this is
-       not my horse", which is used to deny reponsibility for
-       one's actions. 
+    /*
+      This makes me think of the Russian idiom "I am not I, and this is
+      not my horse", which is used to deny reponsibility for
+      one's actions. 
     */
     set_io = !set_io;
     set_sql = !set_sql;
@@ -164,13 +169,16 @@ static byte* get_table_key(TABLE_RULE_ENT* e, uint* len,
 }
 
 // TODO: check proper initialization of master_log_name/master_log_pos
+
 int init_relay_log_pos(RELAY_LOG_INFO* rli,const char* log,
 		       ulonglong pos, bool need_data_lock,
 		       const char** errmsg)
 {
+  DBUG_ENTER("init_relay_log_pos");
+
   *errmsg=0;
   if (rli->log_pos_current)
-    return 0;
+    DBUG_RETURN(0);
   pthread_mutex_t *log_lock=rli->relay_log.get_log_lock();
   pthread_mutex_lock(log_lock);
   if (need_data_lock)
@@ -190,8 +198,10 @@ int init_relay_log_pos(RELAY_LOG_INFO* rli,const char* log,
   else
     rli->relay_log_pos = pos;
 
-  // test to see if the previous run was with the skip of purging
-  // if yes, we do not purge when we restart
+  /*
+    Test to see if the previous run was with the skip of purging
+    If yes, we do not purge when we restart
+  */
   if (rli->relay_log.find_first_log(&rli->linfo,""))
   {
     *errmsg="Could not find first log during relay log initialization";
@@ -213,34 +223,31 @@ int init_relay_log_pos(RELAY_LOG_INFO* rli,const char* log,
   if (rli->relay_log.is_active(rli->linfo.log_file_name))
   {
     if (my_b_tell((rli->cur_log=rli->relay_log.get_log_file())) == 0 &&
-		  check_binlog_magic(rli->cur_log,errmsg))
-    {
+	check_binlog_magic(rli->cur_log,errmsg))
       goto err;
-    }
-    rli->cur_log_init_count=rli->cur_log->init_count;
+    rli->cur_log_old_open_count=rli->relay_log.get_open_count();
   }
   else
   {
     if (rli->inited)
       end_io_cache(&rli->cache_buf);
-    if (rli->cur_log_fd>=0)
+    if (rli->cur_log_fd >= 0)
       my_close(rli->cur_log_fd,MYF(MY_WME));
     if ((rli->cur_log_fd=open_binlog(&rli->cache_buf,
 				     rli->linfo.log_file_name,errmsg)) < 0)
-    {
       goto err;
-    }
     rli->cur_log = &rli->cache_buf;
   }
-  if (pos > 4)
-   my_b_seek(rli->cur_log,(off_t)pos);
- rli->log_pos_current=1;
+  if (pos > BIN_LOG_HEADER_SIZE)
+    my_b_seek(rli->cur_log,(off_t)pos);
+  rli->log_pos_current=1;
+
 err:
- pthread_cond_broadcast(&rli->data_cond);
- if (need_data_lock)
-   pthread_mutex_unlock(&rli->data_lock);
- pthread_mutex_unlock(log_lock);
- return (*errmsg) ? 1 : 0;
+  pthread_cond_broadcast(&rli->data_cond);
+  if (need_data_lock)
+    pthread_mutex_unlock(&rli->data_lock);
+  pthread_mutex_unlock(log_lock);
+  DBUG_RETURN ((*errmsg) ? 1 : 0);
 }
 
 /* called from get_options() in mysqld.cc on start-up */
@@ -274,8 +281,9 @@ void init_slave_skip_errors(const char* arg)
   }
 }
 
+
 /*
-  We assume we have a run lock on rli and that the both slave thread
+  We assume we have a run lock on rli and that both slave thread
   are not running
 */
 
@@ -284,9 +292,11 @@ int purge_relay_logs(RELAY_LOG_INFO* rli, bool just_reset, const char** errmsg)
   DBUG_ENTER("purge_relay_logs");
   if (!rli->inited)
     DBUG_RETURN(0); /* successfully do nothing */
+  int error=0;
+
   DBUG_ASSERT(rli->slave_running == 0);
   DBUG_ASSERT(rli->mi->slave_running == 0);
-  int error=0;
+
   rli->slave_skip_counter=0;
   pthread_mutex_lock(&rli->data_lock);
   rli->pending=0;
@@ -301,17 +311,19 @@ int purge_relay_logs(RELAY_LOG_INFO* rli, bool just_reset, const char** errmsg)
   }
   strnmov(rli->relay_log_name,rli->linfo.log_file_name,
 	  sizeof(rli->relay_log_name)-1);
-  rli->log_space_total=4; //just first log with magic number and nothing else
-  rli->relay_log_pos=4;
+  // Just first log with magic number and nothing else
+  rli->log_space_total= BIN_LOG_HEADER_SIZE;
+  rli->relay_log_pos=   BIN_LOG_HEADER_SIZE;
   rli->relay_log.reset_bytes_written();
   rli->log_pos_current=0;
   if (!just_reset)
-    error =  init_relay_log_pos(rli,0,0,0/*do not need data lock*/,errmsg);
+    error =  init_relay_log_pos(rli,0,0,0 /* do not need data lock */,errmsg);
+
 err:
 #ifndef DBUG_OFF
   char buf[22];
 #endif  
-  DBUG_PRINT("info",("log_space_total=%s",llstr(rli->log_space_total,buf)));
+  DBUG_PRINT("info",("log_space_total: %s",llstr(rli->log_space_total,buf)));
   pthread_mutex_unlock(&rli->data_lock);
   DBUG_RETURN(error);
 }
@@ -451,10 +463,12 @@ int start_slave_thread(pthread_handler h_func, pthread_mutex_t* start_lock,
 					  "Waiting for slave thread to start");
       pthread_cond_wait(start_cond,cond_lock);
       thd->exit_cond(old_msg);
-      // TODO: in a very rare case of init_slave_thread failing, it is
-      // possible that we can get stuck here since slave_running will not
-      // be set. We need to change slave_running to int and have -1 as
-      // error code
+      /*
+	TODO: in a very rare case of init_slave_thread failing, it is
+	possible that we can get stuck here since slave_running will not
+	be set. We need to change slave_running to int and have -1 as
+	error code.
+      */
       if (thd->killed)
       {
 	pthread_mutex_unlock(cond_lock);
@@ -466,10 +480,14 @@ int start_slave_thread(pthread_handler h_func, pthread_mutex_t* start_lock,
     pthread_mutex_unlock(start_lock);
   return 0;
 }
-/* SLAVE_FORCE_ALL is not implemented here on purpose since it does not make
-   sense to do that for starting a slave - we always care if it actually
-   started the threads that were not previously running
+
+
+/*
+  SLAVE_FORCE_ALL is not implemented here on purpose since it does not make
+  sense to do that for starting a slave - we always care if it actually
+  started the threads that were not previously running
 */
+
 int start_slave_threads(bool need_slave_mutex, bool wait_for_start,
 			MASTER_INFO* mi, const char* master_info_fname,
 			const char* slave_info_fname, int thread_mask)
@@ -567,9 +585,10 @@ int tables_ok(THD* thd, TABLE_LIST* tables)
       return 0;
   }
 
-  // if no explicit rule found
-  // and there was a do list, do not replicate. If there was
-  // no do list, go ahead
+  /*
+    If no explicit rule found and there was a do list, do not replicate.
+    If there was no do list, go ahead
+  */
   return !do_table_inited && !wild_do_table_inited;
 }
 
@@ -577,12 +596,12 @@ int tables_ok(THD* thd, TABLE_LIST* tables)
 int add_table_rule(HASH* h, const char* table_spec)
 {
   const char* dot = strchr(table_spec, '.');
-  if(!dot) return 1;
+  if (!dot) return 1;
   // len is always > 0 because we know the there exists a '.'
   uint len = (uint)strlen(table_spec);
   TABLE_RULE_ENT* e = (TABLE_RULE_ENT*)my_malloc(sizeof(TABLE_RULE_ENT)
 						 + len, MYF(MY_WME));
-  if(!e) return 1;
+  if (!e) return 1;
   e->db = (char*)e + sizeof(TABLE_RULE_ENT);
   e->tbl_name = e->db + (dot - table_spec) + 1;
   e->key_len = len;
@@ -594,11 +613,11 @@ int add_table_rule(HASH* h, const char* table_spec)
 int add_wild_table_rule(DYNAMIC_ARRAY* a, const char* table_spec)
 {
   const char* dot = strchr(table_spec, '.');
-  if(!dot) return 1;
+  if (!dot) return 1;
   uint len = (uint)strlen(table_spec);
   TABLE_RULE_ENT* e = (TABLE_RULE_ENT*)my_malloc(sizeof(TABLE_RULE_ENT)
 						 + len, MYF(MY_WME));
-  if(!e) return 1;
+  if (!e) return 1;
   e->db = (char*)e + sizeof(TABLE_RULE_ENT);
   e->tbl_name = e->db + (dot - table_spec) + 1;
   e->key_len = len;
@@ -627,9 +646,11 @@ static int end_slave_on_walk(MASTER_INFO* mi, gptr /*unused*/)
 
 void end_slave()
 {
-  // TODO: replace the line below with
-  // list_walk(&master_list, (list_walk_action)end_slave_on_walk,0);
-  // once multi-master code is ready
+  /*
+    TODO: replace the line below with
+    list_walk(&master_list, (list_walk_action)end_slave_on_walk,0);
+    once multi-master code is ready.
+  */
   terminate_slave_threads(active_mi,SLAVE_FORCE_ALL);
   end_master_info(active_mi);
   if (do_table_inited)
@@ -671,65 +692,68 @@ void skip_load_data_infile(NET* net)
 {
   (void)my_net_write(net, "\xfb/dev/null", 10);
   (void)net_flush(net);
-  (void)my_net_read(net); // discard response
-  send_ok(net); // the master expects it
+  (void)my_net_read(net);			// discard response
+  send_ok(net);					// the master expects it
 }
 
 char* rewrite_db(char* db)
 {
-  if(replicate_rewrite_db.is_empty() || !db) return db;
+  if (replicate_rewrite_db.is_empty() || !db)
+    return db;
   I_List_iterator<i_string_pair> it(replicate_rewrite_db);
   i_string_pair* tmp;
 
-  while((tmp=it++))
-    {
-      if(!strcmp(tmp->key, db))
-	return tmp->val;
-    }
-
+  while ((tmp=it++))
+  {
+    if (!strcmp(tmp->key, db))
+      return tmp->val;
+  }
   return db;
 }
 
+
 int db_ok(const char* db, I_List<i_string> &do_list,
 	  I_List<i_string> &ignore_list )
 {
   if (do_list.is_empty() && ignore_list.is_empty())
     return 1; // ok to replicate if the user puts no constraints
 
-  // if the user has specified restrictions on which databases to replicate
-  // and db was not selected, do not replicate
-  if(!db)
+  /*
+    If the user has specified restrictions on which databases to replicate
+    and db was not selected, do not replicate.
+  */
+  if (!db)
     return 0;
 
-  if(!do_list.is_empty()) // if the do's are not empty
-    {
-      I_List_iterator<i_string> it(do_list);
-      i_string* tmp;
+  if (!do_list.is_empty()) // if the do's are not empty
+  {
+    I_List_iterator<i_string> it(do_list);
+    i_string* tmp;
 
-      while((tmp=it++))
-	{
-	  if(!strcmp(tmp->ptr, db))
-	    return 1; // match
-	}
-      return 0;
+    while ((tmp=it++))
+    {
+      if (!strcmp(tmp->ptr, db))
+	return 1; // match
     }
+    return 0;
+  }
   else // there are some elements in the don't, otherwise we cannot get here
-    {
-      I_List_iterator<i_string> it(ignore_list);
-      i_string* tmp;
+  {
+    I_List_iterator<i_string> it(ignore_list);
+    i_string* tmp;
 
-      while((tmp=it++))
-	{
-	  if(!strcmp(tmp->ptr, db))
-	    return 0; // match
-	}
-      
-      return 1;
+    while ((tmp=it++))
+    {
+      if (!strcmp(tmp->ptr, db))
+	return 0; // match
     }
+      
+    return 1;
+  }
 }
 
-static int init_strvar_from_file(char* var, int max_size, IO_CACHE* f,
-			       char* default_val)
+static int init_strvar_from_file(char *var, int max_size, IO_CACHE *f,
+				 const char *default_val)
 {
   uint length;
   if ((length=my_b_gets(f,var, max_size)))
@@ -739,10 +763,12 @@ static int init_strvar_from_file(char* var, int max_size, IO_CACHE* f,
       *last_p = 0; // if we stopped on newline, kill it
     else
     {
-      // if we truncated a line or stopped on last char, remove all chars
-      // up to and including newline
+      /*
+	If we truncated a line or stopped on last char, remove all chars
+	up to and including newline.
+      */
       int c;
-      while( ((c=my_b_get(f)) != '\n' && c != my_b_EOF));
+      while (((c=my_b_get(f)) != '\n' && c != my_b_EOF));
     }
     return 0;
   }
@@ -763,7 +789,7 @@ static int init_intvar_from_file(int* var, IO_CACHE* f, int default_val)
     *var = atoi(buf);
     return 0;
   }
-  else if(default_val)
+  else if (default_val)
   {
     *var = default_val;
     return 0;
@@ -796,12 +822,12 @@ static int check_master_version(MYSQL* mysql, MASTER_INFO* mi)
     goto err;
   }
   
-  switch (*version)
-  {
+  switch (*version) {
   case '3':
     mi->old_format = 1;
     break;
   case '4':
+  case '5':
     mi->old_format = 0;
     break;
   default:
@@ -895,9 +921,11 @@ static int create_table_from_dump(THD* thd, NET* net, const char* db,
   check_opt.init();
   check_opt.flags|= T_VERY_SILENT | T_CALC_CHECKSUM | T_QUICK;
   thd->proc_info = "Rebuilding the index on master dump table";
-  // we do not want repair() to spam us with messages
-  // just send them to the error log, and report the failure in case of
-  // problems
+  /*
+    We do not want repair() to spam us with messages
+    just send them to the error log, and report the failure in case of
+    problems.
+  */
   save_vio = thd->net.vio;
   thd->net.vio = 0;
   error=file->repair(thd,&check_opt) != 0;
@@ -978,15 +1006,15 @@ void end_master_info(MASTER_INFO* mi)
 int init_relay_log_info(RELAY_LOG_INFO* rli, const char* info_fname)
 {
   DBUG_ENTER("init_relay_log_info");
-  if (rli->inited)
-    DBUG_RETURN(0);
   MY_STAT stat_area;
   char fname[FN_REFLEN+128];
   int info_fd;
   const char* msg = 0;
   int error = 0;
-  fn_format(fname, info_fname,
-	    mysql_data_home, "", 4+32);
+
+  if (rli->inited)
+    DBUG_RETURN(0);
+  fn_format(fname, info_fname, mysql_data_home, "", 4+32);
   pthread_mutex_lock(&rli->data_lock);
   info_fd = rli->info_fd;
   rli->pending = 0;
@@ -1001,8 +1029,9 @@ int init_relay_log_info(RELAY_LOG_INFO* rli, const char* info_fname)
   if (!opt_relay_logname)
   {
     char tmp[FN_REFLEN];
-    /* TODO: The following should be using fn_format();  We just need to
-       first change fn_format() to cut the file name if it's too long.
+    /*
+      TODO: The following should be using fn_format();  We just need to
+      first change fn_format() to cut the file name if it's too long.
     */
     strmake(tmp,glob_hostname,FN_REFLEN-5);
     strmov(strcend(tmp,'.'),"-relay-bin");
@@ -1011,72 +1040,76 @@ int init_relay_log_info(RELAY_LOG_INFO* rli, const char* info_fname)
   rli->relay_log.set_index_file_name(opt_relaylog_index_name);
   open_log(&rli->relay_log, glob_hostname, opt_relay_logname, "-relay-bin",
 	   LOG_BIN, 1 /* read_append cache */,
-	   1 /* no auto events*/);
+	   1 /* no auto events */);
   
   /* if file does not exist */
   if (!my_stat(fname, &stat_area, MYF(0)))
   {
-    // if someone removed the file from underneath our feet, just close
-    // the old descriptor and re-create the old file
+    /*
+      If someone removed the file from underneath our feet, just close
+      the old descriptor and re-create the old file
+    */
     if (info_fd >= 0)
       my_close(info_fd, MYF(MY_WME));
-    if ((info_fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0
-	|| init_io_cache(&rli->info_file, info_fd, IO_SIZE*2, READ_CACHE, 0L,0,
-			 MYF(MY_WME)))
+    if ((info_fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0 ||
+	init_io_cache(&rli->info_file, info_fd, IO_SIZE*2, READ_CACHE, 0L,0,
+		      MYF(MY_WME)))
     {
-      if(info_fd >= 0)
+      if (info_fd >= 0)
 	my_close(info_fd, MYF(0));
-      rli->info_fd=-1;
+      rli->info_fd= -1;
       pthread_mutex_unlock(&rli->data_lock);
       DBUG_RETURN(1);
     }
-    if (init_relay_log_pos(rli,"",4,0/*no data mutex*/,&msg))
+    if (init_relay_log_pos(rli,"",BIN_LOG_HEADER_SIZE,0 /*no data mutex*/,
+			   &msg))
       goto err;
     rli->master_log_pos = 0;			// uninitialized
     rli->info_fd = info_fd;
   }
   else // file exists
   {
-    if(info_fd >= 0)
+    if (info_fd >= 0)
       reinit_io_cache(&rli->info_file, READ_CACHE, 0L,0,0);
-    else if((info_fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0
-	    || init_io_cache(&rli->info_file, info_fd,
-			     IO_SIZE*2, READ_CACHE, 0L,
-			     0, MYF(MY_WME)))
+    else if ((info_fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0 ||
+	     init_io_cache(&rli->info_file, info_fd,
+			   IO_SIZE*2, READ_CACHE, 0L, 0, MYF(MY_WME)))
     {
       if (info_fd >= 0)
 	my_close(info_fd, MYF(0));
-      rli->info_fd=-1;
+      rli->info_fd= -1;
       pthread_mutex_unlock(&rli->data_lock);
       DBUG_RETURN(1);
     }
       
     rli->info_fd = info_fd;
     if (init_strvar_from_file(rli->relay_log_name,
-			     sizeof(rli->relay_log_name), &rli->info_file,
-			     (char*)"") ||
+			      sizeof(rli->relay_log_name), &rli->info_file,
+			      "") ||
        init_intvar_from_file((int*)&rli->relay_log_pos,
-			     &rli->info_file, 4) ||
+			     &rli->info_file, BIN_LOG_HEADER_SIZE) ||
        init_strvar_from_file(rli->master_log_name,
 			     sizeof(rli->master_log_name), &rli->info_file,
-			     (char*)"") ||
+			     "") ||
        init_intvar_from_file((int*)&rli->master_log_pos,
 			     &rli->info_file, 0))
     {
       msg="Error reading slave log configuration";
       goto err;
     }
-    if (init_relay_log_pos(rli,0 /*log already inited*/,
-			   0 /*pos already inited*/,
+    if (init_relay_log_pos(rli,0 /* log already inited */,
+			   0 /* pos already inited */,
 			   0 /* no data lock*/,
 			   &msg))
 	goto err;
   }
-  DBUG_ASSERT(rli->relay_log_pos >= 4);
+  DBUG_ASSERT(rli->relay_log_pos >= BIN_LOG_HEADER_SIZE);
   DBUG_ASSERT(my_b_tell(rli->cur_log) == rli->relay_log_pos);
   rli->inited = 1;
-  // now change the cache from READ to WRITE - must do this
-  // before flush_relay_log_info
+  /*
+    Now change the cache from READ to WRITE - must do this
+    before flush_relay_log_info
+  */
   reinit_io_cache(&rli->info_file, WRITE_CACHE,0L,0,1);
   error=test(flush_relay_log_info(rli));
   if (count_relay_log_space(rli))
@@ -1091,7 +1124,7 @@ err:
   sql_print_error(msg);
   end_io_cache(&rli->info_file);
   my_close(info_fd, MYF(0));
-  rli->info_fd=-1;
+  rli->info_fd= -1;
   pthread_mutex_unlock(&rli->data_lock);
   DBUG_RETURN(1);
 }
@@ -1135,6 +1168,7 @@ static bool wait_for_relay_log_space(RELAY_LOG_INFO* rli)
   DBUG_RETURN(slave_killed);
 }
 
+
 static int count_relay_log_space(RELAY_LOG_INFO* rli)
 {
   LOG_INFO linfo;
@@ -1145,31 +1179,32 @@ static int count_relay_log_space(RELAY_LOG_INFO* rli)
     sql_print_error("Could not find first log while counting relay log space");
     DBUG_RETURN(1);
   }
-  if (add_relay_log(rli,&linfo))
-    DBUG_RETURN(1);
-  while (!rli->relay_log.find_next_log(&linfo))
+  do
   {
     if (add_relay_log(rli,&linfo))
       DBUG_RETURN(1);
-  }
+  } while (!rli->relay_log.find_next_log(&linfo));
   DBUG_RETURN(0);
 }
 
+
 int init_master_info(MASTER_INFO* mi, const char* master_info_fname,
 		     const char* slave_info_fname)
 {
+  int fd,error;
+  MY_STAT stat_area;
+  char fname[FN_REFLEN+128];
+  const char *msg;
+  DBUG_ENTER("init_master_info");
+
   if (mi->inited)
-    return 0;
+    DBUG_RETURN(0);
   if (init_relay_log_info(&mi->rli, slave_info_fname))
-    return 1;
+    DBUG_RETURN(1);
   mi->rli.mi = mi;
   mi->mysql=0;
   mi->file_id=1;
   mi->ignore_stop_event=0;
-  int fd,error;
-  MY_STAT stat_area;
-  char fname[FN_REFLEN+128];
-  const char *msg;
   fn_format(fname, master_info_fname, mysql_data_home, "", 4+32);
 
   /*
@@ -1183,23 +1218,19 @@ int init_master_info(MASTER_INFO* mi, const char* master_info_fname,
   // we do not want any messages if the file does not exist
   if (!my_stat(fname, &stat_area, MYF(0)))
   {
-    // if someone removed the file from underneath our feet, just close
-    // the old descriptor and re-create the old file
+    /*
+      if someone removed the file from underneath our feet, just close
+      the old descriptor and re-create the old file
+    */
     if (fd >= 0)
       my_close(fd, MYF(MY_WME));
-    if ((fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0
-	|| init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,0,
-			 MYF(MY_WME)))
-    {
-      if(fd >= 0)
-	my_close(fd, MYF(0));
-      mi->fd=-1;
-      end_relay_log_info(&mi->rli);
-      pthread_mutex_unlock(&mi->data_lock);
-      return 1;
-    }
+    if ((fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0 ||
+	init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,0,
+		      MYF(MY_WME)))
+      goto err;
+
     mi->master_log_name[0] = 0;
-    mi->master_log_pos = 4;			// skip magic number
+    mi->master_log_pos = BIN_LOG_HEADER_SIZE;		// skip magic number
     mi->fd = fd;
       
     if (master_host)
@@ -1213,24 +1244,17 @@ int init_master_info(MASTER_INFO* mi, const char* master_info_fname,
   }
   else // file exists
   {
-    if(fd >= 0)
+    if (fd >= 0)
       reinit_io_cache(&mi->file, READ_CACHE, 0L,0,0);
-    else if((fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0
-	    || init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,
-			     0, MYF(MY_WME)))
-    {
-      if(fd >= 0)
-	my_close(fd, MYF(0));
-      mi->fd=-1;
-      end_relay_log_info(&mi->rli);
-      pthread_mutex_unlock(&mi->data_lock);
-      return 1;
-    }
+    else if ((fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0 ||
+	     init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,
+			   0, MYF(MY_WME)))
+      goto err;
 
     mi->fd = fd;
     if (init_strvar_from_file(mi->master_log_name,
 			      sizeof(mi->master_log_name), &mi->file,
-			      (char*)"") ||
+			      "") ||
 	init_intvar_from_file((int*)&mi->master_log_pos, &mi->file, 4) ||
 	init_strvar_from_file(mi->host, sizeof(mi->host), &mi->file,
 			      master_host) ||
@@ -1242,7 +1266,7 @@ int init_master_info(MASTER_INFO* mi, const char* master_info_fname,
 	init_intvar_from_file((int*)&mi->connect_retry, &mi->file,
 			      master_connect_retry))
     {
-      msg="Error reading master configuration";
+      sql_print_error("Error reading master configuration");
       goto err;
     }
   }
@@ -1252,17 +1276,18 @@ int init_master_info(MASTER_INFO* mi, const char* master_info_fname,
   reinit_io_cache(&mi->file, WRITE_CACHE,0L,0,1);
   error=test(flush_master_info(mi));
   pthread_mutex_unlock(&mi->data_lock);
-  return error;
+  DBUG_RETURN(error);
 
 err:
-  sql_print_error(msg);
-  end_io_cache(&mi->file);
   end_relay_log_info(&mi->rli);
-  DBUG_ASSERT(fd>=0);
-  my_close(fd, MYF(0));
-  mi->fd=-1;
+  if (fd >= 0)
+  {
+    my_close(fd, MYF(0));
+    end_io_cache(&mi->file);
+  }
+  mi->fd= -1;
   pthread_mutex_unlock(&mi->data_lock);
-  return 1;
+  DBUG_RETURN(1);
 }
 
 int register_slave_on_master(MYSQL* mysql)
@@ -1282,7 +1307,7 @@ int register_slave_on_master(MYSQL* mysql)
   else
     packet.append((char)0);
   
-  if(report_password)
+  if (report_password)
     net_store_data(&packet, report_user);
   else
     packet.append((char)0);
@@ -1333,7 +1358,7 @@ int show_master_info(THD* thd, MASTER_INFO* mi)
   field_list.push_back(new Item_empty_string("Skip_counter", 12));
   field_list.push_back(new Item_empty_string("Exec_master_log_pos", 12));
   field_list.push_back(new Item_empty_string("Relay_log_space", 12));
-  if(send_fields(thd, field_list, 1))
+  if (send_fields(thd, field_list, 1))
     DBUG_RETURN(-1);
 
   String* packet = &thd->packet;
@@ -1502,8 +1527,10 @@ static int safe_sleep(THD* thd, int sec, CHECK_KILLED_FUNC thread_killed,
     */
     thr_alarm(&alarmed, 2 * nap_time,&alarm_buff);
     sleep(nap_time);
-    // if we wake up before the alarm goes off, hit the button
-    // so it will not wake up the wife and kids :-)
+    /*
+      If we wake up before the alarm goes off, hit the button
+      so it will not wake up the wife and kids :-)
+    */
     if (thr_alarm_in_use(&alarmed))
       thr_end_alarm(&alarmed);
     
@@ -1528,9 +1555,11 @@ static int request_dump(MYSQL* mysql, MASTER_INFO* mi)
   memcpy(buf + 10, logname,len);
   if (mc_simple_command(mysql, COM_BINLOG_DUMP, buf, len + 10, 1))
   {
-    // something went wrong, so we will just reconnect and retry later
-    // in the future, we should do a better error analysis, but for
-    // now we just fill up the error log :-)
+    /*
+      Something went wrong, so we will just reconnect and retry later
+      in the future, we should do a better error analysis, but for
+      now we just fill up the error log :-)
+    */
     sql_print_error("Error on COM_BINLOG_DUMP: %s, will retry in %d secs",
 		    mc_mysql_error(mysql), master_connect_retry);
     return 1;
@@ -1545,7 +1574,7 @@ static int request_table_dump(MYSQL* mysql, const char* db, const char* table)
   char * p = buf;
   uint table_len = (uint) strlen(table);
   uint db_len = (uint) strlen(db);
-  if(table_len + db_len > sizeof(buf) - 2)
+  if (table_len + db_len > sizeof(buf) - 2)
     {
       sql_print_error("request_table_dump: Buffer overrun");
       return 1;
@@ -1571,8 +1600,10 @@ static ulong read_event(MYSQL* mysql, MASTER_INFO *mi)
 {
   ulong len = packet_error;
 
-  // my_real_read() will time us out
-  // we check if we were told to die, and if not, try reading again
+  /*
+    my_real_read() will time us out
+    We check if we were told to die, and if not, try reading again
+  */
 #ifndef DBUG_OFF
   if (disconnect_slave_event_count && !(events_till_disconnect--))
     return packet_error;      
@@ -1643,12 +1674,14 @@ static int exec_relay_log_event(THD* thd, RELAY_LOG_INFO* rli)
 		   type_code != STOP_EVENT ? ev->log_pos : LL(0),
 		   1/* skip lock*/);
       flush_relay_log_info(rli);
-      if (rli->slave_skip_counter && /* protect against common user error of
-				  setting the counter to 1 instead of 2
-			          while recovering from an failed
-			          auto-increment insert */
-	 	 !((type_code == INTVAR_EVENT || type_code == STOP_EVENT) &&
-				 rli->slave_skip_counter == 1))
+
+      /*
+	Protect against common user error of setting the counter to 1
+	instead of 2 while recovering from an failed auto-increment insert
+      */
+      if (rli->slave_skip_counter && 
+	  !((type_code == INTVAR_EVENT || type_code == STOP_EVENT) &&
+	    rli->slave_skip_counter == 1))
         --rli->slave_skip_counter;
       pthread_mutex_unlock(&rli->data_lock);
       delete ev;     
@@ -1718,7 +1751,7 @@ slave_begin:
   pthread_cond_broadcast(&mi->start_cond);
   pthread_mutex_unlock(&mi->run_lock);
   
-  DBUG_PRINT("info",("master info: log_file_name=%s, position=%s",
+  DBUG_PRINT("info",("master info: log_file_name='%s', position=%s",
 		     mi->master_log_name, llstr(mi->master_log_pos,llbuff)));
   
   if (!(mi->mysql = mysql = mc_mysql_init(NULL)))
@@ -1768,7 +1801,7 @@ connected:
     if (request_dump(mysql, mi))
     {
       sql_print_error("Failed on request_dump()");
-      if(io_slave_killed(thd,mi))
+      if (io_slave_killed(thd,mi))
       {
 	sql_print_error("Slave I/O thread killed while requesting master \
 dump");
@@ -1855,7 +1888,7 @@ reconnect done to recover from failed read");
 	  goto err;
 	}
 	goto connected;
-      } // if(event_len == packet_error)
+      } // if (event_len == packet_error)
 	  
       thd->proc_info = "Queueing event from master";
       if (queue_event(mi,(const char*)mysql->net.read_pos + 1,
@@ -1909,11 +1942,11 @@ err:
   THD_CHECK_SENTRY(thd);
   delete thd;
   pthread_mutex_unlock(&LOCK_thread_count);
-  my_thread_end(); // clean-up before broadcast
-  pthread_cond_broadcast(&mi->stop_cond); // tell the world we are done
+  my_thread_end();				// clean-up before broadcast
+  pthread_cond_broadcast(&mi->stop_cond);	// tell the world we are done
   pthread_mutex_unlock(&mi->run_lock);
 #ifndef DBUG_OFF
-  if(abort_slave_event_count && !events_till_abort)
+  if (abort_slave_event_count && !events_till_abort)
     goto slave_begin;
 #endif  
   pthread_exit(0);
@@ -1970,22 +2003,22 @@ slave_begin:
   rli->abort_slave = 0;
   pthread_cond_broadcast(&rli->start_cond);
   pthread_mutex_unlock(&rli->run_lock);
-  rli->pending = 0;  //this should always be set to 0 when the slave thread
-  // is started
-  if (init_relay_log_pos(rli,0,0,1/*need data lock*/,&errmsg))
+  // This should always be set to 0 when the slave thread is started
+  rli->pending = 0;
+  if (init_relay_log_pos(rli,0,0,1 /*need data lock*/, &errmsg))
   {
     sql_print_error("Error initializing relay log position: %s",
 		    errmsg);
     goto err;
   }
-  DBUG_ASSERT(rli->relay_log_pos >= 4);
+  DBUG_ASSERT(rli->relay_log_pos >= BIN_LOG_HEADER_SIZE);
   DBUG_ASSERT(my_b_tell(rli->cur_log) == rli->relay_log_pos);
 
-  DBUG_PRINT("info",("master info: log_file_name=%s, position=%s",
+  DBUG_PRINT("info",("master info: log_file_name: %s, position: %s",
 		     rli->master_log_name, llstr(rli->master_log_pos,llbuff)));
   DBUG_ASSERT(rli->sql_thd == thd);
   sql_print_error("Slave SQL thread initialized, starting replication in \
-log '%s' at position %s,relay log: name='%s',pos='%s'", RPL_LOG_NAME,
+log '%s' at position %s, relay log '%s' position: %s", RPL_LOG_NAME,
 		  llstr(rli->master_log_pos,llbuff),rli->relay_log_name,
 		  llstr(rli->relay_log_pos,llbuff1));
   while (!sql_slave_killed(thd,rli))
@@ -2004,7 +2037,7 @@ the slave SQL thread with \"SLAVE START\". We stopped at log \
 		      RPL_LOG_NAME, llstr(rli->master_log_pos, llbuff));
       goto err;
     }
-  } // while(!sql_slave_killed(thd,rli)) - read/exec loop
+  } // while (!sql_slave_killed(thd,rli)) - read/exec loop
 
   // error = 0;
  err:
@@ -2053,16 +2086,17 @@ static int process_io_create_file(MASTER_INFO* mi, Create_file_log_event* cev)
   bool cev_not_written;
   THD* thd;
   NET* net = &mi->mysql->net;
+  DBUG_ENTER("process_io_create_file");
 
   if (unlikely(!cev->is_valid()))
-    return 1;
+    DBUG_RETURN(1);
   /*
     TODO: fix to honor table rules, not only db rules
   */
   if (!db_ok(cev->db, replicate_do_db, replicate_ignore_db))
   {
     skip_load_data_infile(net);
-    return 0;
+    DBUG_RETURN(0);
   }
   DBUG_ASSERT(cev->inited_from_old);
   thd = mi->io_thd;
@@ -2137,10 +2171,13 @@ relay log");
   }
   error=0;
 err:
-  return error;
+  DBUG_RETURN(error);
 }
 
-// We assume we already locked mi->data_lock
+/*
+  We assume we already locked mi->data_lock
+*/
+
 static int process_io_rotate(MASTER_INFO* mi, Rotate_log_event* rev)
 {
   if (unlikely(!rev->is_valid()))
@@ -2175,6 +2212,8 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
   bool inc_pos = 1;
   bool processed_stop_event = 0;
   char* tmp_buf = 0;
+  DBUG_ENTER("queue_old_event");
+
   /* if we get Load event, we need to pass a non-reusable buffer
      to read_log_event, so we do a trick
   */
@@ -2183,7 +2222,7 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
     if (unlikely(!(tmp_buf=(char*)my_malloc(event_len+1,MYF(MY_WME)))))
     {
       sql_print_error("Slave I/O: out of memory for Load event");
-      return 1;
+      DBUG_RETURN(1);
     }
     memcpy(tmp_buf,buf,event_len);
     tmp_buf[event_len]=0; // Create_file constructor wants null-term buffer
@@ -2196,8 +2235,8 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
     sql_print_error("Read invalid event from master: '%s',\
  master could be corrupt but a more likely cause of this is a bug",
 		    errmsg);
-    my_free((char*)tmp_buf, MYF(MY_ALLOW_ZERO_PTR));
-    return 1;
+    my_free((char*) tmp_buf, MYF(MY_ALLOW_ZERO_PTR));
+    DBUG_RETURN(1);
   }
   pthread_mutex_lock(&mi->data_lock);
   ev->log_pos = mi->master_log_pos;
@@ -2208,7 +2247,7 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
       delete ev;
       pthread_mutex_unlock(&mi->data_lock);
       DBUG_ASSERT(!tmp_buf);      
-      return 1;
+      DBUG_RETURN(1);
     }
     mi->ignore_stop_event=1;
     inc_pos = 0;
@@ -2224,7 +2263,7 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
     pthread_mutex_unlock(&mi->data_lock);
     DBUG_ASSERT(tmp_buf);
     my_free((char*)tmp_buf, MYF(0));
-    return error;
+    DBUG_RETURN(error);
   }
   default:
     mi->ignore_stop_event=0;
@@ -2237,7 +2276,7 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
       delete ev;
       pthread_mutex_unlock(&mi->data_lock);
       DBUG_ASSERT(!tmp_buf);
-      return 1;
+      DBUG_RETURN(1);
     }
     mi->rli.relay_log.harvest_bytes_written(&mi->rli.log_space_total);
   }
@@ -2248,7 +2287,7 @@ static int queue_old_event(MASTER_INFO *mi, const char *buf,
     mi->ignore_stop_event=1;
   pthread_mutex_unlock(&mi->data_lock);
   DBUG_ASSERT(!tmp_buf);
-  return 0;
+  DBUG_RETURN(0);
 }
 
 /*
@@ -2261,8 +2300,10 @@ int queue_event(MASTER_INFO* mi,const char* buf, ulong event_len)
   int error=0;
   bool inc_pos = 1;
   bool processed_stop_event = 0;
+  DBUG_ENTER("queue_event");
+
   if (mi->old_format)
-    return queue_old_event(mi,buf,event_len);
+    DBUG_RETURN(queue_old_event(mi,buf,event_len));
 
   pthread_mutex_lock(&mi->data_lock);
   
@@ -2278,7 +2319,7 @@ int queue_event(MASTER_INFO* mi,const char* buf, ulong event_len)
   {
     Rotate_log_event rev(buf,event_len,0);
     if (unlikely(process_io_rotate(mi,&rev)))
-      return 1;
+      DBUG_RETURN(1);
     inc_pos=0;
     mi->ignore_stop_event=1;
     break;
@@ -2298,7 +2339,7 @@ int queue_event(MASTER_INFO* mi,const char* buf, ulong event_len)
   if (unlikely(processed_stop_event))
     mi->ignore_stop_event=1;
   pthread_mutex_unlock(&mi->data_lock);
-  return error;
+  DBUG_RETURN(error);
 }
 
 
@@ -2425,18 +2466,27 @@ int flush_relay_log_info(RELAY_LOG_INFO* rli)
   return 0;
 }
 
-IO_CACHE* reopen_relay_log(RELAY_LOG_INFO* rli, const char** errmsg)
+
+/*
+  This function is called when we notice that the current "hot" log
+  got rotated under our feet.
+*/
+
+static IO_CACHE *reopen_relay_log(RELAY_LOG_INFO *rli, const char **errmsg)
 {
   DBUG_ASSERT(rli->cur_log != &rli->cache_buf);
-  IO_CACHE* cur_log = rli->cur_log=&rli->cache_buf;
   DBUG_ASSERT(rli->cur_log_fd == -1);
+  DBUG_ENTER("reopen_relay_log");
+
+  IO_CACHE *cur_log = rli->cur_log=&rli->cache_buf;
   if ((rli->cur_log_fd=open_binlog(cur_log,rli->relay_log_name,
 				   errmsg)) <0)
-    return 0;
+    DBUG_RETURN(0);
   my_b_seek(cur_log,rli->relay_log_pos);
-  return cur_log;
+  DBUG_RETURN(cur_log);
 }
 
+
 Log_event* next_event(RELAY_LOG_INFO* rli)
 {
   Log_event* ev;
@@ -2445,6 +2495,7 @@ Log_event* next_event(RELAY_LOG_INFO* rli)
   const char* errmsg=0;
   THD* thd = rli->sql_thd;
   bool was_killed;
+  DBUG_ENTER("next_event");
   DBUG_ASSERT(thd != 0);
 
   /*
@@ -2456,16 +2507,18 @@ Log_event* next_event(RELAY_LOG_INFO* rli)
   */
   pthread_mutex_lock(&rli->data_lock);
   
-  for (; !(was_killed=sql_slave_killed(thd,rli)) ;)
+  while (!(was_killed=sql_slave_killed(thd,rli)))
   {
     /*
       We can have two kinds of log reading:
-      hot_log - rli->cur_log points at the IO_CACHE of relay_log, which
-      is actively being updated by the I/O thread. We need to be careful
-      in this case and make sure that we are not looking at a stale log that
-      has already been rotated. If it has been, we reopen the log
-      the other case is much simpler - we just have a read only log that
-      nobody else will be updating.
+      hot_log:
+        rli->cur_log points at the IO_CACHE of relay_log, which
+        is actively being updated by the I/O thread. We need to be careful
+        in this case and make sure that we are not looking at a stale log that
+        has already been rotated. If it has been, we reopen the log.
+
+      The other case is much simpler:
+        We just have a read only log that nobody else will be updating.
     */
     bool hot_log;
     if ((hot_log = (cur_log != &rli->cache_buf)))
@@ -2474,43 +2527,43 @@ Log_event* next_event(RELAY_LOG_INFO* rli)
       pthread_mutex_lock(log_lock);
 
       /*
-	Reading cur_log->init_count here is safe because the log will only
+	Reading xxx_file_id is safe because the log will only
 	be rotated when we hold relay_log.LOCK_log
       */
-      if (cur_log->init_count != rli->cur_log_init_count)
+      if (rli->relay_log.get_open_count() != rli->cur_log_old_open_count)
       {
-	if (!(cur_log=reopen_relay_log(rli,&errmsg)))
-	{
-	  pthread_mutex_unlock(log_lock);
+	// The master has switched to a new log file; Reopen the old log file
+	cur_log=reopen_relay_log(rli, &errmsg);
+	pthread_mutex_unlock(log_lock);
+	if (!cur_log)				// No more log files
 	  goto err;
-	}
-        pthread_mutex_unlock(log_lock);
-	hot_log=0;
+	hot_log=0;				// Using old binary log
       }
     }
-    DBUG_ASSERT(my_b_tell(cur_log) >= 4);
+    DBUG_ASSERT(my_b_tell(cur_log) >= BIN_LOG_HEADER_SIZE);
     DBUG_ASSERT(my_b_tell(cur_log) == rli->relay_log_pos + rli->pending);
-    /* relay log is always in new format - if the master is 3.23, the
-       I/O thread will convert the format for us
+    /*
+      Relay log is always in new format - if the master is 3.23, the
+      I/O thread will convert the format for us
     */
-    if ((ev=Log_event::read_log_event(cur_log,0,(bool)0/*new format*/)))
+    if ((ev=Log_event::read_log_event(cur_log,0,(bool)0 /* new format */)))
     {
       DBUG_ASSERT(thd==rli->sql_thd);
       if (hot_log)
 	pthread_mutex_unlock(log_lock);
       pthread_mutex_unlock(&rli->data_lock);
-      return ev;
+      DBUG_RETURN(ev);
     }
     DBUG_ASSERT(thd==rli->sql_thd);
-    if (opt_reckless_slave)
+    if (opt_reckless_slave)			// For mysql-test
       cur_log->error = 0;
-    if ( cur_log->error < 0)
+    if (cur_log->error < 0)
     {
       errmsg = "slave SQL thread aborted because of I/O error";
+      if (hot_log)
+	pthread_mutex_unlock(log_lock);
       goto err;
     }
-    
-
     if (!cur_log->error) /* EOF */
     {
       /*
@@ -2520,7 +2573,7 @@ Log_event* next_event(RELAY_LOG_INFO* rli)
       */
       if (hot_log)
       {
-	DBUG_ASSERT(cur_log->init_count == rli->cur_log_init_count);
+	DBUG_ASSERT(rli->relay_log.get_open_count() == rli->cur_log_old_open_count);
 	/*
 	  We can, and should release data_lock while we are waiting for
 	  update. If we do not, show slave status will block
@@ -2528,7 +2581,7 @@ Log_event* next_event(RELAY_LOG_INFO* rli)
 	pthread_mutex_unlock(&rli->data_lock);
 	
 	/*
-	  IMPORTANT: note that wait_for_update will unlock LOCK_log, but
+	  IMPORTANT: note that wait_for_update will unlock lock_log, but
 	  expects the caller to lock it
 	*/
 	rli->relay_log.wait_for_update(rli->sql_thd);
@@ -2537,102 +2590,108 @@ Log_event* next_event(RELAY_LOG_INFO* rli)
 	pthread_mutex_lock(&rli->data_lock);
 	continue;
       }
+      /*
+	If the log was not hot, we need to move to the next log in
+	sequence. The next log could be hot or cold, we deal with both
+	cases separately after doing some common initialization
+      */
+      end_io_cache(cur_log);
+      DBUG_ASSERT(rli->cur_log_fd >= 0);
+      my_close(rli->cur_log_fd, MYF(MY_WME));
+      rli->cur_log_fd = -1;
+	
+      /*
+	TODO: make skip_log_purge a start-up option. At this point this
+	is not critical priority
+      */
+      if (!rli->skip_log_purge)
+      {
+	// purge_first_log will properly set up relay log coordinates in rli
+	if (rli->relay_log.purge_first_log(rli))
+	{
+	  errmsg = "Error purging processed log";
+	  goto err;
+	}
+      }
       else
       {
 	/*
-	  If the log was not hot, we need to move to the next log in
-	  sequence. The next log could be hot or cold, we deal with both
-	  cases separately after doing some common initialization
+	  TODO: verify that no lock is ok here. At this point, if we
+	  get this wrong, this is actually no big deal - the only time
+	  this code will ever be executed is if we are recovering from
+	  a bug when a full reload of the slave is not feasible or
+	  desirable.
 	*/
-	end_io_cache(cur_log);
-	DBUG_ASSERT(rli->cur_log_fd >= 0);
-	my_close(rli->cur_log_fd, MYF(MY_WME));
-	rli->cur_log_fd = -1;
-	
-	// TODO: make skip_log_purge a start-up option. At this point this
-	// is not critical priority
-	if (!rli->skip_log_purge)
-	{
-	// purge_first_log will properly set up relay log coordinates in rli
-	  if (rli->relay_log.purge_first_log(rli))
-	  {
-	    errmsg = "Error purging processed log";
-	    goto err;
-	  }
-	}
-	else
+	if (rli->relay_log.find_next_log(&rli->linfo,0/*no lock*/))
 	{
-	  // TODO: verify that no lock is ok here. At this point, if we
-	  // get this wrong, this is actually no big deal - the only time
-	  // this code will ever be executed is if we are recovering from
-	  // a bug when a full reload of the slave is not feasible or
-	  // desirable. 
-	  if (rli->relay_log.find_next_log(&rli->linfo,0/*no lock*/))
-	  {
-	    errmsg = "error switching to the next log";
-	    goto err;
-	  }
-	  rli->relay_log_pos = 4;
-	  rli->pending=0;
-	  strnmov(rli->relay_log_name,rli->linfo.log_file_name,
-		  sizeof(rli->relay_log_name));
-	  flush_relay_log_info(rli);
+	  errmsg = "error switching to the next log";
+	  goto err;
 	}
+	rli->relay_log_pos = BIN_LOG_HEADER_SIZE;
+	rli->pending=0;
+	strnmov(rli->relay_log_name,rli->linfo.log_file_name,
+		sizeof(rli->relay_log_name));
+	flush_relay_log_info(rli);
+      }
 	
-	// next log is hot 
-	if (rli->relay_log.is_active(rli->linfo.log_file_name))
-	{
+      // next log is hot 
+      if (rli->relay_log.is_active(rli->linfo.log_file_name))
+      {
 #ifdef EXTRA_DEBUG
-	  sql_print_error("next log '%s' is currently active",
-			  rli->linfo.log_file_name);
+	sql_print_error("next log '%s' is currently active",
+			rli->linfo.log_file_name);
 #endif	  
-	  rli->cur_log = cur_log = rli->relay_log.get_log_file();
-	  rli->cur_log_init_count = cur_log->init_count;
-          DBUG_ASSERT(rli->cur_log_fd == -1);
+	rli->cur_log= cur_log= rli->relay_log.get_log_file();
+	rli->cur_log_old_open_count= rli->relay_log.get_open_count();
+	DBUG_ASSERT(rli->cur_log_fd == -1);
 	  
-	  /*
-	    Read pointer has to be at the start since we are the only
-	    reader
-	  */
-	  if (check_binlog_magic(cur_log,&errmsg))
-	    goto err;
-	  continue;
-	}
 	/*
-	  if we get here, the log was not hot, so we will have to
-	  open it ourselves
+	  Read pointer has to be at the start since we are the only
+	  reader
 	*/
-#ifdef EXTRA_DEBUG
-	  sql_print_error("next log '%s' is not active",
-			  rli->linfo.log_file_name);
-#endif	  
-	// open_binlog() will check the magic header
-	if ((rli->cur_log_fd=open_binlog(cur_log,rli->linfo.log_file_name,
-					 &errmsg)) <0)
+	if (check_binlog_magic(cur_log,&errmsg))
 	  goto err;
+	continue;
       }
+      /*
+	if we get here, the log was not hot, so we will have to
+	open it ourselves
+      */
+#ifdef EXTRA_DEBUG
+      sql_print_error("next log '%s' is not active",
+		      rli->linfo.log_file_name);
+#endif	  
+      // open_binlog() will check the magic header
+      if ((rli->cur_log_fd=open_binlog(cur_log,rli->linfo.log_file_name,
+				       &errmsg)) <0)
+	goto err;
     }
-    else // read failed with a non-EOF error
+    else
     {
-      // TODO: come up with something better to handle this error
+      /*
+	Read failed with a non-EOF error.
+	TODO: come up with something better to handle this error
+      */
+      if (hot_log)
+	pthread_mutex_unlock(log_lock);
       sql_print_error("Slave SQL thread: I/O error reading \
-event(errno=%d,cur_log->error=%d)",
+event(errno: %d  cur_log->error: %d)",
 		      my_errno,cur_log->error);
       // set read position to the beginning of the event
       my_b_seek(cur_log,rli->relay_log_pos+rli->pending);
       /* otherwise, we have had a partial read */
-      /* TODO; see if there is a way to do this without this goto */
       errmsg = "Aborting slave SQL thread because of partial event read";
+      /* TODO; see if there is a way to do this without this goto */
       goto err;
     }
-
   }
   if (!errmsg && was_killed)
     errmsg = "slave SQL thread was killed";
+
 err:
   pthread_mutex_unlock(&rli->data_lock);
   sql_print_error("Error reading relay log event: %s", errmsg);
-  return 0;
+  DBUG_RETURN(0);
 }