Fix for BUG#791:

a safer way of initing the mutexes in MYSQL_LOG.
is_open() is now always thread-safe.
See each file for details.


sql/handler.cc:
  is_open() with locks
sql/item_func.cc:
  is_open() with locks
sql/log.cc:
  No more 'inited'.
  We now always use is_open() in a thread-safe manner.
  This simplifies some functions (no more need to test is_open() twice).
sql/log_event.cc:
  is_open() with locks
sql/mysqld.cc:
  Init mutexes for the global MYSQL_LOG objects.
  We care about no_rotate, because we can't do it in open() anymore (because
  we don't have 'inited' anymore).
sql/repl_failsafe.cc:
  is_open() with locks
sql/slave.cc:
  init pthread objects (mutexes, conds) in the constructor of st_relay_log_info.
  Some better locking in rotate_relay_log().
sql/sql_base.cc:
  is_open() with locks
sql/sql_class.h:
  Before, we inited LOCK_log in MYSQL_LOG::open(), so in other places of the code
  when we were never 100% sure that it had been inited. For example, if the server
  was running without --log-bin, ::open() was not called so the mutex was not
  inited. We could detect it with !inited, but not safely as 'inited' was not
  protected by any mutex.
  So now:
  we *always* init the LOCK_log mutex, even if the log is not used. We can't init
  the mutex in MYSQL_LOG's constructor, because for global objects like
  mysql_bin_log, mysql_log etc, the constructor is called before MY_INIT(), but
  safe_mutex depends on MY_INIT(). So we have a new function MYSQL_LOG::init_pthread_objects
  which we call in main(), after MY_INIT().
  For the relay log, we call this function in the constructor of
  st_relay_log_info, which is called before any function tries to
  use the relay log (the relay log is always invoked as rli.relay_log).
  So now we should be safe in all cases and we don't need 'inited'.
sql/sql_db.cc:
  is_open() with locks
sql/sql_delete.cc:
  is_open() with locks
sql/sql_insert.cc:
  is_open() with locks
sql/sql_load.cc:
  is_open() with locks
sql/sql_parse.cc:
  is_open() with locks
sql/sql_rename.cc:
  is_open() with locks
sql/sql_repl.cc:
  is_open() with locks
sql/sql_table.cc:
  is_open() with locks
sql/sql_update.cc:
  is_open() with locks

1 files changed, 7 insertions, 7 deletions

diff --git a/sql/sql_repl.cc b/sql/sql_repl.cc
index e775a5d712e..a671facdc08 100644
--- a/sql/sql_repl.cc
+++ b/sql/sql_repl.cc
@@ -269,7 +269,7 @@ int purge_master_logs(THD* thd, const char* to_log)
   const char* errmsg = 0;
   int res;
 
-  if (!mysql_bin_log.is_open())
+  if (!mysql_bin_log.is_open(1))
     goto end;
 
   mysql_bin_log.make_log_name(search_file_name, to_log);
@@ -335,7 +335,7 @@ void mysql_binlog_send(THD* thd, char* log_ident, my_off_t pos,
   }
 #endif
 
-  if (!mysql_bin_log.is_open())
+  if (!mysql_bin_log.is_open(1))
   {
     errmsg = "Binary log is not open";
     my_errno= ER_MASTER_FATAL_ERROR_READING_BINLOG;
@@ -972,7 +972,7 @@ int change_master(THD* thd, MASTER_INFO* mi)
 
 int reset_master(THD* thd)
 {
-  if (!mysql_bin_log.is_open())
+  if (!mysql_bin_log.is_open(1))
   {
     my_error(ER_FLUSH_MASTER_BINLOG_CLOSED,  MYF(ME_BELL+ME_WAITTANG));
     return 1;
@@ -1010,7 +1010,7 @@ int show_binlog_events(THD* thd)
   if (send_fields(thd, field_list, 1))
     DBUG_RETURN(-1);
 
-  if (mysql_bin_log.is_open())
+  if (mysql_bin_log.is_open(1))
   {
     LEX_MASTER_INFO *lex_mi = &thd->lex.mi;
     ha_rows event_count, limit_start, limit_end;
@@ -1110,7 +1110,7 @@ int show_binlog_info(THD* thd)
   String* packet = &thd->packet;
   packet->length(0);
 
-  if (mysql_bin_log.is_open())
+  if (mysql_bin_log.is_open(1))
   {
     LOG_INFO li;
     mysql_bin_log.get_current_log(&li);
@@ -1128,7 +1128,7 @@ int show_binlog_info(THD* thd)
 
 
 /*
-  Send a lost of all binary logs to client
+  Send a list of all binary logs to client
 
   SYNOPSIS
     show_binlogs()
@@ -1148,7 +1148,7 @@ int show_binlogs(THD* thd)
   String *packet = &thd->packet;
   uint length;
 
-  if (!mysql_bin_log.is_open())
+  if (!mysql_bin_log.is_open(1))
   {
     //TODO:  Replace with ER() error message
     send_error(net, 0, "You are not using binary logging");