sys_vars changes and cleanups

7 files changed, 91 insertions, 138 deletions

diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index 3d586a7b0ae..e1b52a300f1 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -6180,6 +6180,10 @@ struct my_option my_long_options[]=
      option if compiled with valgrind support.
    */
    IF_VALGRIND(0,1), 0, 0, 0, 0, 0},
+  {"sync_sys", 0,
+   "Enable/disable system sync calls. Should only be turned off when running "
+   "tests or debugging!!",
+   &opt_sync, &opt_sync, 0, GET_BOOL, NO_ARG, 1, 0, 0, 0, 0, 0},
   {"sysdate-is-now", 0,
    "Non-default option to alias SYSDATE() to NOW() to make it safe-replicable. "
    "Since 5.0, SYSDATE() returns a `dynamic' value different for different "
@@ -7496,7 +7500,7 @@ static int get_options(int *argc_ptr, char ***argv_ptr)
        opt < my_long_options + array_elements(my_long_options) - 1;
        opt++)
     insert_dynamic(&all_options, (uchar*) opt);
-  sys_var_add_options(&all_options, sys_var::PARSE_NORMAL);
+  sys_var_add_options(&all_options, 0);
   add_terminator(&all_options);
 
   /* Skip unknown options so that they may be processed later by plugins */
diff --git a/sql/scheduler.cc b/sql/scheduler.cc
index df1fc68dddc..43d80137bac 100644
--- a/sql/scheduler.cc
+++ b/sql/scheduler.cc
@@ -60,13 +60,13 @@ static void scheduler_wait_lock_end(void) {
 
 static void scheduler_wait_sync_begin(void) {
   THD *thd=current_thd;
-  scheduler_functions *func= thd->scheduler;
+  scheduler_functions *func= thd ? thd->scheduler : thread_scheduler;
   MYSQL_CALLBACK(func, thd_wait_begin, (thd, THD_WAIT_TABLE_LOCK));
 }
 
 static void scheduler_wait_sync_end(void) {
   THD *thd=current_thd;
-  scheduler_functions *func= thd->scheduler;
+  scheduler_functions *func= thd ? thd->scheduler : thread_scheduler;
   MYSQL_CALLBACK(func, thd_wait_end, (thd));
 }
 };
diff --git a/sql/set_var.cc b/sql/set_var.cc
index 8e48e0213f0..45b630a3ba9 100644
--- a/sql/set_var.cc
+++ b/sql/set_var.cc
@@ -137,7 +137,6 @@ void sys_var_end()
   @param deprecated_version if not 0 - when this variable will go away
   @param substitute if not 0 - what one should use instead when this
                    deprecated variable
-  @param parse_flag either PARSE_EARLY or PARSE_NORMAL
 */
 sys_var::sys_var(sys_var_chain *chain, const char *name_arg,
                  const char *comment, int flags_arg, ptrdiff_t off,
@@ -146,11 +145,10 @@ sys_var::sys_var(sys_var_chain *chain, const char *name_arg,
                  PolyLock *lock, enum binlog_status_enum binlog_status_arg,
                  on_check_function on_check_func,
                  on_update_function on_update_func,
-                 uint deprecated_version, const char *substitute,
-                 int parse_flag) :
+                 uint deprecated_version, const char *substitute) :
   next(0),
   binlog_status(binlog_status_arg),
-  flags(flags_arg), m_parse_flag(parse_flag), show_val_type(show_val_type_arg),
+  flags(flags_arg), show_val_type(show_val_type_arg),
   guard(lock), offset(off), on_check(on_check_func), on_update(on_update_func),
   is_os_charset(FALSE)
 {
@@ -163,7 +161,7 @@ sys_var::sys_var(sys_var_chain *chain, const char *name_arg,
     in the first (PARSE_EARLY) stage.
     See handle_options() for details.
   */
-  DBUG_ASSERT(parse_flag == PARSE_NORMAL || getopt_id <= 0 || getopt_id >= 255);
+  DBUG_ASSERT(!(flags & PARSE_EARLY) || getopt_id <= 0 || getopt_id >= 255);
 
   name.str= name_arg;     // ER_NO_DEFAULT relies on 0-termination of name_arg
   name.length= strlen(name_arg);                // and so does this.
diff --git a/sql/set_var.h b/sql/set_var.h
index acfc1d54aa4..af96fabe3dc 100644
--- a/sql/set_var.h
+++ b/sql/set_var.h
@@ -59,9 +59,7 @@ public:
   sys_var *next;
   LEX_CSTRING name;
   enum flag_enum { GLOBAL, SESSION, ONLY_SESSION, SCOPE_MASK=1023,
-                   READONLY=1024, ALLOCATED=2048 };
-  static const int PARSE_EARLY= 1;
-  static const int PARSE_NORMAL= 2;
+                   READONLY=1024, ALLOCATED=2048, PARSE_EARLY=4096 };
   /**
     Enumeration type to indicate for a system variable whether
     it will be written to the binlog or not.
@@ -74,7 +72,6 @@ protected:
   typedef bool (*on_update_function)(sys_var *self, THD *thd, enum_var_type type);
 
   int flags;            ///< or'ed flag_enum values
-  int m_parse_flag;     ///< either PARSE_EARLY or PARSE_NORMAL.
   const SHOW_TYPE show_val_type; ///< what value_ptr() returns for sql_show.cc
   my_option option;     ///< min, max, default values are stored here
   PolyLock *guard;      ///< *second* lock that protects the variable
@@ -90,7 +87,7 @@ public:
           enum get_opt_arg_type getopt_arg_type, SHOW_TYPE show_val_type_arg,
           longlong def_val, PolyLock *lock, enum binlog_status_enum binlog_status_arg,
           on_check_function on_check_func, on_update_function on_update_func,
-          uint deprecated_version, const char *substitute, int parse_flag);
+          uint deprecated_version, const char *substitute);
 
   virtual ~sys_var() {}
 
@@ -133,7 +130,7 @@ public:
   }
   bool register_option(DYNAMIC_ARRAY *array, int parse_flags)
   {
-    return (option.id != -1) && (m_parse_flag & parse_flags) &&
+    return (option.id != -1) && ((flags & PARSE_EARLY) == parse_flags) &&
            insert_dynamic(array, (uchar*)&option);
   }
 
diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
index eb7fa3222e5..5e46a5ebf82 100644
--- a/sql/sql_plugin.cc
+++ b/sql/sql_plugin.cc
@@ -243,7 +243,7 @@ public:
              (plugin_var_arg->flags & PLUGIN_VAR_THDLOCAL ? SESSION : GLOBAL) |
              (plugin_var_arg->flags & PLUGIN_VAR_READONLY ? READONLY : 0),
              0, -1, NO_ARG, pluginvar_show_type(plugin_var_arg), 0, 0,
-             VARIABLE_NOT_IN_BINLOG, 0, 0, 0, 0, PARSE_NORMAL),
+             VARIABLE_NOT_IN_BINLOG, 0, 0, 0, 0),
     plugin_var(plugin_var_arg), orig_pluginvar_name(plugin_var_arg->name)
   { plugin_var->name= name_arg; }
   sys_var_pluginvar *cast_pluginvar() { return this; }
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index ba86a06847a..8126ae091f2 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -61,136 +61,117 @@
 
 #ifdef WITH_PERFSCHEMA_STORAGE_ENGINE
 
-#define PFS_TRAILING_PROPERTIES \
-  NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL), ON_UPDATE(NULL), \
-  0, NULL, sys_var::PARSE_EARLY
-
 static Sys_var_mybool Sys_pfs_enabled(
        "performance_schema",
        "Enable the performance schema.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_enabled),
-       CMD_LINE(OPT_ARG), DEFAULT(FALSE),
-       PFS_TRAILING_PROPERTIES);
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_enabled),
+       CMD_LINE(OPT_ARG), DEFAULT(FALSE));
 
 static Sys_var_ulong Sys_pfs_events_waits_history_long_size(
        "performance_schema_events_waits_history_long_size",
        "Number of rows in EVENTS_WAITS_HISTORY_LONG.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_events_waits_history_long_sizing),
+       PARSED_EARLY READ_ONLY
+       GLOBAL_VAR(pfs_param.m_events_waits_history_long_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_WAITS_HISTORY_LONG_SIZE),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_WAITS_HISTORY_LONG_SIZE), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_events_waits_history_size(
        "performance_schema_events_waits_history_size",
        "Number of rows per thread in EVENTS_WAITS_HISTORY.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_events_waits_history_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_events_waits_history_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024),
-       DEFAULT(PFS_WAITS_HISTORY_SIZE),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_WAITS_HISTORY_SIZE), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_cond_classes(
        "performance_schema_max_cond_classes",
        "Maximum number of condition instruments.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_cond_class_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_cond_class_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 256),
-       DEFAULT(PFS_MAX_COND_CLASS),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_COND_CLASS), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_cond_instances(
        "performance_schema_max_cond_instances",
        "Maximum number of instrumented condition objects.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_cond_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_cond_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_MAX_COND),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_COND), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_file_classes(
        "performance_schema_max_file_classes",
        "Maximum number of file instruments.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_file_class_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_file_class_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 256),
-       DEFAULT(PFS_MAX_FILE_CLASS),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_FILE_CLASS), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_file_handles(
        "performance_schema_max_file_handles",
        "Maximum number of opened instrumented files.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_file_handle_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_file_handle_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_MAX_FILE_HANDLE),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_FILE_HANDLE), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_file_instances(
        "performance_schema_max_file_instances",
        "Maximum number of instrumented files.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_file_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_file_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_MAX_FILE),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_FILE), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_mutex_classes(
        "performance_schema_max_mutex_classes",
        "Maximum number of mutex instruments.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_mutex_class_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_mutex_class_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 256),
-       DEFAULT(PFS_MAX_MUTEX_CLASS),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_MUTEX_CLASS), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_mutex_instances(
        "performance_schema_max_mutex_instances",
        "Maximum number of instrumented MUTEX objects.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_mutex_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_mutex_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 100*1024*1024),
-       DEFAULT(PFS_MAX_MUTEX),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_MUTEX), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_rwlock_classes(
        "performance_schema_max_rwlock_classes",
        "Maximum number of rwlock instruments.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_rwlock_class_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_rwlock_class_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 256),
-       DEFAULT(PFS_MAX_RWLOCK_CLASS),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_RWLOCK_CLASS), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_rwlock_instances(
        "performance_schema_max_rwlock_instances",
        "Maximum number of instrumented RWLOCK objects.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_rwlock_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_rwlock_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 100*1024*1024),
-       DEFAULT(PFS_MAX_RWLOCK),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_RWLOCK), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_table_handles(
        "performance_schema_max_table_handles",
        "Maximum number of opened instrumented tables.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_table_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_table_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_MAX_TABLE),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_TABLE), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_table_instances(
        "performance_schema_max_table_instances",
        "Maximum number of instrumented tables.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_table_share_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_table_share_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_MAX_TABLE_SHARE),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_TABLE_SHARE), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_thread_classes(
        "performance_schema_max_thread_classes",
        "Maximum number of thread instruments.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_thread_class_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_thread_class_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 256),
-       DEFAULT(PFS_MAX_THREAD_CLASS),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_THREAD_CLASS), BLOCK_SIZE(1));
 
 static Sys_var_ulong Sys_pfs_max_thread_instances(
        "performance_schema_max_thread_instances",
        "Maximum number of instrumented threads.",
-       READ_ONLY GLOBAL_VAR(pfs_param.m_thread_sizing),
+       PARSED_EARLY READ_ONLY GLOBAL_VAR(pfs_param.m_thread_sizing),
        CMD_LINE(REQUIRED_ARG), VALID_RANGE(0, 1024*1024),
-       DEFAULT(PFS_MAX_THREAD),
-       BLOCK_SIZE(1), PFS_TRAILING_PROPERTIES);
+       DEFAULT(PFS_MAX_THREAD), BLOCK_SIZE(1));
 
 #endif /* WITH_PERFSCHEMA_STORAGE_ENGINE */
 
@@ -1029,8 +1010,7 @@ static bool session_readonly(sys_var *self, THD *thd, set_var *var)
   return true;
 }
 
-static bool
-check_max_allowed_packet(sys_var *self, THD *thd,  set_var *var)
+static bool check_max_allowed_packet(sys_var *self, THD *thd,  set_var *var)
 {
   longlong val;
   if (session_readonly(self, thd, var))
@@ -1285,8 +1265,7 @@ static Sys_var_mybool Sys_named_pipe(
 #endif
 
 
-static bool 
-check_net_buffer_length(sys_var *self, THD *thd,  set_var *var)
+static bool check_net_buffer_length(sys_var *self, THD *thd,  set_var *var)
 {
   longlong val;
   if (session_readonly(self, thd, var))
@@ -1894,7 +1873,7 @@ static Sys_var_enum Slave_exec_mode(
        "between the master and the slave",
        GLOBAL_VAR(slave_exec_mode_options), CMD_LINE(REQUIRED_ARG),
        slave_exec_mode_names, DEFAULT(SLAVE_EXEC_MODE_STRICT));
-const char *slave_type_conversions_name[]= {"ALL_LOSSY", "ALL_NON_LOSSY", 0};
+static const char *slave_type_conversions_name[]= {"ALL_LOSSY", "ALL_NON_LOSSY", 0};
 static Sys_var_set Slave_type_conversions(
        "slave_type_conversions",
        "Set of slave type conversions that are enabled. Legal values are:"
@@ -2128,32 +2107,6 @@ static bool check_tx_isolation(sys_var *self, THD *thd, set_var *var)
   return FALSE;
 }
 
-
-bool Sys_var_tx_isolation::session_update(THD *thd, set_var *var)
-{
-  if (var->type == OPT_SESSION && Sys_var_enum::session_update(thd, var))
-    return TRUE;
-  if (var->type == OPT_DEFAULT || !thd->in_active_multi_stmt_transaction())
-  {
-    /*
-      Update the isolation level of the next transaction.
-      I.e. if one did:
-      COMMIT;
-      SET SESSION ISOLATION LEVEL ...
-      BEGIN; <-- this transaction has the new isolation
-      Note, that in case of:
-      COMMIT;
-      SET TRANSACTION ISOLATION LEVEL ...
-      SET SESSION ISOLATION LEVEL ...
-      BEGIN; <-- the session isolation level is used, not the
-      result of SET TRANSACTION statement.
-     */
-    thd->tx_isolation= (enum_tx_isolation) var->save_result.ulonglong_value;
-  }
-  return FALSE;
-}
-
-
 // NO_CMD_LINE - different name of the option
 static Sys_var_tx_isolation Sys_tx_isolation(
        "tx_isolation", "Default transaction isolation level",
@@ -3324,11 +3277,6 @@ static Sys_var_ulong Sys_mrr_buffer_size(
        SESSION_VAR(mrr_buff_size), CMD_LINE(REQUIRED_ARG),
        VALID_RANGE(IO_SIZE*2, INT_MAX32), DEFAULT(256*1024), BLOCK_SIZE(1));
 
-/*  {"sync_sys", OPT_SYNC,
-   "Enable/disable system sync calls. Should only be turned off when running "
-   "tests or debugging!!",
-   &opt_sync, &opt_sync, 0, GET_BOOL, NO_ARG, 1, 0, 0, 0, 0, 0},*/
-
 static Sys_var_ulong Sys_rowid_merge_buff_size(
        "rowid_merge_buff_size",
        "The size of the buffers used [NOT] IN evaluation via partial matching",
diff --git a/sql/sys_vars.h b/sql/sys_vars.h
index 348fede994b..943b26fa5c4 100644
--- a/sql/sys_vars.h
+++ b/sql/sys_vars.h
@@ -53,6 +53,7 @@
 #define READ_ONLY sys_var::READONLY+
 // this means that Sys_var_charptr initial value was malloc()ed
 #define PREALLOCATED sys_var::ALLOCATED+
+#define PARSED_EARLY sys_var::PARSE_EARLY+
 /*
   Sys_var_bit meaning is reversed, like in
   @@foreign_key_checks <-> OPTION_NO_FOREIGN_KEY_CHECKS
@@ -109,12 +110,10 @@ public:
           enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
           on_check_function on_check_func=0,
           on_update_function on_update_func=0,
-          uint deprecated_version=0, const char *substitute=0,
-          int parse_flag= PARSE_NORMAL)
+          uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOWT, def_val, lock, binlog_status_arg,
-              on_check_func, on_update_func, deprecated_version,
-              substitute, parse_flag)
+              on_check_func, on_update_func, deprecated_version, substitute)
   {
     option.var_type= ARGT;
     option.min_value= min_val;
@@ -197,11 +196,11 @@ public:
           ulonglong def_val, PolyLock *lock,
           enum binlog_status_enum binlog_status_arg,
           on_check_function on_check_func, on_update_function on_update_func,
-          uint deprecated_version, const char *substitute, int parse_flag= PARSE_NORMAL)
+          uint deprecated_version, const char *substitute)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, show_val_type_arg, def_val, lock,
               binlog_status_arg, on_check_func,
-              on_update_func, deprecated_version, substitute, parse_flag)
+              on_update_func, deprecated_version, substitute)
   {
     for (typelib.count= 0; values[typelib.count]; typelib.count++) /*no-op */;
     typelib.name="";
@@ -311,12 +310,11 @@ public:
           enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
           on_check_function on_check_func=0,
           on_update_function on_update_func=0,
-          uint deprecated_version=0, const char *substitute=0,
-          int parse_flag= PARSE_NORMAL)
+          uint deprecated_version=0, const char *substitute=0)
     : Sys_var_typelib(name_arg, comment, flag_args, off, getopt,
                       SHOW_MY_BOOL, bool_values, def_val, lock,
                       binlog_status_arg, on_check_func, on_update_func,
-                      deprecated_version, substitute, parse_flag)
+                      deprecated_version, substitute)
   {
     option.var_type= GET_BOOL;
     global_var(my_bool)= def_val;
@@ -367,12 +365,11 @@ public:
           enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
           on_check_function on_check_func=0,
           on_update_function on_update_func=0,
-          uint deprecated_version=0, const char *substitute=0,
-          int parse_flag= PARSE_NORMAL)
+          uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOW_CHAR_PTR, (intptr)def_val,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag)
+              deprecated_version, substitute)
   {
     is_os_charset= is_os_charset_arg == IN_FS_CHARSET;
     /*
@@ -461,7 +458,7 @@ public:
     : sys_var(&all_sys_vars, name_arg, comment,
               sys_var::READONLY+sys_var::ONLY_SESSION, 0, -1,
               NO_ARG, SHOW_CHAR, 0, NULL, VARIABLE_NOT_IN_BINLOG,
-              NULL, NULL, 0, NULL, PARSE_NORMAL)
+              NULL, NULL, 0, NULL)
   {
     is_os_charset= is_os_charset_arg == IN_FS_CHARSET;
     option.var_type= GET_STR;
@@ -574,12 +571,11 @@ public:
                enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
                on_check_function on_check_func=0,
                on_update_function on_update_func=0,
-               uint deprecated_version=0, const char *substitute=0,
-               int parse_flag= PARSE_NORMAL)
+               uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, 0, getopt.id,
               getopt.arg_type, SHOW_CHAR, (intptr)def_val,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag)
+              deprecated_version, substitute)
   { option.var_type= GET_NO_ARG; }
   bool do_check(THD *thd, set_var *var)
   {
@@ -819,12 +815,11 @@ public:
           enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
           on_check_function on_check_func=0,
           on_update_function on_update_func=0,
-          uint deprecated_version=0, const char *substitute=0,
-          int parse_flag= PARSE_NORMAL)
+          uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOW_DOUBLE, (longlong) double2ulonglong(def_val),
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag)
+              deprecated_version, substitute)
   {
     option.var_type= GET_DOUBLE;
     option.min_value= (longlong) double2ulonglong(min_val);
@@ -1142,12 +1137,11 @@ public:
           enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
           on_check_function on_check_func=0,
           on_update_function on_update_func=0,
-          uint deprecated_version=0, const char *substitute=0,
-          int parse_flag= PARSE_NORMAL)
+          uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOW_CHAR, (intptr)def_val,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag),
+              deprecated_version, substitute),
     plugin_type(plugin_type_arg)
   {
     option.var_type= GET_STR;
@@ -1256,12 +1250,11 @@ public:
                enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
                on_check_function on_check_func=0,
                on_update_function on_update_func=0,
-               uint deprecated_version=0, const char *substitute=0,
-               int parse_flag= PARSE_NORMAL)
+               uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, 0, getopt.id,
               getopt.arg_type, SHOW_CHAR, (intptr)def_val,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag)
+              deprecated_version, substitute)
   {
     DBUG_ASSERT(scope() == ONLY_SESSION);
     option.var_type= GET_NO_ARG;
@@ -1475,12 +1468,11 @@ public:
                enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
                on_check_function on_check_func=0,
                on_update_function on_update_func=0,
-               uint deprecated_version=0, const char *substitute=0,
-               int parse_flag= PARSE_NORMAL)
+               uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOW_CHAR, 0,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag)
+              deprecated_version, substitute)
   {
     DBUG_ASSERT(scope() == GLOBAL);
     DBUG_ASSERT(getopt.id == -1);
@@ -1544,12 +1536,11 @@ public:
           enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
           on_check_function on_check_func=0,
           on_update_function on_update_func=0,
-          uint deprecated_version=0, const char *substitute=0,
-          int parse_flag= PARSE_NORMAL)
+          uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOW_CHAR, (intptr)def_val,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag),
+              deprecated_version, substitute),
       name_offset(name_off)
   {
     option.var_type= GET_STR;
@@ -1617,12 +1608,11 @@ public:
              enum binlog_status_enum binlog_status_arg=VARIABLE_NOT_IN_BINLOG,
              on_check_function on_check_func=0,
              on_update_function on_update_func=0,
-             uint deprecated_version=0, const char *substitute=0,
-             int parse_flag= PARSE_NORMAL)
+             uint deprecated_version=0, const char *substitute=0)
     : sys_var(&all_sys_vars, name_arg, comment, flag_args, off, getopt.id,
               getopt.arg_type, SHOW_CHAR, (intptr)def_val,
               lock, binlog_status_arg, on_check_func, on_update_func,
-              deprecated_version, substitute, parse_flag)
+              deprecated_version, substitute)
   {
     DBUG_ASSERT(getopt.id == -1);
     DBUG_ASSERT(size == sizeof(Time_zone *));
@@ -1684,7 +1674,16 @@ public:
   { return type != STRING_RESULT; }
 };
 
+/**
+  Special implementation for transaction isolation, that
+  distingushes between
+
+  SET GLOBAL TRANSACTION ISOLATION (stored in global_system_variables)
+  SET SESSION TRANSACTION ISOLATION (stored in thd->variables)
+  SET TRANSACTION ISOLATION (stored in thd->tx_isolation)
 
+  where the last statement sets isolation level for the next transaction only
+*/
 class Sys_var_tx_isolation: public Sys_var_enum
 {
 public:
@@ -1697,7 +1696,14 @@ public:
     :Sys_var_enum(name_arg, comment, flag_args, off, size, getopt,
                   values, def_val, lock, binlog_status_arg, on_check_func)
   {}
-  virtual bool session_update(THD *thd, set_var *var);
+  bool session_update(THD *thd, set_var *var)
+  {
+    if (var->type == OPT_SESSION && Sys_var_enum::session_update(thd, var))
+      return TRUE;
+    if (var->type == OPT_DEFAULT || !thd->in_active_multi_stmt_transaction())
+      thd->tx_isolation= (enum_tx_isolation) var->save_result.ulonglong_value;
+    return FALSE;
+  }
 };
 
 /****************************************************************************