Bug#24822: Patch: uptime_since_flush_status

Provide the number of seconds since flush as a new status variable
named "Uptime_since_flush_status".
---
Override the post-flush value, as a second could pass between the two
statements.


mysql-test/r/information_schema.result:
  Test new status variable.
  ---
  Override the post-flush value, as a second could pass between the two
  statements.
mysql-test/t/information_schema.test:
  Test new status variable.
  ---
  Override the post-flush value, as a second could pass between the two
  statements.
sql/mysql_priv.h:
  Add variable to hold previous flush time.
sql/mysqld.cc:
  Add variable to hold previous flush time.  Insert name for 
  referring to it, and initialize the value.
sql/sql_show.cc:
  Yield value of elapsed time since flush when asked.
sql/structs.h:
  Add new show-flush-time to SHOW types enumeration.

BitKeeper/etc/collapsed

@@ -32,3 +32,5 @@
 459c03b9N_mqF2XJKK6DwSrIt7e6_g
 459c1965_BQMBzBO8S_gVqjTHYQrmw
 459c2098XoAUsUn8N07IVRDD6CTM-A
+459ea845XenN-uWqEM5LFvUT60tW_A
+45af88c9RIIJWPfBxs3o7zekI-ELPQ

mysql-test/r/information_schema.result

@@ -1269,3 +1269,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
 2	DERIVED	tables	ALL	NULL	NULL	NULL	NULL	2	
 drop view v1;
+show global status like "Uptime_%";
+Variable_name	Value
+Uptime_since_flush_status	#
+flush status;
+show global status like "Uptime_%";
+Variable_name	Value
+Uptime_since_flush_status	#

mysql-test/t/information_schema.test

@@ -971,9 +971,6 @@ SELECT COLUMN_NAME, MD5(COLUMN_DEFAULT), LENGTH(COLUMN_DEFAULT), COLUMN_DEFAULT=
 DROP TABLE bug23037;
 DROP FUNCTION get_value;
 
-
-
-
 #
 # Bug#22413: EXPLAIN SELECT FROM view with ORDER BY yield server crash
 #
@@ -987,4 +984,14 @@ explain select * from v1;
 explain select * from (select table_name from information_schema.tables) as a;
 drop view v1;
 
+#
+# Bug#24822: Patch: uptime_since_flush_status
+#
+--replace_column 2 #
+show global status like "Uptime_%";
+flush status;
+--replace_column 2 #
+show global status like "Uptime_%";  # Almost certainly zero
+
+
 # End of 5.0 tests.

sql/mysql_priv.h

@@ -1190,7 +1190,7 @@ void my_dbopt_free(void);
   External variables
 */
 
-extern time_t start_time;
+extern time_t start_time, flush_status_time;
 extern char *mysql_data_home,server_version[SERVER_VERSION_LENGTH],
 	    mysql_real_data_home[], *opt_mysql_tmpdir, mysql_charsets_dir[],
             def_ft_boolean_syntax[sizeof(ft_boolean_syntax)];

sql/mysqld.cc

@@ -428,7 +428,7 @@ ulong expire_logs_days = 0;
 ulong rpl_recovery_rank=0;
 
 double log_10[32];			/* 10 potences */
-time_t start_time;
+time_t start_time, flush_status_time;
 
 char mysql_home[FN_REFLEN], pidfile_name[FN_REFLEN], system_time_zone[30];
 char *default_tz_name;
@@ -2589,7 +2589,7 @@ static int init_common_variables(const char *conf_file_name, int argc,
   tzset();			// Set tzname
 
   max_system_variables.pseudo_thread_id= (ulong)~0;
-  start_time=time((time_t*) 0);
+  start_time= flush_status_time= time((time_t*) 0);
   if (init_thread_environment())
     return 1;
   mysql_init_variables();
@@ -6264,6 +6264,7 @@ struct show_var_st status_vars[]= {
   {"Threads_created",	       (char*) &thread_created,		SHOW_LONG_CONST},
   {"Threads_running",          (char*) &thread_running,         SHOW_INT_CONST},
   {"Uptime",                   (char*) 0,                       SHOW_STARTTIME},
+  {"Uptime_since_flush_status",(char*) 0,                       SHOW_FLUSHTIME},
   {NullS, NullS, SHOW_LONG}
 };
 
@@ -7534,6 +7535,7 @@ void refresh_status(THD *thd)
 
   /* Reset the counters of all key caches (default and named). */
   process_key_caches(reset_key_cache_counters);
+  flush_status_time= time((time_t*) 0);
   pthread_mutex_unlock(&LOCK_status);
 
   /*

sql/sql_show.cc

@@ -1492,6 +1492,10 @@ static bool show_status_array(THD *thd, const char *wild,
           nr= (long) (thd->query_start() - start_time);
           end= int10_to_str(nr, buff, 10);
           break;
+        case SHOW_FLUSHTIME:
+          nr= (long) (thd->query_start() - flush_status_time);
+          end= int10_to_str(nr, buff, 10);
+          break;
         case SHOW_QUESTION:
           end= int10_to_str((long) thd->query_id, buff, 10);
           break;

sql/structs.h

@@ -174,6 +174,7 @@ enum SHOW_TYPE
   SHOW_BOOL, SHOW_MY_BOOL, SHOW_OPENTABLES, SHOW_STARTTIME, SHOW_QUESTION,
   SHOW_LONG_CONST, SHOW_INT_CONST, SHOW_HAVE, SHOW_SYS, SHOW_HA_ROWS,
   SHOW_VARS,
+  SHOW_FLUSHTIME,
 #ifdef HAVE_OPENSSL
   SHOW_SSL_CTX_SESS_ACCEPT, 	SHOW_SSL_CTX_SESS_ACCEPT_GOOD,
   SHOW_SSL_GET_VERSION, 	SHOW_SSL_CTX_GET_SESSION_CACHE_MODE,