BUG#12228: Post review fixes: Added test case, code cleanup.

mysql-test/r/sp-threads.result:
  Testcase for BUG#12228
mysql-test/t/sp-threads.test:
  Testcase for BUG#12228
sql/sp_cache.cc:
  BUG#12228: Post-review fixes: small code cleanup
sql/sp_cache.h:
  BUG#12228: Post-review fixes: fixed the comment
sql/sql_parse.cc:
  BUG#12228: Post-review fixes: in mysql_parse, flush obsolete SPs from the caches only if 
   the query hasn't been handled by the query cache.
sql/sql_prepare.cc:
  BUG#12228: Post-review fixes: in mysql_stmt_prepare/execute, flush SP caches 
   "closer to the execution"

mysql-test/r/sp-threads.result

@@ -37,6 +37,7 @@ Id	User	Host	db	Command	Time	State	Info
 #	root	localhost	test	Sleep	#		NULL
 #	root	localhost	test	Query	#	Locked	update t1, t2 set val= 1 where id1=id2
 #	root	localhost	test	Query	#	NULL	show processlist
+#	root	localhost	test	Sleep	#		NULL
 unlock tables;
 drop procedure bug9486;
 drop table t1, t2;
@@ -64,3 +65,27 @@ insert into t1 (select f from v1);
 drop function bug11554;
 drop table t1;
 drop view v1;
+drop procedure if exists p1;
+drop procedure if exists p2;
+create table t1 (s1 int)|
+create procedure p1() select * from t1|
+create procedure p2()
+begin
+insert into t1 values (1);
+call p1();
+select * from t1;
+end|
+use test;
+lock table t1 write;
+ call p2();
+use test;
+drop procedure p1;
+create procedure p1() select * from t1;
+unlock tables;
+s1
+1
+s1
+1
+drop procedure p1;
+drop procedure p2;
+drop table t1;

mysql-test/t/sp-threads.test

@@ -5,6 +5,7 @@
 
 connect (con1root,localhost,root,,);
 connect (con2root,localhost,root,,);
+connect (con3root,localhost,root,,);
 
 connection con1root;
 use test;
@@ -130,6 +131,48 @@ drop function bug11554;
 drop table t1;
 drop view v1;
 
+
+# BUG#12228 
+--disable_warnings
+drop procedure if exists p1;
+drop procedure if exists p2;
+--enable_warnings
+
+connection con1root;
+delimiter |;
+create table t1 (s1 int)|
+create procedure p1() select * from t1|
+create procedure p2()
+begin
+  insert into t1 values (1);
+  call p1();
+  select * from t1;
+end|
+delimiter ;|
+
+connection con2root;
+use test;
+lock table t1 write;
+
+connection con1root;
+send call p2();
+
+connection con3root;
+use test;
+drop procedure p1;
+create procedure p1() select * from t1;
+
+connection con2root;
+unlock tables;
+
+connection con1root;
+# Crash will be here if we hit BUG#12228 
+reap;
+
+drop procedure p1;
+drop procedure p2;
+drop table t1;
+
 #
 # BUG#NNNN: New bug synopsis
 #

sql/sp_cache.cc

@@ -122,15 +122,11 @@ void sp_cache_insert(sp_cache **cp, sp_head *sp)
 {
   sp_cache *c= *cp;
 
-  if (! c)
+  if (!c && (c= new sp_cache()))
   {
-    ulong v;
-    c= new sp_cache();
     pthread_mutex_lock(&Cversion_lock); // LOCK
-    v= Cversion;
+    c->version= Cversion;
     pthread_mutex_unlock(&Cversion_lock); // UNLOCK
-    if (c)
-      c->version= v;
   }
   if (c)
   {

sql/sp_cache.h

@@ -46,7 +46,7 @@ class sp_cache;
     sp_cache_insert();
     sp_cache_invalidate();
   
-  2.2 When not holding any sp_head* pointers (at query end):
+  2.2 When not holding any sp_head* pointers:
     sp_cache_flush_obsolete();
   
   3. Before thread exit:

sql/sql_parse.cc

@@ -5347,12 +5347,12 @@ void mysql_init_multi_delete(LEX *lex)
 void mysql_parse(THD *thd, char *inBuf, uint length)
 {
   DBUG_ENTER("mysql_parse");
-  sp_cache_flush_obsolete(&thd->sp_proc_cache);
-  sp_cache_flush_obsolete(&thd->sp_func_cache);
   mysql_init_query(thd, (uchar*) inBuf, length);
   if (query_cache_send_result_to_client(thd, inBuf, length) <= 0)
   {
     LEX *lex= thd->lex;
+    sp_cache_flush_obsolete(&thd->sp_proc_cache);
+    sp_cache_flush_obsolete(&thd->sp_func_cache);
     if (!yyparse((void *)thd) && ! thd->is_fatal_error)
     {
 #ifndef NO_EMBEDDED_ACCESS_CHECKS

sql/sql_prepare.cc

@@ -1730,8 +1730,6 @@ bool mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
   DBUG_ENTER("mysql_stmt_prepare");
 
   DBUG_PRINT("prep_query", ("%s", packet));
-  sp_cache_flush_obsolete(&thd->sp_proc_cache);
-  sp_cache_flush_obsolete(&thd->sp_func_cache);
 
   /*
     If this is an SQLCOM_PREPARE, we also increase Com_prepare_sql.
@@ -1785,6 +1783,9 @@ bool mysql_stmt_prepare(THD *thd, char *packet, uint packet_length,
   lex= thd->lex;
   lex->safe_to_cache_query= 0;
 
+  sp_cache_flush_obsolete(&thd->sp_proc_cache);
+  sp_cache_flush_obsolete(&thd->sp_func_cache);
+
   error= yyparse((void *)thd) || thd->is_fatal_error ||
          thd->net.report_error || init_param_array(stmt);
   /*
@@ -1981,8 +1982,6 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
   Prepared_statement *stmt;
   DBUG_ENTER("mysql_stmt_execute");
 
-  sp_cache_flush_obsolete(&thd->sp_proc_cache);
-  sp_cache_flush_obsolete(&thd->sp_func_cache);
   packet+= 9;                               /* stmt_id + 5 bytes of flags */
 
   statistic_increment(thd->status_var.com_stmt_execute, &LOCK_status);
@@ -2063,6 +2062,8 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
   thd->protocol= &thd->protocol_prep;           // Switch to binary protocol
   if (!(specialflag & SPECIAL_NO_PRIOR))
     my_pthread_setprio(pthread_self(),QUERY_PRIOR);
+  sp_cache_flush_obsolete(&thd->sp_proc_cache);
+  sp_cache_flush_obsolete(&thd->sp_func_cache);
   mysql_execute_command(thd);
   if (!(specialflag & SPECIAL_NO_PRIOR))
     my_pthread_setprio(pthread_self(), WAIT_PRIOR);