From 0d588f8882b122b586378c735fb4058345d80286 Mon Sep 17 00:00:00 2001 From: "kroki/tomash@moonlight.intranet" <> Date: Tue, 21 Nov 2006 16:49:18 +0300 Subject: [PATCH 1/3] BUG#23159: prepared_stmt_count should be status variable Make Prepared_stmt_count a global status variable, accessible via SHOW STATUS LIKE 'Prepared_stmt_count';. Documentation should be updated. --- mysql-test/r/ps.result | 101 +++++++++++++++++++++-------------------- mysql-test/t/ps.test | 57 ++++++++++------------- sql/mysqld.cc | 2 + sql/set_var.cc | 14 ------ 4 files changed, 79 insertions(+), 95 deletions(-) diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result index 2bb5df6e6cf..94c51fdc18b 100644 --- a/mysql-test/r/ps.result +++ b/mysql-test/r/ps.result @@ -775,12 +775,12 @@ set @old_max_prepared_stmt_count= @@max_prepared_stmt_count; show variables like 'max_prepared_stmt_count'; Variable_name Value max_prepared_stmt_count 16382 -show variables like 'prepared_stmt_count'; +show status like 'prepared_stmt_count'; Variable_name Value -prepared_stmt_count 0 -select @@max_prepared_stmt_count, @@prepared_stmt_count; -@@max_prepared_stmt_count @@prepared_stmt_count -16382 0 +Prepared_stmt_count 0 +select @@max_prepared_stmt_count; +@@max_prepared_stmt_count +16382 set global max_prepared_stmt_count=-1; select @@max_prepared_stmt_count; @@max_prepared_stmt_count @@ -799,67 +799,70 @@ set max_prepared_stmt_count=1; ERROR HY000: Variable 'max_prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL set local max_prepared_stmt_count=1; ERROR HY000: Variable 'max_prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL -set local prepared_stmt_count=0; -ERROR HY000: Variable 'prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL -set @@prepared_stmt_count=0; -ERROR HY000: Variable 'prepared_stmt_count' is a GLOBAL variable and should be set with SET GLOBAL -set global prepared_stmt_count=1; -ERROR 42000: Incorrect argument type to variable 'prepared_stmt_count' set global max_prepared_stmt_count=1; select @@max_prepared_stmt_count; @@max_prepared_stmt_count 1 set global max_prepared_stmt_count=0; -select @@max_prepared_stmt_count, @@prepared_stmt_count; -@@max_prepared_stmt_count @@prepared_stmt_count -0 0 +select @@max_prepared_stmt_count; +@@max_prepared_stmt_count +0 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 prepare stmt from "select 1"; ERROR HY000: Unknown error -select @@prepared_stmt_count; -@@prepared_stmt_count -0 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 set global max_prepared_stmt_count=1; prepare stmt from "select 1"; -select @@prepared_stmt_count; -@@prepared_stmt_count -1 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 1 prepare stmt1 from "select 1"; ERROR HY000: Unknown error -select @@prepared_stmt_count; -@@prepared_stmt_count -1 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 1 deallocate prepare stmt; -select @@prepared_stmt_count; -@@prepared_stmt_count -0 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 prepare stmt from "select 1"; -select @@prepared_stmt_count; -@@prepared_stmt_count -1 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 1 prepare stmt from "select 2"; -select @@prepared_stmt_count; -@@prepared_stmt_count +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 1 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 1 +select @@max_prepared_stmt_count; +@@max_prepared_stmt_count 1 -select @@prepared_stmt_count, @@max_prepared_stmt_count; -@@prepared_stmt_count @@max_prepared_stmt_count -1 1 set global max_prepared_stmt_count=0; prepare stmt from "select 1"; ERROR HY000: Unknown error execute stmt; ERROR HY000: Unknown prepared statement handler (stmt) given to EXECUTE -select @@prepared_stmt_count; -@@prepared_stmt_count -0 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 prepare stmt from "select 1"; ERROR HY000: Unknown error -select @@prepared_stmt_count; -@@prepared_stmt_count -0 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 set global max_prepared_stmt_count=3; -select @@max_prepared_stmt_count, @@prepared_stmt_count; -@@max_prepared_stmt_count @@prepared_stmt_count -3 0 +select @@max_prepared_stmt_count; +@@max_prepared_stmt_count +3 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 prepare stmt from "select 1"; prepare stmt from "select 2"; prepare stmt1 from "select 3"; @@ -867,13 +870,13 @@ prepare stmt2 from "select 4"; ERROR HY000: Unknown error prepare stmt2 from "select 4"; ERROR HY000: Unknown error -select @@max_prepared_stmt_count, @@prepared_stmt_count; -@@max_prepared_stmt_count @@prepared_stmt_count -3 3 +select @@max_prepared_stmt_count; +@@max_prepared_stmt_count +3 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 3 deallocate prepare stmt; -select @@max_prepared_stmt_count, @@prepared_stmt_count; -@@max_prepared_stmt_count @@prepared_stmt_count -3 0 set global max_prepared_stmt_count= @old_max_prepared_stmt_count; drop table if exists t1; create temporary table if not exists t1 (a1 int); diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test index 5b488ae4393..fbeaaa494e0 100644 --- a/mysql-test/t/ps.test +++ b/mysql-test/t/ps.test @@ -811,6 +811,9 @@ drop table t1; # Bug#16365 Prepared Statements: DoS with too many open statements # Check that the limit @@max_prpeared_stmt_count works. # +# This is also the test for bug#23159 prepared_stmt_count should be +# status variable. +# # Save the old value set @old_max_prepared_stmt_count= @@max_prepared_stmt_count; # @@ -820,17 +823,17 @@ set @old_max_prepared_stmt_count= @@max_prepared_stmt_count; # --disable_ps_protocol # -# A. Check that the new variables are present in SHOW VARIABLES list. +# A. Check that the new variables are present in SHOW VARIABLES and +# SHOW STATUS lists. # show variables like 'max_prepared_stmt_count'; -show variables like 'prepared_stmt_count'; +show status like 'prepared_stmt_count'; # -# B. Check that the new variables are selectable. +# B. Check that the new system variable is selectable. # -select @@max_prepared_stmt_count, @@prepared_stmt_count; +select @@max_prepared_stmt_count; # -# C. Check that max_prepared_stmt_count is settable (global only), -# whereas prepared_stmt_count is readonly. +# C. Check that max_prepared_stmt_count is settable (global only). # set global max_prepared_stmt_count=-1; select @@max_prepared_stmt_count; @@ -844,12 +847,6 @@ set @@max_prepared_stmt_count=1; set max_prepared_stmt_count=1; --error 1229 # ER_GLOBAL_VARIABLE set local max_prepared_stmt_count=1; ---error 1229 # ER_GLOBAL_VARIABLE -set local prepared_stmt_count=0; ---error 1229 # ER_GLOBAL_VARIABLE -set @@prepared_stmt_count=0; ---error 1232 # ER_WRONG_TYPE_FOR_VAR -set global prepared_stmt_count=1; # set to a reasonable limit works set global max_prepared_stmt_count=1; select @@max_prepared_stmt_count; @@ -857,47 +854,50 @@ select @@max_prepared_stmt_count; # D. Check that the variables actually work. # set global max_prepared_stmt_count=0; -select @@max_prepared_stmt_count, @@prepared_stmt_count; +select @@max_prepared_stmt_count; +show status like 'prepared_stmt_count'; --error 1105 # ER_UNKNOWN_ERROR prepare stmt from "select 1"; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; set global max_prepared_stmt_count=1; prepare stmt from "select 1"; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; --error 1105 # ER_UNKNOWN_ERROR prepare stmt1 from "select 1"; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; deallocate prepare stmt; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; # # E. Check that we can prepare a statement with the same name # successfully, without hitting the limit. # prepare stmt from "select 1"; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; prepare stmt from "select 2"; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; # # F. We can set the max below the current count. In this case no new # statements should be allowed to prepare. # -select @@prepared_stmt_count, @@max_prepared_stmt_count; +show status like 'prepared_stmt_count'; +select @@max_prepared_stmt_count; set global max_prepared_stmt_count=0; --error 1105 # ER_UNKNOWN_ERROR prepare stmt from "select 1"; # Result: the old statement is deallocated, the new is not created. --error 1243 # ER_UNKNOWN_STMT_HANDLER execute stmt; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; --error 1105 # ER_UNKNOWN_ERROR prepare stmt from "select 1"; -select @@prepared_stmt_count; +show status like 'prepared_stmt_count'; # # G. Show that the variables are up to date even after a connection with all # statements in it was terminated. # set global max_prepared_stmt_count=3; -select @@max_prepared_stmt_count, @@prepared_stmt_count; +select @@max_prepared_stmt_count; +show status like 'prepared_stmt_count'; prepare stmt from "select 1"; connect (con1,localhost,root,,); connection con1; @@ -908,18 +908,11 @@ prepare stmt2 from "select 4"; connection default; --error 1105 # ER_UNKNOWN_ERROR prepare stmt2 from "select 4"; -select @@max_prepared_stmt_count, @@prepared_stmt_count; +select @@max_prepared_stmt_count; +show status like 'prepared_stmt_count'; disconnect con1; connection default; -# Wait for the connection to die: deal with a possible race deallocate prepare stmt; -let $count= `select @@prepared_stmt_count`; -if ($count) -{ ---sleep 2 - let $count= `select @@prepared_stmt_count`; -} -select @@max_prepared_stmt_count, @@prepared_stmt_count; # # Restore the old value. # diff --git a/sql/mysqld.cc b/sql/mysqld.cc index dbb1838c3d7..3327224be46 100644 --- a/sql/mysqld.cc +++ b/sql/mysqld.cc @@ -5722,6 +5722,7 @@ struct show_var_st status_vars[]= { {"Open_streams", (char*) &my_stream_opened, SHOW_LONG_CONST}, {"Open_tables", (char*) 0, SHOW_OPENTABLES}, {"Opened_tables", (char*) &opened_tables, SHOW_LONG}, + {"Prepared_stmt_count", (char*) &prepared_stmt_count, SHOW_LONG_CONST}, #ifdef HAVE_QUERY_CACHE {"Qcache_free_blocks", (char*) &query_cache.free_memory_blocks, SHOW_LONG_CONST}, @@ -5892,6 +5893,7 @@ static void mysql_init_variables(void) binlog_cache_use= binlog_cache_disk_use= 0; max_used_connections= slow_launch_threads = 0; mysqld_user= mysqld_chroot= opt_init_file= opt_bin_logname = 0; + prepared_stmt_count= 0; errmesg= 0; mysqld_unix_port= opt_mysql_tmpdir= my_bind_addr_str= NullS; bzero((gptr) &mysql_tmpdir_list, sizeof(mysql_tmpdir_list)); diff --git a/sql/set_var.cc b/sql/set_var.cc index 4433b6bf7d8..71ca382f9d9 100644 --- a/sql/set_var.cc +++ b/sql/set_var.cc @@ -119,7 +119,6 @@ static KEY_CACHE *create_key_cache(const char *name, uint length); void fix_sql_mode_var(THD *thd, enum_var_type type); static byte *get_error_count(THD *thd); static byte *get_warning_count(THD *thd); -static byte *get_prepared_stmt_count(THD *thd); static byte *get_have_innodb(THD *thd); /* @@ -482,9 +481,6 @@ static sys_var_readonly sys_warning_count("warning_count", OPT_SESSION, SHOW_LONG, get_warning_count); -static sys_var_readonly sys_prepared_stmt_count("prepared_stmt_count", - OPT_GLOBAL, SHOW_LONG, - get_prepared_stmt_count); /* alias for last_insert_id() to be compatible with Sybase */ #ifdef HAVE_REPLICATION @@ -604,7 +600,6 @@ sys_var *sys_variables[]= &sys_new_mode, &sys_old_passwords, &sys_preload_buff_size, - &sys_prepared_stmt_count, &sys_pseudo_thread_id, &sys_query_alloc_block_size, &sys_query_cache_size, @@ -860,7 +855,6 @@ struct show_var_st init_vars[]= { {"pid_file", (char*) pidfile_name, SHOW_CHAR}, {"port", (char*) &mysqld_port, SHOW_INT}, {sys_preload_buff_size.name, (char*) &sys_preload_buff_size, SHOW_SYS}, - {sys_prepared_stmt_count.name, (char*) &sys_prepared_stmt_count, SHOW_SYS}, {"protocol_version", (char*) &protocol_version, SHOW_INT}, {sys_query_alloc_block_size.name, (char*) &sys_query_alloc_block_size, SHOW_SYS}, @@ -2715,14 +2709,6 @@ static byte *get_have_innodb(THD *thd) } -static byte *get_prepared_stmt_count(THD *thd) -{ - pthread_mutex_lock(&LOCK_prepared_stmt_count); - thd->sys_var_tmp.ulong_value= prepared_stmt_count; - pthread_mutex_unlock(&LOCK_prepared_stmt_count); - return (byte*) &thd->sys_var_tmp.ulong_value; -} - /**************************************************************************** Main handling of variables: - Initialisation From cb69318963b1fd8330f6a6c0430b15b03edddc63 Mon Sep 17 00:00:00 2001 From: "kroki/tomash@moonlight.intranet" <> Date: Tue, 21 Nov 2006 16:57:23 +0300 Subject: [PATCH 2/3] Fix after manual merge. --- mysql-test/r/ps.result | 12 ++++++------ mysql-test/t/ps.test | 20 ++++++++++---------- 2 files changed, 16 insertions(+), 16 deletions(-) diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result index b44c4c21780..eb07bb8e672 100644 --- a/mysql-test/r/ps.result +++ b/mysql-test/r/ps.result @@ -831,7 +831,7 @@ show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 0 prepare stmt from "select 1"; -ERROR HY000: Unknown error +ERROR 42000: Can't create more than max_prepared_stmt_count statements (current value: 0) show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 0 @@ -841,7 +841,7 @@ show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 1 prepare stmt1 from "select 1"; -ERROR HY000: Unknown error +ERROR 42000: Can't create more than max_prepared_stmt_count statements (current value: 1) show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 1 @@ -865,14 +865,14 @@ select @@max_prepared_stmt_count; 1 set global max_prepared_stmt_count=0; prepare stmt from "select 1"; -ERROR HY000: Unknown error +ERROR 42000: Can't create more than max_prepared_stmt_count statements (current value: 0) execute stmt; ERROR HY000: Unknown prepared statement handler (stmt) given to EXECUTE show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 0 prepare stmt from "select 1"; -ERROR HY000: Unknown error +ERROR 42000: Can't create more than max_prepared_stmt_count statements (current value: 0) show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 0 @@ -887,9 +887,9 @@ prepare stmt from "select 1"; prepare stmt from "select 2"; prepare stmt1 from "select 3"; prepare stmt2 from "select 4"; -ERROR HY000: Unknown error +ERROR 42000: Can't create more than max_prepared_stmt_count statements (current value: 3) prepare stmt2 from "select 4"; -ERROR HY000: Unknown error +ERROR 42000: Can't create more than max_prepared_stmt_count statements (current value: 3) select @@max_prepared_stmt_count; @@max_prepared_stmt_count 3 diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test index 459a77762bc..1c8d7b419a3 100644 --- a/mysql-test/t/ps.test +++ b/mysql-test/t/ps.test @@ -878,11 +878,11 @@ set global max_prepared_stmt_count=10000000000000000; select @@max_prepared_stmt_count; set global max_prepared_stmt_count=default; select @@max_prepared_stmt_count; ---error 1229 # ER_GLOBAL_VARIABLE +--error ER_GLOBAL_VARIABLE set @@max_prepared_stmt_count=1; ---error 1229 # ER_GLOBAL_VARIABLE +--error ER_GLOBAL_VARIABLE set max_prepared_stmt_count=1; ---error 1229 # ER_GLOBAL_VARIABLE +--error ER_GLOBAL_VARIABLE set local max_prepared_stmt_count=1; # set to a reasonable limit works set global max_prepared_stmt_count=1; @@ -893,13 +893,13 @@ select @@max_prepared_stmt_count; set global max_prepared_stmt_count=0; select @@max_prepared_stmt_count; show status like 'prepared_stmt_count'; ---error 1105 # ER_UNKNOWN_ERROR +--error ER_MAX_PREPARED_STMT_COUNT_REACHED prepare stmt from "select 1"; show status like 'prepared_stmt_count'; set global max_prepared_stmt_count=1; prepare stmt from "select 1"; show status like 'prepared_stmt_count'; ---error 1105 # ER_UNKNOWN_ERROR +--error ER_MAX_PREPARED_STMT_COUNT_REACHED prepare stmt1 from "select 1"; show status like 'prepared_stmt_count'; deallocate prepare stmt; @@ -919,13 +919,13 @@ show status like 'prepared_stmt_count'; show status like 'prepared_stmt_count'; select @@max_prepared_stmt_count; set global max_prepared_stmt_count=0; ---error 1105 # ER_UNKNOWN_ERROR +--error ER_MAX_PREPARED_STMT_COUNT_REACHED prepare stmt from "select 1"; # Result: the old statement is deallocated, the new is not created. ---error 1243 # ER_UNKNOWN_STMT_HANDLER +--error ER_UNKNOWN_STMT_HANDLER execute stmt; show status like 'prepared_stmt_count'; ---error 1105 # ER_UNKNOWN_ERROR +--error ER_MAX_PREPARED_STMT_COUNT_REACHED prepare stmt from "select 1"; show status like 'prepared_stmt_count'; # @@ -940,10 +940,10 @@ connect (con1,localhost,root,,); connection con1; prepare stmt from "select 2"; prepare stmt1 from "select 3"; ---error 1105 # ER_UNKNOWN_ERROR +--error ER_MAX_PREPARED_STMT_COUNT_REACHED prepare stmt2 from "select 4"; connection default; ---error 1105 # ER_UNKNOWN_ERROR +--error ER_MAX_PREPARED_STMT_COUNT_REACHED prepare stmt2 from "select 4"; select @@max_prepared_stmt_count; show status like 'prepared_stmt_count'; From f6235bc58caaab9fb76bfd82b5fe9f1f0a1b2606 Mon Sep 17 00:00:00 2001 From: "kroki/tomash@moonlight.intranet" <> Date: Tue, 21 Nov 2006 17:23:54 +0300 Subject: [PATCH 3/3] Update after merge. Use mutex when reading prepared_stmt_count global status variable. Update test case for bug 16365 and bug 23159: add test for prepared_stmt_count being decreased when some connection that had prepared statements is closed. --- mysql-test/r/ps.result | 6 ++++++ mysql-test/t/ps.test | 11 +++++++++++ sql/mysqld.cc | 12 +++++++++++- 3 files changed, 28 insertions(+), 1 deletion(-) diff --git a/mysql-test/r/ps.result b/mysql-test/r/ps.result index 0334a52c7ae..a6c16a9d15d 100644 --- a/mysql-test/r/ps.result +++ b/mysql-test/r/ps.result @@ -898,6 +898,12 @@ show status like 'prepared_stmt_count'; Variable_name Value Prepared_stmt_count 3 deallocate prepare stmt; +select @@max_prepared_stmt_count; +@@max_prepared_stmt_count +3 +show status like 'prepared_stmt_count'; +Variable_name Value +Prepared_stmt_count 0 set global max_prepared_stmt_count= @old_max_prepared_stmt_count; drop table if exists t1; create temporary table if not exists t1 (a1 int); diff --git a/mysql-test/t/ps.test b/mysql-test/t/ps.test index 0a739c05eda..a64764f623f 100644 --- a/mysql-test/t/ps.test +++ b/mysql-test/t/ps.test @@ -950,7 +950,18 @@ select @@max_prepared_stmt_count; show status like 'prepared_stmt_count'; disconnect con1; connection default; +# Wait for the connection to die: deal with a possible race deallocate prepare stmt; +let $query= select variable_value from information_schema.global_status + where variable_name = 'prepared_stmt_count'; +let $count= `$query`; +if ($count) +{ +--sleep 1 + let $count= `$query`; +} +select @@max_prepared_stmt_count; +show status like 'prepared_stmt_count'; # # Restore the old value. # diff --git a/sql/mysqld.cc b/sql/mysqld.cc index 21a37843e51..5d28d0663e7 100644 --- a/sql/mysqld.cc +++ b/sql/mysqld.cc @@ -6337,6 +6337,16 @@ static int show_open_tables(THD *thd, SHOW_VAR *var, char *buff) return 0; } +static int show_prepared_stmt_count(THD *thd, SHOW_VAR *var, char *buff) +{ + var->type= SHOW_LONG; + var->value= buff; + pthread_mutex_lock(&LOCK_prepared_stmt_count); + *((long *)buff)= (long)prepared_stmt_count; + pthread_mutex_unlock(&LOCK_prepared_stmt_count); + return 0; +} + static int show_table_definitions(THD *thd, SHOW_VAR *var, char *buff) { var->type= SHOW_LONG; @@ -6747,7 +6757,7 @@ SHOW_VAR status_vars[]= { {"Open_table_definitions", (char*) &show_table_definitions, SHOW_FUNC}, {"Open_tables", (char*) &show_open_tables, SHOW_FUNC}, {"Opened_tables", (char*) offsetof(STATUS_VAR, opened_tables), SHOW_LONG_STATUS}, - {"Prepared_stmt_count", (char*) &prepared_stmt_count, SHOW_LONG_CONST}, + {"Prepared_stmt_count", (char*) &show_prepared_stmt_count, SHOW_FUNC}, #ifdef HAVE_QUERY_CACHE {"Qcache_free_blocks", (char*) &query_cache.free_memory_blocks, SHOW_LONG_NOFLUSH}, {"Qcache_free_memory", (char*) &query_cache.free_memory, SHOW_LONG_NOFLUSH},