Committing on behalf or Dmitry Lenev:

Fix for bug #46947 "Embedded SELECT without FOR UPDATE is
causing a lock", with after-review fixes.

SELECT statements with subqueries referencing InnoDB tables
were acquiring shared locks on rows in these tables when they
were executed in REPEATABLE-READ mode and with statement or
mixed mode binary logging turned on.

This was a regression which were introduced when fixing
bug 39843.

The problem was that for tables belonging to subqueries
parser set TL_READ_DEFAULT as a lock type. In cases when
statement/mixed binary logging at open_tables() time this
type of lock was converted to TL_READ_NO_INSERT lock at
open_tables() time and caused InnoDB engine to acquire
shared locks on reads from these tables. Although in some
cases such behavior was correct (e.g. for subqueries in
DELETE) in case of SELECT it has caused unnecessary locking.

This patch tries to solve this problem by rethinking our
approach to how we handle locking for SELECT and subqueries.
Now we always set TL_READ_DEFAULT lock type for all cases
when we read data. When at open_tables() time this lock
is interpreted as TL_READ_NO_INSERT or TL_READ depending
on whether this statement as a whole or call to function
which uses particular table should be written to the
binary log or not (if yes then statement should be properly
serialized with concurrent statements and stronger lock
should be acquired).

Test coverage is added for both InnoDB and MyISAM.

This patch introduces an "incompatible" change in locking
scheme for subqueries used in SELECT ... FOR UPDATE and
SELECT .. IN SHARE MODE.
In 4.1 the server would use a snapshot InnoDB read for 
subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE
statements, regardless of whether the binary log is on or off.
If the user required a different type of read (i.e. locking read),
he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE
clause for each individual subquery.
On of the patches for 5.0 broke this behaviour (which was not documented
or tested), and started to use locking reads fora all subqueries in SELECT ... 
FOR UPDATE/IN SHARE MODE. This patch restored 4.1 behaviour.

mysql-test/include/check_concurrent_insert.inc:
  Added auxiliary script which allows to check if statement
  reading table allows concurrent inserts in it.
mysql-test/include/check_no_concurrent_insert.inc:
  Added auxiliary script which allows to check that statement
  reading table doesn't allow concurrent inserts in it.
mysql-test/include/check_no_row_lock.inc:
  Added auxiliary script which allows to check if statement
  reading table doesn't take locks on its rows.
mysql-test/include/check_shared_row_lock.inc:
  Added auxiliary script which allows to check if statement
  reading table takes shared locks on some of its rows.
mysql-test/r/bug39022.result:
  After bug #46947 'Embedded SELECT without FOR UPDATE is
  causing a lock' was fixed test case for bug 39022 has to
  be adjusted in order to trigger execution path on which
  original problem was encountered.
mysql-test/r/innodb_mysql_lock2.result:
  Added coverage for handling of locking in various cases when
  we read data from InnoDB tables (includes test case for
  bug #46947 'Embedded SELECT without FOR UPDATE is causing a
  lock').
mysql-test/r/lock_sync.result:
  Added coverage for handling of locking in various cases when
  we read data from MyISAM tables.
mysql-test/t/bug39022.test:
  After bug #46947 'Embedded SELECT without FOR UPDATE is
  causing a lock' was fixed test case for bug 39022 has to
  be adjusted in order to trigger execution path on which
  original problem was encountered.
mysql-test/t/innodb_mysql_lock2.test:
  Added coverage for handling of locking in various cases when
  we read data from InnoDB tables (includes test case for
  bug #46947 'Embedded SELECT without FOR UPDATE is causing a
  lock').
mysql-test/t/lock_sync.test:
  Added coverage for handling of locking in various cases when
  we read data from MyISAM tables.
sql/log_event.cc:
  Since LEX::lock_option member was removed we no longer can
  rely on its value in Load_log_event::print_query() to
  determine that log event correponds to LOAD DATA CONCURRENT
  statement (this was not correct in all situations anyway).
  A new Load_log_event's member was introduced as a replacement.
  It is initialized at event object construction time and
  explicitly indicates whether LOAD DATA was concurrent.
sql/log_event.h:
  Since LEX::lock_option member was removed we no longer can
  rely on its value in Load_log_event::print_query() to
  determine that log event correponds to LOAD DATA CONCURRENT
  statement (this was not correct in all situations anyway).
  A new Load_log_event's member was introduced as a replacement.
  It is initialized at event object construction time and
  explicitly indicates whether LOAD DATA was concurrent.
sql/sp_head.cc:
  sp_head::reset_lex():
    Before parsing substatement reset part of parser state
    which needs this (e.g. set Yacc_state::m_lock_type to
    default value).
sql/sql_acl.cc:
  Since LEX::reset_n_backup_query_tables_list() now also
  resets LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore it in cases
  when while working with proxy Query_table_list we assume
  that LEX::sql_command still corresponds to original SQL
  command being executed (for example, when we are logging
  statement to the binary log while having Query_tables_list
  reset and backed up).
sql/sql_base.cc:
  Changed read_lock_type_for_table() to return a weak TL_READ
  type of lock in cases when we are executing statement which
  won't update tables directly and table doesn't belong to
  statement's prelocking list and thus can't be used by a
  stored function. It is OK to do so since in this case table
  won't be used by statement or function call which will be
  written to the binary log, so serializability requirements
  for it can be relaxed.
  One of results from this change is that SELECTs on InnoDB
  tables no longer takes shared row locks for tables which
  are used in subqueries (i.e. bug #46947 is fixed).
  Another result is that for similar SELECTs on MyISAM tables
  concurrent inserts are allowed.
  In order to implement this change signature of
  read_lock_type_for_table() function was changed to take
  pointers to Query_tables_list and TABLE_LIST objects.
sql/sql_base.h:
  - Function read_lock_type_for_table() now takes pointers
    to Query_tables_list and TABLE_LIST elements as its
    arguments since to correctly determine lock type it needs
    to know what statement is being performed and whether table
    element for which lock type to be determined belongs to
    prelocking list.
sql/sql_lex.cc:
  - Removed LEX::lock_option and st_select_lex::lock_option
    members. Places in parser that were using them now use
    Yacc_state::m_lock_type instead.
  - To emphasize that LEX::sql_command member is used during
    process of opening and locking of tables it was moved to
    Query_tables_list class. It is now reset by
    Query_tables_list::reset_query_tables_list() method.
sql/sql_lex.h:
  - Removed st_select_lex::lock_option member as there is no
    real need for per-SELECT lock type (HIGH_PRIORITY option
    should apply to the whole statement. FOR UPDATE/LOCK IN
    SHARE MODE clauses can be handled without this member).
    The main effect which was achieved by introduction of this
    member, i.e. using TL_READ_DEFAULT lock type for
    subqueries, is now achieved by setting LEX::lock_option
    (or rather its replacement - Yacc_state::m_lock_type) to
    TL_READ_DEFAULT in almost all cases.
  - To emphasize that LEX::sql_command member is used during
    process of opening and locking of tables it was moved to
    Query_tables_list class.
  - Replaced LEX::lock_option with Yacc_state::m_lock_type
    in order to emphasize that this value is relevant only
    during parsing. Unlike for LEX::lock_option the default
    value for Yacc_state::m_lock_type is TL_READ_DEFAULT.
    Note that for cases when it is OK to take a "weak" read
    lock (e.g. simple SELECT) this lock type will be converted
    to TL_READ at open_tables() time. So this change won't
    cause negative change in behavior for such statements.
    OTOH this change ensures that, for example, for SELECTs
    which are used in stored functions TL_READ_NO_INSERT lock
    is taken when necessary and as result calls to such stored
    functions can be written to the binary log with correct
    serialization.
sql/sql_load.cc:
  Load_log_event constructor now requires a parameter that
  indicates whether LOAD DATA is concurrent.
sql/sql_parse.cc:
  LEX::lock_option was replaced with Yacc_state::m_lock_type.
  And instead of resetting the latter implicitly in
  mysql_init_multi_delete() we do it explicitly in the
  places in parser which call this function.
sql/sql_priv.h:
  - To be able more easily distinguish high-priority SELECTs
    in st_select_lex::print() method added flag for
    HIGH_PRIORITY option.
sql/sql_select.cc:
  Changed code not to rely on LEX::lock_option to determine
  that it is high-priority SELECT. It was replaced with
  Yacc_state::m_lock_type which is accessible only at
  parse time. So instead of LEX::lock_option we now rely
  on a newly introduced flag for st_select_lex::options -
  SELECT_HIGH_PRIORITY.
sql/sql_show.cc:
  Since LEX::reset_n_backup_query_tables_list() now also
  resets LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore it in cases
  when while working with proxy Query_table_list we assume
  that LEX::sql_command still corresponds to original SQL
  command being executed.
sql/sql_table.cc:
  Since LEX::reset_query_tables_list() now also resets
  LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore value of this
  member when this method is called by mysql_admin_table(),
  to make this code safe for re-execution.
sql/sql_trigger.cc:
  Since LEX::reset_n_backup_query_tables_list() now also
  resets LEX::sql_command member (as it became part of
  Query_tables_list class) we have to restore it in cases
  when while working with proxy Query_table_list we assume
  that LEX::sql_command still corresponds to original SQL
  command being executed (for example, when we are logging
  statement to the binary log while having Query_tables_list
  reset and backed up).
sql/sql_update.cc:
  Function read_lock_type_for_table() now takes pointers
  to Query_tables_list and TABLE_LIST elements as its
  arguments since to correctly determine lock type it needs
  to know what statement is being performed and whether table
  element for which lock type to be determined belongs to
  prelocking list.
sql/sql_yacc.yy:
  - Removed st_select_lex::lock_option member as there is no
    real need for per-SELECT lock type (HIGH_PRIORITY option
    should apply to the whole statement. FOR UPDATE/LOCK IN
    SHARE MODE clauses can be handled without this member).
    The main effect which was achieved by introduction of this
    member, i.e. using TL_READ_DEFAULT lock type for
    subqueries, is now achieved by setting LEX::lock_option
    (or rather its replacement - Yacc_state::m_lock_type) to
    TL_READ_DEFAULT in almost all cases.
  - Replaced LEX::lock_option with Yacc_state::m_lock_type
    in order to emphasize that this value is relevant only
    during parsing. Unlike for LEX::lock_option the default
    value for Yacc_state::m_lock_type is TL_READ_DEFAULT.
    Note that for cases when it is OK to take a "weak" read
    lock (e.g. simple SELECT) this lock type will be converted
    to TL_READ at open_tables() time. So this change won't
    cause negative change in behavior for such statements.
    OTOH this change ensures that, for example, for SELECTs
    which are used in stored functions TL_READ_NO_INSERT lock
    is taken when necessary and as result calls to such stored
    functions can be written to the binary log with correct
    serialization.
  - To be able more easily distinguish high-priority SELECTs
    in st_select_lex::print() method we now use new flag
    in st_select_lex::options bit-field.

1 files changed, 592 insertions, 0 deletions

diff --git a/mysql-test/r/lock_sync.result b/mysql-test/r/lock_sync.result
index 18f3f6bc1a7..299b5546716 100644
--- a/mysql-test/r/lock_sync.result
+++ b/mysql-test/r/lock_sync.result
@@ -1,4 +1,596 @@
 #
+# Test how we handle locking in various cases when
+# we read data from MyISAM tables.
+#
+# In this test we mostly check that the SQL-layer correctly
+# determines the type of thr_lock.c lock for a table being
+# read.
+# I.e. that it disallows concurrent inserts when the statement
+# is going to be written to the binary log and therefore
+# should be serialized, and allows concurrent inserts when
+# such serialization is not necessary (e.g. when 
+# the statement is not written to binary log).
+#
+# Force concurrent inserts to be performed even if the table
+# has gaps. This allows to simplify clean up in scripts
+# used below (instead of backing up table being inserted
+# into and then restoring it from backup at the end of the
+# script we can simply delete rows which were inserted).
+set @old_concurrent_insert= @@global.concurrent_insert;
+set @@global.concurrent_insert= 2;
+select @@global.concurrent_insert;
+@@global.concurrent_insert
+ALWAYS
+# Prepare playground by creating tables, views,
+# routines and triggers used in tests.
+drop table if exists t0, t1, t2, t3, t4, t5;
+drop view if exists v1, v2;
+drop procedure if exists p1;
+drop procedure if exists p2;
+drop function if exists f1;
+drop function if exists f2;
+drop function if exists f3;
+drop function if exists f4;
+drop function if exists f5;
+drop function if exists f6;
+drop function if exists f7;
+drop function if exists f8;
+drop function if exists f9;
+drop function if exists f10;
+drop function if exists f11;
+drop function if exists f12;
+drop function if exists f13;
+drop function if exists f14;
+drop function if exists f15;
+create table t1 (i int primary key);
+insert into t1 values (1), (2), (3), (4), (5);
+create table t2 (j int primary key);
+insert into t2 values (1), (2), (3), (4), (5);
+create table t3 (k int primary key);
+insert into t3 values (1), (2), (3);
+create table t4 (l int primary key);
+insert into t4 values (1);
+create table t5 (l int primary key);
+insert into t5 values (1);
+create view v1 as select i from t1;
+create view v2 as select j from t2 where j in (select i from t1);
+create procedure p1(k int) insert into t2 values (k);
+create function f1() returns int
+begin
+declare j int;
+select i from t1 where i = 1 into j;
+return j;
+end|
+create function f2() returns int
+begin
+declare k int;
+select i from t1 where i = 1 into k;
+insert into t2 values (k + 5);
+return 0;
+end|
+create function f3() returns int
+begin
+return (select i from t1 where i = 3);
+end|
+create function f4() returns int
+begin
+if (select i from t1 where i = 3) then
+return 1;
+else
+return 0;
+end if;
+end|
+create function f5() returns int
+begin
+insert into t2 values ((select i from t1 where i = 1) + 5);
+return 0;
+end|
+create function f6() returns int
+begin
+declare k int;
+select i from v1 where i = 1 into k;
+return k;
+end|
+create function f7() returns int
+begin
+declare k int;
+select j from v2 where j = 1 into k;
+return k;
+end|
+create function f8() returns int
+begin
+declare k int;
+select i from v1 where i = 1 into k;
+insert into t2 values (k+5);
+return k;
+end|
+create function f9() returns int
+begin
+update v2 set j=j+10 where j=1;
+return 1;
+end|
+create function f10() returns int
+begin
+return f1();
+end|
+create function f11() returns int
+begin
+declare k int;
+set k= f1();
+insert into t2 values (k+5);
+return k;
+end|
+create function f12(p int) returns int
+begin
+insert into t2 values (p);
+return p;
+end|
+create function f13(p int) returns int
+begin
+return p;
+end|
+create procedure p2(inout p int)
+begin
+select i from t1 where i = 1 into p;
+end|
+create function f14() returns int
+begin
+declare k int;
+call p2(k);
+insert into t2 values (k+5);
+return k;
+end|
+create function f15() returns int
+begin
+declare k int;
+call p2(k);
+return k;
+end|
+create trigger t4_bi before insert on t4 for each row
+begin
+declare k int;
+select i from t1 where i=1 into k;
+set new.l= k+1;
+end|
+create trigger t4_bu before update on t4 for each row
+begin
+if (select i from t1 where i=1) then
+set new.l= 2;
+end if;
+end|
+create trigger t4_bd before delete on t4 for each row
+begin
+if !(select i from v1 where i=1) then
+signal sqlstate '45000';
+end if;
+end|
+create trigger t5_bi before insert on t5 for each row
+begin
+set new.l= f1()+1;
+end|
+create trigger t5_bu before update on t5 for each row
+begin
+declare j int;
+call p2(j);
+set new.l= j + 1;
+end|
+#
+# Set common variables to be used by the scripts
+# called below.
+#
+# Switch to connection 'con1'.
+# Cache all functions used in the tests below so statements
+# calling them won't need to open and lock mysql.proc table
+# and we can assume that each statement locks its tables
+# once during its execution.
+show create procedure p1;
+show create procedure p2;
+show create function f1;
+show create function f2;
+show create function f3;
+show create function f4;
+show create function f5;
+show create function f6;
+show create function f7;
+show create function f8;
+show create function f9;
+show create function f10;
+show create function f11;
+show create function f12;
+show create function f13;
+show create function f14;
+show create function f15;
+# Switch back to connection 'default'.
+#
+# 1. Statements that read tables and do not use subqueries.
+#
+#
+# 1.1 Simple SELECT statement.
+#
+# No locks are necessary as this statement won't be written
+# to the binary log and thanks to how MyISAM works SELECT
+# will see version of the table prior to concurrent insert.
+Success: 'select * from t1' allows concurrent inserts into 't1'.
+#
+# 1.2 Multi-UPDATE statement.
+#
+# Has to take shared locks on rows in the table being read as this
+# statement will be written to the binary log and therefore should
+# be serialized with concurrent statements.
+Success: 'update t2, t1 set j= j - 1 where i = j' doesn't allow concurrent inserts into 't1'.
+#
+# 1.3 Multi-DELETE statement.
+#
+# The above is true for this statement as well.
+Success: 'delete t2 from t1, t2 where i = j' doesn't allow concurrent inserts into 't1'.
+#
+# 1.4 DESCRIBE statement.
+#
+# This statement does not really read data from the
+# target table and thus does not take any lock on it.
+# We check this for completeness of coverage.
+lock table t1 write;
+# Switching to connection 'con1'.
+# This statement should not be blocked.
+describe t1;
+# Switching to connection 'default'.
+unlock tables;
+#
+# 1.5 SHOW statements.
+# 
+# The above is true for SHOW statements as well.
+lock table t1 write;
+# Switching to connection 'con1'.
+# These statements should not be blocked.
+show keys from t1;
+# Switching to connection 'default'.
+unlock tables;
+#
+# 2. Statements which read tables through subqueries.
+#
+#
+# 2.1 CALL with a subquery.
+# 
+# A strong lock is not necessary as this statement is not
+# written to the binary log as a whole (it is written
+# statement-by-statement).
+Success: 'call p1((select i + 5 from t1 where i = 1))' allows concurrent inserts into 't1'.
+#
+# 2.2 CREATE TABLE with a subquery.
+#
+# Has to take a strong lock on the table being read as
+# this statement is written to the binary log and therefore
+# should be serialized with concurrent statements.
+Success: 'create table t0 select * from t1' doesn't allow concurrent inserts into 't1'.
+drop table t0;
+Success: 'create table t0 select j from t2 where j in (select i from t1)' doesn't allow concurrent inserts into 't1'.
+drop table t0;
+#
+# 2.3 DELETE with a subquery.
+#
+# The above is true for this statement as well.
+Success: 'delete from t2 where j in (select i from t1)' doesn't allow concurrent inserts into 't1'.
+#
+# 2.4 MULTI-DELETE with a subquery.
+#
+# Same is true for this statement as well.
+Success: 'delete t2 from t3, t2 where k = j and j in (select i from t1)' doesn't allow concurrent inserts into 't1'.
+#
+# 2.5 DO with a subquery.
+#
+# A strong lock is not necessary as it is not logged.
+Success: 'do (select i from t1 where i = 1)' allows concurrent inserts into 't1'.
+#
+# 2.6 INSERT with a subquery.
+#
+# Has to take a strong lock on the table being read as
+# this statement is written to the binary log and therefore
+# should be serialized with concurrent inserts.
+Success: 'insert into t2 select i+5 from t1' doesn't allow concurrent inserts into 't1'.
+Success: 'insert into t2 values ((select i+5 from t1 where i = 4))' doesn't allow concurrent inserts into 't1'.
+#
+# 2.7 LOAD DATA with a subquery.
+# 
+# The above is true for this statement as well.
+Success: 'load data infile '../../std_data/rpl_loaddata.dat' into table t2 (@a, @b) set j= @b + (select i from t1 where i = 1)' doesn't allow concurrent inserts into 't1'.
+#
+# 2.8 REPLACE with a subquery.
+# 
+# Same is true for this statement as well.
+Success: 'replace into t2 select i+5 from t1' doesn't allow concurrent inserts into 't1'.
+Success: 'replace into t2 values ((select i+5 from t1 where i = 4))' doesn't allow concurrent inserts into 't1'.
+#
+# 2.9 SELECT with a subquery.
+#
+# Strong locks are not necessary as this statement is not written
+# to the binary log and thanks to how MyISAM works this statement
+# sees a version of the table prior to the concurrent insert.
+Success: 'select * from t2 where j in (select i from t1)' allows concurrent inserts into 't1'.
+#
+# 2.10 SET with a subquery.
+#
+# The same is true for this statement as well.
+Success: 'set @a:= (select i from t1 where i = 1)' allows concurrent inserts into 't1'.
+#
+# 2.11 SHOW with a subquery.
+# 
+# And for this statement too.
+Success: 'show tables from test where Tables_in_test = 't2' and (select i from t1 where i = 1)' allows concurrent inserts into 't1'.
+Success: 'show columns from t2 where (select i from t1 where i = 1)' allows concurrent inserts into 't1'.
+#
+# 2.12 UPDATE with a subquery.
+#
+# Has to take a strong lock on the table being read as
+# this statement is written to the binary log and therefore
+# should be serialized with concurrent inserts.
+Success: 'update t2 set j= j-10 where j in (select i from t1)' doesn't allow concurrent inserts into 't1'.
+#
+# 2.13 MULTI-UPDATE with a subquery.
+#
+# Same is true for this statement as well.
+Success: 'update t2, t3 set j= j -10 where j=k and j in (select i from t1)' doesn't allow concurrent inserts into 't1'.
+#
+# 3. Statements which read tables through a view.
+#
+#
+# 3.1 SELECT statement which uses some table through a view.
+#
+# Since this statement is not written to the binary log and
+# an old version of the table is accessible thanks to how MyISAM
+# handles concurrent insert, no locking is necessary.
+Success: 'select * from v1' allows concurrent inserts into 't1'.
+Success: 'select * from v2' allows concurrent inserts into 't1'.
+Success: 'select * from t2 where j in (select i from v1)' allows concurrent inserts into 't1'.
+Success: 'select * from t3 where k in (select j from v2)' allows concurrent inserts into 't1'.
+#
+# 3.2 Statements which modify a table and use views.
+#
+# Since such statements are going to be written to the binary
+# log they need to be serialized against concurrent statements
+# and therefore should take strong locks on the data read.
+Success: 'update t2 set j= j-10 where j in (select i from v1)' doesn't allow concurrent inserts into 't1'.
+Success: 'update t3 set k= k-10 where k in (select j from v2)' doesn't allow concurrent inserts into 't1'.
+Success: 'update t2, v1 set j= j-10 where j = i' doesn't allow concurrent inserts into 't1'.
+Success: 'update v2 set j= j-10 where j = 3' doesn't allow concurrent inserts into 't1'.
+#
+# 4. Statements which read tables through stored functions.
+#
+#
+# 4.1 SELECT/SET with a stored function which does not 
+#     modify data and uses SELECT in its turn.
+#
+# In theory there is no need to take strong locks on the table
+# being selected from in SF as the call to such function
+# won't get into the binary log. In practice, however, we
+# discover that fact too late in the process to be able to
+# affect the decision what locks should be taken.
+# Hence, strong locks are taken in this case.
+Success: 'select f1()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f1()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.2 INSERT (or other statement which modifies data) with
+#     a stored function which does not modify data and uses
+#     SELECT.
+#
+# Since such statement is written to the binary log it should
+# be serialized with concurrent statements affecting the data
+# it uses. Therefore it should take strong lock on the data
+# it reads.
+Success: 'insert into t2 values (f1() + 5)' doesn't allow concurrent inserts into 't1'.
+#
+# 4.3 SELECT/SET with a stored function which
+#     reads and modifies data.
+#
+# Since a call to such function is written to the binary log,
+# it should be serialized with concurrent statements affecting
+# the data it uses. Hence, a strong lock on the data read
+# should be taken.
+Success: 'select f2()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f2()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.4. SELECT/SET with a stored function which does not
+#      modify data and reads a table through subselect
+#      in a control construct.
+#
+# Again, in theory a call to this function won't get to the
+# binary log and thus no strong lock is needed. But in practice
+# we don't detect this fact early enough (get_lock_type_for_table())
+# to avoid taking a strong lock.
+Success: 'select f3()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f3()' doesn't allow concurrent inserts into 't1'.
+Success: 'select f4()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f4()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.5. INSERT (or other statement which modifies data) with
+#      a stored function which does not modify data and reads
+#      the table through a subselect in one of its control
+#      constructs.
+#
+# Since such statement is written to the binary log it should
+# be serialized with concurrent statements affecting data it
+# uses. Therefore it should take a strong lock on the data
+# it reads.
+Success: 'insert into t2 values (f3() + 5)' doesn't allow concurrent inserts into 't1'.
+Success: 'insert into t2 values (f4() + 6)' doesn't allow concurrent inserts into 't1'.
+#
+# 4.6 SELECT/SET which uses a stored function with
+#      DML which reads a table via a subquery.
+#
+# Since call to such function is written to the binary log
+# it should be serialized with concurrent statements.
+# Hence reads should take a strong lock.
+Success: 'select f5()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f5()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.7 SELECT/SET which uses a stored function which
+#     doesn't modify data and reads tables through
+#     a view.
+#
+# Once again, in theory, calls to such functions won't
+# get into the binary log and thus don't need strong
+# locks. But in practice this fact is discovered
+# too late to have any effect.
+Success: 'select f6()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f6()' doesn't allow concurrent inserts into 't1'.
+Success: 'select f7()' doesn't allow concurrent inserts into 't1'.
+Success: 'set @a:= f7()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.8 INSERT which uses stored function which
+#     doesn't modify data and reads a table
+#     through a view.
+#
+# Since such statement is written to the binary log and 
+# should be serialized with concurrent statements affecting
+# the data it uses. Therefore it should take a strong lock on
+# the table it reads.
+Success: 'insert into t3 values (f6() + 5)' doesn't allow concurrent inserts into 't1'.
+Success: 'insert into t3 values (f7() + 5)' doesn't allow concurrent inserts into 't1'.
+#
+# 4.9 SELECT which uses a stored function which 
+#     modifies data and reads tables through a view.
+#
+# Since a call to such function is written to the binary log
+# it should be serialized with concurrent statements.
+# Hence, reads should take strong locks.
+Success: 'select f8()' doesn't allow concurrent inserts into 't1'.
+Success: 'select f9()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.10 SELECT which uses a stored function which doesn't modify
+#      data and reads a table indirectly, by calling another
+#      function. 
+#
+# In theory, calls to such functions won't get into the binary
+# log and thus don't need to acquire strong locks. But in practice
+# this fact is discovered too late to have any effect.
+Success: 'select f10()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.11 INSERT which uses a stored function which doesn't modify
+#      data and reads a table indirectly, by calling another
+#      function. 
+#
+# Since such statement is written to the binary log, it should
+# be serialized with concurrent statements affecting the data it
+# uses. Therefore it should take strong locks on data it reads.
+Success: 'insert into t2 values (f10() + 5)' doesn't allow concurrent inserts into 't1'.
+#
+# 4.12 SELECT which uses a stored function which modifies
+#      data and reads a table indirectly, by calling another
+#      function. 
+#
+# Since a call to such function is written to the binary log
+# it should be serialized from concurrent statements.
+# Hence, read should take a strong lock.
+Success: 'select f11()' doesn't allow concurrent inserts into 't1'.
+#
+# 4.13 SELECT that reads a table through a subquery passed
+#      as a parameter to a stored function which modifies
+#      data.
+#
+# Even though a call to this function is written to the
+# binary log, values of its parameters are written as literals.
+# So there is no need to acquire strong locks for tables used in
+# the subquery.
+Success: 'select f12((select i+10 from t1 where i=1))' allows concurrent inserts into 't1'.
+#
+# 4.14 INSERT that reads a table via a subquery passed
+#      as a parameter to a stored function which doesn't
+#      modify data.
+#
+# Since this statement is written to the binary log it should
+# be serialized with concurrent statements affecting the data it
+# uses. Therefore it should take strong locks on the data it reads.
+Success: 'insert into t2 values (f13((select i+10 from t1 where i=1)))' doesn't allow concurrent inserts into 't1'.
+#
+# 5. Statements that read tables through stored procedures.
+#
+#
+# 5.1 CALL statement which reads a table via SELECT.
+#
+# Since neither this statement nor its components are
+# written to the binary log, there is no need to take
+# strong locks on the data read it reads.
+Success: 'call p2(@a)' allows concurrent inserts into 't1'.
+#
+# 5.2 Function that modifes data and uses CALL, 
+#     which reads a table through SELECT.
+#
+# Since a call to such function is written to the binary
+# log, it should be serialized with concurrent statements.
+# Hence, in this case reads should take strong locks on data.
+Success: 'select f14()' doesn't allow concurrent inserts into 't1'.
+#
+# 5.3 SELECT that calls a function that doesn't modify data and
+#     uses a CALL statement that reads a table via SELECT.
+#
+# In theory, calls to such functions won't get into the binary
+# log and thus don't need to acquire strong locks. But in practice
+# this fact is discovered too late to have any effect.
+Success: 'select f15()' doesn't allow concurrent inserts into 't1'.
+#
+# 5.4 INSERT which calls function which doesn't modify data and
+#     uses CALL statement which reads table through SELECT.
+#
+# Since such statement is written to the binary log it should
+# be serialized with concurrent statements affecting data it
+# uses. Therefore it should take strong locks on data it reads.
+Success: 'insert into t2 values (f15()+5)' doesn't allow concurrent inserts into 't1'.
+#
+# 6. Statements that use triggers.
+#
+#
+# 6.1 Statement invoking a trigger that reads table via SELECT.
+#
+# Since this statement is written to the binary log it should
+# be serialized with concurrent statements affecting the data
+# it uses. Therefore, it should take strong locks on the data
+#  it reads.
+Success: 'insert into t4 values (2)' doesn't allow concurrent inserts into 't1'.
+#
+# 6.2 Statement invoking a trigger that reads table through
+#     a subquery in a control construct.
+#
+# The above is true for this statement as well.
+Success: 'update t4 set l= 2 where l = 1' doesn't allow concurrent inserts into 't1'.
+#
+# 6.3 Statement invoking a trigger that reads a table through
+#     a view.
+#
+# And for this statement.
+Success: 'delete from t4 where l = 1' doesn't allow concurrent inserts into 't1'.
+#
+# 6.4 Statement invoking a trigger that reads a table through
+#     a stored function.
+#
+# And for this statement.
+Success: 'insert into t5 values (2)' doesn't allow concurrent inserts into 't1'.
+#
+# 6.5 Statement invoking a trigger that reads a table through
+#     stored procedure.
+#
+# And for this statement.
+Success: 'update t5 set l= 2 where l = 1' doesn't allow concurrent inserts into 't1'.
+# Clean-up.
+drop function f1;
+drop function f2;
+drop function f3;
+drop function f4;
+drop function f5;
+drop function f6;
+drop function f7;
+drop function f8;
+drop function f9;
+drop function f10;
+drop function f11;
+drop function f12;
+drop function f13;
+drop function f14;
+drop function f15;
+drop view v1, v2;
+drop procedure p1;
+drop procedure p2;
+drop table t1, t2, t3, t4, t5;
+set @@global.concurrent_insert= @old_concurrent_insert;
+#
 # Test for bug #45143 "All connections hang on concurrent ALTER TABLE".
 #
 # Concurrent execution of statements which required weak write lock