Tests of syncronization of stored procedure execution.
SET DEBUG_SYNC= 'RESET';
#
# Bug #30977 Concurrent statement using stored function and
#            DROP FUNCTION breaks SBR
#
# A stored routine could change after dispatch_command()
# but before a MDL lock is taken. This must be noticed and the
# sp cache flushed so the correct version can be loaded.
#
# Connection default
CREATE FUNCTION f1() RETURNS INT RETURN 1;
# Get f1 cached
SELECT f1();
f1()
1
# Then start executing it again...
SET DEBUG_SYNC= 'before_execute_sql_command SIGNAL before WAIT_FOR changed';
# Sending:
SELECT f1();
# Connection 2
SET DEBUG_SYNC= 'now WAIT_FOR before';
# ... but before f1 is locked, change it.
DROP FUNCTION f1;
CREATE FUNCTION f1() RETURNS INT RETURN 2;
SET DEBUG_SYNC= 'now SIGNAL changed';
# Connection default
# We should now get '2' and not '1'.
# Reaping: SELECT f1()
f1()
2
DROP FUNCTION f1;
SET DEBUG_SYNC= 'RESET';
#
# Field translation items must be cleared in case of back-offs
# for queries that use Information Schema tables. Otherwise 
# memory allocated in fix_fields() for views may end up referring
# to freed memory.
#
DROP FUNCTION IF EXISTS f1;
# Connection default
CREATE FUNCTION f1() RETURNS INT RETURN 0;
# Connection con2
SET DEBUG_SYNC= 'after_wait_locked_pname SIGNAL locked WAIT_FOR issued';
# con2 will now have an x-lock on f1
# Sending:
ALTER FUNCTION f1 COMMENT 'comment';
# Connection default
SET DEBUG_SYNC= 'now WAIT_FOR locked';
# This query will block due to the x-lock on f1 and back-off
SHOW OPEN TABLES WHERE f1()=0;
# Connection con3
# Check that the IS query is blocked before releasing the x-lock
SET DEBUG_SYNC= 'now SIGNAL issued';
# Connection default
# Reaping: ALTER FUNCTION f1 COMMENT 'comment'
DROP FUNCTION f1;
SET DEBUG_SYNC= 'RESET';
#
# Bug #48246 assert in close_thread_table
#
CREATE TABLE t1 (a INTEGER);
CREATE FUNCTION f1(b INTEGER) RETURNS INTEGER RETURN 1;
CREATE PROCEDURE p1() SELECT COUNT(f1(a)) FROM t1;
INSERT INTO t1 VALUES(1), (2);
# Connection 2
CALL p1();
COUNT(f1(a))
2
# Connection default
SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR called';
# Sending:
CREATE TABLE t1 (a INTEGER);
# Connection 2
SET DEBUG_SYNC= 'now WAIT_FOR locked';
SET DEBUG_SYNC= 'before_open_table_wait_refresh SIGNAL called WAIT_FOR created';
# This call used to cause an assertion. MDL locking conflict will
# cause back-off and retry. A variable indicating if a prelocking list
# exists, used to be not reset properly causing an eventual assert.
# Sending:
CALL p1();
# Connection default
# Reaping: CREATE TABLE t1 (a INTEGER)
ERROR 42S01: Table 't1' already exists
SET DEBUG_SYNC= 'now SIGNAL created';
# Connection 2
# Reaping: CALL p1()
COUNT(f1(a))
2
# Connection default
DROP PROCEDURE p1;
DROP FUNCTION f1;
DROP TABLE t1;
SET DEBUG_SYNC= 'RESET';