mariadb/mysql-test/t/query_cache_debug.test

--source include/not_embedded.inc
--source include/have_query_cache.inc
--source include/have_debug.inc

#
# Bug #30887 Server crashes on SET GLOBAL query_cache_size=0
#
flush status;
set query_cache_type=DEMAND;
set global query_cache_size= 1024*768;
--disable_warnings
drop table if exists t1;
--enable_warnings
create table t1 (a varchar(100));
insert into t1 values ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
connect (bug30887con1, localhost, root, ,test);
connect (bug30887con2, localhost, root, ,test);

connection bug30887con1;
--echo Activate debug hook and attempt to retrieve the statement from the cache.
set session debug='+d,wait_in_query_cache_insert';
--send select SQL_CACHE * from t1;

connection default;
let $wait_condition= select count(*)= 1 from information_schema.processlist where state= 'wait_in_query_cache_insert';
--source include/wait_condition.inc

connection bug30887con2;
--echo On a second connection; clear the query cache.
show status like 'Qcache_queries_in_cache';
set global query_cache_size= 0;

connection default;
--echo Signal the debug hook to release the lock.
select id from information_schema.processlist where state='wait_in_query_cache_insert' into @thread_id;
kill query @thread_id;

--echo Show query cache status.
show status like 'Qcache_queries_in_cache';

disconnect bug30887con1;
disconnect bug30887con2;
set global query_cache_size= 0;
use test;
drop table t1;

#
# Bug#41098: Query Cache returns wrong result with concurrent insert
#

SET @old_concurrent_insert= @@GLOBAL.concurrent_insert;
SET @old_query_cache_size= @@GLOBAL.query_cache_size;

--disable_warnings
DROP TABLE IF EXISTS t1, t2;
--enable_warnings
CREATE TABLE t1 (a INT);
CREATE TABLE t2 (a INT);
INSERT INTO t1 VALUES (1),(2),(3);

SET GLOBAL concurrent_insert= 1;
SET GLOBAL query_cache_size= 1024*512;
SET GLOBAL query_cache_type= ON;

connect(con1,localhost,root,,test,,);
connect(con2,localhost,root,,test,,);

connection con1;
--echo # Switch to connection con1
SET SESSION debug='+d,wait_after_query_cache_invalidate';
--echo # Send concurrent insert, will wait in the query cache table invalidate
--send INSERT INTO t1 VALUES (4)

connection default;
--echo # Switch to connection default
--echo # Wait for concurrent insert to reach the debug point
let $wait_condition=
  SELECT COUNT(*) = 1 FROM INFORMATION_SCHEMA.PROCESSLIST
  WHERE STATE = "wait_after_query_cache_invalidate" AND
        INFO = "INSERT INTO t1 VALUES (4)";
--source include/wait_condition.inc

connection con2;
--echo # Switch to connection con2
--echo # Send SELECT that shouldn't be cached
SELECT * FROM t1;

connection default;
--echo # Switch to connection default
--echo # Notify the concurrent insert to proceed
SELECT ID FROM INFORMATION_SCHEMA.PROCESSLIST
  WHERE STATE = 'wait_after_query_cache_invalidate' INTO @thread_id;
KILL QUERY @thread_id;

connection con1;
--echo # Switch to connection con1
--echo # Gather insert result
--reap
SHOW STATUS LIKE "Qcache_queries_in_cache";
--echo # Test that it's cacheable
SELECT * FROM t1;
SHOW STATUS LIKE "Qcache_queries_in_cache";

--echo # Disconnect
disconnect con1;
disconnect con2;

connection default;
--echo # Restore defaults
RESET QUERY CACHE;
DROP TABLE t1,t2;
SET GLOBAL concurrent_insert= DEFAULT;
SET GLOBAL query_cache_size= DEFAULT;
SET GLOBAL query_cache_type= DEFAULT;


--echo #
--echo # Bug43758 Query cache can lock up threads in 'freeing items' state
--echo #
FLUSH STATUS;
SET GLOBAL query_cache_type=DEMAND;
SET GLOBAL query_cache_size= 1024*768;
--disable_warnings
DROP TABLE IF EXISTS t1,t2,t3,t4,t5;
--enable_warnings
CREATE TABLE t1 (a VARCHAR(100));
CREATE TABLE t2 (a VARCHAR(100));
CREATE TABLE t3 (a VARCHAR(100));
CREATE TABLE t4 (a VARCHAR(100));
CREATE TABLE t5 (a VARCHAR(100));

INSERT INTO t1 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
INSERT INTO t2 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
INSERT INTO t3 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
INSERT INTO t4 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
INSERT INTO t5 VALUES ('aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'),('bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');

connect (thd2, localhost, root, ,test);
connect (thd3, localhost, root, ,test);
connect (thd1, localhost, root, ,test);

connection thd1;
--echo =================================== Connection thd1
--echo **
--echo ** Load Query Cache with a result set and one table.
--echo **
SELECT SQL_CACHE * FROM t1;
--echo *************************************************************************
--echo ** We want to accomplish the following state:
--echo **  - Query cache status: TABLE_FLUSH_IN_PROGRESS
--echo **  - THD1: invalidate_table_internal (iterating query blocks)
--echo **  - THD2: query_cache_insert (cond_wait)
--echo **  - THD3: query_cache_insert (cond_wait)
--echo **  - No thread should be holding the structure_guard_mutex.
--echo **
--echo ** First step is to place a DELETE-statement on the debug hook just
--echo ** before the mutex lock in invalidate_table_internal.
--echo ** This will allow new result sets to be written into the QC.
--echo ** 
SET SESSION debug='+d,wait_in_query_cache_invalidate1';
SET SESSION debug='+d,wait_in_query_cache_invalidate2';
--send DELETE FROM t1 WHERE a like '%a%';

connection default;
--echo =================================== Connection default
--echo ** Assert that the expect process status is obtained.
LET $wait_condition= SELECT SQL_NO_CACHE COUNT(*)= 1 FROM information_schema.processlist WHERE state= 'wait_in_query_cache_invalidate1';
--source include/wait_condition.inc
-- echo **

connection thd2;
--echo =================================== Connection thd2
--echo ** On THD2: Insert a result into the cache. This attempt will be blocked
--echo ** because of a debug hook placed just before the mutex lock after which
--echo ** the first part of the result set is written.
SET SESSION debug='+d,wait_in_query_cache_insert';
--send SELECT SQL_CACHE * FROM t2 UNION SELECT * FROM t3

connection thd3;
--echo =================================== Connection thd3
--echo ** On THD3: Insert another result into the cache and block on the same
--echo ** debug hook.
SET SESSION debug='+d,wait_in_query_cache_insert';
--send SELECT SQL_CACHE * FROM t4 UNION SELECT * FROM t5;

connection default;
--echo =================================== Connection default
--echo ** Assert that the two SELECT-stmt threads to reach the hook.
LET $wait_condition= SELECT SQL_NO_CACHE COUNT(*)= 2 FROM information_schema.processlist WHERE state='wait_in_query_cache_insert';
--source include/wait_condition.inc
--echo **
--echo **

--echo ** Signal the DELETE thread, THD1, to continue. It will enter the mutex
--echo ** lock and set query cache status to TABLE_FLUSH_IN_PROGRESS and then
--echo ** unlock the mutex before stopping on the next debug hook.
SELECT SQL_NO_CACHE id FROM information_schema.processlist WHERE state='wait_in_query_cache_invalidate1' LIMIT 1 INTO @flush_thread_id;
KILL QUERY @flush_thread_id;
--echo ** Assert that we reach the next debug hook.
LET $wait_condition= SELECT SQL_NO_CACHE COUNT(*)= 1 FROM information_schema.processlist WHERE state='wait_in_query_cache_invalidate2';
--source include/wait_condition.inc

--echo **
--echo ** Signal the remaining debug hooks blocking THD2 and THD3.
--echo ** The threads will grab the guard mutex enter the wait condition and
--echo ** and finally release the mutex. The threads will continue to wait
--echo ** until a broadcast signal reaches them causing both threads to 
--echo ** come alive and check the condition.
SELECT SQL_NO_CACHE id FROM information_schema.processlist WHERE state='wait_in_query_cache_insert' ORDER BY id ASC LIMIT 1 INTO @thread_id;
KILL QUERY @thread_id;
SELECT SQL_NO_CACHE id FROM information_schema.processlist WHERE state='wait_in_query_cache_insert' ORDER BY id DESC LIMIT 1 INTO @thread_id;
KILL QUERY @thread_id;

--echo **
--echo ** Finally signal the DELETE statement on THD1 one last time.
--echo ** The stmt will complete the query cache invalidation and return 
--echo ** cache status to NO_FLUSH_IN_PROGRESS. On the status change
--echo ** One signal will be sent to the thread group waiting for executing
--echo ** invalidations and a broadcast signal will be sent to the thread 
--echo ** group holding result set writers.
SELECT SQL_NO_CACHE id FROM information_schema.processlist WHERE state='wait_in_query_cache_invalidate2' LIMIT 1 INTO @flush_thread_id;
KILL QUERY @flush_thread_id;

--echo **
--echo *************************************************************************
--echo ** No tables should be locked
connection thd2;
--echo =================================== Connection thd2
reap;
DELETE FROM t1;
DELETE FROM t2;
DELETE FROM t3;

connection thd3;
--echo =================================== Connection thd3
reap;
DELETE FROM t4;
DELETE FROM t5;

connection thd1;
--echo =================================== Connection thd1
reap;

--echo ** Done.

connection default;
disconnect thd1;
disconnect thd2;
disconnect thd3;
SET GLOBAL query_cache_size= 0;

connection default;
--echo # Restore defaults
RESET QUERY CACHE;
FLUSH STATUS;
DROP TABLE t1,t2,t3,t4,t5;
SET GLOBAL query_cache_size= DEFAULT;
SET GLOBAL query_cache_type= DEFAULT;
exit;