Edit File: mdl_sync.result
SET DEBUG_SYNC= 'RESET'; drop table if exists t1,t2,t3; create table t1 (i int); create table t2 (i int); connection: default lock tables t2 read; connection: con1 set debug_sync='mdl_upgrade_shared_lock_to_exclusive SIGNAL parked WAIT_FOR go'; alter table t1 rename t3; connection: default set debug_sync= 'now WAIT_FOR parked'; connection: con2 set debug_sync='mdl_acquire_lock_wait SIGNAL go'; drop table t1,t2; connection: con1 connection: default unlock tables; connection: con2 ERROR 42S02: Unknown table 't1' drop table t3; SET DEBUG_SYNC= 'RESET'; # # Basic test coverage for type-of-operation aware metadata locks. # drop table if exists t1, t2, t3; set debug_sync= 'RESET'; create table t1 (c1 int); # # A) First let us check compatibility rules between differend kinds of # type-of-operation aware metadata locks. # Of course, these rules are already covered by the tests scattered # across the test suite. But it still makes sense to have one place # which covers all of them. # # 1) Acquire S (simple shared) lock on the table (by using HANDLER): # handler t1 open; # # Switching to connection 'mdl_con1'. # Check that S, SH, SR and SW locks are compatible with it. handler t1 open t; handler t close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 select count(*) from t1; count(*) 0 insert into t1 values (1), (1); # Check that SNW lock is compatible with it. To do this use ALTER TABLE # which will fail after opening the table and thus obtaining SNW metadata # lock. alter table t1 add primary key (c1); ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # Check that SNRW lock is compatible with S lock. lock table t1 write; insert into t1 values (1); unlock tables; # Check that X lock is incompatible with S lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con2'. # Check that the above RENAME is blocked because of S lock. # # Switching to connection 'default'. # Unblock RENAME TABLE. handler t1 close; # # Switching to connection 'mdl_con1'. # Reaping RENAME TABLE. # Restore the original state of the things. rename table t2 to t1; # # Switching to connection 'default'. handler t1 open; # # Switching to connection 'mdl_con1'. # Check that upgrade from SNW to X is blocked by presence of S lock. # Sending: alter table t1 add column c2 int;; # # Switching to connection 'mdl_con2'. # Check that the above ALTER TABLE is blocked because of S lock. # # Switching to connection 'default'. # Unblock ALTER TABLE. handler t1 close; # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. # Restore the original state of the things. alter table t1 drop column c2; # # Switching to connection 'default'. handler t1 open; # # Switching to connection 'mdl_con1'. # Check that upgrade from SNRW to X is blocked by presence of S lock. lock table t1 write; # Sending: alter table t1 add column c2 int;; # # Switching to connection 'mdl_con2'. # Check that the above upgrade of SNRW to X in ALTER TABLE is blocked # because of S lock. # # Switching to connection 'default'. # Unblock ALTER TABLE. handler t1 close; # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. # Restore the original state of the things. alter table t1 drop column c2; unlock tables; # # Switching to connection 'default'. # # 2) Acquire SH (shared high-priority) lock on the table. # We have to involve DEBUG_SYNC facility for this as usually # such kind of locks are short-lived. # set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t1';; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that S, SH, SR and SW locks are compatible with it. handler t1 open; handler t1 close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 select count(*) from t1; count(*) 3 insert into t1 values (1); # Check that SNW lock is compatible with it. To do this use ALTER TABLE # which will fail after opening the table and thus obtaining SNW metadata # lock. alter table t1 add primary key (c1); ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # Check that SNRW lock is compatible with SH lock. lock table t1 write; delete from t1 limit 1; unlock tables; # Check that X lock is incompatible with SH lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con2'. # Check that the above RENAME is blocked because of SH lock. # Unblock RENAME TABLE. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping SELECT ... FROM I_S. table_name table_type auto_increment table_comment t1 BASE TABLE NULL # # Switching to connection 'mdl_con1'. # Reaping RENAME TABLE. # Restore the original state of the things. rename table t2 to t1; # # Switching to connection 'default'. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t1';; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that upgrade from SNW to X is blocked by presence of SH lock. # Sending: alter table t1 add column c2 int;; # # Switching to connection 'mdl_con2'. # Check that the above ALTER TABLE is blocked because of SH lock. # Unblock RENAME TABLE. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping SELECT ... FROM I_S. table_name table_type auto_increment table_comment t1 BASE TABLE NULL # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. # Restore the original state of the things. alter table t1 drop column c2; # # Switching to connection 'default'. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t1';; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that upgrade from SNRW to X is blocked by presence of S lock. lock table t1 write; # Sending: alter table t1 add column c2 int;; # # Switching to connection 'mdl_con2'. # Check that the above upgrade of SNRW to X in ALTER TABLE is blocked # because of S lock. # Unblock RENAME TABLE. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping SELECT ... FROM I_S. table_name table_type auto_increment table_comment t1 BASE TABLE NULL # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. # Restore the original state of the things. alter table t1 drop column c2; unlock tables; # # Switching to connection 'default'. # # # 3) Acquire SR lock on the table. # # begin; select count(*) from t1; count(*) 3 # # Switching to connection 'mdl_con1'. # Check that S, SH, SR and SW locks are compatible with it. handler t1 open; handler t1 close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 select count(*) from t1; count(*) 3 insert into t1 values (1); # Check that SNW lock is compatible with it. To do this use ALTER TABLE # which will fail after opening the table and thus obtaining SNW metadata # lock. alter table t1 add primary key (c1); ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # Check that SNRW lock is not compatible with SR lock. # Sending: lock table t1 write;; # # Switching to connection 'default'. # Check that the above LOCK TABLES is blocked because of SR lock. # Unblock LOCK TABLES. commit; # # Switching to connection 'mdl_con1'. # Reaping LOCK TABLES. delete from t1 limit 1; unlock tables; # # Switching to connection 'default'. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'mdl_con1'. # Check that X lock is incompatible with SR lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con2'. # Check that the above RENAME is blocked because of SR lock. # # Switching to connection 'default'. # Unblock RENAME TABLE. commit; # # Switching to connection 'mdl_con1'. # Reaping RENAME TABLE. # Restore the original state of the things. rename table t2 to t1; # # Switching to connection 'default'. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'mdl_con1'. # Check that upgrade from SNW to X is blocked by presence of SR lock. # Sending: alter table t1 add column c2 int;; # # Switching to connection 'mdl_con2'. # Check that the above ALTER TABLE is blocked because of SR lock. # # Switching to connection 'default'. # Unblock ALTER TABLE. commit; # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. # Restore the original state of the things. alter table t1 drop column c2; # # There is no need to check that upgrade from SNRW to X is blocked # by presence of SR lock because SNRW is incompatible with SR anyway. # # # Switching to connection 'default'. # # # 4) Acquire SW lock on the table. # # begin; insert into t1 values (1); # # Switching to connection 'mdl_con1'. # Check that S, SH, SR and SW locks are compatible with it. handler t1 open; handler t1 close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 # Disable result log to make test robust against # effects of concurrent insert. select * from t1; insert into t1 values (1); # Check that SNW lock is not compatible with SW lock. # Again we use ALTER TABLE which fails after opening # the table to avoid upgrade of SNW -> X. # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'default'. # Check that the above ALTER TABLE is blocked because of SW lock. # Unblock ALTER TABLE. commit; # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'default'. begin; insert into t1 values (1); # # Switching to connection 'mdl_con1'. # Check that SNRW lock is not compatible with SW lock. # Sending: lock table t1 write;; # # Switching to connection 'default'. # Check that the above LOCK TABLES is blocked because of SW lock. # Unblock LOCK TABLES. commit; # # Switching to connection 'mdl_con1'. # Reaping LOCK TABLES. delete from t1 limit 2; unlock tables; # # Switching to connection 'default'. begin; insert into t1 values (1); # # Switching to connection 'mdl_con1'. # Check that X lock is incompatible with SW lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con2'. # Check that the above RENAME is blocked because of SW lock. # # Switching to connection 'default'. # Unblock RENAME TABLE. commit; # # Switching to connection 'mdl_con1'. # Reaping RENAME TABLE. # Restore the original state of the things. rename table t2 to t1; # # There is no need to check that upgrade from SNW/SNRW to X is # blocked by presence of SW lock because SNW/SNRW is incompatible # with SW anyway. # # # Switching to connection 'default'. # # # 5) Acquire SNW lock on the table. We have to use DEBUG_SYNC for # this, to prevent SNW from being immediately upgraded to X. # set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that S, SH and SR locks are compatible with it. handler t1 open; handler t1 close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 select count(*) from t1; count(*) 5 # Check that SW lock is incompatible with SNW lock. # Sending: delete from t1 limit 2;; # # Switching to connection 'mdl_con2'. # Check that the above DELETE is blocked because of SNW lock. # Unblock ALTER and thus DELETE. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con1'. # Reaping DELETE. # # Switching to connection 'default'. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that SNW lock is incompatible with SNW lock. # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con2'. # Check that the above ALTER is blocked because of SNW lock. # Unblock ALTERs. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping first ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con1'. # Reaping another ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'default'. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that SNRW lock is incompatible with SNW lock. # Sending: lock table t1 write;; # # Switching to connection 'mdl_con2'. # Check that the above LOCK TABLES is blocked because of SNW lock. # Unblock ALTER and thus LOCK TABLES. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con1'. # Reaping LOCK TABLES insert into t1 values (1); unlock tables; # # Switching to connection 'default'. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con1'. set debug_sync= 'now WAIT_FOR locked'; # Check that X lock is incompatible with SNW lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con2'. # Check that the above RENAME is blocked because of SNW lock. # Unblock ALTER and thus RENAME TABLE. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'default'. # Reaping ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con1'. # Reaping RENAME TABLE # Revert back to original state of things. rename table t2 to t1; # # There is no need to check that upgrade from SNW/SNRW to X is # blocked by presence of another SNW lock because SNW/SNRW is # incompatible with SNW anyway. # # Switching to connection 'default'. # # # 6) Acquire SNRW lock on the table. # # lock table t1 write; # # Switching to connection 'mdl_con1'. # Check that S and SH locks are compatible with it. handler t1 open; handler t1 close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 # Check that SR lock is incompatible with SNRW lock. # Sending: select count(*) from t1;; # # Switching to connection 'default'. # Check that the above SELECT is blocked because of SNRW lock. # Unblock SELECT. unlock tables; # # Switching to connection 'mdl_con1'. # Reaping SELECT. count(*) 4 # # Switching to connection 'default'. lock table t1 write; # # Switching to connection 'mdl_con1'. # Check that SW lock is incompatible with SNRW lock. # Sending: delete from t1 limit 1;; # # Switching to connection 'default'. # Check that the above DELETE is blocked because of SNRW lock. # Unblock DELETE. unlock tables; # # Switching to connection 'mdl_con1'. # Reaping DELETE. # # Switching to connection 'default'. lock table t1 write; # # Switching to connection 'mdl_con1'. # Check that SNW lock is incompatible with SNRW lock. # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'default'. # Check that the above ALTER is blocked because of UNWR lock. # Unblock ALTER. unlock tables; # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'default'. lock table t1 write; # # Switching to connection 'mdl_con1'. # Check that SNRW lock is incompatible with SNRW lock. # Sending: lock table t1 write;; # # Switching to connection 'default'. # Check that the above LOCK TABLES is blocked because of SNRW lock. # Unblock waiting LOCK TABLES. unlock tables; # # Switching to connection 'mdl_con1'. # Reaping LOCK TABLES insert into t1 values (1); unlock tables; # # Switching to connection 'default'. lock table t1 write; # # Switching to connection 'mdl_con1'. # Check that X lock is incompatible with SNRW lock. # Sending: rename table t1 to t2;; # # Switching to connection 'default'. # Check that the above RENAME is blocked because of SNRW lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'mdl_con1'. # Reaping RENAME TABLE # Revert back to original state of things. rename table t2 to t1; # # There is no need to check that upgrade from SNW/SNRW to X is # blocked by presence of another SNRW lock because SNW/SNRW is # incompatible with SNRW anyway. # # Switching to connection 'default'. # # # 7) Now do the same round of tests for X lock. We use additional # table to get long-lived lock of this type. # create table t2 (c1 int); # # Switching to connection 'mdl_con2'. # Take a lock on t2, so RENAME TABLE t1 TO t2 will get blocked # after acquiring X lock on t1. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that S lock in incompatible with X lock. # Sending: handler t1 open;; # # Switching to connection 'mdl_con2'. # Check that the above HANDLER statement is blocked because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping HANDLER. handler t1 close; # # Switching to connection 'mdl_con2'. # Prepare for blocking RENAME TABLE. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that SH lock in incompatible with X lock. # Sending: select column_name from information_schema.columns where table_schema='test' and table_name='t1';; # # Switching to connection 'mdl_con2'. # Check that the above SELECT ... FROM I_S ... statement is blocked # because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping SELECT ... FROM I_S. column_name c1 # # Switching to connection 'mdl_con2'. # Prepare for blocking RENAME TABLE. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that SR lock in incompatible with X lock. # Sending: select count(*) from t1;; # # Switching to connection 'mdl_con2'. # Check that the above SELECT statement is blocked # because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping SELECT. count(*) 4 # # Switching to connection 'mdl_con2'. # Prepare for blocking RENAME TABLE. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that SW lock in incompatible with X lock. # Sending: delete from t1 limit 1;; # # Switching to connection 'mdl_con2'. # Check that the above DELETE statement is blocked # because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping DELETE. # # Switching to connection 'mdl_con2'. # Prepare for blocking RENAME TABLE. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that SNW lock is incompatible with X lock. # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con2'. # Check that the above ALTER statement is blocked # because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping ALTER. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con2'. # Prepare for blocking RENAME TABLE. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that SNRW lock is incompatible with X lock. # Sending: lock table t1 write;; # # Switching to connection 'mdl_con2'. # Check that the above LOCK TABLE statement is blocked # because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping LOCK TABLE. unlock tables; # # Switching to connection 'mdl_con2'. # Prepare for blocking RENAME TABLE. lock tables t2 read; # # Switching to connection 'default'. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME has acquired X lock on t1 and is waiting for t2. # Check that X lock is incompatible with X lock. # Sending: rename table t1 to t3;; # # Switching to connection 'mdl_con2'. # Check that the above RENAME statement is blocked # because of X lock. # Unblock RENAME TABLE unlock tables; # # Switching to connection 'default'. # Reaping RENAME TABLE ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping RENAME. rename table t3 to t1; # # B) Now let us test compatibility in cases when both locks # are pending. I.e. let us test rules for priorities between # different types of metadata locks. # # # Switching to connection 'mdl_con2'. # # 1) Check compatibility for pending SNW lock. # # Acquire SW lock in order to create pending SNW lock later. begin; insert into t1 values (1); # # Switching to connection 'default'. # Add pending SNW lock. # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con1'. # Check that ALTER TABLE is waiting with pending SNW lock. # Check that S, SH and SR locks are compatible with pending SNW handler t1 open t; handler t close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 select count(*) from t1; count(*) 4 # Check that SW is incompatible with pending SNW # Sending: delete from t1 limit 1;; # # Switching to connection 'mdl_con2'. # Check that the above DELETE is blocked because of pending SNW lock. # Unblock ALTER TABLE. commit; # # Switching to connection 'default'. # Reaping ALTER. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con1'. # Reaping DELETE. # # We can't do similar check for SNW, SNRW and X locks because # they will also be blocked by active SW lock. # # # Switching to connection 'mdl_con2'. # # 2) Check compatibility for pending SNRW lock. # # Acquire SR lock in order to create pending SNRW lock. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'default'. # Add pending SNRW lock. # Sending: lock table t1 write;; # # Switching to connection 'mdl_con1'. # Check that LOCK TABLE is waiting with pending SNRW lock. # Check that S and SH locks are compatible with pending SNRW handler t1 open t; handler t close; select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 # Check that SR is incompatible with pending SNRW # Sending: select count(*) from t1;; # # Switching to connection 'mdl_con2'. # Check that the above SELECT is blocked because of pending SNRW lock. # Unblock LOCK TABLE. commit; # # Switching to connection 'default'. # Reaping LOCK TABLE. unlock tables; # # Switching to connection 'mdl_con1'. # Reaping SELECT. count(*) 3 # Restore pending SNRW lock. # # Switching to connection 'mdl_con2'. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'default'. # Sending: lock table t1 write;; # # Switching to connection 'mdl_con1'. # Check that LOCK TABLE is waiting with pending SNRW lock. # Check that SW is incompatible with pending SNRW # Sending: insert into t1 values (1);; # # Switching to connection 'mdl_con2'. # Check that the above INSERT is blocked because of pending SNRW lock. # Unblock LOCK TABLE. commit; # # Switching to connection 'default'. # Reaping LOCK TABLE. unlock tables; # # Switching to connection 'mdl_con1'. # Reaping INSERT. # Restore pending SNRW lock. # # Switching to connection 'mdl_con2'. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'default'. # Sending: lock table t1 write;; # # Switching to connection 'mdl_con1'. # Check that LOCK TABLE is waiting with pending SNRW lock. # Check that SNW is compatible with pending SNRW # So ALTER TABLE statements are not starved by LOCK TABLEs. alter table t1 add primary key (c1); ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'mdl_con2'. # Unblock LOCK TABLE. commit; # # Switching to connection 'default'. # Reaping LOCK TABLE. unlock tables; # # We can't do similar check for SNRW and X locks because # they will also be blocked by active SR lock. # # # Switching to connection 'mdl_con2'. # # 3) Check compatibility for pending X lock. # # Acquire SR lock in order to create pending X lock. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'default'. # Add pending X lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME TABLE is waiting with pending X lock. # Check that SH locks are compatible with pending X select column_name from information_schema.columns where table_schema='test' and table_name='t1'; column_name c1 # Check that S is incompatible with pending X # Sending: handler t1 open;; # # Switching to connection 'mdl_con2'. # Check that the above HANDLER OPEN is blocked because of pending X lock. # Unblock RENAME TABLE. commit; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping HANDLER t1 OPEN. handler t1 close; # Restore pending X lock. # # Switching to connection 'mdl_con2'. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'default'. # Add pending X lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME TABLE is waiting with pending X lock. # Check that SR is incompatible with pending X # Sending: select count(*) from t1;; # # Switching to connection 'mdl_con2'. # Check that the above SELECT is blocked because of pending X lock. # Unblock RENAME TABLE. commit; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping SELECT. count(*) 4 # Restore pending X lock. # # Switching to connection 'mdl_con2'. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'default'. # Add pending X lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME TABLE is waiting with pending X lock. # Check that SW is incompatible with pending X # Sending: delete from t1 limit 1;; # # Switching to connection 'mdl_con2'. # Check that the above DELETE is blocked because of pending X lock. # Unblock RENAME TABLE. commit; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping DELETE. # Restore pending X lock. # # Switching to connection 'mdl_con2'. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'default'. # Add pending X lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME TABLE is waiting with pending X lock. # Check that SNW is incompatible with pending X # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'mdl_con2'. # Check that the above ALTER TABLE is blocked because of pending X lock. # Unblock RENAME TABLE. commit; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # Restore pending X lock. # # Switching to connection 'mdl_con2'. handler t1 open; # # Switching to connection 'default'. # Add pending X lock. # Sending: rename table t1 to t2;; # # Switching to connection 'mdl_con1'. # Check that RENAME TABLE is waiting with pending X lock. # Check that SNRW is incompatible with pending X # Sending: lock table t1 write;; # # Switching to connection 'mdl_con3'. # Check that the above LOCK TABLES is blocked because of pending X lock. # # Switching to connection 'mdl_con2'. # Unblock RENAME TABLE. handler t1 close; # # Switching to connection 'default'. # Reaping RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'mdl_con1'. # Reaping LOCK TABLES. unlock tables; # # Switching to connection 'default'. # # # C) Now let us test how type-of-operation locks are handled in # transactional context. Obviously we are mostly interested # in conflicting types of locks. # # # 1) Let us check how various locks used within transactional # context interact with active/pending SNW lock. # # We start with case when we are acquiring lock on the table # which was not used in the transaction before. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'mdl_con1'. # Create an active SNW lock on t2. # We have to use DEBUG_SYNC facility as otherwise SNW lock # will be immediately released (or upgraded to X lock). insert into t2 values (1), (1); set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: alter table t2 add primary key (c1);; # # Switching to connection 'default'. set debug_sync= 'now WAIT_FOR locked'; # SR lock should be acquired without any waiting. select count(*) from t2; count(*) 2 commit; # Now let us check that we will wait in case of SW lock. begin; select count(*) from t1; count(*) 3 # Sending: insert into t2 values (1);; # # Switching to connection 'mdl_con2'. # Check that the above INSERT is blocked. # Unblock ALTER TABLE and thus INSERT. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'mdl_con1'. # Reap ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'default'. # Reap INSERT. commit; # # Now let us see what happens when we are acquiring lock on the table # which is already used in transaction. # # *) First, case when transaction which has SR lock on the table also # locked in SNW mode acquires yet another SR lock and then tries # to acquire SW lock. begin; select count(*) from t1; count(*) 3 # # Switching to connection 'mdl_con1'. # Create an active SNW lock on t1. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'default'. set debug_sync= 'now WAIT_FOR locked'; # We should still be able to get SR lock without waiting. select count(*) from t1; count(*) 3 # Since the above ALTER TABLE is not upgrading SNW lock to X by waiting # for SW lock we won't create deadlock. # So the below INSERT should not end-up with ER_LOCK_DEADLOCK error. # Sending: insert into t1 values (1);; # # Switching to connection 'mdl_con2'. # Check that the above INSERT is blocked. # Unblock ALTER TABLE and thus INSERT. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'mdl_con1'. # Reap ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'default'. # Reap INSERT. commit; # # **) Now test in which transaction that has SW lock on the table # against which there is pending SNW lock acquires SR and SW # locks on this table. # begin; insert into t1 values (1); # # Switching to connection 'mdl_con1'. # Create pending SNW lock on t1. # Sending: alter table t1 add primary key (c1);; # # Switching to connection 'default'. # Wait until ALTER TABLE starts waiting for SNW lock. # We should still be able to get both SW and SR locks without waiting. select count(*) from t1; count(*) 5 delete from t1 limit 1; # Unblock ALTER TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap ALTER TABLE. ERROR 23000: Duplicate entry '1' for key 'PRIMARY' # # Switching to connection 'default'. # # 2) Now similar tests for active SNW lock which is being upgraded # to X lock. # # Again we start with case when we are acquiring lock on the # table which was not used in the transaction before. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con2'. # Start transaction which will prevent SNW -> X upgrade from # completing immediately. begin; select count(*) from t2; count(*) 3 # # Switching to connection 'mdl_con1'. # Create SNW lock pending upgrade to X on t2. # Sending: alter table t2 add column c2 int;; # # Switching to connection 'default'. # Wait until ALTER TABLE starts waiting X lock. # Check that attempt to acquire SR lock on t2 causes waiting. # Sending: select count(*) from t2;; # # Switching to connection 'mdl_con2'. # Check that the above SELECT is blocked. # Unblock ALTER TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap ALTER TABLE. # # Switching to connection 'default'. # Reap SELECT. count(*) 3 commit; # Do similar check for SW lock. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con2'. # Start transaction which will prevent SNW -> X upgrade from # completing immediately. begin; select count(*) from t2; count(*) 3 # # Switching to connection 'mdl_con1'. # Create SNW lock pending upgrade to X on t2. # Sending: alter table t2 drop column c2;; # # Switching to connection 'default'. # Wait until ALTER TABLE starts waiting X lock. # Check that attempt to acquire SW lock on t2 causes waiting. # Sending: insert into t2 values (1);; # # Switching to connection 'mdl_con2'. # Check that the above INSERT is blocked. # Unblock ALTER TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap ALTER TABLE. # # Switching to connection 'default'. # Reap INSERT. commit; # # Test for the case in which we are acquiring lock on the table # which is already used in transaction. # begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con1'. # Create SNW lock pending upgrade to X. # Sending: alter table t1 add column c2 int;; # # Switching to connection 'default'. # Wait until ALTER TABLE starts waiting X lock. # Check that transaction is still able to acquire SR lock. select count(*) from t1; count(*) 4 # Waiting trying to acquire SW lock will cause deadlock and # therefore should cause an error. delete from t1 limit 1; ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # Unblock ALTER TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap ALTER TABLE. # # Switching to connection 'default'. # # 3) Check how various locks used within transactional context # interact with active/pending SNRW lock. # # Once again we start with case when we are acquiring lock on # the table which was not used in the transaction before. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con1'. lock table t2 write; # # Switching to connection 'default'. # Attempt to acquire SR should be blocked. It should # not cause errors as it does not creates deadlock. # Sending: select count(*) from t2;; # # Switching to connection 'mdl_con1'. # Check that the above SELECT is blocked # Unblock SELECT. unlock tables; # # Switching to connection 'default'. # Reap SELECT. count(*) 4 commit; # Repeat the same test for SW lock. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con1'. lock table t2 write; # # Switching to connection 'default'. # Again attempt to acquire SW should be blocked and should # not cause any errors. # Sending: delete from t2 limit 1;; # # Switching to connection 'mdl_con1'. # Check that the above DELETE is blocked # Unblock DELETE. unlock tables; # # Switching to connection 'default'. # Reap DELETE. commit; # # Now coverage for the case in which we are acquiring lock on # the table which is already used in transaction and against # which there is a pending SNRW lock request. # # *) Let us start with case when transaction has only a SR lock. # begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con1'. # Sending: lock table t1 write;; # # Switching to connection 'default'. # Wait until LOCK TABLE is blocked creating pending request for X lock. # Check that another instance of SR lock is granted without waiting. select count(*) from t1; count(*) 4 # Attempt to wait for SW lock will lead to deadlock, thus # the below statement should end with ER_LOCK_DEADLOCK error. delete from t1 limit 1; ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # Unblock LOCK TABLES. commit; # # Switching to connection 'mdl_con1'. # Reap LOCK TABLES. unlock tables; # # Switching to connection 'default'. # # **) Now case when transaction has a SW lock. # begin; delete from t1 limit 1; # # Switching to connection 'mdl_con1'. # Sending: lock table t1 write;; # # Switching to connection 'default'. # Wait until LOCK TABLE is blocked creating pending request for X lock. # Check that both SR and SW locks are granted without waiting # and errors. select count(*) from t1; count(*) 3 insert into t1 values (1, 1); # Unblock LOCK TABLES. commit; # # Switching to connection 'mdl_con1'. # Reap LOCK TABLES. unlock tables; # # Switching to connection 'default'. # # 4) Check how various locks used within transactional context # interact with active/pending X lock. # # As usual we start with case when we are acquiring lock on # the table which was not used in the transaction before. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con2'. # Start transaction which will prevent X lock from going away # immediately. begin; select count(*) from t2; count(*) 3 # # Switching to connection 'mdl_con1'. # Create pending X lock on t2. # Sending: rename table t2 to t3;; # # Switching to connection 'default'. # Wait until RENAME TABLE starts waiting with pending X lock. # Check that attempt to acquire SR lock on t2 causes waiting. # Sending: select count(*) from t2;; # # Switching to connection 'mdl_con2'. # Check that the above SELECT is blocked. # Unblock RENAME TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap RENAME TABLE. # # Switching to connection 'default'. # Reap SELECT. ERROR 42S02: Table 'test.t2' doesn't exist commit; rename table t3 to t2; # The same test for SW lock. begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con2'. # Start transaction which will prevent X lock from going away # immediately. begin; select count(*) from t2; count(*) 3 # # Switching to connection 'mdl_con1'. # Create pending X lock on t2. # Sending: rename table t2 to t3;; # # Switching to connection 'default'. # Wait until RENAME TABLE starts waiting with pending X lock. # Check that attempt to acquire SW lock on t2 causes waiting. # Sending: delete from t2 limit 1;; # # Switching to connection 'mdl_con2'. # Check that the above DELETE is blocked. # Unblock RENAME TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap RENAME TABLE. # # Switching to connection 'default'. # Reap DELETE. ERROR 42S02: Table 'test.t2' doesn't exist commit; rename table t3 to t2; # # Coverage for the case in which we are acquiring lock on # the table which is already used in transaction and against # which there is a pending X lock request. # # *) The first case is when transaction has only a SR lock. # begin; select count(*) from t1; count(*) 4 # # Switching to connection 'mdl_con1'. # Sending: rename table t1 to t2;; # # Switching to connection 'default'. # Wait until RENAME TABLE is blocked creating pending request for X lock. # Check that another instance of SR lock is granted without waiting. select count(*) from t1; count(*) 4 # Attempt to wait for SW lock will lead to deadlock, thus # the below statement should end with ER_LOCK_DEADLOCK error. delete from t1 limit 1; ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # Unblock RENAME TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'default'. # # **) The second case is when transaction has a SW lock. # begin; delete from t1 limit 1; # # Switching to connection 'mdl_con1'. # Sending: rename table t1 to t2;; # # Switching to connection 'default'. # Wait until RENAME TABLE is blocked creating pending request for X lock. # Check that both SR and SW locks are granted without waiting # and errors. select count(*) from t1; count(*) 3 insert into t1 values (1, 1); # Unblock RENAME TABLE. commit; # # Switching to connection 'mdl_con1'. # Reap RENAME TABLE. ERROR 42S01: Table 't2' already exists # # Switching to connection 'default'. # Clean-up. set debug_sync= 'RESET'; drop table t1, t2; # # Additional coverage for some scenarios in which not quite # correct use of S metadata locks by HANDLER statement might # have caused deadlocks. # drop table if exists t1, t2; create table t1 (i int); create table t2 (j int); insert into t1 values (1); # # First, check scenario in which we upgrade SNRW lock to X lock # on a table while having HANDLER READ trying to acquire TL_READ # on the same table. # handler t1 open; # # Switching to connection 'handler_con1'. lock table t1 write; # Upgrade SNRW to X lock. # Sending: alter table t1 add column j int;; # # Switching to connection 'handler_con2'. # Wait until ALTER is blocked during upgrade. # # Switching to connection 'default'. # The below statement should not cause deadlock. handler t1 read first;; # # Switching to connection 'handler_con1'. # Reap ALTER TABLE. unlock tables; # # Switching to connection 'default'. # Reap HANDLER READ. i j 1 NULL handler t1 close; # # Now, check scenario in which upgrade of SNRW lock to X lock # can be blocked by HANDLER which is open in connection currently # waiting to get table-lock owned by connection doing upgrade. # handler t1 open; # # Switching to connection 'handler_con1'. lock table t1 write, t2 read; # # Switching to connection 'default'. # Execute statement which will be blocked on table-level lock # owned by connection 'handler_con1'. # Sending: insert into t2 values (1);; # # Switching to connection 'handler_con1'. # Wait until INSERT is blocked on table-level lock. # Sending 'alter table t1 drop column j'. It should not cause # deadlock. alter table t1 drop column j; # Switching to connection 'handler_con2'. # Wait until ALTER is blocked during upgrade. # # Switching to connection 'default'. # Reap INSERT. ERROR HY000: Wait on a lock was aborted due to a pending exclusive lock handler t1 close; # # Switching to connection 'handler_con1'. # Reaping 'alter table t1 drop column j' unlock tables; # Switching to connection 'default'. # Then, check the scenario in which upgrade of SNRW lock to X # lock is blocked by HANDLER which is open in connection currently # waiting to get SW lock on the same table. # handler t1 open; # # Switching to connection 'handler_con1'. lock table t1 write; # # Switching to connection 'default'. # The below insert should be blocked because active SNRW lock on 't1'. # Sending: insert into t1 values (1);; # # Switching to connection 'handler_con1'. # Wait until INSERT is blocked because of SNRW lock. # The below ALTER TABLE will be blocked because of presence of HANDLER. # Sending: alter table t1 add column j int;; # # Switching to connection 'default'. # INSERT should be chosen as victim for resolving deadlock. # Reaping INSERT. ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # Close HANDLER to unblock ALTER TABLE. handler t1 close; # # Switching to connection 'handler_con1'. # Reaping ALTER TABLE. unlock tables; # # Switching to connection 'default'. # # Finally, test in which upgrade of SNRW lock to X lock is blocked # by HANDLER which is open in connection currently waiting to get # SR lock on the table on which lock is upgraded. # handler t1 open; # # Switching to connection 'handler_con1'. lock table t1 write, t2 write; # # Switching to connection 'default'. # The below insert should be blocked because active SNRW lock on 't1'. # Sending: insert into t2 values (1);; # # Switching to connection 'handler_con1'. # Wait until INSERT is blocked because of SNRW lock. # The below ALTER TABLE will be blocked because of presence of HANDLER. # Sending: alter table t1 drop column j;; # # Switching to connection 'default'. # INSERT should be chosen as victim for resolving deadlock. # Reaping INSERT. ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # Close HANDLER to unblock ALTER TABLE. handler t1 close; # # Switching to connection 'handler_con1'. # Reaping ALTER TABLE. unlock tables; # # Switching to connection 'default'. # Clean-up. drop tables t1, t2; # # Test coverage for basic deadlock detection in metadata # locking subsystem. # drop tables if exists t0, t1, t2, t3, t4, t5; set debug_sync= 'RESET'; create table t1 (i int); create table t2 (j int); create table t3 (k int); create table t4 (k int); # # Test for the case in which no deadlock occurs. # # # Switching to connection 'deadlock_con1'. begin; insert into t1 values (1); # # Switching to connection 'deadlock_con2'. begin; insert into t2 values (1); # # Switching to connection 'default'. # Send: rename table t2 to t0, t3 to t2, t0 to t3;; # # Switching to connection 'deadlock_con1'. # Wait until the above RENAME TABLE is blocked because it has to wait # for 'deadlock_con2' which holds shared metadata lock on 't2'. # The below statement should wait for exclusive metadata lock # on 't2' to go away and should not produce ER_LOCK_DEADLOCK # as no deadlock is possible in this situation. # Send: select * from t2;; # # Switching to connection 'deadlock_con2'. # Wait until the above SELECT * FROM t2 is starts waiting # for an exclusive metadata lock to go away. # # Unblock RENAME TABLE by releasing shared metadata lock on t2. commit; # # Switching to connection 'default'. # Reap RENAME TABLE. # # Switching to connection 'deadlock_con1'. # Reap SELECT. k # # Switching to connection 'default'. # # Let us check that in the process of waiting for conflicting lock # on table 't2' to go away transaction in connection 'deadlock_con1' # has not released metadata lock on table 't1'. # Send: rename table t1 to t0, t3 to t1, t0 to t3;; # # Switching to connection 'deadlock_con1'. # Wait until the above RENAME TABLE is blocked because it has to wait # for 'deadlock_con1' which should still hold shared metadata lock on # table 't1'. # Commit transaction to unblock RENAME TABLE. commit; # # Switching to connection 'default'. # Reap RENAME TABLE. # # Test for case when deadlock occurs and should be detected immediately. # # # Switching to connection 'deadlock_con1'. begin; insert into t2 values (2); # # Switching to connection 'default'. # Send: rename table t2 to t0, t1 to t2, t0 to t1;; # # Switching to connection 'deadlock_con1'. # Wait until the above RENAME TABLE is blocked because it has to wait # for 'deadlock_con1' which holds shared metadata lock on 't2'. # # The below statement should not wait as doing so will cause deadlock. # Instead it should fail and emit ER_LOCK_DEADLOCK statement and # transaction should be rolled back. select * from t1; ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # # Switching to connection 'default'. # Reap RENAME TABLE. # # Test for the case in which deadlock also occurs but not immediately. # # # Switching to connection 'deadlock_con1'. begin; insert into t2 values (1); # # Switching to connection 'default'. lock table t1 write; # # Switching to connection 'deadlock_con1'. # The below SELECT statement should wait for metadata lock # on table 't1' and should not produce ER_LOCK_DEADLOCK # immediately as no deadlock is possible at the moment. select * from t1;; # # Switching to connection 'deadlock_con2'. # Wait until the above SELECT * FROM t1 is starts waiting # for an UNRW metadata lock to go away. # Send RENAME TABLE statement that will deadlock with the # SELECT statement and thus should abort the latter. rename table t1 to t0, t2 to t1, t0 to t2;; # # Switching to connection 'default'. # Wait till above RENAME TABLE is blocked while holding # pending X lock on t1. # Allow the above RENAME TABLE to acquire lock on t1 and # create pending lock on t2 thus creating deadlock. unlock tables; # # Switching to connection 'deadlock_con1'. # Since the latest RENAME TABLE entered in deadlock with SELECT # statement the latter should be aborted and emit ER_LOCK_DEADLOCK # error and transaction should be rolled back. # Reap SELECT * FROM t1. ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # # Switching to connection 'deadlock_con2'. # Reap RENAME TABLE ... . # # Switching to connection 'default'. drop tables t1, t2, t3, t4; # # Now, test case which shows that deadlock detection empiric # also takes into account requests for metadata lock upgrade. # create table t1 (i int); insert into t1 values (1); # Avoid race which occurs when SELECT in 'deadlock_con1' connection # accesses table before the above INSERT unlocks the table and thus # its result becomes visible to other connections. select * from t1; i 1 # # Switching to connection 'deadlock_con1'. begin; select * from t1; i 1 # # Switching to connection 'default'. # Send: alter table t1 add column j int, rename to t2;; # # Switching to connection 'deadlock_con1'. # Wait until the above ALTER TABLE ... RENAME acquires exclusive # metadata lock on 't2' and starts waiting for connection # 'deadlock_con1' which holds shared lock on 't1'. # The below statement should not wait as it will cause deadlock. # An appropriate error should be reported instead and transaction # should be rolled back. select * from t2; ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # # Switching to connection 'default'. # Reap ALTER TABLE ... RENAME. drop table t2; # # Test that in situation when MDL subsystem detects a deadlock # but it turns out that it can be resolved by backing-off locks # acquired by one of participating transactions (which is # possible when one of transactions consists only of currently # executed statement, e.g. in autocommit mode) no error is # reported. # create table t1 (i int); create table t2 (j int); # Ensure that the below SELECT stops once it has acquired metadata # lock on table 't2'. set debug_sync= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; # Sending: select * from t2, t1; # # Switching to connection 'deadlock_con1'. # Wait till SELECT acquires MDL on 't2' and starts waiting for signal. set debug_sync= 'now WAIT_FOR locked'; # Sending: lock tables t1 write, t2 write; # # Switching to connection 'deadlock_con2'. # Wait until LOCK TABLES acquires SNRW lock on 't1' and is blocked # while trying to acquire SNRW lock on 't1'. # Resume SELECT execution, this should eventually unblock LOCK TABLES. set debug_sync= 'now SIGNAL finish'; # # Switching to connection 'deadlock_con1'. # Reaping LOCK TABLES. unlock tables; # # Switching to connection 'default'. # Reaping SELECT. It succeed and not report ER_LOCK_DEADLOCK error. j i drop tables t1, t2; # # Test coverage for situation in which a race has happened # during deadlock detection process which led to unwarranted # ER_LOCK_DEADLOCK error. # create table t1 (i int); # Ensure that ALTER waits once it has acquired SNW lock. set debug_sync='after_open_table_mdl_shared SIGNAL parked1 WAIT_FOR go1'; # Sending: alter table t1 add column j int; # # Switching to connection 'deadlock_con1'. # Wait till ALTER acquires SNW lock and stops. set debug_sync='now WAIT_FOR parked1'; # Ensure that INSERT is paused once it detects that there is # a conflicting metadata lock so it has to wait, but before # deadlock detection is run. set debug_sync='mdl_acquire_lock_wait SIGNAL parked2 WAIT_FOR go2'; # Sending: insert into t1 values (); # # Switching to connection 'deadlock_con2'. # Wait till INSERT is paused. set debug_sync='now WAIT_FOR parked2'; # Resume ALTER execution. Eventually it will release its # metadata lock and INSERT's request for SW lock will be # satisified. set debug_sync='now SIGNAL go1'; # # Switching to connection 'default'. # Reaping ALTER TABLE. # Add a new request for SNW lock to waiting graph. # Sending: alter table t1 drop column j; # # Switching to connection 'deadlock_con2'. # Wait until ALTER is blocked. # Resume INSERT so it can start deadlock detection. # # At this point there is a discrepancy between the fact that INSERT's # SW lock is already satisfied, but INSERT's connection is still # marked as waiting for it. Looking for a loop in waiters graph # without additional checks has detected a deadlock (INSERT waits # for SW lock; which is not granted because of pending SNW lock from # ALTER; which waits for active SW lock from INSERT). Since requests # for SW and SNW locks have same weight ALTER was selected as a victim # and ended with ER_LOCK_DEADLOCK error. set debug_sync='now SIGNAL go2'; # # Switching to connection 'deadlock_con1'. # Reaping INSERT. # # Switching to connection 'default'. # Reaping ALTER. It should succeed and not produce ER_LOCK_DEADLOCK. drop table t1; # # Now, test for a situation in which deadlock involves waiting not # only in MDL subsystem but also for TDC. Such deadlocks should be # successfully detected. If possible, they should be resolved without # resorting to ER_LOCK_DEADLOCK error. # create table t1(i int); create table t2(j int); # # First, let us check how we handle a simple scenario involving # waits in MDL and TDC. # set debug_sync= 'RESET'; # Switching to connection 'deadlock_con1'. # Start a statement, which will acquire SR metadata lock on t1, open it # and then stop, before trying to acquire SW lock on t2 and opening it. set debug_sync='open_tables_after_open_and_process_table SIGNAL parked WAIT_FOR go'; # Sending: select * from t1 where i in (select j from t2 for update); # Switching to connection 'deadlock_con2'. # Wait till the above SELECT stops. set debug_sync='now WAIT_FOR parked'; # The below FLUSH TABLES WITH READ LOCK should acquire # SNW locks on t1 and t2 and wait till SELECT closes t1. # Sending: flush tables t1, t2 with read lock; # Switching to connection 'deadlock_con3'. # Wait until FLUSH TABLES WITH t1, t2 READ LOCK starts waiting # for SELECT to close t1. # Resume SELECT, so it tries to acquire SW lock on t1 and blocks, # creating a deadlock. This deadlock should be detected and resolved # by backing-off SELECT. As a result FTWRL should be able to finish. set debug_sync='now SIGNAL go'; # Switching to connection 'deadlock_con2'. # Reap FLUSH TABLES WITH READ LOCK. unlock tables; # Switching to connection 'deadlock_con1'. # Reap SELECT. i # # The same scenario with a slightly different order of events # which emphasizes that setting correct deadlock detector weights # for flush waits is important. # set debug_sync= 'RESET'; # Switching to connection 'deadlock_con2'. set debug_sync='flush_tables_with_read_lock_after_acquire_locks SIGNAL parked WAIT_FOR go'; # The below FLUSH TABLES WITH READ LOCK should acquire # SNW locks on t1 and t2 and wait on debug sync point. # Sending: flush tables t1, t2 with read lock; # Switching to connection 'deadlock_con1'. # Wait till FLUSH TABLE WITH READ LOCK stops. set debug_sync='now WAIT_FOR parked'; # Start statement which will acquire SR metadata lock on t1, open # it and then will block while trying to acquire SW lock on t2. # Sending: select * from t1 where i in (select j from t2 for update); # Switching to connection 'deadlock_con3'. # Wait till the above SELECT blocks. # Resume FLUSH TABLES, so it tries to flush t1, thus creating # a deadlock. This deadlock should be detected and resolved by # backing-off SELECT. As a result FTWRL should be able to finish. set debug_sync='now SIGNAL go'; # Switching to connection 'deadlock_con2'. # Reap FLUSH TABLES WITH READ LOCK. unlock tables; # Switching to connection 'deadlock_con1'. # Reap SELECT. i # # Now a more complex scenario involving two connections # waiting for MDL and one for TDC. # set debug_sync= 'RESET'; # Switching to connection 'deadlock_con1'. # Start a statement which will acquire SR metadata lock on t2, open it # and then stop, before trying to acquire SR on t1 and opening it. set debug_sync='open_tables_after_open_and_process_table SIGNAL parked WAIT_FOR go'; # Sending: select * from t2, t1; # Switching to connection 'deadlock_con2'. # Wait till the above SELECT stops. set debug_sync='now WAIT_FOR parked'; # The below FLUSH TABLES WITH READ LOCK should acquire # SNW locks on t2 and wait till SELECT closes t2. # Sending: flush tables t2 with read lock; # Switching to connection 'deadlock_con3'. # Wait until FLUSH TABLES WITH READ LOCK starts waiting # for SELECT to close t2. # The below DROP TABLES should acquire X lock on t1 and start # waiting for X lock on t2. # Sending: drop tables t1, t2; # Switching to connection 'default'. # Wait until DROP TABLES starts waiting for X lock on t2. # Resume SELECT, so it tries to acquire SR lock on t1 and blocks, # creating a deadlock. This deadlock should be detected and resolved # by backing-off SELECT. As a result, FTWRL should be able to finish. set debug_sync='now SIGNAL go'; # Switching to connection 'deadlock_con2'. # Reap FLUSH TABLES WITH READ LOCK. # Unblock DROP TABLES. unlock tables; # Switching to connection 'deadlock_con3'. # Reap DROP TABLES. # Switching to connection 'deadlock_con1'. # Reap SELECT. It should emit error about missing table. ERROR 42S02: Table 'test.t2' doesn't exist # Switching to connection 'default'. set debug_sync= 'RESET'; # # Test for a scenario in which FLUSH TABLES <list> WITH READ LOCK # used to erroneously release metadata locks. # drop tables if exists t1, t2; set debug_sync= 'RESET'; create table t1(i int); create table t2(j int); # Switching to connection 'con2'. set debug_sync='open_tables_after_open_and_process_table SIGNAL parked WAIT_FOR go'; # The below FLUSH TABLES <list> WITH READ LOCK should acquire # SNW locks on t1 and t2, open table t1 and block on the debug # sync point. # Sending: flush tables t1, t2 with read lock; # Switching to connection 'con1'. # Wait till FLUSH TABLES <list> WITH READ LOCK stops. set debug_sync='now WAIT_FOR parked'; # Start a statement which will flush all tables and thus # invalidate table t1 open by FLUSH TABLES <list> WITH READ LOCK. # Sending: flush tables; # Switching to connection 'default'. # Wait till the above FLUSH TABLES blocks. # Resume FLUSH TABLES <list> WITH READ LOCK, so it tries to open t2 # discovers that its t1 is obsolete and tries to reopen all tables. # Such reopen should not cause releasing of SNW metadata locks # which would result in assertion failures. set debug_sync='now SIGNAL go'; # Switching to connection 'con2'. # Reap FLUSH TABLES <list> WITH READ LOCK. unlock tables; # Switching to connection 'con1'. # Reap FLUSH TABLES. # Clean-up. # Switching to connection 'default'. drop tables t1, t2; set debug_sync= 'RESET'; # # Test for bug #46748 "Assertion in MDL_context::wait_for_locks() # on INSERT + CREATE TRIGGER". # drop tables if exists t1, t2, t3, t4, t5; # Let us simulate scenario in which we open some tables from extended # part of prelocking set but then encounter conflicting metadata lock, # so have to back-off and wait for it to go away. create table t1 (i int); create table t2 (j int); create table t3 (k int); create table t4 (l int); create trigger t1_bi before insert on t1 for each row insert into t2 values (new.i); create trigger t2_bi before insert on t2 for each row insert into t3 values (new.j); # # Switching to connection 'con1root'. lock tables t4 read; # # Switching to connection 'con2root'. # Send : rename table t3 to t5, t4 to t3;; # # Switching to connection 'default'. # Wait until the above RENAME TABLE adds pending requests for exclusive # metadata lock on its tables and blocks due to 't4' being used by LOCK # TABLES. # Send : insert into t1 values (1);; # # Switching to connection 'con1root'. # Wait until INSERT statement waits due to encountering pending # exclusive metadata lock on 't3'. unlock tables; # # Switching to connection 'con2root'. # Reap RENAME TABLE. # # Switching to connection 'default'. # Reap INSERT. # Clean-up. drop tables t1, t2, t3, t5; # # Bug#42546 - Backup: RESTORE fails, thinking it finds an existing table # DROP TABLE IF EXISTS t1; set @save_log_output=@@global.log_output; set global log_output=file; # # Test 1: CREATE TABLE # # Connection 2 # Start insert on the not-yet existing table # Wait after taking the MDL lock SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; INSERT INTO t1 VALUES(1,"def"); # Connection 1 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Now INSERT has a MDL on the non-existent table t1. # # Continue the INSERT once CREATE waits for exclusive lock SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL finish'; # Try to create that table. CREATE TABLE t1 (c1 INT, c2 VARCHAR(100), KEY(c1)); # Connection 2 # Insert fails ERROR 42S02: Table 'test.t1' doesn't exist # Connection 1 SET DEBUG_SYNC= 'RESET'; SHOW TABLES; Tables_in_test t1 DROP TABLE IF EXISTS t1; # # Test 2: CREATE TABLE LIKE # CREATE TABLE t2 (c1 INT, c2 VARCHAR(100), KEY(c1)); # Connection 2 # Start insert on the not-yet existing table # Wait after taking the MDL SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL locked WAIT_FOR finish'; INSERT INTO t1 VALUES(1,"def"); # Connection 1 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Now INSERT has a MDL on the non-existent table t1. # # Continue the INSERT once CREATE waits for exclusive lock SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL finish'; # Try to create that table. CREATE TABLE t1 LIKE t2; # Connection 2 # Insert fails ERROR 42S02: Table 'test.t1' doesn't exist # Connection 1 SET DEBUG_SYNC= 'RESET'; SHOW TABLES; Tables_in_test t1 t2 DROP TABLE t2; DROP TABLE IF EXISTS t1; set global log_output=@save_log_output; # # Bug #46044 "MDL deadlock on LOCK TABLE + CREATE TABLE HIGH_PRIORITY # FOR UPDATE" # drop tables if exists t1, t2; create table t1 (i int); # Let us check that we won't deadlock if during filling # of I_S table we encounter conflicting metadata lock # which owner is in its turn waiting for our connection. lock tables t1 read; # Switching to connection 'con46044'. # Sending: create table t2 select * from t1 for update;; # Switching to connection 'default'. # Waiting until CREATE TABLE ... SELECT ... is blocked. # First let us check that SHOW FIELDS/DESCRIBE doesn't # gets blocked and emits and error. show fields from t2; ERROR HY000: Table 'test'.'t2' was skipped since its definition is being modified by concurrent DDL statement # Now test for I_S query which reads only .FRMs. # # Query below should only emit a warning. select column_name from information_schema.columns where table_schema='test' and table_name='t2'; column_name Warnings: Warning 1684 Table 'test'.'t2' was skipped since its definition is being modified by concurrent DDL statement # Finally, test for I_S query which does full-blown table open. # # Query below should not be blocked. Warning message should be # stored in the 'table_comment' column. select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t2'; table_name table_type auto_increment table_comment t2 BASE TABLE NULL Table 'test'.'t2' was skipped since its definition is being modified by concurrent DDL statement Warnings: Warning 1684 Table 'test'.'t2' was skipped since its definition is being modified by concurrent DDL statement # Switching to connection 'default'. unlock tables; # Switching to connection 'con46044'. # Reaping CREATE TABLE ... SELECT ... . drop table t2; # # Let us also check that queries to I_S wait for conflicting metadata # locks to go away instead of skipping table with a warning in cases # when deadlock is not possible. This is a nice thing from compatibility # and ease of use points of view. # # We check same three queries to I_S in this new situation. # Switching to connection 'con46044_2'. lock tables t1 read; # Switching to connection 'con46044'. # Sending: create table t2 select * from t1 for update;; # Switching to connection 'default'. # Waiting until CREATE TABLE ... SELECT ... is blocked. # Let us check that SHOW FIELDS/DESCRIBE gets blocked. # Sending: show fields from t2;; # Switching to connection 'con46044_2'. # Wait until SHOW FIELDS gets blocked. unlock tables; # Switching to connection 'con46044'. # Reaping CREATE TABLE ... SELECT ... . # Switching to connection 'default'. # Reaping SHOW FIELDS ... Field Type Null Key Default Extra i int(11) YES NULL drop table t2; # Switching to connection 'con46044_2'. lock tables t1 read; # Switching to connection 'con46044'. # Sending: create table t2 select * from t1 for update;; # Switching to connection 'default'. # Waiting until CREATE TABLE ... SELECT ... is blocked. # Check that I_S query which reads only .FRMs gets blocked. # Sending: select column_name from information_schema.columns where table_schema='test' and table_name='t2';; # Switching to connection 'con46044_2'. # Wait until SELECT COLUMN_NAME FROM I_S.COLUMNS gets blocked. unlock tables; # Switching to connection 'con46044'. # Reaping CREATE TABLE ... SELECT ... . # Switching to connection 'default'. # Reaping SELECT COLUMN_NAME FROM I_S.COLUMNS column_name i drop table t2; # Switching to connection 'con46044_2'. lock tables t1 read; # Switching to connection 'con46044'. # Sending: create table t2 select * from t1 for update;; # Switching to connection 'default'. # Waiting until CREATE TABLE ... SELECT ... is blocked. # Finally, check that I_S query which does full-blown table open # also gets blocked. # Sending: select table_name, table_type, auto_increment, table_comment from information_schema.tables where table_schema='test' and table_name='t2';; # Switching to connection 'con46044_2'. # Wait until SELECT ... FROM I_S.TABLES gets blocked. unlock tables; # Switching to connection 'con46044'. # Reaping CREATE TABLE ... SELECT ... . # Switching to connection 'default'. # Reaping SELECT ... FROM I_S.TABLES table_name table_type auto_increment table_comment t2 BASE TABLE NULL drop table t2; # Switching to connection 'default'. # Clean-up. drop table t1; # # Test for bug #46273 "MySQL 5.4.4 new MDL: Bug#989 is not fully fixed # in case of ALTER". # drop table if exists t1; set debug_sync= 'RESET'; create table t1 (c1 int primary key, c2 int, c3 int); insert into t1 values (1,1,0),(2,2,0),(3,3,0),(4,4,0),(5,5,0); begin; select * from t1 where c2 = 3; c1 c2 c3 3 3 0 # # Switching to connection 'con46273'. set debug_sync='after_lock_tables_takes_lock SIGNAL alter_table_locked WAIT_FOR alter_go'; alter table t1 add column e int, rename to t2;; # # Switching to connection 'default'. set debug_sync='now WAIT_FOR alter_table_locked'; set debug_sync='mdl_acquire_lock_wait SIGNAL alter_go'; # The below statement should get ER_LOCK_DEADLOCK error # (i.e. it should not allow ALTER to proceed, and then # fail due to 't1' changing its name to 't2'). update t1 set c3=c3+1 where c2 = 3; ERROR 40001: Deadlock found when trying to get lock; try restarting transaction # # Switching to connection 'con46273'. # Reap ALTER TABLE. # # Switching to connection 'default'. # Clean-up. set debug_sync= 'RESET'; drop table t2; # # Test for bug #46673 "Deadlock between FLUSH TABLES WITH READ LOCK # and DML". # drop tables if exists t1; create table t1 (i int); # Switching to connection 'con46673'. begin; insert into t1 values (1); # Switching to connection 'default'. # Statement below should not get blocked. And if after some # changes to code it is there should not be a deadlock between # it and transaction from connection 'con46673'. flush tables with read lock; unlock tables; # Switching to connection 'con46673'. delete from t1 where i = 1; commit; # Switching to connection 'default'. # Clean-up drop table t1; # # Bug#48210 FLUSH TABLES WITH READ LOCK deadlocks # against concurrent CREATE PROCEDURE # # Test 1: CREATE PROCEDURE # Connection 1 # Start CREATE PROCEDURE and open mysql.proc SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL table_opened WAIT_FOR grlwait'; CREATE PROCEDURE p1() SELECT 1; # Connection 2 SET DEBUG_SYNC= 'now WAIT_FOR table_opened'; # Check that FLUSH must wait to get the GRL # and let CREATE PROCEDURE continue SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL grlwait'; FLUSH TABLES WITH READ LOCK; # Connection 1 # Connection 2 UNLOCK TABLES; # Connection 1 SET DEBUG_SYNC= 'RESET'; # Test 2: DROP PROCEDURE # Start DROP PROCEDURE and open tables SET DEBUG_SYNC= 'after_open_table_mdl_shared SIGNAL table_opened WAIT_FOR grlwait'; DROP PROCEDURE p1; # Connection 2 SET DEBUG_SYNC= 'now WAIT_FOR table_opened'; # Check that FLUSH must wait to get the GRL # and let DROP PROCEDURE continue SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL grlwait'; FLUSH TABLES WITH READ LOCK; # Connection 1 # Once FLUSH TABLES WITH READ LOCK starts waiting # DROP PROCEDURE will be waked up and will drop # procedure. Global read lock will be granted after # this statement ends. # # Reaping DROP PROCEDURE. # Connection 2 # Reaping FTWRL. UNLOCK TABLES; # Connection 1 SET DEBUG_SYNC= 'RESET'; # # Bug#50786 Assertion `thd->mdl_context.trans_sentinel() == __null' # failed in open_ltable() # # Supress warnings written to the log file call mtr.add_suppression("Wait on a lock was aborted due to a pending exclusive lock"); DROP TABLE IF EXISTS t1, t2; CREATE TABLE t1 (i INT); CREATE TABLE t2 (i INT); SET @old_general_log= @@global.general_log; SET @@global.general_log= 1; SET @old_log_output= @@global.log_output; SET @@global.log_output= 'TABLE'; SET @old_sql_log_off= @@session.sql_log_off; SET @@session.sql_log_off= 1; # connection: con1 HANDLER t1 OPEN; # connection: con3 SET @@session.sql_log_off= 1; # connection: con2 SET DEBUG_SYNC= 'thr_multi_lock_after_thr_lock SIGNAL parked WAIT_FOR go'; # Sending: SELECT 1; # connection: con3 SET DEBUG_SYNC= 'now WAIT_FOR parked'; # connection: con1 # Sending: SELECT 1; # connection: con3 ALTER TABLE t1 ADD COLUMN j INT; # connection: default SET DEBUG_SYNC= 'now SIGNAL go'; # connection: con1 # Reaping SELECT 1 1 1 HANDLER t1 CLOSE; # connection: con2 # Reaping SELECT 1 1 1 # connection: default DROP TABLE t1, t2; SET DEBUG_SYNC= 'RESET'; SET @@global.general_log= @old_general_log; SET @@global.log_output= @old_log_output; SET @@session.sql_log_off= @old_sql_log_off; # # Additional coverage for bug #50913 "Deadlock between # open_and_lock_tables_derived and MDL". The main test # case is in lock_multi.test # drop table if exists t1; set debug_sync= 'RESET'; create table t1 (i int) engine=InnoDB; # Switching to connection 'con50913_1'. set debug_sync= 'thr_multi_lock_after_thr_lock SIGNAL parked WAIT_FOR go'; # Sending: alter table t1 add column j int; # Switching to connection 'default'. # Wait until ALTER TABLE gets blocked on a sync point after # acquiring thr_lock.c lock. set debug_sync= 'now WAIT_FOR parked'; # The below statement should wait on MDL lock and not deadlock on # thr_lock.c lock. # Sending: truncate table t1; # Switching to connection 'con50913_2'. # Wait until TRUNCATE TABLE is blocked on MDL lock. # Unblock ALTER TABLE. set debug_sync= 'now SIGNAL go'; # Switching to connection 'con50913_1'. # Reaping ALTER TABLE. # Switching to connection 'default'. # Reaping TRUNCATE TABLE. set debug_sync= 'RESET'; drop table t1; # # Test for bug #50998 "Deadlock in MDL code during test # rqg_mdl_stability". # Also provides coverage for the case when addition of # waiting statement adds several loops in the waiters # graph and therefore several searches for deadlock # should be performed. drop table if exists t1; set debug_sync= 'RESET'; create table t1 (i int); # Switching to connection 'con1'. begin; select * from t1; i # Switching to connection 'con2'. begin; select * from t1; i # Switching to connection 'default'. # Start ALTER TABLE which will acquire SNW lock and # table lock and get blocked on sync point. set debug_sync= 'thr_multi_lock_after_thr_lock SIGNAL parked WAIT_FOR go'; # Sending: alter table t1 add column j int; # Switching to connection 'con1'. # Wait until ALTER TABLE gets blocked on a sync point. set debug_sync= 'now WAIT_FOR parked'; # Sending: insert into t1 values (1); # Switching to connection 'con2'. # Sending: insert into t1 values (1); # Switching to connection 'con3'. # Wait until both 'con1' and 'con2' are blocked trying to acquire # SW lock on the table. # Unblock ALTER TABLE. Since it will try to upgrade SNW to X lock # deadlock with two loops in waiting graph will occur. Both loops # should be found and DML statements in both 'con1' and 'con2' # should be aborted with ER_LOCK_DEADLOCK errors. set debug_sync= 'now SIGNAL go'; # Switching to connection 'con1'. # Reaping INSERT. It should end with ER_LOCK_DEADLOCK error and # not wait indefinitely (as it happened before the bugfix). ERROR 40001: Deadlock found when trying to get lock; try restarting transaction commit; # Switching to connection 'con2'. # Reaping INSERT. ERROR 40001: Deadlock found when trying to get lock; try restarting transaction commit; # Switching to connection 'default'. # Reap ALTER TABLE. set debug_sync= 'RESET'; drop table t1; # # Bug#42643: InnoDB does not support replication of TRUNCATE TABLE # # Ensure that a acquired lock is not given up due to a conflict. # DROP TABLE IF EXISTS t1; CREATE TABLE t1 (a INT) ENGINE=InnoDB; INSERT INTO t1 VALUES (1),(2),(3); # Connection: con1 LOCK TABLES t1 WRITE; SET debug_sync='upgrade_lock_for_truncate SIGNAL parked_truncate WAIT_FOR go_truncate'; TRUNCATE TABLE t1; # Connection: default SET debug_sync='now WAIT_FOR parked_truncate'; # Connection: con2 SET debug_sync='after_open_table_ignore_flush SIGNAL parked_show WAIT_FOR go_show'; SHOW FIELDS FROM t1; # Connection: default SET debug_sync='now WAIT_FOR parked_show'; # Connection: con3 SET debug_sync='after_flush_unlock SIGNAL parked_flush WAIT_FOR go_flush'; FLUSH TABLES t1; # Connection: default SET debug_sync='now WAIT_FOR parked_flush'; SET debug_sync='now SIGNAL go_truncate'; # Ensure that truncate waits for a exclusive lock SET debug_sync= 'now SIGNAL go_show'; # Connection: con1 (TRUNCATE) # Reaping... UNLOCK TABLES; # Connection: con2 (SHOW FIELDS FROM t1) # Reaping... Field Type Null Key Default Extra a int(11) YES NULL # Connection: default SET debug_sync= 'now SIGNAL go_flush'; # Connection: con3 (FLUSH TABLES t1) # Reaping... # Connection: default SET debug_sync= 'RESET'; DROP TABLE t1; # # Bug#52856 concurrent show columns or show full columns causes a crash!!! # CREATE TABLE t1(a CHAR(255)); SET DEBUG_SYNC= "get_schema_column SIGNAL waiting WAIT_FOR completed"; SHOW FULL COLUMNS FROM t1; SET DEBUG_SYNC= "now WAIT_FOR waiting"; SHOW FULL COLUMNS FROM t1; Field Type Collation Null Key Default Extra Privileges Comment a char(255) latin1_swedish_ci YES NULL # SET DEBUG_SYNC= "now SIGNAL completed"; Field Type Collation Null Key Default Extra Privileges Comment a char(255) latin1_swedish_ci YES NULL # DROP TABLE t1; # # Tests for schema-scope locks # DROP DATABASE IF EXISTS db1; DROP DATABASE IF EXISTS db2; # Test 1: # CREATE DATABASE blocks database DDL on the same database, but # not database DDL on different databases. Tests X vs X lock. # # Connection default SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: CREATE DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: CREATE DATABASE db1; # Connection con3 CREATE DATABASE db2; ALTER DATABASE db2 DEFAULT CHARACTER SET utf8; DROP DATABASE db2; SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: CREATE DATABASE db1 # Connection con2 # Reaping: CREATE DATABASE db1 ERROR HY000: Can't create database 'db1'; database exists # Test 2: # ALTER DATABASE blocks database DDL on the same database, but # not database DDL on different databases. Tests X vs X lock. # # Connection default SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8; # Connection con3 CREATE DATABASE db2; ALTER DATABASE db2 DEFAULT CHARACTER SET utf8; DROP DATABASE db2; SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8 # Connection con2 # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8 # Connection default SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: DROP DATABASE db1; # Connection con3 SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8 # Connection con2 # Reaping: DROP DATABASE db1 CREATE DATABASE db1; # Test 3: # Two ALTER..UPGRADE of the same database are mutually exclusive, but # two ALTER..UPGRADE of different databases are not. Tests X vs X lock. # # Connection default SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: ALTER DATABASE `#mysql50#a-b-c` UPGRADE DATA DIRECTORY NAME; # Connection con3 ALTER DATABASE `#mysql50#a-b-c-d` UPGRADE DATA DIRECTORY NAME; SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: ALTER DATABASE '#mysql50#a-b-c' UPGRADE DATA DIRECTORY NAME # Connection con2 # Reaping: ALTER DATABASE '#mysql50#a-b-c' UPGRADE DATA DIRECTORY NAME ERROR 42000: Unknown database '#mysql50#a-b-c' DROP DATABASE `a-b-c`; DROP DATABASE `a-b-c-d`; # Test 4: # DROP DATABASE blocks database DDL on the same database, but # not database DDL on different databases. Tests X vs X lock. # # Connection default SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: DROP DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: DROP DATABASE db1; # Connection con3 CREATE DATABASE db2; ALTER DATABASE db2 DEFAULT CHARACTER SET utf8; DROP DATABASE db2; SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: DROP DATABASE db1 # Connection con2 # Reaping: DROP DATABASE db1 ERROR HY000: Can't drop database 'db1'; database doesn't exist # Connection default CREATE DATABASE db1; SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: DROP DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8; # Connection con3 SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: DROP DATABASE db1 # Connection con2 # Reaping: ALTER DATABASE db1 DEFAULT CHARACTER SET utf8 Got one of the listed errors # Test 5: # Locked database name prevents CREATE of tables in that database. # Tests X vs IX lock. # # Connection default CREATE DATABASE db1; SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: DROP DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: CREATE TABLE db1.t1 (a INT); # Connection con3 SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: DROP DATABASE db1 # Connection con2 # Reaping: CREATE TABLE db1.t1 (a INT) ERROR 42000: Unknown database 'db1' # Test 6: # Locked database name prevents RENAME of tables to/from that database. # Tests X vs IX lock. # # Connection default CREATE DATABASE db1; CREATE TABLE db1.t1 (a INT); SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: DROP DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: RENAME TABLE db1.t1 TO test.t1; # Connection con3 SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: DROP DATABASE db1 # Connection con2 # Reaping: RENAME TABLE db1.t1 TO test.t1 Got one of the listed errors # Connection default CREATE DATABASE db1; CREATE TABLE test.t2 (a INT); SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: DROP DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: RENAME TABLE test.t2 TO db1.t2; # Connection con3 SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: DROP DATABASE db1 # Connection con2 # Reaping: RENAME TABLE test.t2 TO db1.t2 Got one of the listed errors DROP TABLE test.t2; # Test 7: # Locked database name prevents DROP of tables in that database. # Tests X vs IX lock. # # Connection default CREATE DATABASE db1; CREATE TABLE db1.t1 (a INT); SET DEBUG_SYNC= 'after_wait_locked_schema_name SIGNAL locked WAIT_FOR blocked'; # Sending: DROP DATABASE db1; # Connection con2 SET DEBUG_SYNC= 'now WAIT_FOR locked'; # Sending: DROP TABLE db1.t1; # Connection con3 SET DEBUG_SYNC= 'now SIGNAL blocked'; # Connection default # Reaping: DROP DATABASE db1 # Connection con2 # Reaping: DROP TABLE db1.t1 ERROR 42S02: Unknown table 't1' # Connection default SET DEBUG_SYNC= 'RESET'; # # End of tests for schema-scope locks # # # Tests of granted global S lock (FLUSH TABLE WITH READ LOCK) # CREATE DATABASE db1; CREATE TABLE db1.t1(a INT); # Connection default FLUSH TABLE WITH READ LOCK; # Connection con2 CREATE TABLE db1.t2(a INT); # Connection default UNLOCK TABLES; # Connection con2 # Reaping CREATE TABLE db1.t2(a INT) # Connection default FLUSH TABLE WITH READ LOCK; # Connection con2 ALTER DATABASE db1 DEFAULT CHARACTER SET utf8; # Connection default UNLOCK TABLES; # Connection con2 # Reaping ALTER DATABASE db1 DEFAULT CHARACTER SET utf8 # Connection default FLUSH TABLE WITH READ LOCK; # Connection con2 FLUSH TABLE WITH READ LOCK; UNLOCK TABLES; # Connection default UNLOCK TABLES; DROP DATABASE db1; # # Bug#56292 Deadlock with ALTER TABLE and MERGE tables # DROP TABLE IF EXISTS t1, t2, m1; CREATE TABLE t1(a INT) engine=MyISAM; CREATE TABLE t2(a INT) engine=MyISAM; CREATE TABLE m1(a INT) engine=MERGE UNION=(t1, t2); INSERT INTO t1 VALUES (1), (2); INSERT INTO t2 VALUES (3), (4); # Connection con1 SET DEBUG_SYNC= 'mdl_upgrade_shared_lock_to_exclusive SIGNAL upgrade WAIT_FOR continue'; # Sending: ALTER TABLE m1 engine=MERGE UNION=(t2, t1); # Connection con2 # Waiting for ALTER TABLE to try lock upgrade SET DEBUG_SYNC= 'now WAIT_FOR upgrade'; # Sending: DELETE FROM t2 WHERE a = 3; # Connection default # Check that DELETE is waiting on a metadata lock and not a table lock. # Now that DELETE blocks on a metadata lock, we should be able to do # SELECT * FROM m1 here. SELECT used to be blocked by a DELETE table # lock request. SELECT * FROM m1; a 1 2 3 4 # Resuming ALTER TABLE SET DEBUG_SYNC= 'now SIGNAL continue'; # Connection con1 # Reaping: ALTER TABLE m1 engine=MERGE UNION=(t2, t1) # Connection con2 # Reaping: DELETE FROM t2 WHERE a = 3 # Connection default DROP TABLE m1, t1, t2; SET DEBUG_SYNC= 'RESET';
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