diff options
| -rw-r--r-- | mysql-test/suite/innodb/r/innodb-lock.result | 22 | ||||
| -rw-r--r-- | mysql-test/suite/innodb/t/innodb-lock.test | 26 | ||||
| -rw-r--r-- | storage/innobase/lock/lock0lock.cc | 25 |
3 files changed, 67 insertions, 6 deletions
diff --git a/mysql-test/suite/innodb/r/innodb-lock.result b/mysql-test/suite/innodb/r/innodb-lock.result index 8d069991f90..75fb41f1cb4 100644 --- a/mysql-test/suite/innodb/r/innodb-lock.result +++ b/mysql-test/suite/innodb/r/innodb-lock.result @@ -334,3 +334,25 @@ ERROR 40001: Deadlock found when trying to get lock; try restarting transaction connection default; disconnect con1; drop table t1; +# +# MDEV-10962 Deadlock with 3 concurrent DELETEs by unique key +# +create table t1 (a int unique) engine innodb; +insert into t1 values (1); +connect con1, localhost, root,, test; +connect con2, localhost, root,, test; +connect con3, localhost, root,, test; +connection con1; +delete from t1 where a = 1; +connection con2; +delete from t1 where a = 1; +connection con3; +delete from t1 where a = 1; +connection con1; +connection con2; +connection con3; +connection default; +disconnect con1; +disconnect con2; +disconnect con3; +drop table t1; diff --git a/mysql-test/suite/innodb/t/innodb-lock.test b/mysql-test/suite/innodb/t/innodb-lock.test index f73bf0d5a99..d17d73991aa 100644 --- a/mysql-test/suite/innodb/t/innodb-lock.test +++ b/mysql-test/suite/innodb/t/innodb-lock.test @@ -401,4 +401,28 @@ drop table t1; # TODO (MDEV-10962): H) Insert into an already passed locked gap (15) - +--echo # +--echo # MDEV-10962 Deadlock with 3 concurrent DELETEs by unique key +--echo # +create table t1 (a int unique) engine innodb; +insert into t1 values (1); +connect (con1, localhost, root,, test); +connect (con2, localhost, root,, test); +connect (con3, localhost, root,, test); +connection con1; +send delete from t1 where a = 1; +connection con2; +send delete from t1 where a = 1; +connection con3; +send delete from t1 where a = 1; +connection con1; +reap; +connection con2; +reap; +connection con3; +reap; +connection default; +disconnect con1; +disconnect con2; +disconnect con3; +drop table t1; diff --git a/storage/innobase/lock/lock0lock.cc b/storage/innobase/lock/lock0lock.cc index 771fc406fbd..68bfea0456b 100644 --- a/storage/innobase/lock/lock0lock.cc +++ b/storage/innobase/lock/lock0lock.cc @@ -985,25 +985,40 @@ lock_rec_other_has_conflicting( ulint heap_no,/*!< in: heap number of the record */ const trx_t* trx) /*!< in: our transaction */ { - lock_t* res = NULL; + lock_t* conflict = NULL; + bool skip_waiting = false; bool is_supremum = (heap_no == PAGE_HEAP_NO_SUPREMUM); for (lock_t* lock = lock_sys_t::get_first(cell, id, heap_no); lock; lock = lock_rec_get_next(heap_no, lock)) { + + if (skip_waiting && lock->is_waiting()) { + continue; + } + /* If current trx already acquired a lock not weaker covering same types then we don't have to wait for any locks. */ if (lock->is_stronger(mode, heap_no, trx)) { return(NULL); - } + } else if (lock->trx == trx && !lock->is_waiting()) { + if (conflict && conflict->is_waiting()) { + conflict = NULL; + } + skip_waiting = true; + } else if (lock_rec_has_to_wait(true, trx, mode, lock, + is_supremum)) { - if (!res && lock_rec_has_to_wait(true, trx, mode, lock, is_supremum)) { - res = lock; + if (!conflict || (conflict->is_waiting() + && !lock->is_waiting())) { + + conflict = lock; + } } } - return(res); + return(conflict); } /*********************************************************************//** |