Auto-merge from mysql-next-4284.

mysql-test/include/handler.inc

@@ -1681,3 +1681,25 @@ handler t1 close;
 --echo # Clean-up.
 drop function f1;
 drop tables t1, t2;
+
+
+--echo #
+--echo # Test for bug #51136 "Crash in pthread_rwlock_rdlock on TEMPORARY +
+--echo #                      HANDLER + LOCK + SP".
+--echo # Also see additional coverage for this bug in flush.test.
+--echo #
+--disable_warnings
+drop tables if exists t1, t2;
+--enable_warnings
+create table t1 (i int);
+create temporary table t2 (j int);
+handler t1 open;
+lock table t2 read;
+--echo # This commit should not release any MDL locks.
+commit;
+unlock tables;
+--echo # The below statement crashed before the bug fix as it
+--echo # has attempted to release metadata lock which was
+--echo # already released by commit.
+handler t1 close;
+drop tables t1, t2;

mysql-test/r/flush.result

@@ -94,3 +94,20 @@ unlock tables;
 set global general_log= @old_general_log;
 set global read_only= @old_read_only;
 End of 5.1 tests
+#
+# Additional test for bug #51136 "Crash in pthread_rwlock_rdlock
+#                                 on TEMPORARY + HANDLER + LOCK + SP".
+# Also see the main test for this bug in include/handler.inc.
+#
+drop tables if exists t1, t2;
+create table t1 (i int);
+create temporary table t2 (j int);
+flush tables with read lock;
+lock table t2 read;
+# This commit should not release any MDL locks.
+commit;
+# The below statement crashed before the bug fix as it
+# has attempted to release global shared metadata lock
+# which was already released by commit.
+unlock tables;
+drop tables t1, t2;

mysql-test/r/handler_innodb.result

@@ -1667,3 +1667,21 @@ handler t1 close;
 # Clean-up.
 drop function f1;
 drop tables t1, t2;
+#
+# Test for bug #51136 "Crash in pthread_rwlock_rdlock on TEMPORARY +
+#                      HANDLER + LOCK + SP".
+# Also see additional coverage for this bug in flush.test.
+#
+drop tables if exists t1, t2;
+create table t1 (i int);
+create temporary table t2 (j int);
+handler t1 open;
+lock table t2 read;
+# This commit should not release any MDL locks.
+commit;
+unlock tables;
+# The below statement crashed before the bug fix as it
+# has attempted to release metadata lock which was
+# already released by commit.
+handler t1 close;
+drop tables t1, t2;

mysql-test/r/handler_myisam.result

@@ -1664,6 +1664,24 @@ handler t1 close;
 drop function f1;
 drop tables t1, t2;
 #
+# Test for bug #51136 "Crash in pthread_rwlock_rdlock on TEMPORARY +
+#                      HANDLER + LOCK + SP".
+# Also see additional coverage for this bug in flush.test.
+#
+drop tables if exists t1, t2;
+create table t1 (i int);
+create temporary table t2 (j int);
+handler t1 open;
+lock table t2 read;
+# This commit should not release any MDL locks.
+commit;
+unlock tables;
+# The below statement crashed before the bug fix as it
+# has attempted to release metadata lock which was
+# already released by commit.
+handler t1 close;
+drop tables t1, t2;
+#
 # BUG #46456: HANDLER OPEN + TRUNCATE + DROP (temporary) TABLE, crash 
 #
 CREATE TABLE t1 AS SELECT 1 AS f1;

mysql-test/r/lock_multi.result

@@ -436,3 +436,29 @@ UNLOCK TABLES;
 # Reaping: DROP TABLE t1, t2
 # Connection default
 # Cleanup
+#
+# Test for bug #51134 "Crash in MDL_lock::destroy on a concurrent
+#                      DDL workload".
+#
+drop tables if exists t1, t2, t3;
+create table t3 (i int);
+# Switching to connection 'con1'
+# Lock 't3' so upcoming RENAME is blocked.
+lock table t3 read;
+# Switching to connection 'con2'
+# Remember ID for this connection.
+# Start statement which will try to acquire two instances
+# of X metadata lock on the same object.
+# Sending:
+rename tables t1 to t2, t2 to t3;;
+# Switching to connection 'default'
+# Wait until RENAME TABLE is blocked on table 't3'.
+# Kill RENAME TABLE.
+kill query ID;
+# Switching to connection 'con2'
+# RENAME TABLE should be aborted but should not crash.
+ERROR 70100: Query execution was interrupted
+# Switching to connection 'con1'
+unlock tables;
+# Switching to connection 'default'
+drop table t3;

mysql-test/t/flush.test

@@ -203,3 +203,24 @@ set global general_log= @old_general_log;
 set global read_only= @old_read_only;
 
 --echo End of 5.1 tests
+
+
+--echo #
+--echo # Additional test for bug #51136 "Crash in pthread_rwlock_rdlock
+--echo #                                 on TEMPORARY + HANDLER + LOCK + SP".
+--echo # Also see the main test for this bug in include/handler.inc.
+--echo #
+--disable_warnings
+drop tables if exists t1, t2;
+--enable_warnings
+create table t1 (i int);
+create temporary table t2 (j int);
+flush tables with read lock;
+lock table t2 read;
+--echo # This commit should not release any MDL locks.
+commit;
+--echo # The below statement crashed before the bug fix as it
+--echo # has attempted to release global shared metadata lock
+--echo # which was already released by commit.
+unlock tables;
+drop tables t1, t2;

mysql-test/t/lock_multi.test

@@ -1038,5 +1038,59 @@ disconnect con2;
 disconnect con3;
 
 
+--echo #
+--echo # Test for bug #51134 "Crash in MDL_lock::destroy on a concurrent
+--echo #                      DDL workload".
+--echo #
+--disable_warnings
+drop tables if exists t1, t2, t3;
+--enable_warnings
+connect (con1, localhost, root, , );
+connect (con2, localhost, root, , );
+connection default;
+create table t3 (i int);
+
+--echo # Switching to connection 'con1'
+connection con1;
+--echo # Lock 't3' so upcoming RENAME is blocked.
+lock table t3 read;
+
+--echo # Switching to connection 'con2'
+connection con2;
+--echo # Remember ID for this connection.
+let $ID= `select connection_id()`;
+--echo # Start statement which will try to acquire two instances
+--echo # of X metadata lock on the same object.
+--echo # Sending:
+--send rename tables t1 to t2, t2 to t3;
+
+--echo # Switching to connection 'default'
+connection default;
+--echo # Wait until RENAME TABLE is blocked on table 't3'.
+let $wait_condition=
+  select count(*) = 1 from information_schema.processlist
+  where state = "Waiting for table" and info = "rename tables t1 to t2, t2 to t3";
+--source include/wait_condition.inc
+--echo # Kill RENAME TABLE.
+--replace_result $ID ID
+eval kill query $ID;
+
+--echo # Switching to connection 'con2'
+connection con2;
+--echo # RENAME TABLE should be aborted but should not crash.
+--error ER_QUERY_INTERRUPTED
+--reap
+
+--echo # Switching to connection 'con1'
+connection con1;
+unlock tables;
+
+--echo # Switching to connection 'default'
+connection default;
+disconnect con1;
+disconnect con2;
+drop table t3;
+
+
 # Wait till all disconnects are completed
 --source include/wait_until_count_sessions.inc

sql/mdl.cc

@@ -1532,6 +1532,7 @@ bool MDL_context::acquire_locks(MDL_request_list *mdl_requests,
 {
   MDL_request_list::Iterator it(*mdl_requests);
   MDL_request **sort_buf, **p_req;
+  MDL_ticket *mdl_svp= mdl_savepoint();
   ssize_t req_count= static_cast<ssize_t>(mdl_requests->elements());
 
   if (req_count == 0)
@@ -1565,12 +1566,16 @@ bool MDL_context::acquire_locks(MDL_request_list *mdl_requests,
   return FALSE;
 
 err:
-  /* Release locks we have managed to acquire so far. */
+  /*
+    Release locks we have managed to acquire so far.
+    Use rollback_to_savepoint() since there may be duplicate
+    requests that got assigned the same ticket.
+  */
+  rollback_to_savepoint(mdl_svp);
+  /* Reset lock requests back to its initial state. */
   for (req_count= p_req - sort_buf, p_req= sort_buf;
        p_req < sort_buf + req_count; p_req++)
   {
-    release_lock((*p_req)->ticket);
-    /* Reset lock request back to its initial state. */
     (*p_req)->ticket= NULL;
   }
   my_free(sort_buf, MYF(0));

sql/mdl.h

@@ -501,7 +501,7 @@ class MDL_context
 
   void set_trans_sentinel()
   {
-    m_trans_sentinel= mdl_savepoint();
+    m_trans_sentinel= m_tickets.front();
   }
   MDL_ticket *trans_sentinel() const { return m_trans_sentinel; }