branches/5.1: Make

SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED
a true replacement of SET GLOBAL INNODB_LOCKS_UNSAFE_FOR_BINLOG=1.
This fixes an error that was introduced in r370, causing
semi-consistent read not to not unlock rows in READ COMMITTED mode.
(Bug #41671, Issue #146)

rb://67 approved by Heikki Tuuri

handler/ha_innodb.cc

@@ -4129,7 +4129,8 @@ ha_innobase::unlock_row(void)
 	switch (prebuilt->row_read_type) {
 	case ROW_READ_WITH_LOCKS:
 		if (!srv_locks_unsafe_for_binlog
-		|| prebuilt->trx->isolation_level == TRX_ISO_READ_COMMITTED) {
+		    && prebuilt->trx->isolation_level
+		    != TRX_ISO_READ_COMMITTED) {
 			break;
 		}
 		/* fall through */

mysql-test/innodb-semi-consistent-master.opt

---innodb_locks_unsafe_for_binlog=true --innodb_lock_wait_timeout=2
+--innodb_lock_wait_timeout=2

mysql-test/innodb-semi-consistent.result

 drop table if exists t1;
 set binlog_format=mixed;
-set session transaction isolation level read committed;
+set session transaction isolation level repeatable read;
 create table t1(a int not null) engine=innodb DEFAULT CHARSET=latin1;
 insert into t1 values (1),(2),(3),(4),(5),(6),(7);
 set autocommit=0;
@@ -8,11 +8,12 @@ select * from t1 where a=3 lock in share mode;
 a
 3
 set binlog_format=mixed;
-set session transaction isolation level read committed;
+set session transaction isolation level repeatable read;
 set autocommit=0;
 update t1 set a=10 where a=5;
 ERROR HY000: Lock wait timeout exceeded; try restarting transaction
 commit;
+set session transaction isolation level read committed;
 update t1 set a=10 where a=5;
 select * from t1 where a=2 for update;
 ERROR HY000: Lock wait timeout exceeded; try restarting transaction

mysql-test/innodb-semi-consistent.test

@@ -11,7 +11,7 @@ connect (a,localhost,root,,);
 connect (b,localhost,root,,);
 connection a;
 set binlog_format=mixed;
-set session transaction isolation level read committed;
+set session transaction isolation level repeatable read;
 create table t1(a int not null) engine=innodb DEFAULT CHARSET=latin1;
 insert into t1 values (1),(2),(3),(4),(5),(6),(7);
 set autocommit=0;
@@ -19,13 +19,15 @@ set autocommit=0;
 select * from t1 where a=3 lock in share mode;
 connection b;
 set binlog_format=mixed;
-set session transaction isolation level read committed;
+set session transaction isolation level repeatable read;
 set autocommit=0;
 -- error ER_LOCK_WAIT_TIMEOUT
 update t1 set a=10 where a=5;
 connection a;
 commit;
 connection b;
+# perform a semi-consisent read (and unlock non-matching rows)
+set session transaction isolation level read committed;
 update t1 set a=10 where a=5;
 connection a;
 -- error ER_LOCK_WAIT_TIMEOUT
@@ -33,6 +35,7 @@ select * from t1 where a=2 for update;
 # this should lock the records (1),(2)
 select * from t1 where a=2 limit 1 for update;
 connection b;
+# semi-consistent read will skip non-matching locked rows a=1, a=2
 update t1 set a=11 where a=6;
 -- error ER_LOCK_WAIT_TIMEOUT
 update t1 set a=12 where a=2;

row/row0mysql.c

@@ -1486,12 +1486,13 @@ row_unlock_for_mysql(
 	ut_ad(prebuilt && trx);
 	ut_ad(trx->mysql_thread_id == os_thread_get_curr_id());
 
-	if (!(srv_locks_unsafe_for_binlog
-	      || trx->isolation_level == TRX_ISO_READ_COMMITTED)) {
+	if (UNIV_UNLIKELY
+	    (!srv_locks_unsafe_for_binlog
+	     && trx->isolation_level != TRX_ISO_READ_COMMITTED)) {
 
 		fprintf(stderr,
 			"InnoDB: Error: calling row_unlock_for_mysql though\n"
-			"InnoDB: srv_locks_unsafe_for_binlog is FALSE and\n"
+			"InnoDB: innodb_locks_unsafe_for_binlog is FALSE and\n"
 			"InnoDB: this session is not using"
 			" READ COMMITTED isolation level.\n");