From c9dc936a2bf850132513059732bc8f7fe8441e53 Mon Sep 17 00:00:00 2001 From: Davi Arnaut Date: Tue, 3 Feb 2009 15:16:24 -0200 Subject: Bug#40536: SELECT is blocked by INSERT DELAYED waiting on upgrading lock, even with low_priority_updates The problem is that there is no mechanism to control whether a delayed insert takes a high or low priority lock on a table. The solution is to modify the delayed insert thread ("handler") to take into account the global value of low_priority_updates when taking table locks. The value of low_priority_updates is retrieved when the insert delayed thread is created and will remain the same for the duration of the thread. include/thr_lock.h: Update prototype. mysql-test/r/delayed.result: Add test case result for Bug#40536 mysql-test/t/delayed.test: Add test case for Bug#40536 mysys/thr_lock.c: Add function parameter which specifies the write lock type. sql/sql_insert.cc: Take a low priority write lock if global value of low_priority_updates was ON when the thread was created. --- mysql-test/r/delayed.result | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'mysql-test/r/delayed.result') diff --git a/mysql-test/r/delayed.result b/mysql-test/r/delayed.result index bcda6ddb6ab..4d5d656f3ce 100644 --- a/mysql-test/r/delayed.result +++ b/mysql-test/r/delayed.result @@ -284,4 +284,30 @@ ERROR 22007: Incorrect date value: '0000-00-00' for column 'f1' at row 1 INSERT DELAYED INTO t2 VALUES (0,'2007-00-00'); ERROR 22007: Incorrect date value: '2007-00-00' for column 'f1' at row 1 DROP TABLE t1,t2; +set @old_delayed_updates = @@global.low_priority_updates; +set global low_priority_updates = 1; +select @@global.low_priority_updates; +@@global.low_priority_updates +1 +drop table if exists t1; +create table t1 (a int, b int); +insert into t1 values (1,1); +lock table t1 read; +connection: update +insert delayed into t1 values (2,2);; +connection: select +select * from t1; +a b +1 1 +connection: default +select * from t1; +a b +1 1 +unlock tables; +select * from t1; +a b +1 1 +2 2 +drop table t1; +set global low_priority_updates = @old_delayed_updates; End of 5.1 tests -- cgit v1.2.1