On one of my machines, I can consistently get the following test failure, because of an exception throw here:
As you can see, we get an ObjectDisposedException here, which cause the test to fail. There is only one problem with that:
We only dispose the queue manager on the dispose method, and that can only be called if the test itself was completed.
On the face of it, it looks like I am doing things correctly, but there is a bug here. The CLR’s threading semantics are not broken, even though on first glance it appears so.
As a side note, people keep asking me how I blog so much. This post is a perfect example. When I started writing this blog post, I was truly stamped. By the time I finished, I already noticed where the bug was and fixed it.
Can you tell?
More posts in "Challenge" series:
- (28 Sep 2018) The loop that leaks–Answer
- (27 Sep 2018) The loop that leaks
- (03 Apr 2018) The invisible concurrency bug–Answer
- (02 Apr 2018) The invisible concurrency bug
- (31 Jan 2018) Find the bug in the fix–answer
- (30 Jan 2018) Find the bug in the fix
- (19 Jan 2017) What does this code do?
- (26 Jul 2016) The race condition in the TCP stack, answer
- (25 Jul 2016) The race condition in the TCP stack
- (28 Apr 2015) What is the meaning of this change?
- (26 Sep 2013) Spot the bug
- (27 May 2013) The problem of locking down tasks…
- (17 Oct 2011) Minimum number of round trips
- (23 Aug 2011) Recent Comments with Future Posts
- (02 Aug 2011) Modifying execution approaches
- (29 Apr 2011) Stop the leaks
- (23 Dec 2010) This code should never hit production
- (17 Dec 2010) Your own ThreadLocal
- (03 Dec 2010) Querying relative information with RavenDB
- (29 Jun 2010) Find the bug
- (23 Jun 2010) Dynamically dynamic
- (28 Apr 2010) What killed the application?
- (19 Mar 2010) What does this code do?
- (04 Mar 2010) Robust enumeration over external code
- (16 Feb 2010) Premature optimization, and all of that…
- (12 Feb 2010) Efficient querying
- (10 Feb 2010) Find the resource leak
- (21 Oct 2009) Can you spot the bug?
- (18 Oct 2009) Why is this wrong?
- (17 Oct 2009) Write the check in comment
- (15 Sep 2009) NH Prof Exporting Reports
- (02 Sep 2009) The lazy loaded inheritance many to one association OR/M conundrum
- (01 Sep 2009) Why isn’t select broken?
- (06 Aug 2009) Find the bug fixes
- (26 May 2009) Find the bug
- (14 May 2009) multi threaded test failure
- (11 May 2009) The regex that doesn’t match
- (24 Mar 2009) probability based selection
- (13 Mar 2009) C# Rewriting
- (18 Feb 2009) write a self extracting program
- (04 Sep 2008) Don't stop with the first DSL abstraction
- (02 Aug 2008) What is the problem?
- (28 Jul 2008) What does this code do?
- (26 Jul 2008) Find the bug fix
- (05 Jul 2008) Find the deadlock
- (03 Jul 2008) Find the bug
- (02 Jul 2008) What is wrong with this code
- (05 Jun 2008) why did the tests fail?
- (27 May 2008) Striving for better syntax
- (13 Apr 2008) calling generics without the generic type
- (12 Apr 2008) The directory tree
- (24 Mar 2008) Find the version
- (21 Jan 2008) Strongly typing weakly typed code
- (28 Jun 2007) Windsor Null Object Dependency Facility