Gil Zilberfeld's presentation from ADC2011 on identifying and preventing multithreading issues.

1. Rise of the Heisenbug Gil Zilberfeld

3. Product Manager at Typemock

4. @gil_zilberfeld

6. My First TDD Project

7. Progress has beaten us The Multicore Mainstream Languages don’t help Tools are complex

8. We can do so much more

9. Concurrency problems State problems Race conditions Deadlocks

10. Heisenberg’s Uncertainty Principle It is impossible to know both the exact position and the exact velocity of an object at the same time

11. Heisenbug The process of hunting the bug impacts our ability to catch it

12. Heisenbugs Identification is hard Reproduction is hard Fixing is easy Checking the fix is hard

13. A Methodological Solution Reproduce Write a failing test Fix it Keep the test

14. It should work! Works for logic Shouldn’t it work for concurrency?

15. Repeatability is the issue Produce the same result Any computer Any configuration

16. What’s the Solution? Proper tools

17. Catching Race Conditions Example using CThru

18. Catching deadlocks Using Racer

19. Other Tools Static Analysis http://en.wikipedia.org/wiki/List_of_tools_for_static_code_analysis AOP http://www.bodden.de/tools/aop-dot-net/ Microsoft CHESS http://research.microsoft.com/en-us/projects/chess/

20. Back to Basics Code reviews Awareness Architecture Safe guards Tools

21. Questions? Twitter: @gil_zilberfeld http://www.gilzilberfeld.com gilz@typemock.com