1. Concurrency
How to shoot yourself in both feet.
Simultaneously.
Victor Haydin
R&D Manager @ ELEKS

2. The Problem

3. Multithreading?
Parallelism?
Concurrency?

6. Concurrent programming*
* as you imagine it

7. * in real world

9. Shared state

10. Traditional way

13. WTF?!

14. Web 2.0 – 2003
First dual-core CPU – 2005
Cloud Computing - 2006

15. C++ - 1983
Java - 1995
C# - 2001

16. Alternate ways

17. Transactional memory
Functional programming
Messaging

19. atomic {
if (from.Ballance < amount)
throw new InsufficientBalanceException("Not enough money");
from.Debit(amount);
to.Credit(amount);
}

20. Atomic.Do(() => {
if (from.Ballance < amount)
throw new InsufficientBalanceException("Not enough money");
from.Debit(amount);
to.Credit(amount);
});

21. STM HTM

23. Immutable data means no side
effects. No side effects – no
concurrency problems!*
* except if you need I/O

24. Wait a second, what about I/O?

26. FP != easy concurrency
FP == easy parallelism

32. NAct
Stact
Retlang

34. …or use single thread.

35. Q&A