Another Concurrency FUD

Today I've stumbled on an article entitled Locks, Actors, And STM In Pictures which looks rather cool, but is a total FUD. It tells a FoxNews kind of story of how troublesome using locks are compared to the new synchronization primitives.

First of all, the author uses an example synchronization problem that is very well solved with locks, and just tells that it is a bad solution without any concrete argumentation.

What's more important though is that he needs to modify the original problem to fit with the alternative solutions.

In the Actor's case we need to resort to a waiter. Can the problem be solved without it? Surely, but the code will be, probably twice as big, and very complicated compared to the lock-based solution. Not to mentioned that it will also be prone to a deadlock. The philosophers code-based solution with a waiter is even simpler: lock the waiter, tell it what to do, unlock it.

And in the STM case we are only taking 2 forks at once, but in the task we need to do it one by one. This seems like a minor issue, but now try to add printing to the mix: can we print "Aristotle took left fork" after he takes left fork, "Aristotle put left fork" if he couldn't take right fork?

PS. I like actors and STM and try to use them where appropriate. I also teach them to students as part of the Operating Systems course.

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