Comment by nocman | Hacker News Reader

Comment by nocman | Hacker News Reader

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In fairness the person you were responding to was referring to their own personal experience. They certainly are not the first person to conclude that doing non-trivial concurrent programming is too difficult for them. I agree that it is achievable with an appropriate level of care and experience, but I know there are many very smart people that conclude that multithreaded programming in C++ is too difficult for their taste.

Even Rich Hickey, when discussing concurrency in Java/C#/C++ said "I am tired of trying to get right, because it is simply far too difficult."

> In particular, talk about shared state, how we do it today, how you do it in C#, Java, or C++, what happens when we get into a multi-threaded context, and specifically what are some of the current solutions for that in those spaces. Locking, in particular. That is something I have done a lot of, over a long period of time, and I am tired of trying to get right, because it is simply far too difficult.

( https://github.com/matthiasn/talk-transcripts/blob/master/Hi... )

The first point to understand is that a knowledge of Concurrent Programming (in all its guises) is mandatory for all programmers today.

The second point to note is that when people like Rich Hickey or John Ousterhout talk about multi-threaded programming being "hard" they are talking about a level of depth far beyond what a "normal" application programmer will encounter in his/her entire career. These guys span everything from Apps/OS/Compilers/Language/Hardware and hence by necessity know the full gamut of complexity involved in concurrency. Trying to understand concurrency across all the above abstraction layers is very difficult and that is what they mean when they say it is "hard".

But for most application programmers the above is simply not relevant and they can comfortably stay at higher-level abstractions given by their language/library and ignore lower-level details unless and until forced by other needs like performance etc. One can do a lot with this knowledge alone and indeed that is what most of us do.

So instead of making wild statements like "random crashes and segfaults" and "too hard to program" learn to use heuristics/commonsense to simplify the code structure eg. a) copy code patterns given by reputed authors so one does not make unnecessary errors b) Keep the number of locks to a minimum by using a few "global locks" rather than a lot of "granular locks" c) Learn to use Thread Local Storage d) Acquire locks/resources in the same order to avoid deadlocks etc etc.

> Java/C#/C++

These three have different memory models, concurrency primitives and adopted practices...it's odd that they are lobbed together.

It's not odd at all. The underlying problems to be solved are identical.

Also, Rich has many years of experience using all three of those languages.

The two out of three have evolved in this area since.

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