Linked by Thom Holwerda on Sun 9th Sep 2007 18:08 UTC, submitted by koki
BeOS & Derivatives "The primary intention of my previous article was to make it very clear why and when locking is needed in multithreaded applications. In this article, I want to present my experiences in writing a new prototype for a replacement of the document model in WonderBrush and how it is manipulated and rendered asynchronously."
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Writing multithreaded applications in C++
by tuttle on Mon 10th Sep 2007 08:44 UTC
tuttle
Member since:
2006-03-01

...is like pulling teeth. Many BeOS applications were full of multithreading bugs. They always kind of worked, but were never really stable.

Modern languages like scala make writing multithreaded apps much easier. Scala has a very powerful message passing library (actors) that is somewhat similar to the erlang approach. The pattern matching of scala makes writing message handlers extremely pleasant.

http://lamp.epfl.ch/~phaller/doc/ActorsTutorial.html

Reply Score: 1

stippi Member since:
2006-01-19

"Writing multithreaded applications in C++ is like pulling teeth"

That's a bit of a weird statement. Doesn't that totally depend on the available API?

Reply Parent Score: 4

tuttle Member since:
2006-03-01

It does depend on the available API to a certain degree. Writing multithreaded applications using the BeOS api is certainly less painful then writing them using the Win32 API.

And using a transactional memory library writing low level/high performance multithreaded code can be almost bearable.

But for example implementing message passing is much more pleasant in a language that has support for pattern matching. And generally writing multithreaded code requires good support for immutable data structures.

A garbage collector is also immensely helpful for message passing. C++ has neither of those, so it is just a bad choice for multithreaded applications.

Reply Parent Score: 1

Vanders Member since:
2005-07-06

Writing multithreaded applications in C++ is like pulling teeth.


I don't agree. The problem is that a lot of developers just won't or will not understand multi-threading. Using a language that "hides" the locking & message passing details may help mitigate that problem somewhat, but they'll still have very little idea of how it works.

Writing multi-threaded C++ is easy. There are three or four rules to remember and that's about it. Any developer should be capable of it.

Reply Parent Score: 7

TQH ! Member since:
2006-03-16

Exactly.

Reply Parent Score: 1

tuttle Member since:
2006-03-01

I don't agree. The problem is that a lot of developers just won't or will not understand multi-threading.


The majority of developers are incapable of writing multithreaded code with fine-grained locking. That is just a fact. So your approach is to tell these people to learn low level multithreading primitives or go to hell. Great way to get new developers for your niche platform.

Using a language that "hides" the locking & message passing details may help mitigate that problem somewhat, but they'll still have very little idea of how it works.


First of all, scala does not hide the message passing details. It just lets you write a message handler in 1/10th the lines of code compared to C++.

And what is the problem about hiding complexity? Many people use the stl without having the slightest idea about the alorithms used by it. Are you saying that abstraction is bad?

Besides, just because somebody does not get low level threading primitives like semaphores and mutexes does not mean that he is a bad programmer. Maybe he has valuable domain specific knowledge.

And I guess all those people using Erlang to program high performance telecommunications gear must be idiots because they use a language that hides many multithreading problems...

Reply Parent Score: 1

dylansmrjones Member since:
2005-10-02

Most unstable applications for BeOS were/are those ported from other platforms (usually with focus on single-threaded behaviour). Native BeOS applications have a reputation for being quite stable.

Reply Parent Score: 4