Last week, Asaf Shelly described the evolution of computer languages from early days Assembly to Object Oriented languages favored today in his post titled, “Flaws of Object Oriented Modeling“. In this post, the author talks about whether MS DOS is an ideal parallel system.

“These questions are raised only today because until now we had only a single core CPU and we used a few threads very carefully. Today we are facing a revolution that could bring 128 CPU cores very soon. In order to utilize the CPU we must use multiple threads. To fully utilize a 128 core CPU we must use at least 128 threads (worker threads, not waiting threads). The bad news is that most applications do not have 128 different processes at the same time. Usually it is between one to a few CPU consuming processes simultaneously which means that we will end up having multiple threads doing the same job. Using locks is out of the question because a lock is a way to pin down a resource to a single core which is the opposite of using multiple cores.

Before we go any further to talk about advanced solutions and new models, we should take a look at existing technologies that are available today. The technology that most affects us is the environments in which out code runs. We must familiarize ourselves with these environments – the operating systems and its services.

Going from the most commonly used to the least, I will start with Windows (NT based) OS. It is important to mention that the Windows OS is made out of two completely different operating systems. One is User Mode With its Win32 API and the other is Kernel Mode that has a completely different programming model, API, and execution environment. We start with Windows User Mode, then UNIX, continue to Windows Kernel, and last explore DOS as an ideal parallel system.

This article is broken into four parts because of it’s length.”

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