Entries Tagged ‘Concurrency’

What tools do you use to program multiple processor cores?

Wednesday, July 27th, 2011 by Robert Cravotta

Developers have been designing and building multi-processor systems for decades. New multicore processors are entering the market on a regular basis. However, it seems that the market for new development tools that help designers analyze, specify, code, test, and maintain software targeting multi-processor systems is lagging further and further behind the hardware offerings.

A key function of development tools is to help abstract the complexity that developers must deal with to build the systems they are working on. The humble assembler abstracted the zeros and ones of machine code into more easily remembered mnemonics that enabled developers to build larger and more complex programs. Likewise, compilers have been evolving to provide yet another important level of abstraction for programmers and have all but replaced the use of assemblers for the vast majority of software projects. A key value of operating systems is that it abstracts the configuration, access, and scheduling of the increasing number of hardware resources available in a system from the developer.

If multicore and multi-processor designs are to experience an explosion in use in the embedded and computing markets, it seems that development tools should provide more abstractions to simplify the complexity of building with these significantly more complex processor configurations.

In general, programming languages do not understand the concept of concurrency, and the extensions that do exist usually require the developer to identify the concurrency and explicitly identify where and when such concurrency exists. Developing software as a set of threads is an approach for abstracting concurrency; however, it is not clear how using a threading design method will be able to scale as systems approach ever larger numbers of cores within a single system. How do you design a system with enough threads to occupy more than a thousand cores – or is that the right question?

What tools do you use when programming a multicore or multi-processor system? Does your choice of programming language and compiler reduce your complexity in such designs or does it require you to actively engage more complexity by explicitly identifying areas for parallelism? Do your debugging tools provide you with adequate visibility and control of a multicore/multi-processor system to be able to understand what is going on within the system without requiring you to spend ever more time at the debugging bench with each new design? Does using a hypervisor help you, and if so, what are the most important functions you look for in a hypervisor?