Bulldozer00's Blog

On my latest assignment, I have to reverse engineer and understand a large monolithic block of computationally intense, single-threaded product code that’s been feature-enhanced and bug-fixed many times, by many people, over many years (sound familiar?). In addition to the piled on new features, a boatload of nested if-else structures has been injected into the multi-K SLOC code base over the years to handle special and weird cases observed and reported in from the field.

As you can guess, it’s no one’s fault that the code is a tangled mess. It’s because the second law of thermodynamics has been in action doing its dirty work destroying the system without being periodically harnessed by scheduled acts of husbandry. A handful of maintenance developers imbued with a sense of personal responsibility and ownership have tried their best to refactor the beast into submission; under the radar.

Because the code is CPU intensive and single threaded, it’s not scalable to higher input data rates and its viability has hit “the wall”. Thus, besides refactoring the existing functionality into a more maintainable design, I have to simultaneously morph the mess into a multi-threaded structure that can transparently leverage the increased CPU power supplied by multicore hardware.

Note that redesigning for distributed flexibility and higher throughput doesn’t come for free. Essential complexity is added and additional latency is incurred because each input sample must traverse the 3 thread pipeline.

Piece of cake, no? Since lowly “programmers” are interchangeable, anyone could do it, right? I love this job and I’m having a blast!