What Makes Parallel Programming Difficult? 196
An anonymous reader writes "Intel's Aater Suleman writes about why parallel programming is difficult. ... I was unaware ... that a major challenge in multi-threaded programming lies in optimizing parallel programs not just getting them to run. His analysis is insightful and the case study is very enlightening if you are unfamiliar with parallel code debugging. "
Re:unaware? WTF? (Score:5, Insightful)
synchronization with data separation, mutex's and avoiding deadlocks and race conditions has been solved since almost the beginning of parallelism
And yet people constantly get these details wrong in practice.
It's an extra layer of complexity and it introduces extra chances to make mistakes, even around areas where a programmer could know better. There's not much way around that. If people only made coding mistakes around difficult problems software would be dramatically more bulletproof than it actually is.
"What Makes Parallel Programming Difficult?" (Score:2, Insightful)
That you have to do everything all at once. How would you tell 50 kids to sort 50 toy cars? How would you tell 50 footballers to line up by height all at once? How would you have 50 editors edit the 50 pages of a screenplay all at once so that it makes sense from a continuity perspective? All these problems are very easy, but become very hard when you have to do it all at once...