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I have a huge collection which I would like to process each of the object in a parallel fashion. Doing the same synchronously typically involves a simple "foreach".
Just wondering, what to use in my scenario i.e., either Parallel.ForEach or MyCollection.AsParallel().ForAll().
Can you shed me some light on benefits of using the one vs the other.
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Note, in this situation Parallel. ForEach expects you to store your results in a thread-safe manner, while PLINQ handles those details for you.
The execution of Parallel. Foreach is faster than normal ForEach.
The short answer is no, you should not just use Parallel. ForEach or related constructs on each loop that you can. Parallel has some overhead, which is not justified in loops with few, fast iterations. Also, break is significantly more complex inside these loops.
The Parallel. ForEach method splits the work to be done into multiple tasks, one for each item in the collection. Parallel. ForEach is like the foreach loop in C#, except the foreach loop runs on a single thread and processing take place sequentially, while the Parallel.
The way I see it, if all you want to do is to parallelize a foreach, you should use its parallel version, which is Parallel.ForEach().
ParallelEnumerable.ForAll() is for the specific case where you have a LINQ query followed by a foreach and you want to parallelize both of them. So, what you do is that you parallelize the LINQ query by adding AsParallel() and then you parallelize the foreach by changing it into ForAll().
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Time both and pick the winner.
I have found Parallel.ForEach to perform better in most delightfully parallel scenarios. It would seem that it uses a more advanced work balancing model. PLINQ is primarily aimed at parallelising queries.
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