The 15 ways of doing concurrency in .NET

A reliable source told me that there are 15 ways to do concurrency in .NET. The goal of this post is to write them all down with a brief note for each.

I am not an expert in concurrency , so will not succeed without your help. Do you know one that I missed? Tell me on Twitter @dicshaunary .

1. Task-based Asynchronous Pattern (TAP).
   • This includes the await syntactic sugar.
   • See MSDN .
2. Event-based Asynchronous Pattern (EAP).
   • This is the MethodNameAsync and MethodNameCompleted pattern.
   • See MSDN .
3. Asynchronous Programming Model (APM).
   • This is the BeginOperationName and EndOperationName pattern.
   • See MSDN.
4. Background Worker.
   • Run an operation on a dedicated, separate thread.
   • See MSDN.
5. Interlocked.
   • Run atomic operations on variables that exist on multiple threads.
   • “Lock free concurrency.”
   • See MSDN.
   • Thank you @lwischik
6. Raw Threading.
   • Directly create and control a thread.
   • See MSDN and this MSDN tutorial.
   • Thank you @boguscoder
7. Parallel Linq.
   • Run LINQ to Objects’ queries in parallel.
   • See MSDN.
   • Thank you @mmjuraszek
8. Thread Pooling.
   • Add tasks to a queue and start tasks as threads become available.
   • See MSDN.
   • Thank you @boguscoder
9. Process.
   • Use System.Diagnostics.Process.Start() to start a process.
   • See MSDN.
   • Thank you @mmjuraszek
10. Parallel Loops.
    • Use Parallel.For and Parallel.ForEach to run loops in parallel.
    • See MSDN.
    • Thank you @lwischik
11. Control.MailBoxProcessor<`Msg>. (F#).
    • Post messages to a message-processing agent, which processes the messages asynchronously.
    • See MSDN.
    • Thank you @monkeyonahill
12. Reactive Extensions.
    • Use Observables, LINQ, and Schedulers to compose asynchronous and event-based programs.
    • See MSDN.
    • Thank you @monkeyonahill
13. Action Block
    • TODO. Add a note.
    • See MSDN
    • Thank you @mmjuraszek
14. Monitor.Wait & Monitor.Pulse with Plain Old Locks
    • This is syntactic sugar over top of Plain Old Locks.
    • See MSDN
    • Thank you @gusev_p
15. Plain Old Locks
    • TODO. Add a note.
    • See MSDN
    • Thank you @gusev_p

Know one that isn’t listed? Help the list reach 15 on Twitter @dicshaunary .

Thank you to Lucian for starting the conversation.

How many ways to do concurrency in .NET? https://t.co/4qDWcBvQHr also Interlocked.CompareExchange for lock-free concurrency @dicshaunary

— Lucian Wischik (@lwischik) November 15, 2015

TODO

• Organize the above into paradigms and their various implementations.
• Add an example for each, perhaps as a Gist or a .NET Fiddle.
• Add advantages and disadvantages of each.
• Add appropriate use cases for each.
• Legacy vs current. Make a note of which are current and which are legacy. (Thank you Reddit https://redd.it/3uvs84 )