Use BlockingCollection in SharedTextWriter

[bjorkstromm]

Did some profiling and noticed a lot of time was spent on ShareTextWriter.WriteLine and SharedTextWriter.WriteLineAsync.

Noticed the lock and figured we could use SemaphoreSlim instead.

[bjorkstromm]

[bjorkstromm]

Could do some benchmarks to see if there's any actual performance boost.

[david-driscoll]

I just figure if we can avoid blocking a thread at all it would probably be better.

[rchande]

@mholo65 What do you think of implementing this with BlockingCollection<T>? https://docs.microsoft.com/en-us/dotnet/api/system.collections.concurrent.blockingcollection-1?view=netcore-3.0

[david-driscoll]

@rchande I'd be fine with that.

@mholo65 lsp already has this with the output handler https://github.com/OmniSharp/csharp-language-server-protocol/blob/7d8567c09c88d27b4b4a2209959f689df8e9419d/src/JsonRpc/OutputHandler.cs

[rchande]

Actually, blockingCollection blocks a thread, so this is probably better.

[david-driscoll]

A blocking collection will only block it's own thread, not the calling task, assuming you just queue the item up. For input / output it probably makes more sense to just have the dedicated thread, then we can queue data up for it as fast as we're allowed, but it'll write out at whatever rate it can.

As long as the order is guaranteed (which by default BlockingCollection uses ConcurrentQueue) I think dumping handling the writing in another thread might make sense.

Thoughts? @mholo65 @rchande

As it is I'm fine with this change, but it might almost make more sense to refactor it entirely.

[bjorkstromm]

@david-driscoll @rchande I think that BlockingCollection is even better, then we'll dump the IO to another thread, and won't block main thread.

[bjorkstromm]

@david-driscoll @rchande @filipw I modified this PR to use BlockingCollection instead, also no need for the Async version anymore.

[filipw]

thanks 👏