stephencleary/asyncex

AsyncEx is a helper library for C# developers working with async and await, which are language features that let programs do multiple things at once without freezing up. When you write code that runs asynchronously, you sometimes need tools to coordinate different parts of your program so they do not step on each other, and that coordination is what AsyncEx provides. The most commonly used piece is AsyncLock, which is a way to make sure only one part of your program can enter a section of code at a time. This kind of control is called mutual exclusion, and it is a standard problem in concurrent programming. AsyncEx's version works properly with async and await, which older approaches do not, because the older tools were built before those language features existed. You can also set a timeout so that if a lock is not available within a certain window, the waiting code gives up rather than hanging forever. Beyond AsyncLock, the library includes a full set of coordination tools: AsyncSemaphore, AsyncManualResetEvent, AsyncAutoResetEvent, AsyncConditionVariable, AsyncMonitor, AsyncCountdownEvent, and AsyncReaderWriterLock. Each of these is a standard building block that programmers use to manage timing and access between concurrent tasks, adapted here to work correctly with C#'s async model. The library targets .NET Standard, which means it works across .NET 4.6.NET Core, Xamarin for iOS and Android, and Universal Windows apps. It is distributed as a NuGet package, which is the standard way C# developers add libraries to their projects. The README is brief and points to separate documentation files for the full API details.