Concurrency in C# Cookbook, 2nd Edition

Appendix A. Legacy Platform Support

Many of the technologies discussed in this book have some support for older platforms as well. If you’re in the unfortunate situation where you need to support these platforms, the information in this appendix may help you determine which technologies are available. Using these technologies on older platforms isn’t ideal; and even if you get it working, bear in mind that the only long-term solution is to update the platform target for your code. This appendix is intended mainly as a historical reference and not as a recommendation; that said, maintainers of old code may find it useful.

Table A-1 summarizes the support of legacy platforms for different techniques.

Table A-1. Legacy platform support

Platform	async	Parallel	Reactive	Dataflow	Concurrent collections	Immutable collections
.NET 4.5	✓	✓	NuGet	NuGet	✓	NuGet
.NET 4.0	NuGet	✓	NuGet	✗	✓	✗
Windows Phone Apps 8.1	✓	✓	NuGet	NuGet	✓	NuGet
Windows Phone SL 8.0	✓	✗	NuGet	NuGet	✗	NuGet
Windows Phone SL 7.1	NuGet	✗	NuGet	✗	✗	✗
Silverlight 5	NuGet	✗	NuGet	✗	✗	✗

Legacy Platform Support for Async

If you need async support on older legacy platforms, install the NuGet package for Microsoft.Bcl.Async.

Warning

Do not use Microsoft.Bcl.Async to enable async code on ASP.NET running on .NET 4.0! The ASP.NET pipeline was updated in .NET 4.5 to be async-aware, and you must use .NET 4.5 or newer for async ASP.NET projects. Microsoft.Bcl.Async is only for non-ASP.NET applications.

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