Asynchronous programming in .NET by Gerardo Lijs Twitter @GerardoLijs C# MeetUp Barcelona April 2019 Content What is Asynchronous Programming CPU-bound vs IO-bound Obsolete patterns Tasks and general you will not need other methods of TaskFactory class @GerardoLijs Synchronous method Asynchronous method IO-bound operations • Hard drive • Network • Database • API calls • Hardware read/write the time you will need asynchronous to deal with IO-bound operations and the times you will use CPU-bound operations you will probably use a library that provides asynchronous methods for you to interact

microbenchmarks and a real-world application • Conclusion 26Synchronous/Asynchronous Mechanisms Boil the water Synchronous Asynchronous Wait Polling Callback Check Do your things Multitasking! 27Taro’s motivation behind Taro • We have presented the Taro C++ programming model - Synchronous and Asynchronous mechanisms • We have presented the Taro coroutine-aware scheduling algorithm • We have presented

Tornado [http://www.tornadoweb.org] is a Python web framework and asynchronous networking library, originally developed at FriendFeed [http://friendfeed.com]. By using non-blocking network I/O, Tornado listen(8888) tornado.ioloop.IOLoop.current().start() This example does not use any of Tornado’s asynchronous features; for that see this simple chat room [https://github.com/tornadoweb/tornado/tree/stable/demos/chat] Epub formats [https://readthedocs.org/projects/tornado/downloads/]. User’s guide Introduction Asynchronous and non-Blocking I/O Coroutines Queue example - a concurrent web spider Structure of a Tornado

clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 4.4 Asynchronous networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Index 209 i ii Tornado Documentation, Release 4.5.3 Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado listen(8888) tornado.ioloop.IOLoop.current().start() This example does not use any of Tornado’s asynchronous features; for that see this simple chat room. 5 Tornado Documentation, Release 4.5.3 6 Chapter

clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 5.4 Asynchronous networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Index 229 i ii Tornado Documentation, Release 5.1.1 Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado listen(8888) tornado.ioloop.IOLoop.current().start() This example does not use any of Tornado’s asynchronous features; for that see this simple chat room. 5 Tornado Documentation, Release 5.1.1 6 Chapter

Tornado [http://www.tornadoweb.org] is a Python web framework and asynchronous networking library, originally developed at FriendFeed [http://friendfeed.com]. By using non-blocking network I/O, Tornado listen(8888) tornado.ioloop.IOLoop.current().start() This example does not use any of Tornado’s asynchronous features; for that see this simple chat room [https://github.com/tornadoweb/tornado/tree/stable/demos/chat] typically run with only one thread per process. See the User’s guide for more on Tornado’s approach to asynchronous programming. While some support of WSGI is available in the tornado.wsgi module, it is not a

clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 6.4 Asynchronous networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 231 Index 233 i ii Tornado Documentation, Release 6.1 Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado listen(8888) tornado.ioloop.IOLoop.current().start() This example does not use any of Tornado’s asynchronous features; for that see this simple chat room. 5 Tornado Documentation, Release 6.1 6 Chapter

clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 6.4 Asynchronous networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Index 233 i ii Tornado Documentation, Release 6.0.4 Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado listen(8888) tornado.ioloop.IOLoop.current().start() This example does not use any of Tornado’s asynchronous features; for that see this simple chat room. 5 Tornado Documentation, Release 6.0.4 6 Chapter

clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 6.4 Asynchronous networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 253 Index 255 i ii Tornado Documentation, Release 6.4 Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado wait() if __name__ == "__main__": asyncio.run(main()) This example does not use any of Tornado’s asynchronous features; for that see this simple chat room. 5 Tornado Documentation, Release 6.4 6 Chapter

clients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 6.4 Asynchronous networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 253 Index 255 i ii Tornado Documentation, Release 6.4 Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. By using non-blocking network I/O, Tornado wait() if __name__ == "__main__": asyncio.run(main()) This example does not use any of Tornado’s asynchronous features; for that see this simple chat room. 5 Tornado Documentation, Release 6.4 6 Chapter