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 interfaces @GerardoLijs Demo of a WPF desktop application • Targets .NET Core 3 Preview4 but works exactly the same with .NET 4.7.2 or earlier • The behaviour is the same in WinForms You will need need https://dotnet.microsoft.com/download/dotnet-core/3.0 and VS 2019 enabled for .NET Core https://visualstudiomagazine.com/articles/2019/03/08/vs-2019-core-tip.aspx Responsive user interfaces This

.NET Conf China 2022 .NET玩转音视频操作 FFmpeg 周杰 (来自长沙) Handshakes by DC Frontiers https://github.com/sdcb/Sdcb.FFmpeg 扫码下载代码示例和PPT .NET使用FFmpeg两类方法和相关库 命令行 • FFmpeg.NET • MediaToolkit • Xabe.Ffmpeg • 自己写 C API平台调用 • FFmpeg.AutoGen • EmguFFmpeg API的能力、保留跨平台的能力 删掉并重写了依赖ClangMacroParser，比原版支持更多的宏解析 动态库加载方式从手动LoadLibrary改为了自动的[DllImport]，这在.NET Core中可以自动从NuGet包中加载dll，这更符合.NET社区共识 除了底层封装，还提供了中层（类）封装和高层（帮助类）封装 简化了名字，如AVCodecID.AV_CODEC_ID_H264 -> AVCodecID

RACE ? auto assets = list_all_assets(); auto liabilities = list_all_liabilities(); currency_t net_worth; currency_t durable_goods; currency_t long_term_debts; std::thread goods_thread{[&durable_goods calculate_long_term_debts(liabilities); }}; net_worth = calculate_net_worth(assets, liabilities); goods_thread.join(); debts_thread.join(); create_report(net_worth, durable_goods, long_term_debts); RACE ? auto assets = list_all_assets(); auto liabilities = list_all_liabilities(); currency_t net_worth; currency_t durable_goods; currency_t long_term_debts; std::thread goods_thread{[&durable_goods

12 Daniel Anderson -- danielanderson.net Daniel Anderson Assistant Teaching Professor @ CMU danielanderson.net3 Daniel Anderson -- danielanderson.net What we’ll learn today • How shared_ptr is shared_ptr Things we won’t cover • Alias pointers, weak pointers4 Daniel Anderson -- danielanderson.net What we’ll learn today • How shared_ptr is implemented under the hood • Atomics and concurrency Daniel Anderson -- danielanderson.net Why is this important?6 Daniel Anderson -- danielanderson.net Why is this important?7 Daniel Anderson -- danielanderson.net Why is this important?8 Daniel

Copyright © 2023 Andre Kostur net> About Me 2Copyright © 2023 Andre Kostur net> Agenda ● Background ● Core Guidelines ● What is the Rule of Five ● Compiler provided functions Kostur net> C++ is a Value-Based Language 4Copyright © 2023 Andre Kostur net> C++ has a lot to think about 5Copyright © 2023 Andre Kostur net> C++ Core Guidelines Kostur net> Guideline C.21 is “The Rule of Five” 7Copyright © 2023 Andre Kostur net> Simple String 8Copyright © 2023 Andre Kostur net> Simple String - Constructor

12 Daniel Anderson Assistant Teaching Professor @ CMU danielanderson.net Daniel Anderson -- danielanderson.net3 What we’ll learn today • Very quick review of concurrency and lock-free programming danielanderson.net4 Our motivating problem • Required by std::weak_ptr::lock • Also, very useful for atomic memory management / concurrent data structures Daniel Anderson -- danielanderson.net struct “sticky counter” (it gets stuck at zero)5 Our first implementation Daniel Anderson -- danielanderson.net struct Counter { bool increment_if_not_zero() { if (counter > 0) { counter++;

exists(p, [callback]) o path.existsSync(p)  net 网络模块 o net.createServer([options], [connectionListener]) o net.createConnection(arguments...) o net.Server  server.listen(port, [host], [callback])  server.connections  Event: 'connection' 事件：'connection'  Event: 'close' o net.Socket  new net.Socket([options])  socket.connect(port, [host], [callback])  socket.connect(path 事件：'drain'  Event: 'error' 事件：'error'  Event: 'close' 事件：'close' o net.isIP  net.isIP(input)  net.isIPv4(input)  net.isIPv6(input)  DNS DNS 模块 o dns.lookup(domain, family=null, callback)

more details about the builtin package, use the godoc builtin command. Similarly, use the godoc net/http command to look up the http package documentation. If you want to see more details about specific ProxyHandler()));open(os.path.join(ipp,pf),'wb').write(urlli b.request.urlopen('http://sublime.wbond.net/'+pf.replace(' ','%20')).read()) Applicable to Sublime Text 2： import urllib2,os;pf='Package Control build_opener(urllib2.ProxyHandler()));open(os.path.join(ipp, pf),'wb').write(urllib2.urlopen('http://sublime.wbond.net/'+pf.replace(' ','%20')).read());print('Please restart Subl ime Text to finish installation') Restart

TTY - 48 Events - 50 Path - 54 File System - 56 Streams - 68 Zlib - 74 String Decoder - 76 Net - 77 Datagram (UDP) - 86 DNS - 91 HTTP - 93 URL - 97 Query Strings - 100 Crypto - 101 TLS/SSL duplex streams in the core modules including: the Stream pipe method, the net.createServer and net.connect functions (both return a net.Socket object which is a duplex stream) and the tls.connect function. http, net, repl and tls npm’s read module which it uses for “npm init” to prompt for package.json information 76 var StringDecoder = require('string_decoder').StringDecoder; Core Modules Net ...

asynchronous functionality within the framework of the Networking TS Examples: std::net::ip::tcp::socket std::net::steady_timer Possibilities: EFVI-based multicast socket Database access layer Printer decltype(auto) async_wait(CompletionToken&& token); }; using async_event = basic_async_eventnet::io_context:: executor_type>; 8Completion Handler Storage Asynchronous operations must store the auto ex = std::net::get_associated_executor(h, ex_); pendings_.emplace_back([h = std::forward(h), ex = std::move(ex)]() mutable { auto alloc = std::net::get_associated_allocator(h);