12 C++20’s Calendars and Time Zones in MSVC Miya Natsuhara ("MEE-yuh Not-soo-HAR-uh") Miya.Natsuhara@microsoft.com Software Engineer, Visual C++ LibrariesWelcome to CppCon 2021! Join leap_seconds (https://youtu.be/WX3OmVu4lAs) • time_zone and time_zone_link (https://youtu.be/MODhhr7m-5s) • system_clock::now(), file_clock, leap second awareness (https://youtu.be/c7DT28TV0AY)9 Part II: Safety The “simple” calendrical types (e.g., day, month, year) are very straightforward – what’s the point in creating types for these concepts at all? Couldn’t we just use unsigned int for each

(kenieevan@github) Zhiguohong (honkiko@github) Bypassing conntrack: Optimizing K8s Service By Enhancing IPVS with eBPF Agenda 目录 01 Problems with K8s Service How to optimize 02 Comparison with industry Performance Performance measurement 03 04 Future work 05 06 Lessons from eBPF What is K8s Service • It exposes a set of pods via VIP using a load balancer • Two types • ClusterIP provides in-cluster access • NodePort Move IPVS Netfilter hook from local-in to PREROUTING • The challenges • Skb’s pointer to route is NULL during PREROUTING • No de-fragment is done during PREROUTING IPVS bypass conntrack (con.) • Egress

WAPC_init • Register_function cannot be called inside ping • _start is meant to support tinygo’s wasm • waPC host will still run both "wapc_init" and "_start" during intialization waPC Guest rust 打包所有测试需求 Wasm mock server Why use rust ？ Software testing tool • 模拟数据规则 • 自动化测试 • Company's own protocol • Microservices • Multiple backend product line with complex upstream • Common testing 1\r\nHost: golang.org\r\nConnection: close\r\nUser-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X; de-de)\r\n\r\ n"), HttpBody:vec![], ProxyUrl:String::from("")

developer from China  The main translator of the book «Gray Hat Hacking The Ethical Hacker's Handbook, Fourth Edition» (ISBN ： 9787302428671) & «Linux Hardening in Hostile Networks com/microkernel-in-operating-systems.html I. Background  . Source: https://os.inf.tu-dresden.de/Studium/MkK//SS2021/01_intro.pdf Architecture & Design 1.2 L4 Overview I. Background  https://en https://github.com/seL4/capdl CapDL I. Background  https://sel4.systems/Info/FAQ/proof.pml  seL4’s proof toolchain Status

• cudaAddressModeBorder ：超出范围就用零代替 • 示意： 00 | ABCDE | 00 • cudaAddressModeWrap ：重叠模式（循环） • 示意： DE | ABCDE | AB • cudaAddressModeMirror ：镜像模式 • 示意： BA | ABCDE | ED CUDA 纹理对象：封装 • 其中 cudaTextureFilterMode

字符串 (string) 就是由字符 (character) 组成的数组。 • C 语言中，字符串用双引号 “” 包裹，字符用单引号 ‘’ 包裹 。 • char c = ‘h’; • char s[] = “hello”; C 语言中的字符串 • 正如 ‘ h’ 是个语法糖，等价于 h 的 ASCII 码——整数 104 。 • “hello” 也是个语法糖，他等价于数组 {‘h’, C 语言字符串操作繁琐 封装的 std::string 应运而生 封装的 std::string 应运而生 • string 可以从 const char * 隐式构造： • string s = “hello”; • string 具有 + 、 += 、 == 等直观的运算符重载： • string(“hello”) + string(“world”) == string(“helloworld”) 符合 vector 的接口，例如 begin/end/size/resize…… • string 有一系列成员函数，例如 find/replace/substr…… • string 可以通过 s.c_str() 重新转换回古板的 const char * 。 • string 在离开作用域时自动释放内存 (RAII) ，不用手动 free 。 C++ 字符串和 C 字符串的不同

templateS, class F> ex::sender auto then(S s, F f) { return _then_sender{{}, (S&&) s, (F&&) f}; } ALGORITHM EXAMPLE: THEN39 namespace ex = std::execution; templateS, class F> ex::sender ex::sender auto then(S s, F f) { return _then_sender{{}, (S&&) s, (F&&) f}; } templateS, class F> struct _then_sender : ex::sender_base { S s_; F f_; // Implement connect(sender, receiver) template requires ex::sender_to<S, _then_receiver> decltype(auto) connect(R r) && { return ex::connect( (S&&) s_, _then_receiver{(R&&) r, (F&&) f_}); } };

consteval  Why?  We have std::is_constant_evaluated(), so what’s wrong with: if (std::is_constant_evaluated()) { /*A*/ } else { /*B*/ }  It’s equivalent except for:  if consteval is part of core language the output of the following? int main() { int i = 1 // \ + 42 ; std::cout << i; }  It’s undefined by the standard pre C++23! GCC and Clang write 1, MSVC writes 43  C++23 mandates that whitespace std::println("{}", v); // [(1, 2), (3, 4)] std::set> s { {1, 2}, { 3, 4 } }; std::println("{}", s); // {(1, 2), (3, 4)} std::map m { {1, 2}, { 3, 4 } }; std::println("{}"

Please hold your questions until the end • Write down the slide numbers • Part 0: Overview • What's happened in the last year • Part 1: C++20 STL Features • Everything here is Standard, except as noted using namespace std; int main() { cout << boolalpha; short s = -1; unsigned int ui = 1729; cout << (s < ui) << endl; } • What does this print? • warning C4018: '<': signed/unsigned using namespace std; int main() { cout << boolalpha; short s = -1; unsigned int ui = 1729; cout << cmp_less(s, ui) << endl; } • This prints true ✔10 template

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shared_ptr s1: control_block: atomic ref_count = 1; … control_block* ctrl; T12 Daniel Anderson -- danielanderson.net std::shared_ptr (the basics) T* ptr; shared_ptr s1: control_block: control_block: control_block* ctrl; T T* ptr; shared_ptr s2: control_block* ctrl; atomic ref_count = 2; …13 Daniel Anderson -- danielanderson.net std::shared_ptr (the basics) control_block: control_block: T T* ptr; control_block* ctrl; atomic ref_count = 1; … shared_ptr s2:14 Daniel Anderson -- danielanderson.net std::shared_ptr (the basics) control_block: T atomic ref_count