## Back To Basics Concurrency ## +23 ## DAVID OLSEN ## 3 ## BACK TO BASICS: CONCURRENCY David Olsen, Software Engineer, NVIDIA CppCon, October 5, 2023 ![Image](/uploads/documents/8/2/a/3/82a35 threads ## CONCURRENCY Definition # “Multiple logical threads of execution with unknown inter-task dependencies” - Daisy Hollman, “A Unifying Abstraction for Async,” CppCon 2019 ## CONCURRENCY Definition Unifying Abstraction for Async,” CppCon 2019 ## CONCURRENCY Definition “Multiple logical threads of execution with [some] inter-task dependencies” ## CONCURRENCY Definition “Multiple logical threads of execution

ER ## Concurrency in Rust Alex Crichton ## What's Rust? Rust is a systems programming language that runs blazingly fast, prevents segfaults, and guarantees thread safety. ## Concurrency? Rust? Libraries Futures ## What's concurrency? In computer science, concurrency is a property of systems in which several computations are executing simultaneously, and potentially interacting with each each other. ## Why concurrency?  ## Getting our feet wet // What does this print? int main() { int pid = fork();

## +21 ## Back to Basics: Concurrency ## MIKE SHAH 2021 October 24-29 ## Please do not redistribute slides without prior permission ## Back to Basics: Concurrency Mike Shah, Ph.D. @MichaelShah | mshah about the free lunch being over for programmers? In this talk we provide a gentle introduction to concurrency with the modern C++ std::thread library. We will introduce topics with pragmatic code examples locks, and showing how these programming primitives enable concurrency. In addition, we will show the common pitfalls to be aware of with concurrency: data races, starvation, and deadlock (the most extreme

## +21 ## Concurrency Patterns ## RAINER GRIMM 20 21 October 24-29 ## Definition "Each pattern is a three-part rule, which expresses a relation between a certain context, a problem, and a solution Interaction 7. Solution 8. Example 9. Consequenses 10. Related pattern 11. Known usages ## Concurrency Patterns ## Pattern-Oriented Software Architecture (Volume 2 and 4)  ## Concurrency Patterns ## Synchronization Patterns Concurrent Architecture ## Dealing with Sharing ■ Copied

## Back to Basics: Concurrency I also do C++ training! arthur.j.odwyer@gmail.com ## Outline - What is a data race and how do we fix it? [3–12] • C++11 mutex and RAI lock types [13–23] Questions? • • The blue/green pattern [46–52] ● Bonus C++20 slides [53–58] Questions? ## What is concurrency? - Concurrency means doing two things concurrently — “running together.” Maybe you’re switching back and music - In extremely broad strokes, parallelism is a hardware problem (think multiple CPUs) and concurrency is a software problem (think time-sharing, but also Intel’s “hyperthreading”). ## Why does C++

## Concurrency Patterns in Go Artsiom Bukhautsou Senior Backend Engineer @Nord Security ## Agenda 1. Fan-in 2. Fan-out 3. Pipeline 4. Fan-in, Fan-out, Pipeline 5. Tee 🌱 ## Why learn these patterns

## +24 ## Coroutines and Structured Concurrency in Practice ## DMITRY PROKOPTSEV ## Challenges when onboarding coroutines A lot of existing code mostly callback-based A custom-built I/O event loop object lifetime management • Easier error propagation But we need some structure ## Structured concurrency And why we care ## A typical async framework class Task { ... } represents a unit of background co_return visit(identity{}, v); } } ## Structured concurrency Tasks naturally form a "call tree" • coroutines • leaf awaitables (sleeping, I/O, etc)

## Sender Patterns to Wrangle Concurrency in Embedded Devices ## Michael Caisse michael.caisse@intel.com @MichaelCaisse  Ben the count one digit at a time. 3. When done, yell "End of Line" ## async/concurrency ## async/concurrency  Sender Video Sponsorship Provided By millennium think-cell ## Employing Senders and Receivers to Tame Concurrency in Embedded Systems Michael Caisse ![Image](/uploads/documents/b/6/3/4/b634ea0ff3787e922361221add7688ef/p44_1

Trading/Embedded - Editor: C++ SG5 Transactional Memory Technical Specification • Editor: C++ SG1 Concurrency Technical Specification MISRA C++ and AUTOSAR Chair of Standards Council Canada TC22/SC32 Electrical some from our own contributions • Many joined, average 5-8 per meeting • Also consulted outside concurrency and safety experts • Shared Drive of Phase 1 analysis: https://docs.google.com/document/d/14 • In these cases we wonder if an [[intention:]] attribute might help ## Where should parallel/concurrency/hetero rules go? |Human decidable|Tool decidable|Suitable tools in order of preference| |---|---|---|

## +21 ## The Upcoming Concurrency TS Version 2 for Low-Latency and Lockless Synchronization ## MAGED MICHAEL, MICHAEL WONG & PAUL MCKENNEY pcon The C++ Conference 20 21 October 24-29 Maged Michael Michael ## Agenda ### 1. Don’t we already have a Concurrency TS? • Why do we need a new one? • implementation status 2.TS2 Hazard Pointer • how I learn to love C++ tricks ### 3. TS2 RCU • From C to /f/6/f0f673cc15de005f5c335ee7edeab6dd/p3_1.jpg) ## Concurrency TS1: Don’t we already have a TS? • Produced in 2015 - Produced by the Concurrency Study Group (SG1) with input from LEWG, LWG • Separate