Caching Compiler (RECC) CppCon 2024 September 19, 2024 Shivam Bairoliya Software Engineer© 2024 Bloomberg Finance L.P. All rights reserved. What is RECC? ● Remote Execution Caching Compiler (RECC) ○ Open source build tool that wraps compiler commands and optionally forwards them to a remote build execution service ○ Encompasses the capabilities of both ccache and distcc ○ Supports remote linking linking and caching ● Designed to share caches across diverse toolchains ○ Works with many compiler toolchains (GCC, Clang, Solaris CC) ○ Supports multiple operating systems (Linux, macOS, Solaris)

Go 1.4 runtime Gopher China 2015 1. Memory Allocator 2. Garbage Collector 3. Goroutine Scheduler 1. Memory Allocator 内存分配器 base on tcmalloc. 基于成熟方案，性能优秀。随着版本升级， 针对性改进，以期与垃圾回收器更好协作。 核心：自主管理，缓存复用，无锁分配。 阈值触发，并行标记，并发清理。 定期强制回收，释放物理内存。 版本升级，垃圾回收效率总是核心问题。 gogc. 阈值检查，或强制回收。 malloc next_gc 0 gogc runtime.gc() stop start mark sweep stop start mark sweep 0 2 2 1 forcegc 2m 1 mark. 暂停用户逻辑，并行标记。 scheduler thread processor goroutine max. 系统限制，允许调整。 runtime.GOMAXPROCS 调整 P 数量，会导致 G 任务队列重新分布。 M G P scheduler max = 10000 max = 256 runtime/debug.SetMaxThreads 超出限制，会导致进程崩溃。 newproc. 创建新并发任务。

Top 5 improvements to Debugging Go Code in VS Code in the last year Ramya Rao Software Engineer, Microsoft Maintainer of the Go plugin to VS Code Add/remove breakpoints when in the middle of about remote? Configurable Stacktrace depth Improvements to the Variables pane Show pointer address An interesting year… • All 5 of these improvements were community contributions • About 60 different

第三届中国 Rust 开发者大会 Learning by Contributing to Rust Compiler Yukang github.com/chenyukang Engineer @ Cryptape Leveling Up in Rust • 2011 ~ 2014 EDA startup C/C++ • 2014 ~ 2020 DJI Infra tools, code refactor, algorithms improvements Some PR stories • Rust cares about error messages • We are building a sufficiently empathetic compiler • It’s a trade-off Diagnostic is an art art Simple diagnostic is a good start Compiler is a teacher/friend [# 100502 Avoid infinite loop in function arguments checking] A trivial fix may require a lot of time ? Fix the bug of next_point

Rust 异步 Runtime 的兼容层 施继成 @ DatenLord Introduce what’s rust async runtime # Rust async runtime Analyze the reason of runtime isolation # Async runtime binding # Compatible layer 1 Create a wheel 2 3 # Rust async runtime 1 Light-weight task • Language and compiler define tasks • How to run it? • When to run it? • How does it deal with the I/O? Rust async runtime Runtime responsibilities it’s multi-thread model Rust async runtime Available Runtimes • Tokio • Async-std • Smol • Monoio Rust async runtime # Async runtime binding 2 Which runtime to choose ? • More adopters • Rich

Designing an ultra low-overhead multithreading runtime for Nim Mamy Ratsimbazafy mamy@numforge.co Weave https://github.com/mratsim/weave Hello! I am Mamy Ratsimbazafy During the day blockchain/Ethereum multithreading: definitions and use-cases ◇ Parallel APIs ◇ Sources of overhead and runtime design ◇ Minimum viable runtime plan in a weekend 4 Understanding the design space Concurrency vs parallelism hardware threads The same distinctions can be done at a multithreaded language or multithreading runtime level. The problem 8 How to schedule M tasks on N hardware threads? Latency vs Throughput

Go runtime related problems in TiDB production environment About me ● Arthur Mao(毛康力), Senior Engineer@PingCAP ● TiDB core developer (top3 contributor) ● GitBook about golang internals (@tiancaiamao) IO is ready => goroutine wake up == 4.3ms ○ Sometime even 10ms+ latency here! ○ The time spend on runtime schedule is not negligible ● When CPU is overload, which goroutine should be given priority? Analysis longer to be scheduled ● The runtime scheduling does not consider priority ● CPU dense workload could affect IO latency Conclusion Part II - Memory control ● Go Runtime ○ Allocated from OS (mmaped)

company. Ⓡ © 2021 Apex.AI, Inc. Igor Bogoslavskyi Testing the compilability of the code at runtime© 2021 Apex.AI, Inc. Errors have a high cost, so rigorous testing is a must We use increasingly test_halving.cpp image: Flaticon.com Compiler image: Flaticon.com Test binary GoogleTest ✅ flags© 2021 Apex.AI, Inc. Proposed testing pipeline image: Flaticon.com Compiler image: Flaticon.com Test binary does image: Flaticon.com Test binary GoogleTest StaticTest Fixture ✅ image: Flaticon.com Compiler image: Flaticon.com test_halving.cpp flags image: Flaticon.com test_compile_1.cpp image: Flaticon

with full support for hot code- language with full support for hot code- reloading at runtime reloading at runtime by Viktor Kirilov 1 Me, myself and I Me, myself and I my name is Viktor Kirilov - collected (can do manual memory management too) expressive - some of the most powerful metaprogramming compiler has an interpreter inside compiles to: C/C++/ObjC/Javascript non-idiomatic - not for reading but topic :| generics templates (meta-programming^2) macros (meta-programming^3) - evaluated in the compiler by the NimVM concepts discriminated unions strong typedefs (distinct type) - can has $ currency

浅谈全链路监控： 从应用到数据库到 Runtime 黄东旭, Co-founder & CTO, PingCAP 关于我 黄东旭，联合创始人 & CTO @ PingCAP 做分布式数据库的程序员 ● 现在能写代码的时间是奢侈品 TiDB 的亲爹之一兼首席客服和新功能的第一个用户 ● 冤有头债有主，SQL 慢了来找我。。。 偶尔玩玩音乐 ● 摇滚乐->实验音乐 Go 的粉丝！！！！ tool trace go tool trace ● 优点：好用，好看（UI） ● 缺点：性能损耗太大，不能一直开着 Trace in Go runtime ● go tool trace 的原理是？ Trace 会 Go Runtime 的代码中打桩收集 CPU time，在 Goroutine 开始执行时记录 start_run_time, 在调度退出执行时记录 end_run_time，累加 goroutine 的 CPU time。 A little bit about Go runtime https://learnku.com/articles/41728 https://github.com/golang/go/blob/ma ster/src/runtime/trace.go hack runtime 的思路： follow the tracing event. PingCAP