Execution 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 service ○ Encompasses the capabilities of both ccache and distcc ○ Supports remote linking and caching ● Designed to share caches across diverse toolchains ○ Works with many compiler toolchains (GCC Bloomberg Finance L.P. All rights reserved. Caching Action Cache Redis CAS S3 PostgreSQL recc (compiler launcher) Client Host BuildBox-CASD (Local Caching Proxy) Execution buildbox-run- bubblewrap

C++20 Modules: The Packaging and Binary Redistribution StoryScope ● Brief introduction on C++ modules and their advantages ● Focus on named modules ● Using modules today ○ Can we package module-ready |-- fmt-config.cmake | `-- fmt-targets.cmake └── libfmt.{a|so|dylib|lib} Headers Binary library “Usage requirements”C++ 20: The import keyword clang++ -std=c++20 -o hello_world.cpp.o file with module name <> file mappings) The compiler needs to locate and load the binary module interface (BMI) 👇:Binary module interfaces export module fmt; export namespace fmt { … } fmt.cc fmt

build on composability of bool bool:: control �ow: almost all algorithms and loops, really a lot of caching schemes (or idempotent calculations)bool bool UNDERLIES SO MUCH UNDERLIES SO MUCH It seems so trivial build on composability of bool bool:: control �ow: almost all algorithms and loops, really a lot of caching schemes (or idempotent calculations) polling/non-blocking functionsbool bool UNDERLIES SO MUCH UNDERLIES build on composability of bool bool:: control �ow: almost all algorithms and loops, really a lot of caching schemes (or idempotent calculations) polling/non-blocking functions Chain of Responsibility patternbool

Source: ChatGPTUsing std::vector 33 • Using two vectors (bids and asks) and use std::lower_bound (binary search) std::vector> mBidLevels; std::vector> >> mAskLevels;Using std::vector 34 • Using two vectors (bids and asks) and use std::lower_bound (binary search) • AddOrder: - log(N) if the price level exists - log(N) + N if a new price level is inserted performance ” 43 Source: ChatGPTRunning perf on a benchmark 44 • Can’t run perf on the entire binary if our initialization function is “big” void RunPerf() { pid_t pid = fork(); if (pid == 0) { const

NuGet Custom solutionPreview – 10 conclusions 1. Support building from source 2. Build a verified binary cache 3. Version using baselines 4. Build open-source with a package manager 5. Cache build assets dependencies from source Benefits of building from source: •No waiting for library owner to update binary •Able to view, edit, and debug source code •Easier and cheaper to distribute source packages than Build times are too long when building from source Solution 2: Establish a verified binary cache •Establish a binary cache to store library binaries, shared with all developers and CI builds •For every

• Differences from Game Code • Assumptions and Concepts 2. Techniques • Keep Threads Busy • 3D Caching • Optimise Sorting • Avoid Blocking Threads 3. Questions 2Three sections Background What data building process - requires entire server farm Creates lots of data - even more to process Outputs optimised binary files - loaded quickly and efficiently Only in large studios ▶ Usually in the middle ▶ Depends data building code Functions written in thread-unsafe manner Using function static variables - caching results Assuming not run in parallel code Writing systems as singletons Assuming only one instance

package manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Binary management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conan-center which is moderated, and packages are reviewed before being accepted to ensure quality. 1.3 Binary management One of the most powerful features of Conan is that it can manage pre-compiled binaries sources, what the final binary artifacts are, the package dependencies, etc. When a package recipe is used in the Conan client, and a “binary package” is built from sources, that binary package will be compatible

package manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Binary management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conan-center which is moderated, and packages are reviewed before being accepted to ensure quality. 1.3 Binary management One of the most powerful features of Conan is that it can manage pre-compiled binaries sources, what the final binary artifacts are, the package dependencies, etc. When a package recipe is used in the Conan client, and a “binary package” is built from sources, that binary package will be compatible

package manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Binary management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conan-center which is moderated, and packages are reviewed before being accepted to ensure quality. 1.3 Binary management One of the most powerful features of Conan is that it can manage pre-compiled binaries sources, what the final binary artifacts are, the package dependencies, etc. When a package recipe is used in the Conan client, and a “binary package” is built from sources, that binary package will be compatible

package manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Binary management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . conan-center which is moderated, and packages are reviewed before being accepted to ensure quality. 1.3 Binary management One of the most powerful features of Conan is that it can manage pre-compiled binaries sources, what the final binary artifacts are, the package dependencies, etc. When a package recipe is used in the Conan client, and a “binary package” is built from sources, that binary package will be compatible