C++26 Systems Stack

Buildable C++26 integration stack for systems programming: async I/O, parallelism, JSON/RPC, portable low-latency primitives (include/ll/), and optional industry libraries. CMake 3.28+, Catch2/GTest, examples, and documentation under docs/.

Language	C++26
Build	CMake ≥ 3.28, Make, optional Ninja / CMake Presets
Platforms	macOS (arm64 / x86_64), Linux (x86_64 / aarch64)
License	MIT
Monorepo	Submodule of cpp_agents_benchmark as systems_stack/

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Contents

1. Quick start
2. What this repository provides
3. Documentation index
4. Repository layout
5. Components
6. Dependencies
7. Build
8. Tests and examples
9. Design notes
10. Related repositories
11. License

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Quick start

# Dependencies (macOS / Homebrew)
brew install cmake ninja fmt spdlog tbb asio boost taskflow \
  nlohmann-json simdjson eigen protobuf grpc range-v3 abseil catch2 googletest
make install-industry   # hwloc flatbuffers google-benchmark mimalloc jemalloc

# Build and test
make                    # or: make ninja
make run                # ./build/lib_smoke
make examples

CLion: open the repo root, enable preset clion-debug, build target ide_index.
See docs/clion.md.

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What this repository provides

Area	Description
Library mesh	Asio, Beast, Taskflow, oneTBB, stdexec, simdjson, protobuf/gRPC, fmt, spdlog, Abseil, Eigen, range-v3
Low-latency core	Header-only ll::*: SPSC, arenas, pmr, HDR, SBE, affinity, TSC, NUMA/uring APIs, bypass contract
Industry optional	hwloc, FlatBuffers, struct_pack, moodycamel, Folly PCQ, mimalloc, jemalloc, HdrHistogram_c, Google Benchmark; DPDK/Onload detect when installed
Validation	lib_smoke, Catch2/GTest suites, examples, optional microbenchmarks
Docs	Six-layer blueprint, industry audit map, tutorials (build, tooling, SBE, numa/uring, bypass)

Focus: concurrency and memory primitives plus a modern C++ library mesh.
Kernel-bypass drivers (DPDK / OpenOnload) are detected when present; CI uses a stub RX path. Full status: docs/blueprint/AUDIT.md.

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Documentation index

Blueprint (low-latency layers)

Doc	Topic
docs/blueprint/README.md	Blueprint overview and layer index
docs/blueprint/LOW_LATENCY_STACK.md	Stack narrative
docs/blueprint/AUDIT.md	Checklist: SHIPPED / OPTIONAL / GAP
docs/blueprint/01-hardware-os.md	§1 Hardware & OS (pinning, NUMA, isolation)
docs/blueprint/02-network-ingress.md	§2 Network ingress & encoding
docs/blueprint/03-memory.md	§3 Memory & cache locality
docs/blueprint/04-concurrency.md	§4 Lock-free concurrency
docs/blueprint/05-compiler.md	§5 Compiler & language
docs/blueprint/06-telemetry.md	§6 Benchmarking & telemetry
docs/blueprint/07-industry-libraries.md	Industry library map by layer

Tutorials

Doc	Topic
docs/tutorials/industry-stack.md	Industry libraries on each layer (install & run)
docs/tutorials/sbe-codegen.md	Real Logic SBE schema → C++ codecs
docs/tutorials/linux-numa-uring.md	Linux NUMA + io_uring
docs/tutorials/hdrhistogram-c.md	Portable HDR and HdrHistogram_c
docs/tutorials/kernel-bypass-lab.md	DPDK / OpenOnload lab (contract + stub)
docs/tutorials/ninja-build.md	Building with Ninja
docs/tutorials/modern-cpp-tooling-arm-intel.md	Compilers, flags, ARM & Intel, cross-compilation

Library guides

Doc	Component
docs/libraries/README.md	Library index and selection notes
docs/libraries/asio.md	Asio
docs/libraries/beast.md	Boost.Beast
docs/libraries/taskflow.md	Taskflow
docs/libraries/tbb.md	oneTBB
docs/libraries/stdexec.md	stdexec (P2300)
docs/libraries/simdjson.md	simdjson
docs/libraries/grpc-protobuf.md	gRPC + Protocol Buffers
docs/libraries/folly.md	Folly (optional)
docs/libraries/hpx.md	HPX (optional)

IDE, toolchains, CI, wiki

Doc	Topic
docs/clion.md	CLion presets, IntelliSense (ide_index)
cmake/toolchains/README.md	Example CMake toolchain files (ARM / x86_64 / macOS)
CMakePresets.json	clion-debug, default, Ninja presets
.github/workflows/ci.yml	macOS full stack + Linux roadmap smoke
GitHub Wiki	Published docs mirror (see docs/WIKI.md)

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Repository layout

.
├── CMakeLists.txt
├── CMakePresets.json
├── Makefile
├── include/ll/                 # portable low-latency headers
├── generated/sbe/              # committed SBE C++ codecs
├── schemas/                    # FlatBuffers + SBE XML
├── src/                        # lib_smoke integration binary
├── examples/                   # demos (spsc, pmr, sbe, bypass, …)
├── benchmarks/                 # Google Benchmark targets
├── tests/                      # Catch2 + GTest
├── tools/ide_index.cpp         # CLion / clangd index TU
├── scripts/                    # SBE generator, Linux CI smoke CMake
├── cmake/toolchains/           # cross-compile examples
└── docs/
    ├── blueprint/              # layers 01–07, AUDIT, narrative
    ├── libraries/              # per-library guides
    ├── tutorials/              # hands-on how-tos
    └── clion.md

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Components

Library mesh

Domain	Component	Guide	Tests
Async I/O	Asio (standalone)	asio.md	test_beast_asio
HTTP / WebSocket	Boost.Beast	beast.md	test_beast_asio
Task graphs	Taskflow	taskflow.md	test_taskflow
Data parallel	oneTBB	tbb.md	test_libs
Senders / receivers	stdexec	stdexec.md	test_libs
JSON	simdjson, nlohmann-json	simdjson.md	test_libs
Schema / RPC	protobuf, gRPC	grpc-protobuf.md	test_libs
Optional services	Folly, HPX	folly.md, hpx.md	make folly / make hpx
Utilities	fmt, spdlog, Abseil, range-v3, Eigen	—	test_libs

Low-latency modules (include/ll/)

Header	Role	Layer
ll/spsc_queue.hpp	Lock-free SPSC ring	§4
ll/arena.hpp, ll/pmr_arena.hpp	Arena / object pool / std::pmr	§3
ll/cache_line.hpp	Cache-line constants / padding	§3
ll/sbe_style.hpp, ll/sbe_codec.hpp	SBE-style POD + generated codecs	§2
ll/struct_pack_tick.hpp	struct_pack tick helpers	§2
ll/affinity.hpp	Thread pin / macOS QoS	§1
ll/linux_numa.hpp, ll/linux_uring.hpp	NUMA / io_uring (Linux or stub)	§1–2
ll/kernel_bypass.hpp	Poll-mode RX contract + stub	§2
ll/tsc_clock.hpp, ll/hdr_histogram.hpp, ll/hdr_c.hpp	Timestamps / HDR	§6
ll/branch.hpp	likely/unlikely, CRTP helper	§5
ll/jemalloc_util.hpp	Optional jemalloc helpers	§3
ll/industry.hpp	Umbrella + LL_HAS_* macros	—

Industry libraries (CMake auto-detect)

Library	Role	Enable
Boost.Lockfree	SPSC queue	Always (Boost required)
moodycamel	SPSC (FetchContent)	STACK_WITH_MOODYCAMEL
hwloc	Topology	brew install hwloc
FlatBuffers	Zero-copy tables	brew install flatbuffers
struct_pack	Compile-time pack	FetchContent (yalantinglibs)
mimalloc / jemalloc	Off-path allocators	make install-industry
Folly PCQ	SPSC when Folly present	brew install folly
HdrHistogram_c	Tail latency	FetchContent
Google Benchmark	Microbenchmarks	brew install google-benchmark
libnuma / liburing	Linux only	distro packages
DPDK / OpenOnload	Header detect if installed	lab NIC; stub otherwise

Full map: docs/blueprint/07-industry-libraries.md.

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Dependencies

Base (Homebrew)

brew install cmake ninja fmt spdlog tbb asio boost taskflow \
  nlohmann-json simdjson eigen protobuf grpc \
  range-v3 abseil catch2 googletest

Industry optional

make install-industry     # hwloc flatbuffers google-benchmark mimalloc jemalloc
brew install folly        # optional: ProducerConsumerQueue tests
# Linux: libnuma-dev liburing-dev

Optional heavy runtimes

brew install folly
make install-hpx          # local prefix, default ~/cpp-deps/hpx

make deps-check           # inventory installed packages

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Build

Goal	Command
Configure, build, test (default tree)	make
Ninja tree (build_ninja/)	make ninja
Run integration binary	make run
Examples	make examples
Microbenchmarks	make bench
Folly / HPX / both	make folly · make hpx · make full
CLion debug + index	make clion · make clion-index
Clean all build trees	make distclean

# Explicit CMake
cmake -S . -B build -G Ninja \
  -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_PREFIX_PATH="$(brew --prefix)"
cmake --build build -j
ctest --test-dir build --output-on-failure

Optional CMake flags: LIB_SMOKE_WITH_FOLLY, LIB_SMOKE_WITH_HPX, STACK_WITH_*
(see CMakeLists.txt and cmake --help-variable-cache after configure).

More detail:

• Ninja: docs/tutorials/ninja-build.md
• ARM / Intel / cross: docs/tutorials/modern-cpp-tooling-arm-intel.md
• CLion: docs/clion.md

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Tests and examples

Suites

Target	Framework	Focus
lib_smoke	binary	End-to-end library checks
test_beast_asio	Catch2	Asio / Beast
test_taskflow	Catch2	Task graphs
test_libs	Catch2	Mesh libraries
test_ll_modules	Catch2	ll primitives
test_industry_stack	Catch2	Industry deps + serde + queues
test_roadmap_stack	Catch2	SBE, numa/uring, HDR_c, bypass
test_gtest_smoke	GTest	Framework smoke
test_folly / test_hpx	Catch2	Optional profiles

ctest --test-dir build --output-on-failure
ctest --test-dir build -R 'll|industry|roadmap'

Example binaries

Binary	Topic
example_spsc	Lock-free SPSC handoff
example_arena / example_pmr	Bump / pmr arenas
example_memory_order	acquire/release handoff
example_tsc / example_hdr / example_hdr_c	Timestamps and histograms
example_sbe_style / example_sbe_codegen	POD wire vs generated SBE
example_struct_pack	yalantinglibs struct_pack
example_industry_queues	ll / Boost / moodycamel
example_numa_uring	NUMA + io_uring status
example_kernel_bypass	Stub poll-mode RX + SBE
bench_queues	Google Benchmark

make examples
make bench

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Design notes

1. C++26 as the project standard; industry libraries opt in via CMake.
2. Separate concerns: I/O, parse, schedule, compute, RPC, and hot-path primitives.
3. Prefer proven queues and allocators over reimplementing them on the critical path.
4. Auto-detect optional packages; keep the default configure path usable without Folly/HPX/DPDK.
5. Prefer p99 / p99.9 / max over mean latency for anything timing-sensitive.
6. Keep the hot-path instruction footprint small (i-cache); see blueprint §5.

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Related repositories

Repository	Role
cpp26-systems-stack	This project
hft-asm-l2-conflator	AArch64 assembler L2 conflator
cpp_agents_benchmark	Private monorepo (gitlinks only)

git clone --recurse-submodules https://github.com/Dmdv/cpp_agents_benchmark.git

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License

MIT — see LICENSE.