NOTE: OLSRT v1.3.1 is the current stable release, produced by the Wave 1 stabilization effort that fixed 11 real bugs in v1.3.0 and added a full regression suite (22 assertions, ASan / UBSan / TSan clean).
NOTE: v1.3.x is fully working on Linux and BSD. Windows and macOS are planned for v2.0.
NOTE: 7 self-contained demos live in
demos/— from actor ask/reply to a working HTTP server.NOTE: See
ROADMAP.mdfor the full v1.3.x → v2.0 plan, including the NWP (Non-Waiting Paradigm) integration scheduled for v1.3.6.
OLSRT (OverLab Streams Runtime) is a universal runtime engine — designed to power any language. If your language can talk to C, it can build on OLSRT.
Unlike a single-purpose library, OLSRT provides a full concurrency substrate: actors with process isolation, an event loop with timers and I/O, promises and futures with continuations, channels with backpressure, green threads with work stealing, reactive/stream abstractions, supervisor trees, and a dataflow graph engine — all in portable C11.
OLSRT started as a fragile experiment, smaller than libuv. Today it is a
production-ready runtime with:
- ⚡ Concurrency — Actors, Async/Await, Coroutines, Green Threads
- 🔒 Synchronization — Locks, Mutexes, Semaphores, Supervisors
- 🔄 Reactive/Dataflow — Streams, backpressure, operator composition
- ⏱️ Scheduling/I/O — Event Loop, Poller (epoll/kqueue/select), Deadlines
- 🌊 Composability — Channels, Futures, Promises, Parallel pools
- 💥 Made by OverLab Group — HCR (Hot-Coding References) and ORoutines (OLSRT Coroutines) are planned for v1.3.4 and v1.3.6
Minimal. Hackable. Ruthless.
| Metric | Value |
|---|---|
| Current release | v1.3.1 (Wave 1 stabilization) |
| Previous stable | v1.0.0 (first public release) |
| Regression tests | 22 assertions, 0 failures |
| Sanitizer status | ASan ✅ · UBSan ✅ · TSan ✅ |
| Demos | 7 (all working) |
| Active development | v1.3.2 (Actor Scheduler) |
| Platform | Status |
|---|---|
| 🐧 Linux | ✅ Solid (x86_64 tested; aarch64 CI pending) |
| 🐚 BSD | ✅ Solid (FreeBSD, OpenBSD; NetBSD untested) |
| 🪟 Windows | 🔜 Planned for v2.0 (IOCP backend) |
| 🍎 macOS | 🔜 Planned for v2.0 (kqueue native backend) |
- API reference —
docs/index.html(interactive, JSDoc-style) - Doxygen — run
doxygen Doxyfilein the project root - Sphinx —
cd source && sphinx-build -b html . ../docs/sphinx - Roadmap —
ROADMAP.md - Changelog —
docs/CHANGELOG.md - Demo guide —
demos/README.md
Seven self-contained programs that exercise the core primitives:
cd demos
make
./01_hello_actor # Actor + ask/reply + promises
./02_channel # 1,000,000 messages through a bounded channel
./03_parallel # 4-worker pool, 100 tasks
./04_timers # Event loop, one-shot + periodic timers
./05_promise # Promise states, .then() continuations
./06_dataflow # Graph: source → doubler → sink
./07_http_server # Minimal HTTP server on 0.0.0.0:8080See demos/README.md for details and expected output.
Benchmarks observed on an AMD E2-1800 (dual-core, 1.7 GHz):
| Demo ↕▾ | Metric ↕▾ |
|---|---|
−02_channel |
1,000,000 messages in 2.588 s → ~386k msg/s |
−03_parallel |
100 tasks in 86 ms across 4 workers |
−04_timers |
periodic timer drift < 2 µs over 6 fires |
−07_http_server |
served 3 sequential curl requests correctly |
| ⚙ |
- A C11 compiler (GCC ≥ 9 or Clang ≥ 10 recommended)
makeorcmake≥ 3.12- On Linux:
libnuma-dev(optional — NUMA support is compiled out if missing) libpthread,librt,libdl(standard)
git clone --depth 1 https://github.com/OverLab-Group/OLSRT.git
cd OLSRT
Or download the ZIP:
wget https://github.com/OverLab-Group/OLSRT/archive/refs/heads/main.zip
unzip main.zip && cd OLSRT-main
make linux # build for Linux x86_64
make TARGET=linux ARCH=aarch64 # cross-build for aarch64
make clean # clean current target
make help # show all targets
Output: bin/<platform>/<arch>/libolsrt.so.
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . -j
# Wave 1 regression suite, under ASan + UBSan + TSan
python3 verify.py
Expected output: [OK] asan_tests: PASS, [OK] tsan_tests: PASS.
- Linux / BSD — all features available.
- Windows / macOS — the event loop falls back to
select, which caps file descriptors at 64. Production support arrives in v2.0 with IOCP (Windows) and native kqueue (macOS).
| Version ↕▾ | Codename ↕▾ | Highlights ↕▾ | Status ↕▾ |
|---|---|---|---|
| −v0.1 | Initialize Core | First spark, skeleton features | ✅ |
| −v1.0 | Atom | First public release | ✅ |
| −v1.2 | Atom (stable) | Full Linux/BSD support | ✅ |
| −v1.3.0 | Atom (v1.3) | Actors, Supervisors, Coroutines, platform module | ✅ |
| −v1.3.1 | Wave 1 Stabilization | 11 bug fixes, 22 tests, sanitizer-clean | ✅ CURRENT |
| −v1.3.2 | Actor Scheduler | Green-thread-driven actor loop | 🔜 Next |
| −v1.3.3 | Dataflow Cleanup | Edge inbox fix, cosmetic warnings, LSan re-enable | 🔜 |
| −v1.3.4 | ORoutines | Goroutine-like API + HCR primitives | 🔜 |
| −v1.3.5 | Supervisor 2.0 | Hierarchical supervision, restart strategies | 🔜 |
| −v1.3.6 | NWP MVP | Non-Waiting Paradigm, Branch Units, NWL | 🔜 |
| −v1.3.7 | NWP Integration | Benchmarks, docs, SDK bindings | 🔜 |
| −v2.0 | Apollo | Cross-platform (IOCP/kqueue) + 66 network protocols | 🔮 |
| −v3.0 | Nova | Virtualization support | 🔮 |
| −v4.0 | Core | Utilities foundation | 🔮 |
| −v5.0 | Spark | Utilities expansion | 🔮 |
| −v6.0 | Orion | More utilities | 🔮 |
| −v7.0 | Cosmos | Vast scope | 🔮 |
| −v8.0 | Hermes | Compiler era begins | 🔮 |
| −v9.0 | Kernel | Advanced runtime core | 🔮 |
| −v10.0 | Stream | Architectures added | 🔮 |
| −v11.0 | Flow | Full OS support | 🔮 |
| −v12.0 | Wave | 30% language coverage | 🔮 |
| ⚙ |
See ROADMAP.md for exhaustive details.
We're not a corporate army. We're a crew of builders, breakers, and dreamers.
Before opening a PR:
- Read
ROADMAP.mdto see where the project is heading. - Run
python3 verify.pylocally — all four checks must be green. - Format code to match the existing style (4-space indent,
ol_prefix for public API,OL_for macros). - Update
docs/CHANGELOG.mdunder an "Unreleased" section. - Sign off your commits with
git commit -s.
Pull requests that break the sanitizer pass will not be merged.
Apache 2.0 — free to use, remix, and share. See LICENSE.
Current milestone: v1.3.1 (Wave 1 Stabilization)
By OverLab Group