# Real-Time Interrupt-driven Concurrency
A concurrency framework for building real-time systems.
Formerly known as Real-Time For the Masses.
[](https://crates.io/crates/cortex-m-rtic)
[](https://docs.rs/cortex-m-rtic)
[](https://rtic.rs/)
[](https://github.com/rust-lang/rust/releases/tag/1.36.0)
[](https://matrix.to/#/#rtic:matrix.org)
[](https://hackmd.io/@xmis9JvZT8Gvo9lOEKyZ4Q/SkBJKsjuH)
## Features
- **Tasks** as the unit of concurrency . Tasks can be *event triggered*
(fired in response to asynchronous stimuli) or spawned by the application on
demand.
- **Message passing** between tasks. Specifically, messages can be passed to
software tasks at spawn time.
- **A timer queue** . Software tasks can be scheduled to run at some time
in the future. This feature can be used to implement periodic tasks.
- Support for prioritization of tasks and, thus, **preemptive multitasking**.
- **Efficient and data race free memory sharing** through fine grained *priority
based* critical sections .
- **Deadlock free execution** guaranteed at compile time. This is an stronger
guarantee than what's provided by [the standard `Mutex`
abstraction][std-mutex].
[std-mutex]: https://doc.rust-lang.org/std/sync/struct.Mutex.html
- **Minimal scheduling overhead**. The task scheduler has minimal software
footprint; the hardware does the bulk of the scheduling.
- **Highly efficient memory usage**: All the tasks share a single call stack and
there's no hard dependency on a dynamic memory allocator.
- **All Cortex-M devices are fully supported**.
- This task model is amenable to known WCET (Worst Case Execution Time) analysis
and scheduling analysis techniques. (Though we haven't yet developed Rust
friendly tooling for that.)
## Requirements
- Rust 1.36.0+
- Applications must be written using the 2018 edition.
## [User documentation](https://rtic.rs)
## [API reference](https://rtic.rs/stable/api/)
## Chat
Join us and talk about RTIC in the [Matrix room][matrix-room].
Weekly meeting notes can be found over at [HackMD][hackmd]
[matrix-room]: https://matrix.to/#/#rtic:matrix.org
[hackmd]: https://hackmd.io/@xmis9JvZT8Gvo9lOEKyZ4Q/SkBJKsjuH
## Contributing
New features and big changes should go through the RFC process in the
[dedicated RFC repository][rfcs].
[rfcs]: https://github.com/rtic-rs/rfcs
## Acknowledgments
This crate is based on [the Real-Time For the Masses language][rtfm-lang]
created by the Embedded Systems group at [Luleå University of Technology][ltu],
led by [Prof. Per Lindgren][per].
[rtfm-lang]: http://www.rtfm-lang.org/
[ltu]: https://www.ltu.se/?l=en
[per]: https://www.ltu.se/staff/p/pln-1.11258?l=en
## References
(2013, June). Real-time for the masses, step 1: Programming API and static
priority SRP kernel primitives. In Industrial Embedded Systems (SIES), 2013
8th IEEE International Symposium on (pp. 110-113). IEEE.
L. M. (2016). Abstract timers and their implementation onto the arm cortex-m
family of mcus. ACM SIGBED Review, 13(1), 48-53.
## License
All source code (including code snippets) is licensed under either of
- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or
[https://www.apache.org/licenses/LICENSE-2.0][L1])
- MIT license ([LICENSE-MIT](LICENSE-MIT) or
[https://opensource.org/licenses/MIT][L2])
[L1]: https://www.apache.org/licenses/LICENSE-2.0
[L2]: https://opensource.org/licenses/MIT
at your option.
The written prose contained within the book is licensed under the terms of the
Creative Commons CC-BY-SA v4.0 license ([LICENSE-CC-BY-SA](LICENSE-CC-BY-SA) or
[https://creativecommons.org/licenses/by-sa/4.0/legalcode][L3]).
[L3]: https://creativecommons.org/licenses/by-sa/4.0/legalcode
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
licensed as above, without any additional terms or conditions.