"Lock-Free Ring Buffer" (LFRB) is a minimal, customizable implementation of a ring buffer (a.k.a. circular buffer) in C, specifically suitable for embedded systems, such as single-core microcontrollers with:
- ARM Cortex-M CPU
- MSP430 CPU
- PIC24/dsPIC CPU
- other similar 16/32-bit CPUs
NOTE The presented LFRB implementation is intended for deeply embedded systems, such as single-core ARM Cortex-M MCUs. The presented implementation might not be appropriate for complex multi-core SoCs with cache memory, etc. Please refer to the literature, for example: Correct and Efficient Bounded FIFO Queues.
The ring buffer does not require any "locking" (mutual exclusion mechanism) as long as the following restrictions are met:
- Only one thread/interrupt can produce data into the ring buffer
- Only one thread/interrupt can consume data from the ring buffer
- Both the producer and consumer run on the same CPU
- The system has strong memory consistency
- Additional assumptions about the "atomicity" of the LFRB counters are spelled out in the ring_buf.h header file
In other words, LFRB is a single-producer, single-consumer FIFO. Fortunately, this is the most frequently encountered scenario in deeply embedded applications.
The ring buffer implementation consists of two files located in the src directory:
- ring_buf.h - contains the interface
- ring_buf.c - contains the implementation
The ring buffer holds elements of they type RingBufElement, which
can be customized (typically uint8_t, uint16_t, uint32_t, float,
void* (pointers), etc.)
The directory ET contains the
Embedded Test (ET)
super-simple testing framework. ET is used to test the LFRB.
Specifically, the ET tests and examples of use of LFRB are located in the file:
- test_ring_buf.c - example of use and tests the LFRB.
The LFRB is licensed under the MIT open source license.
If you'd like to discuss LFRB or related subjects, plese use the "Issues" tab.
Please feel free to clone, fork, and make pull requests to improve LFRB. If you like this project, please give it a star (in the upper-right corner of your browser window):
