Expand description
§BBQueue
BBQueue, short for “BipBuffer Queue”, is a Single Producer Single Consumer, lockless, no_std, thread safe, queue, based on BipBuffers. For more info on the design of the lock-free algorithm used by bbqueue, see this blog post.
BBQueue is designed (primarily) to be a First-In, First-Out queue for use with DMA on embedded systems.
While Circular/Ring Buffers allow you to send data between two threads (or from an interrupt to main code), you must push the data one piece at a time. With BBQueue, you instead are granted a block of contiguous memory, which can be filled (or emptied) by a DMA engine.
§Local usage
// The "Churrasco" flavor has inline storage, hardware atomic
// support, no async support, and is not reference counted.
use bbqueue::nicknames::Churrasco;
// Create a buffer with six elements
let bb: Churrasco<6> = Churrasco::new();
let prod = bb.stream_producer();
let cons = bb.stream_consumer();
// Request space for one byte
let mut wgr = prod.grant_exact(1).unwrap();
// Set the data
wgr[0] = 123;
assert_eq!(wgr.len(), 1);
// Make the data ready for consuming
wgr.commit(1);
// Read all available bytes
let rgr = cons.read().unwrap();
assert_eq!(rgr[0], 123);
// Release the space for later writes
rgr.release(1);§Static usage
use bbqueue::nicknames::Churrasco;
use std::{thread::{sleep, spawn}, time::Duration};
// Create a buffer with six elements
static BB: Churrasco<6> = Churrasco::new();
fn receiver() {
let cons = BB.stream_consumer();
loop {
if let Ok(rgr) = cons.read() {
assert_eq!(rgr.len(), 1);
assert_eq!(rgr[0], 123);
rgr.release(1);
break;
}
// don't do this in real code, use Notify!
sleep(Duration::from_millis(10));
}
}
fn main() {
let prod = BB.stream_producer();
// spawn the consumer
let hdl = spawn(receiver);
// Request space for one byte
let mut wgr = prod.grant_exact(1).unwrap();
// Set the data
wgr[0] = 123;
assert_eq!(wgr.len(), 1);
// Make the data ready for consuming
wgr.commit(1);
// make sure the receiver terminated
hdl.join().unwrap();
}§Nicknames
bbqueue uses generics to customize the data structure in four main ways:
- Whether the byte storage is inline (and const-generic), or heap allocated
- Whether the queue is polling-only, or supports async/await sending/receiving
- Whether the queue uses a lock-free algorithm with CAS atomics, or uses a critical section (for targets that don’t have CAS atomics)
- Whether the queue is reference counted, allowing Producer and Consumer halves to be passed around without lifetimes.
See the nicknames module for all sixteen variants.
§Stability
bbqueue v0.6 is a breaking change from the older “classic” v0.5 interfaces. The intent is to
have a few minor breaking changes in early 2026, and to get to v1.0 as quickly as possible.
Modules§
- export
- Re-export of external types/traits
- nicknames
- Type aliases for different generic configurations
- prod_
cons - Producer and consumer interfaces
- traits
- Generic traits
Structs§
- ArcBB
Queue - A BBQueue wrapped in an Arc
- BBQueue
- A standard bbqueue