A concurrent, append-only vector.
The vector provided by this crate suports concurrent get and push operations. All operations are lock-free.
Appending an element to a vector and retrieving it:
let vec = boxcar::Vec::new();
vec.push(42);
assert_eq!(vec[0], 42);The vector can be shared across threads with an Arc:
use std::sync::Arc;
fn main() {
let vec = Arc::new(boxcar::Vec::new());
// spawn 6 threads that append to the vec
let threads = (0..6)
.map(|i| {
let vec = vec.clone();
std::thread::spawn(move || {
vec.push(i); // push through `&Vec`
})
})
.collect::<Vec<_>>();
// wait for the threads to finish
for thread in threads {
thread.join().unwrap();
}
for i in 0..6 {
assert!(vec.iter().any(|(_, &x)| x == i));
}
}Elements can be mutated through fine-grained locking:
use std::sync::{Mutex, Arc};
fn main() {
let vec = Arc::new(boxcar::Vec::new());
// insert an element
vec.push(Mutex::new(1));
let thread = std::thread::spawn({
let vec = vec.clone();
move || {
// mutate through the mutex
*vec[0].lock().unwrap() += 1;
}
});
thread.join().unwrap();
let x = vec[0].lock().unwrap();
assert_eq!(*x, 2);
}