Struct BoundedThreadLocal

Source

pub struct BoundedThreadLocal<'s, T> { /* private fields */ }

Expand description

A one-shot, lock-free, bounded per-value thread local storage.

§Examples

use std::thread;
use std::sync::Arc;

use conquer_util::BoundedThreadLocal;

const THREADS: usize = 4;
let counter = Arc::new(BoundedThreadLocal::<usize>::new(THREADS));

let handles: Vec<_> = (0..THREADS)
    .map(|id| {
        let counter = Arc::clone(&counter);
        thread::spawn(move || {
            let mut token = counter.thread_token().unwrap();
            *token.get_mut() += id;
        })
    })
    .collect();

for handle in handles {
    handle.join().unwrap();
}

let mut counter = Arc::try_unwrap(counter).unwrap();

let sum: usize = counter.into_iter().sum();
assert_eq!(sum, (0..4).sum());

Implementations§

Source §

impl<'s, T: Default> BoundedThreadLocal<'s, T>

Source

pub fn new(max_threads: usize) -> Self

Creates a new Default initialized BoundedThreadLocal that internally allocates a buffer of max_size.

§Panics

This method panics, if max_size is 0.

Source §

impl<'s, T> BoundedThreadLocal<'s, T>

Source

pub fn with_init(max_threads: usize, init: impl Fn() -> T) -> Self

Creates a new BoundedThreadLocal that internally allocates a buffer of max_size and initializes each Local with init.

§Panics

This method panics, if max_size is 0.

Source §

impl<'s, T> BoundedThreadLocal<'s, T>

Source

pub const unsafe fn with_buffer(buf: &'s [Local<T>]) -> Self

Creates a new BoundedThreadLocal that is based on a separate buffer.

§Safety

The given buf must be treated as if it were mutably, i.e. it must not be used or otherwise accessed during the lifetime of the BoundedThreadLocal that borrows it.

§Examples

use conquer_util::{BoundedThreadLocal, Local};

static BUF: [Local<usize>; 4] =
    [Local::new(0), Local::new(0), Local::new(0), Local::new(0)];
static TLS: BoundedThreadLocal<usize> = unsafe { BoundedThreadLocal::with_buffer(&BUF) };
assert_eq!(TLS.thread_token().unwrap().get(), &0);

Source

pub fn thread_token(&self) -> Result<Token<'_, '_, T>, BoundsError>

Returns a thread local token to a unique instance of T.

The thread local instance will not be dropped, when the token itself is dropped and can e.g. be iterated afterwards.

§Errors

This method fails, if the maximum number of tokens for this BoundedThreadLocal has already been acquired.

§Examples

use conquer_util::BoundedThreadLocal;


let tls = BoundedThreadLocal::<usize>::new(1);
let mut token = tls.thread_token()?;
*token.get_mut() += 1;
assert_eq!(token.get(), &1);