Struct Stealer

pub struct Stealer<T> { /* private fields */ }

A stealer handle of a worker queue.

Stealers can be shared among threads.

Task schedulers typically have a single worker queue per worker thread.

Examples

use crossbeam_deque::{Steal, Worker};

let w = Worker::new_lifo();
w.push(1);
w.push(2);

let s = w.stealer();
assert_eq!(s.steal(), Steal::Success(1));
assert_eq!(s.steal(), Steal::Success(2));
assert_eq!(s.steal(), Steal::Empty);

Implementations

impl<T> Stealer<T>

pub fn is_empty(&self) -> bool

Returns true if the queue is empty.

use crossbeam_deque::Worker;

let w = Worker::new_lifo();
let s = w.stealer();

assert!(s.is_empty());
w.push(1);
assert!(!s.is_empty());

pub fn len(&self) -> usize

Returns the number of tasks in the deque.

use crossbeam_deque::Worker;

let w = Worker::new_lifo();
let s = w.stealer();

assert_eq!(s.len(), 0);
w.push(1);
assert_eq!(s.len(), 1);
w.push(2);
assert_eq!(s.len(), 2);

pub fn steal(&self) -> Steal<T>

Steals a task from the queue.

Examples

use crossbeam_deque::{Steal, Worker};

let w = Worker::new_lifo();
w.push(1);
w.push(2);

let s = w.stealer();
assert_eq!(s.steal(), Steal::Success(1));
assert_eq!(s.steal(), Steal::Success(2));

pub fn steal_batch(&self, dest: &Worker<T>) -> Steal<()>

Steals a batch of tasks and pushes them into another worker.

How many tasks exactly will be stolen is not specified. That said, this method will try to steal around half of the tasks in the queue, but also not more than some constant limit.

Examples

use crossbeam_deque::Worker;

let w1 = Worker::new_fifo();
w1.push(1);
w1.push(2);
w1.push(3);
w1.push(4);

let s = w1.stealer();
let w2 = Worker::new_fifo();

let _ = s.steal_batch(&w2);
assert_eq!(w2.pop(), Some(1));
assert_eq!(w2.pop(), Some(2));

pub fn steal_batch_and_pop(&self, dest: &Worker<T>) -> Steal<T>

Steals a batch of tasks, pushes them into another worker, and pops a task from that worker.

How many tasks exactly will be stolen is not specified. That said, this method will try to steal around half of the tasks in the queue, but also not more than some constant limit.

Examples

use crossbeam_deque::{Steal, Worker};

let w1 = Worker::new_fifo();
w1.push(1);
w1.push(2);
w1.push(3);
w1.push(4);

let s = w1.stealer();
let w2 = Worker::new_fifo();

assert_eq!(s.steal_batch_and_pop(&w2), Steal::Success(1));
assert_eq!(w2.pop(), Some(2));

Trait Implementations

impl<T> Clone for Stealer<T>

fn clone(&self) -> Stealer<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Stealer<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T> Send for Stealer<T>

where T: Send,

impl<T> Sync for Stealer<T>

where T: Send,