impl<T> Stealer<T>

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());

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);

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));

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));

fn steal_batch_with_limit(&self, dest: &Worker<T>, limit: usize) -> Steal<()>

Steals no more than limit 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 the given limit.

Examples

use crossbeam_deque::Worker;

let w1 = Worker::new_fifo();
w1.push(1);
w1.push(2);
w1.push(3);
w1.push(4);
w1.push(5);
w1.push(6);

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

let _ = s.steal_batch_with_limit(&w2, 2);
assert_eq!(w2.pop(), Some(1));
assert_eq!(w2.pop(), Some(2));
assert_eq!(w2.pop(), None);

w1.push(7);
w1.push(8);
// Setting a large limit does not guarantee that all elements will be popped. In this case,
// half of the elements are currently popped, but the number of popped elements is considered
// an implementation detail that may be changed in the future.
let _ = s.steal_batch_with_limit(&w2, std::usize::MAX);
assert_eq!(w2.len(), 3);

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));

fn steal_batch_with_limit_and_pop(&self, dest: &Worker<T>, limit: usize) -> Steal<T>

Steals no more than limit 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 the given limit.

Examples

use crossbeam_deque::{Steal, Worker};

let w1 = Worker::new_fifo();
w1.push(1);
w1.push(2);
w1.push(3);
w1.push(4);
w1.push(5);
w1.push(6);

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

assert_eq!(s.steal_batch_with_limit_and_pop(&w2, 2), Steal::Success(1));
assert_eq!(w2.pop(), Some(2));
assert_eq!(w2.pop(), None);

w1.push(7);
w1.push(8);
// Setting a large limit does not guarantee that all elements will be popped. In this case,
// half of the elements are currently popped, but the number of popped elements is considered
// an implementation detail that may be changed in the future.
assert_eq!(s.steal_batch_with_limit_and_pop(&w2, std::usize::MAX), Steal::Success(3));
assert_eq!(w2.pop(), Some(4));
assert_eq!(w2.pop(), Some(5));
assert_eq!(w2.pop(), None);