Struct std::sync::Arc
[−]
[src]
pub struct Arc<T> where T: ?Sized {
// some fields omitted
}An atomically reference counted wrapper for shared state.
Examples
In this example, a large vector of floats is shared between several threads.
With simple pipes, without Arc, a copy would have to be made for each
thread.
When you clone an Arc<T>, it will create another pointer to the data and
increase the reference counter.
use std::sync::Arc; use std::thread; fn main() { let numbers: Vec<_> = (0..100u32).collect(); let shared_numbers = Arc::new(numbers); for _ in 0..10 { let child_numbers = shared_numbers.clone(); thread::spawn(move || { let local_numbers = &child_numbers[..]; // Work with the local numbers }); } }
Methods
impl<T> Arc<T>
fn new(data: T) -> Arc<T>
Constructs a new Arc<T>.
Examples
fn main() { use std::sync::Arc; let five = Arc::new(5); }use std::sync::Arc; let five = Arc::new(5);
impl<T> Arc<T> where T: ?Sized
fn downgrade(&self) -> Weak<T>
Unstable
: Weak pointers may not belong in this module.
Downgrades the Arc<T> to a Weak<T> reference.
Examples
#![feature(alloc)] fn main() { use std::sync::Arc; let five = Arc::new(5); let weak_five = five.downgrade(); }use std::sync::Arc; let five = Arc::new(5); let weak_five = five.downgrade();
impl<T> Arc<T> where T: Clone
fn make_unique(&mut self) -> &mut T
Unstable
Make a mutable reference from the given Arc<T>.
This is also referred to as a copy-on-write operation because the inner data is cloned if the reference count is greater than one.
Examples
#![feature(alloc)] fn main() { use std::sync::Arc; let mut five = Arc::new(5); let mut_five = five.make_unique(); }use std::sync::Arc; let mut five = Arc::new(5); let mut_five = five.make_unique();