# Barrier in spin::barrier - Rust
A primitive that synchronizes the execution of multiple threads.
Keywords: rust, rustlang, rust-lang, Barrier

# Struct spin::barrier::Barrier

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    pub struct Barrier { /* private fields */ }

Expand description

A primitive that synchronizes the execution of multiple threads.

## Example

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

    let mut handles = Vec::with_capacity(10);
    let barrier = Arc::new(spin::Barrier::new(10));
    for _ in 0..10 {
        let c = barrier.clone();
        // The same messages will be printed together.
        // You will NOT see any interleaving.
        handles.push(thread::spawn(move|| {
            println!("before wait");
            c.wait();
            println!("after wait");
        }));
    }
    // Wait for other threads to finish.
    for handle in handles {
        handle.join().unwrap();
    }

## Implementations

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### impl Barrier

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#### pub const fn new(n: usize) -> Barrier

Creates a new barrier that can block a given number of threads.

A barrier will block `n`-1 threads which call `wait` and then wake up all threads at once when the `n`th thread calls `wait`. A Barrier created with n = 0 will behave identically to one created with n = 1.

##### Examples

    use spin;

    let barrier = spin::Barrier::new(10);

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#### pub fn wait(&self) -> BarrierWaitResult

Blocks the current thread until all threads have rendezvoused here.

Barriers are re-usable after all threads have rendezvoused once, and can be used continuously.

A single (arbitrary) thread will receive a `BarrierWaitResult` that returns `true` from `is_leader` when returning from this function, and all other threads will receive a result that will return `false` from `is_leader`.

##### Examples

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

    let mut handles = Vec::with_capacity(10);
    let barrier = Arc::new(spin::Barrier::new(10));
    for _ in 0..10 {
        let c = barrier.clone();
        // The same messages will be printed together.
        // You will NOT see any interleaving.
        handles.push(thread::spawn(move|| {
            println!("before wait");
            c.wait();
            println!("after wait");
        }));
    }
    // Wait for other threads to finish.
    for handle in handles {
        handle.join().unwrap();
    }

## Auto Trait Implementations

### impl !RefUnwindSafe for Barrier

### impl Send for Barrier

### impl Sync for Barrier

### impl Unpin for Barrier

### impl UnwindSafe for Barrier

## Blanket Implementations

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### impl<T> Any for T where
T: 'static + ?Sized,

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more

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### impl<T> Borrow<T> for T where
T: ?Sized,

const: unstable · source

#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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### impl<T> BorrowMut<T> for T where
T: ?Sized,

const: unstable · source

#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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### impl<T> From<T> for T

const: unstable · source

#### fn from(t: T) -> T

Returns the argument unchanged.

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### impl<T, U> Into<U> for T where
U: From<T>,

const: unstable · source

#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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### impl<T, U> TryFrom<U> for T where
U: Into<T>,

#### type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

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### impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

const: unstable · source

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.