# Struct std::sync::Barrier

1.0.0 · source ·

    pub struct Barrier { /* private fields */ }

Expand description

A barrier enables multiple threads to synchronize the beginning of some computation.

## Examples

    use std::sync::{Arc, Barrier};
    use std::thread;

    let n = 10;
    let mut handles = Vec::with_capacity(n);
    let barrier = Arc::new(Barrier::new(n));
    for _ in 0..n {
        let c = Arc::clone(&barrier);
        // 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();
    }

Run

## Implementations§

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### impl Barrier

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#### pub 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()`.

##### Examples

    use std::sync::Barrier;

    let barrier = Barrier::new(10);

Run
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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 `BarrierWaitResult::is_leader()` when returning from this function, and all other threads will receive a result that will return `false` from `BarrierWaitResult::is_leader()`.

##### Examples

    use std::sync::{Arc, Barrier};
    use std::thread;

    let n = 10;
    let mut handles = Vec::with_capacity(n);
    let barrier = Arc::new(Barrier::new(n));
    for _ in 0..n {
        let c = Arc::clone(&barrier);
        // 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();
    }

Run

## Trait Implementations§

1.16.0 · source§

### impl Debug for Barrier

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

Formats the value using the given formatter. Read more

## Auto Trait Implementations§

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### impl RefUnwindSafe for Barrier

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### impl Send for Barrier

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### impl Sync for Barrier

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### impl Unpin for Barrier

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### impl UnwindSafe for Barrier

## Blanket Implementations§

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### impl<T> Any for Twhere 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 Twhere T: ?Sized,

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

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for Twhere T: ?Sized,

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#### 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

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

Returns the argument unchanged.

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

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#### 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 Twhere U: Into<T>,

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#### type Error = Infallible

The type returned in the event of a conversion error.
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#### 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 Twhere U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.