Struct async_sema::Semaphore

pub struct Semaphore { /* private fields */ }

A counter for limiting the number of concurrent operations.

Implementations

impl Semaphore

pub fn new(n: usize) -> Semaphore

Creates a new semaphore with a limit of n concurrent operations.

Examples

use async_sema::Semaphore;

let s = Semaphore::new(5);

pub fn try_acquire(&self) -> bool

Attempts to get a permit for a concurrent operation.

Return whether permit has been acquired

Examples

use async_sema::Semaphore;

let s = Semaphore::new(2);

s.acquire().await;
s.acquire().await;

assert!(!s.try_acquire());
s.add_permits(1);
assert!(s.try_acquire());

pub async fn acquire(&self)

Waits for a permit for a concurrent operation.

Examples

use async_sema::Semaphore;

let s = Semaphore::new(2);

s.acquire().await;

pub async fn acquire_timeout(&self, dur: Duration) -> bool

Waits for a permit for a concurrent operation.

Return whether permit has been acquired

Examples

use async_sema::Semaphore;
use std::time::Duration;

let s = Semaphore::new(2);

s.acquire_timeout(Duration::from_secs(1)).await;

pub fn add_permits(&self, n: usize)

Add permit for a concurrent operations

Examples

use async_sema::Semaphore;

let s = Semaphore::new(0);

assert!(!s.try_acquire());
s.add_permits(1);
assert!(s.try_acquire());

Trait Implementations

impl Clone for Semaphore

fn clone(&self) -> Semaphore

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Semaphore

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

Formats the value using the given formatter.

impl Send for Semaphore