Struct async_sema::Semaphore

pub struct Semaphore { /* private fields */ }

A counter for limiting the number of concurrent operations.

Implementations

impl Semaphore

pub const fn new(n: usize) -> Semaphore

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

Examples

use async_semaphore::Semaphore;

let s = Semaphore::new(5);

pub fn try_acquire(&self) -> bool

Attempts to get a permit for a concurrent operation.

If the permit could not be acquired at this time, then None is returned. Otherwise, a guard is returned that releases the mutex when dropped.

Examples

use async_sema::Semaphore;

let s = Semaphore::new(2);

s.try_acquire().unwrap();
s.try_acquire().unwrap();

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

pub async fn acquire(&self)

Waits for a permit for a concurrent operation.

Returns a guard that releases the permit when dropped.

Examples

use async_sema::Semaphore;

let s = Semaphore::new(2);
s.acquire().await;

pub fn add_permits(&mut self, n: usize)

Add permit for a concurrent operations

Examples

use async_sema::Semaphore;

let s = Semaphore::new(0);
assert!(s.try_acquire().is_none());
s.add_permits(1);
assert!(s.try_acquire().is_some());

Trait Implementations

impl Debug for Semaphore

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

Formats the value using the given formatter.