[−]Struct smol::lock::Semaphore
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_semaphore::Semaphore; let s = Semaphore::new(5);
pub fn try_acquire(&self) -> Option<SemaphoreGuard<'_>>
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_semaphore::Semaphore; let s = Semaphore::new(2); let g1 = s.try_acquire().unwrap(); let g2 = s.try_acquire().unwrap(); assert!(s.try_acquire().is_none()); drop(g2); assert!(s.try_acquire().is_some());
pub async fn acquire(&'_ self) -> SemaphoreGuard<'_>
Waits for a permit for a concurrent operation.
Returns a guard that releases the permit when dropped.
Examples
use async_semaphore::Semaphore; let s = Semaphore::new(2); let guard = s.acquire().await;
impl Semaphore
pub fn try_acquire_arc(self: &Arc<Semaphore>) -> Option<SemaphoreGuardArc>
Attempts to get an owned permit for a concurrent operation.
If the permit could not be acquired at this time, then None
is returned. Otherwise, an
owned guard is returned that releases the mutex when dropped.
Examples
use async_semaphore::Semaphore; use std::sync::Arc; let s = Arc::new(Semaphore::new(2)); let g1 = s.try_acquire_arc().unwrap(); let g2 = s.try_acquire_arc().unwrap(); assert!(s.try_acquire_arc().is_none()); drop(g2); assert!(s.try_acquire_arc().is_some());
pub async fn acquire_arc(self: &'_ Arc<Semaphore>) -> SemaphoreGuardArc
Waits for an owned permit for a concurrent operation.
Returns a guard that releases the permit when dropped.
Examples
use async_semaphore::Semaphore; use std::sync::Arc; let s = Arc::new(Semaphore::new(2)); let guard = s.acquire_arc().await;
Trait Implementations
Auto Trait Implementations
impl RefUnwindSafe for Semaphore
impl Send for Semaphore
impl Sync for Semaphore
impl Unpin for Semaphore
impl UnwindSafe for Semaphore
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
fn borrow_mut(&mut self) -> &mut Tⓘ
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impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,