Struct Semaphore 

pub struct Semaphore { /* private fields */ }

A counting semaphore.

Maintains an internal counter initialised to permits. Calls to acquire block when the counter is 0. Calls to release increment the counter and wake one waiting thread.

Example

use scirs2_core::concurrent::async_utils::Semaphore;
use std::sync::Arc;

let sem = Arc::new(Semaphore::new(2));
sem.acquire().expect("acquire");
sem.acquire().expect("acquire");
sem.release(); // now one thread can proceed
sem.release();

Implementations

impl Semaphore

pub fn new(permits: usize) -> Self

Create a semaphore with permits initial permits.

pub fn acquire(&self) -> CoreResult<()>

Acquire one permit, blocking if none are available.

pub fn acquire_timeout(&self, timeout: Duration) -> CoreResult<bool>

Acquire one permit, blocking for at most timeout.

Returns true if a permit was acquired, false on timeout.

pub fn try_acquire(&self) -> CoreResult<bool>

Try to acquire without blocking. Returns true on success.

pub fn release(&self)

Release one permit.

pub fn release_n(&self, n: usize)

Release n permits at once.

pub fn available(&self) -> usize

Current available permits (informational).