Trait Semaphore

pub trait Semaphore: Sized {
    // Required methods
    fn new(init: u32) -> Option<Self>;
    fn wait(&self);
    fn try_wait(&self) -> bool;
    fn wait_timeout(&self, timeout: Duration) -> bool;
    fn post(&self) -> bool;
    fn signal(&self);

    // Provided methods
    fn lock(&self) -> SemaphoreGuard<'_, Self> { ... }
    fn try_lock(&self) -> Option<SemaphoreGuard<'_, Self>> { ... }
}

Describes Semaphore interface

This primitive provides access to single integer that can be decremented using signal and incremented using wait

Required Methods

fn new(init: u32) -> Option<Self>

Creates new instance, returning None on inability to do so.

init is initial value for the semaphore

fn wait(&self)

Decrements self, returning immediately if it was signaled.

Otherwise awaits for signal

fn try_wait(&self) -> bool

Attempts to decrement self, returning whether self was signaled or not.

Returns true if self was signaled

Returns false otherwise

fn wait_timeout(&self, timeout: Duration) -> bool

Attempts to decrement self within provided time, returning whether self was signaled or not.

Returns true if self was signaled within specified timeout

Returns false otherwise

fn post(&self) -> bool

Increments self, returning whether another thread has been woken as result.

fn signal(&self)

Increments self, waking any awaiting thread as result

Provided Methods

fn lock(&self) -> SemaphoreGuard<'_, Self>

Gets semaphore’s guard, which signal on drop.

Before guard is created, function will await for semaphore to get decremented.

fn try_lock(&self) -> Option<SemaphoreGuard<'_, Self>>

Attempts to acquire semaphore’s guard, which signal on drop.

If semaphore cannot be decremented at the current moment, returns None

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl Semaphore for Sem