Struct MVar

pub struct MVar<T> { /* private fields */ }

An MVar is a primitive that combines synchronization and the exchange of a value. Its semantics are analogous to a synchronous channel of size 1: if the MVar is full, then put blocks until it is emptied; if the MVar is empty, then take blocks until it is filled.

MVars, first introduced in “Concurrent Haskell” are surprisingly versatile in use. They can be used as:

• a communication channel (with put and take corresponding to send and recv);
• a semaphore (with put and take corresponding to signal and wait);
• a mutex (with put and take corresponding to lock and unlock);

Implementations

impl<T> MVar<T>

pub fn full(value: T) -> Self

Create a new full MVar with the provided value.

pub fn empty() -> Self

Create a new empty MVar.

pub async fn take(&self) -> T

Wait until the MVar is full and take its value. This method is cancellation safe.

pub async fn put(&self, new_value: T)

Wait until the MVar is empty and put a new value. This method is cancellation safe.

Trait Implementations

impl<T: Clone> Clone for MVar<T>

fn clone(&self) -> MVar<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for MVar<T>

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

Formats the value using the given formatter.