Struct Mutex

pub struct Mutex<R, T: ?Sized> { /* private fields */ }

A mutual exclusion primitive useful for protecting shared data

This mutex will block threads waiting for the lock to become available. The mutex can also be statically initialized or created via a new constructor. Each mutex has a type parameter which represents the data that it is protecting. The data can only be accessed through the RAII guards returned from lock and try_lock, which guarantees that the data is only ever accessed when the mutex is locked.

Implementations

impl<R, T> Mutex<R, T>

const fn from_raw(raw_mutex: R, val: T) -> Mutex<R, T>

Creates a new mutex based on a pre-existing raw mutex.

const fn const_new(raw_mutex: R, val: T) -> Mutex<R, T>

Creates a new mutex based on a pre-existing raw mutex.

This allows creating a mutex in a constant context on stable Rust.

This method is a legacy alias for from_raw.

impl<R: RawMutex, T> Mutex<R, T>

const fn new(val: T) -> Mutex<R, T>

Creates a new mutex in an unlocked state ready for use.

fn into_inner(self) -> T

Consumes this mutex, returning the underlying data.

impl<R: RawMutex, T: ?Sized> Mutex<R, T>

unsafe fn make_guard_unchecked(&self) -> MutexGuard<'_, R, T>

Creates a new MutexGuard without checking if the mutex is locked.

Safety

This method must only be called if the thread logically holds the lock.

Calling this function when a guard has already been produced is undefined behaviour unless the guard was forgotten with mem::forget.

fn lock(&self) -> MutexGuard<'_, R, T>

Acquires a mutex, blocking the current thread until it is able to do so.

This function will block the local thread until it is available to acquire the mutex. Upon returning, the thread is the only thread with the mutex held. An RAII guard is returned to allow scoped unlock of the lock. When the guard goes out of scope, the mutex will be unlocked.

Attempts to lock a mutex in the thread which already holds the lock will result in a deadlock.

fn try_lock(&self) -> Option<MutexGuard<'_, R, T>>

Attempts to acquire this lock.

If the lock could not be acquired at this time, then None is returned. Otherwise, an RAII guard is returned. The lock will be unlocked when the guard is dropped.

This function does not block.

fn get_mut(&mut self) -> &mut T

Returns a mutable reference to the underlying data.

Since this call borrows the Mutex mutably, no actual locking needs to take place---the mutable borrow statically guarantees no locks exist.

fn is_locked(&self) -> bool

Checks whether the mutex is currently locked.

unsafe fn force_unlock(&self)

Forcibly unlocks the mutex.

This is useful when combined with mem::forget to hold a lock without the need to maintain a MutexGuard object alive, for example when dealing with FFI.

Safety

This method must only be called if the current thread logically owns a MutexGuard but that guard has been discarded using mem::forget. Behavior is undefined if a mutex is unlocked when not locked.

unsafe fn raw(&self) -> &R

Returns the underlying raw mutex object.

Note that you will most likely need to import the RawMutex trait from lock_api to be able to call functions on the raw mutex.

Safety

This method is unsafe because it allows unlocking a mutex while still holding a reference to a MutexGuard.

fn data_ptr(&self) -> *mut T

Returns a raw pointer to the underlying data.

This is useful when combined with mem::forget to hold a lock without the need to maintain a MutexGuard object alive, for example when dealing with FFI.

Safety

You must ensure that there are no data races when dereferencing the returned pointer, for example if the current thread logically owns a MutexGuard but that guard has been discarded using mem::forget.

impl<R: RawMutexFair, T: ?Sized> Mutex<R, T>

unsafe fn force_unlock_fair(&self)

Forcibly unlocks the mutex using a fair unlock protocol.

This is useful when combined with mem::forget to hold a lock without the need to maintain a MutexGuard object alive, for example when dealing with FFI.

Safety

This method must only be called if the current thread logically owns a MutexGuard but that guard has been discarded using mem::forget. Behavior is undefined if a mutex is unlocked when not locked.

impl<R: RawMutexTimed, T: ?Sized> Mutex<R, T>

fn try_lock_for(&self, timeout: R::Duration) -> Option<MutexGuard<'_, R, T>>

Attempts to acquire this lock until a timeout is reached.

If the lock could not be acquired before the timeout expired, then None is returned. Otherwise, an RAII guard is returned. The lock will be unlocked when the guard is dropped.

fn try_lock_until(&self, timeout: R::Instant) -> Option<MutexGuard<'_, R, T>>

Attempts to acquire this lock until a timeout is reached.

If the lock could not be acquired before the timeout expired, then None is returned. Otherwise, an RAII guard is returned. The lock will be unlocked when the guard is dropped.

Trait Implementations

impl<R: RawMutex + Send, T: ?Sized + Send> Send for Mutex<R, T>

impl<R: RawMutex + Sync, T: ?Sized + Send> Sync for Mutex<R, T>

impl<R: RawMutex, T> From<T> for Mutex<R, T>

fn from(t: T) -> Mutex<R, T>

impl<R: RawMutex, T: ?Sized + Debug> Debug for Mutex<R, T>

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

impl<R: RawMutex, T: ?Sized + Default> Default for Mutex<R, T>

fn default() -> Mutex<R, T>

Auto Trait Implementations

impl<R, T> !Freeze for Mutex<R, T>

impl<R, T> !RefUnwindSafe for Mutex<R, T>

impl<R, T> Unpin for Mutex<R, T> where R: Unpin, UnsafeCell<T>: Unpin, T: ?Sized,

impl<R, T> UnsafeUnpin for Mutex<R, T> where R: UnsafeUnpin, UnsafeCell<T>: UnsafeUnpin, T: ?Sized,

impl<R, T> UnwindSafe for Mutex<R, T> where R: UnwindSafe, UnsafeCell<T>: UnwindSafe, T: ?Sized,

Blanket Implementations

impl<T> Any for Mutex<R, T> where T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Mutex<R, T> where T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Mutex<R, T> where T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> From<T> for Mutex<R, T>

fn from(t: T) -> T

Returns the argument unchanged.

impl<T, U> Into<U> for Mutex<R, T> where U: From<T>,

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

impl<T, U> TryFrom<U> for Mutex<R, T> where U: Into<T>,

type Error = never;
fn try_from(value: U) -> Result<T, never>

impl<T, U> TryInto<U> for Mutex<R, T> where U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error;
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>