Struct RwLockReadGuard 

pub struct RwLockReadGuard<'a, R: RawRwLock, T: ?Sized> { /* private fields */ }

An RAII guard which releases shared read access when dropped.

This structure is created by the read and try_read methods on RwLock.

Implementations

impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> RwLockReadGuard<'a, R, T>

pub fn rwlock(s: &Self) -> &'a RwLock<R, T>

Returns a reference to the original reader-writer lock object.

pub fn map<U: ?Sized, F>(s: Self, f: F) -> MappedRwLockReadGuard<'a, R, U>

where F: FnOnce(&T) -> &U,

Makes a new MappedRwLockReadGuard for a component of the locked data.

This is an associated function that needs to be used as RwLockReadGuard::map(...). A method would interfere with methods of the same name on the contents of the locked data.

Panics

If f panics, the original guard is dropped.

pub fn try_map<U: ?Sized, F>( s: Self, f: F, ) -> Result<MappedRwLockReadGuard<'a, R, U>, Self>

where F: FnOnce(&T) -> Option<&U>,

Attempts to make a new MappedRwLockReadGuard for a component of the locked data. Returns the original guard if the closure returns None.

This is an associated function that needs to be used as RwLockReadGuard::try_map(...). A method would interfere with methods of the same name on the contents of the locked data.

Panics

If f panics, the original guard is dropped.

pub fn try_map_or_err<U: ?Sized, F, E>( s: Self, f: F, ) -> Result<MappedRwLockReadGuard<'a, R, U>, (Self, E)>

where F: FnOnce(&T) -> Result<&U, E>,

Attempts to make a new MappedRwLockReadGuard for a component of the locked data. The original guard is returned alongside arbitrary user data if the closure returns Err.

This is an associated function that needs to be used as RwLockReadGuard::try_map_or_err(...). A method would interfere with methods of the same name on the contents of the locked data.

Panics

If f panics, the original guard is dropped.

pub fn unlocked<F, U>(s: &mut Self, f: F) -> U

where F: FnOnce() -> U,

Temporarily unlocks the RwLock to execute the given function.

The mutable reference ensures that no references derived from this guard are live while the lock is temporarily released.

Aborts

Aborts if re-locking the RwLock panics.

impl<'a, R: RawRwLockFair + 'a, T: ?Sized + 'a> RwLockReadGuard<'a, R, T>

pub fn unlock_fair(s: Self)

Unlocks the RwLock using a fair unlock protocol.

A fair unlock gives waiting threads priority over new acquisition attempts. This can prevent starvation, but may reduce throughput by forcing a context switch.

pub fn unlocked_fair<F, U>(s: &mut Self, f: F) -> U

where F: FnOnce() -> U,

Temporarily unlocks the RwLock to execute the given function.

The RwLock is unlocked using a fair unlock protocol.

The mutable reference ensures that no references derived from this guard are live while the lock is temporarily released.

Aborts

Aborts if re-locking the RwLock panics.

pub fn bump(s: &mut Self)

Temporarily yields the RwLock to a waiting thread if there is one.

This method is functionally equivalent to calling unlock_fair followed by read, however it can be much more efficient in the case where there are no waiting threads.

Trait Implementations

impl<'a, R: RawRwLock + 'a, T: Debug + ?Sized + 'a> Debug for RwLockReadGuard<'a, R, T>

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

Formats the value using the given formatter.

impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Deref for RwLockReadGuard<'a, R, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'a, R: RawRwLock + 'a, T: Display + ?Sized + 'a> Display for RwLockReadGuard<'a, R, T>

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

Formats the value using the given formatter.

impl<'a, R: RawRwLock + 'a, T: ?Sized + 'a> Drop for RwLockReadGuard<'a, R, T>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.