Struct lock_api::ArcRwLockUpgradableReadGuard

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

An RAII rwlock guard returned by the Arc locking operations on RwLock. This is similar to the RwLockUpgradableReadGuard struct, except instead of using a reference to unlock the RwLock it uses an Arc<RwLock>. This has several advantages, most notably that it has an 'static lifetime.

Implementations

impl<R: RawRwLockUpgrade, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T>

pub fn rwlock(s: &Self) -> &Arc<RwLock<R, T>>

Returns a reference to the rwlock, contained in its original Arc.

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

where F: FnOnce() -> U,

Temporarily unlocks the RwLock to execute the given function.

This is functionally identical to the unlocked method on RwLockUpgradableReadGuard.

pub fn upgrade(s: Self) -> ArcRwLockWriteGuard<R, T>

Atomically upgrades an upgradable read lock lock into an exclusive write lock, blocking the current thread until it can be acquired.

pub fn try_upgrade(s: Self) -> Result<ArcRwLockWriteGuard<R, T>, Self>

Tries to atomically upgrade an upgradable read lock into an exclusive write lock.

If the access could not be granted at this time, then the current guard is returned.

impl<R: RawRwLockUpgradeFair, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T>

pub fn unlock_fair(s: Self)

Unlocks the RwLock using a fair unlock protocol.

This is functionally identical to the unlock_fair method on RwLockUpgradableReadGuard.

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.

This is functionally equivalent to the unlocked_fair method on RwLockUpgradableReadGuard.

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 bump on RwLockUpgradableReadGuard.

impl<R: RawRwLockUpgradeDowngrade, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T>

pub fn downgrade(s: Self) -> ArcRwLockReadGuard<R, T>

Atomically downgrades an upgradable read lock lock into a shared read lock without allowing any writers to take exclusive access of the lock in the meantime.

Note that if there are any writers currently waiting to take the lock then other readers may not be able to acquire the lock even if it was downgraded.

pub fn with_upgraded<Ret, F: FnOnce(&mut T) -> Ret>(&mut self, f: F) -> Ret

First, atomically upgrades an upgradable read lock lock into an exclusive write lock, blocking the current thread until it can be acquired.

Then, calls the provided closure with an exclusive reference to the lock’s data.

Finally, atomically downgrades the lock back to an upgradable read lock. The closure’s return value is returned.

This function only requires a mutable reference to the guard, unlike upgrade which takes the guard by value.

pub fn try_with_upgraded<Ret, F: FnOnce(&mut T) -> Ret>( &mut self, f: F ) -> Option<Ret>

First, tries to atomically upgrade an upgradable read lock into an exclusive write lock.

If the access could not be granted at this time, then None is returned.

Otherwise, calls the provided closure with an exclusive reference to the lock’s data, and finally downgrades the lock back to an upgradable read lock. The closure’s return value is wrapped in Some and returned.

This function only requires a mutable reference to the guard, unlike try_upgrade which takes the guard by value.

impl<R: RawRwLockUpgradeTimed, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T>

pub fn try_upgrade_for( s: Self, timeout: R::Duration ) -> Result<ArcRwLockWriteGuard<R, T>, Self>

Tries to atomically upgrade an upgradable read lock into an exclusive write lock, until a timeout is reached.

If the access could not be granted before the timeout expires, then the current guard is returned.

pub fn try_upgrade_until( s: Self, timeout: R::Instant ) -> Result<ArcRwLockWriteGuard<R, T>, Self>

Tries to atomically upgrade an upgradable read lock into an exclusive write lock, until a timeout is reached.

If the access could not be granted before the timeout expires, then the current guard is returned.

impl<R: RawRwLockUpgradeTimed + RawRwLockUpgradeDowngrade, T: ?Sized> ArcRwLockUpgradableReadGuard<R, T>

pub fn try_with_upgraded_for<Ret, F: FnOnce(&mut T) -> Ret>( &mut self, timeout: R::Duration, f: F ) -> Option<Ret>

Tries to atomically upgrade an upgradable read lock into an exclusive write lock, until a timeout is reached.

If the access could not be granted before the timeout expires, then None is returned.

Otherwise, calls the provided closure with an exclusive reference to the lock’s data, and finally downgrades the lock back to an upgradable read lock. The closure’s return value is wrapped in Some and returned.

This function only requires a mutable reference to the guard, unlike try_upgrade_for which takes the guard by value.

pub fn try_with_upgraded_until<Ret, F: FnOnce(&mut T) -> Ret>( &mut self, timeout: R::Instant, f: F ) -> Option<Ret>

Tries to atomically upgrade an upgradable read lock into an exclusive write lock, until a timeout is reached.

If the access could not be granted before the timeout expires, then None is returned.

Otherwise, calls the provided closure with an exclusive reference to the lock’s data, and finally downgrades the lock back to an upgradable read lock. The closure’s return value is wrapped in Some and returned.

This function only requires a mutable reference to the guard, unlike try_upgrade_until which takes the guard by value.

Trait Implementations

impl<R: RawRwLockUpgrade, T: Debug + ?Sized> Debug for ArcRwLockUpgradableReadGuard<R, T>

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

Formats the value using the given formatter.

impl<R: RawRwLockUpgrade, T: ?Sized> Deref for ArcRwLockUpgradableReadGuard<R, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<R: RawRwLockUpgrade, T: Display + ?Sized> Display for ArcRwLockUpgradableReadGuard<R, T>

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

Formats the value using the given formatter.

impl<R: RawRwLockUpgrade, T: ?Sized> Drop for ArcRwLockUpgradableReadGuard<R, T>

fn drop(&mut self)

Executes the destructor for this type.