Struct RwLockUpgradableReadGuard 

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

The upgradable read of a RwLock: shared access that can become exclusive without a writer getting in between. Releases on drop, with the progress RwLockReadGuard’s release makes.

It moves to another thread only when T is Send as well as Sync: an upgrade turns it into &mut T, so moving it can move the value. A value that may be shared but not moved, such as a std::sync::MutexGuard, keeps the guard on its thread:

use nuclei::sync::RwLockUpgradableReadGuard;
use std::sync::MutexGuard;

fn moves<T: Send>() {}
moves::<RwLockUpgradableReadGuard<'static, Option<MutexGuard<'static, ()>>>>();

Implementations

impl<'a, T: ?Sized> RwLockUpgradableReadGuard<'a, T>

pub fn upgrade(self) -> Upgrade<'a, T>

Waits for the readers inside to leave, holding new readers back meanwhile, then holds the write.

pub fn try_upgrade(self) -> Result<RwLockWriteGuard<'a, T>, Self>

Holds the write at once if no reader is inside; otherwise hands the upgradable read back.

Trait Implementations

impl<T: ?Sized + Debug> Debug for RwLockUpgradableReadGuard<'_, T>

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

Formats the value using the given formatter.

impl<T: ?Sized> Deref for RwLockUpgradableReadGuard<'_, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T: ?Sized> Drop for RwLockUpgradableReadGuard<'_, 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.

impl<T: ?Sized + Send + Sync> Send for RwLockUpgradableReadGuard<'_, T>

impl<T: ?Sized + Sync> Sync for RwLockUpgradableReadGuard<'_, T>