Type Alias spin::RwLockUpgradableGuard

pub type RwLockUpgradableGuard<'a, T> = RwLockUpgradableGuard<'a, T>;

A guard that provides immutable data access but can be upgraded to RwLockWriteGuard. See rwlock::RwLockUpgradableGuard for documentation.

A note for advanced users: this alias exists to avoid subtle type inference errors due to the default relax strategy type parameter. If you need a non-default relax strategy, use the fully-qualified path.

Aliased Type

struct RwLockUpgradableGuard<'a, T> { /* private fields */ }

Implementations

impl<'rwlock, T: ?Sized, R: RelaxStrategy> RwLockUpgradableGuard<'rwlock, T, R>

pub fn upgrade(self) -> RwLockWriteGuard<'rwlock, T, R>

Upgrades an upgradeable lock guard to a writable lock guard.

let mylock = spin::RwLock::new(0);

let upgradeable = mylock.upgradeable_read(); // Readable, but not yet writable
let writable = upgradeable.upgrade();

impl<'rwlock, T: ?Sized, R> RwLockUpgradableGuard<'rwlock, T, R>

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

Tries to upgrade an upgradeable lock guard to a writable lock guard.

let mylock = spin::RwLock::new(0);
let upgradeable = mylock.upgradeable_read(); // Readable, but not yet writable

match upgradeable.try_upgrade() {
    Ok(writable) => /* upgrade successful - use writable lock guard */ (),
    Err(upgradeable) => /* upgrade unsuccessful */ (),
};

pub fn downgrade(self) -> RwLockReadGuard<'rwlock, T>

Downgrades the upgradeable lock guard to a readable, shared lock guard. Cannot fail and is guaranteed not to spin.

let mylock = spin::RwLock::new(1);

let upgradeable = mylock.upgradeable_read();
assert!(mylock.try_read().is_none());
assert_eq!(*upgradeable, 1);

let readable = upgradeable.downgrade(); // This is guaranteed not to spin
assert!(mylock.try_read().is_some());
assert_eq!(*readable, 1);

pub fn leak(this: Self) -> &'rwlock T

Leak the lock guard, yielding a reference to the underlying data.

Note that this function will permanently lock the original lock.

let mylock = spin::RwLock::new(0);

let data: &i32 = spin::RwLockUpgradableGuard::leak(mylock.upgradeable_read());

assert_eq!(*data, 0);

Trait Implementations

impl<'rwlock, T: ?Sized + Debug, R> Debug for RwLockUpgradableGuard<'rwlock, T, R>

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

Formats the value using the given formatter.

impl<'rwlock, T: ?Sized, R> Deref for RwLockUpgradableGuard<'rwlock, T, R>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'rwlock, T: ?Sized + Display, R> Display for RwLockUpgradableGuard<'rwlock, T, R>

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

Formats the value using the given formatter.

impl<'rwlock, T: ?Sized, R> Drop for RwLockUpgradableGuard<'rwlock, T, R>

fn drop(&mut self)

Executes the destructor for this type.

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

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