Struct parking_lot::RwLockWriteGuard

#[must_use]
pub struct RwLockWriteGuard<'a, T: ?Sized + 'a> { /* fields omitted */ }

RAII structure used to release the exclusive write access of a lock when dropped.

Methods

impl<'a, T: ?Sized + 'a> RwLockWriteGuard<'a, T>

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

Atomically downgrades a write lock into a 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 map<U: ?Sized, F>(orig: Self, f: F) -> RwLockWriteGuard<'a, U> where     F: FnOnce(&mut T) -> &mut U,

Make a new RwLockWriteGuard for a component of the locked data.

This operation cannot fail as the RwLockWriteGuard passed in already locked the data.

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

pub fn unlock_fair(self)

Unlocks the RwLock using a fair unlock protocol.

By default, RwLock is unfair and allow the current thread to re-lock the rwlock before another has the chance to acquire the lock, even if that thread has been blocked on the RwLock for a long time. This is the default because it allows much higher throughput as it avoids forcing a context switch on every rwlock unlock. This can result in one thread acquiring a RwLock many more times than other threads.

However in some cases it can be beneficial to ensure fairness by forcing the lock to pass on to a waiting thread if there is one. This is done by using this method instead of dropping the RwLockWriteGuard normally.

Trait Implementations

impl<'a, T: ?Sized + Sync + 'a> Sync for RwLockWriteGuard<'a, T>

impl<'a, T: ?Sized + 'a> Deref for RwLockWriteGuard<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'a, T: ?Sized + 'a> DerefMut for RwLockWriteGuard<'a, T>

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

Mutably dereferences the value.

impl<'a, T: ?Sized + 'a> Drop for RwLockWriteGuard<'a, T>

fn drop(&mut self)

Executes the destructor for this type.

impl<'a, T: ?Sized> StableAddress for RwLockWriteGuard<'a, T>