Struct ICoWCopy 

pub struct ICoWCopy<'copy, ITEM: Sized> { /* private fields */ }

A write-guard which holds new value to which the new data is written. And previous value too. This type of guard is not exclusive, so multiple CoW operations may be performed in parallel which is not normally needed.

The changes made in the current instance becomes visible for the rest of the threads only after commit.

Implementations

impl<'copy, ITEM: Sized> ICoWCopy<'copy, ITEM>

pub fn prev_val(&self) -> &ITEM

Returns a reference to previous value. To access modified version use Deref or DerefMut.

pub fn commit(self) -> Result<(), (ICoWError, Self)>

Commits the changes made in the guarded variable. A non-blocking function. It will not block the thread completly and returns the ICoWError::WouldBlock if attempt to grab the pointer atomically fails in reasonable time. for blocking commit use Self::commit_blocking.

Returns

If operation was successfull, a Result::Ok is returned.

The Result::Err is retruned as tuple

• 0 - ICoWError with the error type.

• 1 - ICoWCopy instance itself.

Error types:

• ICoWError::ExclusiveLockPending - if exclusivly locked from another thread.

• ICoWError::WouldBlock - if “exponential backoff has completed and blocking the thread is advised”

pub fn commit_blocking(self, ignore_excl: bool) -> Result<(), Self>

Commits the changes to the mainstream instance of ICoW. A partially non-blocking function. It would wait for an exclusive access ignoring the ICoWError::WouldBlock only if the instance is not locked exclusivly.

If argument ignore_excl is set to true, the instance will not return ICoWError::ExclusiveLockPending error and wait until the lock release.

If Result::Err is returned, the instance is locked exclusivly. (only if ignore_excl argument is set to true)

Returns

The Result::Err is returned with:

ICoWCopy commited instance itself.

pub fn into_inner(self) -> ITEM

Drops the instance without commiting changes returning a copy, clone, default, or new i.e what was in the new field of the instance.

Trait Implementations

impl<'copy, ITEM: Debug + Sized> Debug for ICoWCopy<'copy, ITEM>

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

Formats the value using the given formatter.

impl<'copy, ITEM: Sized> Deref for ICoWCopy<'copy, ITEM>

type Target = ITEM

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'copy, ITEM: Sized> DerefMut for ICoWCopy<'copy, ITEM>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.