Struct regex_automata::util::pool::inner::PoolGuard

pub(super) struct PoolGuard<'a, T: Send, F: Fn() -> T> {
    pool: &'a Pool<T, F>,
    value: Result<Box<T>, usize>,
    discard: bool,
}

A guard that is returned when a caller requests a value from the pool.

Fields

pool: &'a Pool<T, F>

The pool that this guard is attached to.

value: Result<Box<T>, usize>

This is Err when the guard represents the special “owned” value. In which case, the value is retrieved from ‘pool.owner_val’. And in the special case of Err(THREAD_ID_DROPPED), it means the guard has been put back into the pool and should no longer be used.

discard: bool

When true, the value should be discarded instead of being pushed back into the pool. We tend to use this under high contention, and this allows us to avoid inflating the size of the pool. (Because under contention, we tend to create more values instead of waiting for access to a stack of existing values.)

Implementations

impl<'a, T: Send, F: Fn() -> T> PoolGuard<'a, T, F>

pub(super) fn value(&self) -> &T

Return the underlying value.

pub(super) fn value_mut(&mut self) -> &mut T

Return the underlying value as a mutable borrow.

pub(super) fn put(this: PoolGuard<'_, T, F>)

Consumes this guard and puts it back into the pool.

fn put_imp(&mut self)

Puts this guard back into the pool by only borrowing the guard as mutable. This should be called at most once.

Trait Implementations

impl<'a, T: Send + Debug, F: Fn() -> T> Debug for PoolGuard<'a, T, F>

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

Formats the value using the given formatter.

impl<'a, T: Send, F: Fn() -> T> Drop for PoolGuard<'a, T, F>

fn drop(&mut self)

Executes the destructor for this type.