Struct more_sync::VersionedParker

pub struct VersionedParker<T> { /* fields omitted */ }

A thread parking and locking primitive that provide version numbers.

Like an std::sync::Condvar, VersionedParker provides a wait method and several notify methods. The wait method blocks the current thread, while the notify methods unblocks waiting threads. Each time notify is called, the parker version is increased. When a blocked thread wakes up, it can check the internal counter and learn how many times it has been notified. The version can be obtained by calling method VersionedParker::version().

VersionedParker holds a piece of data that can be modified during notify and wait operations. The data is versioned also versioned by the same parker version.

use more_sync::VersionedParker;

let versioned_parker = VersionedParker::new(0);
let mut guard = versioned_parker.lock();

let parker_clone = versioned_parker.clone();
std::thread::spawn(move || {
    parker_clone.notify_one_mutate(|i| *i = 16);
    assert_eq!(parker_clone.version(), 1);
    // Version is 1, try_notify_all() should fail.
    assert!(!parker_clone.try_notify_all(0));
});

guard.wait();
assert_eq!(guard.notified_count(), 1);
assert_eq!(*guard, 16);

Implementations

impl<T> VersionedParker<T>

pub fn new(data: T) -> Self

Creates a new VersionedParker, with the initial version being 0, and the shared data being data.

pub fn lock(&self) -> VersionedGuard<'_, T>

Locks the shared data and the version.

A thread can then call VersionedGuard::wait() to wait for version changes.

pub fn notify_one(&self)

Increases the version and notifies one blocked thread.

pub fn notify_one_mutate(&self, mutate: fn(_: &mut T))

Increases the version, mutates the shared data and notifies one blocked thread.

pub fn try_notify_one(&self, expected_version: usize) -> bool

Increases the version and notifies one blocked thread, if the current version is expected_version.

Returns true if the version matches.

pub fn try_notify_one_mutate(
    &self,
    expected_version: usize,
    mutate: fn(_: &mut T)
) -> bool

Increases the version, modifies the shared data and notifies one blocked thread, if the current version is expected_version.

Returns true if the version matches.

pub fn notify_all(&self)

Increases the version and notifies all blocked threads.

pub fn notify_all_mutate(&self, mutate: fn(_: &mut T))

Increases the version, modifies the shared data and notifies all blocked threads.

pub fn try_notify_all(&self, expected_version: usize) -> bool

Increases the version and notifies all blocked threads, if the current version is expected_version.

Returns true if the version matches.

pub fn try_notify_all_mutate(
    &self,
    expected_version: usize,
    mutate: fn(_: &mut T)
) -> bool

Increases the version, modifies the shared data and notifies all blocked threads, if the current version is expected_version.

Returns true if the version matches.

pub fn version(&self) -> usize

Returns the current version.

Trait Implementations

impl<T: Clone> Clone for VersionedParker<T>

fn clone(&self) -> VersionedParker<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for VersionedParker<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for VersionedParker<T>

fn default() -> VersionedParker<T>

Returns the “default value” for a type.