Struct lockfree::tls::ThreadLocal

pub struct ThreadLocal<T> { /* private fields */ }

Per Object Thread Local Storage. The stored data is not dropped on thread exit. It is only dropped when the structure itself is dropped. After the thread exited, the data might be reused for other threads. This TLS’s operation are also wait-free.

Example

extern crate lockfree;

use lockfree::tls::ThreadLocal;
use std::{cell::Cell, sync::Arc, thread};

let tls = Arc::new(ThreadLocal::<Cell<usize>>::new());
let mut threads = Vec::with_capacity(32);

for i in 1 ..= 32 {
    let tls = tls.clone();
    threads.push(thread::spawn(move || {
        tls.with_default().set(i);

        if tls.get().map(|c| assert_eq!(c.get(), i)).is_none() {
            // Some OSes mis-run the destructors for their TLS
            // implementation.
            eprintln!("Warning: OS mis-reset the global thread state")
        }
    }))
}

for thread in threads {
    thread.join().unwrap();
}

Implementations

impl<T> ThreadLocal<T>

pub fn new() -> Self

Creates an empty thread local storage.

pub fn clear(&mut self)

Removes and drops all entries. The TLS is considered empty then. This method is only available with exclusive references. This method is merely for optimization since the TLS is cleared at drop.

pub fn iter(&self) -> Iter<'_, T> where
    T: Sync,

Creates an iterator over immutable refereces of entries.

pub fn iter_mut(&mut self) -> IterMut<'_, T> where
    T: Send,

Creates an iterator over mutable refereces of entries.

pub fn get(&self) -> Option<&T>

Accesses the entry for the current thread. No initialization is performed.

pub fn get_with_id(&self, id: ThreadId) -> Option<&T>

Accesses the entry for the current thread with a given cached ID. Repeated calls with cached IDs should be faster than reloading the ID everytime. No initialization is performed.

pub fn with_init<F>(&self, init: F) -> &Twhere
    F: FnOnce() -> T,

Accesses the entry for the current thread. If necessary, the init closure is called to initialize the entry.

pub fn with_id_and_init<F>(&self, id: ThreadId, init: F) -> &Twhere
    F: FnOnce() -> T,

Accesses the entry for the current thread with a given cached ID. Repeated calls with cached IDs should be faster than reloading the ID everytime. If necessary, the init closure is called to initialize the entry.

pub fn with_default(&self) -> &Twhere
    T: Default,

Accesses the entry for the current thread. If necessary, the entry is initialized with default value.

pub fn with_id_and_default(&self, id: ThreadId) -> &Twhere
    T: Default,

Accesses the entry for the current thread with a given cached ID. Repeated calls with cached IDs should be faster than reloading the ID everytime. If necessary, the entry is initialized with default value.

Trait Implementations

impl<T> Debug for ThreadLocal<T>where
    T: Debug,

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

Formats the value using the given formatter.

impl<T> Default for ThreadLocal<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Drop for ThreadLocal<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<'tls, T> IntoIterator for &'tls ThreadLocal<T>where
    T: Sync,

type IntoIter = Iter<'tls, T>

Which kind of iterator are we turning this into?

type Item = &'tls T

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'tls, T> IntoIterator for &'tls mut ThreadLocal<T>where
    T: Send,

type IntoIter = IterMut<'tls, T>

Which kind of iterator are we turning this into?

type Item = &'tls mut T

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T> IntoIterator for ThreadLocal<T>where
    T: Send,

type IntoIter = IntoIter<T>

Which kind of iterator are we turning this into?

type Item = T

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T> Send for ThreadLocal<T>

impl<T> Sync for ThreadLocal<T>