Struct std::sync::PoisonError

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

A type of error which can be returned whenever a lock is acquired.

Both Mutexes and RwLocks are poisoned whenever a thread fails while the lock is held. The precise semantics for when a lock is poisoned is documented on each lock, but once a lock is poisoned then all future acquisitions will return this error.

Examples

use std::sync::{Arc, Mutex};
use std::thread;

let mutex = Arc::new(Mutex::new(1));

// poison the mutex
let c_mutex = Arc::clone(&mutex);
let _ = thread::spawn(move || {
    let mut data = c_mutex.lock().unwrap();
    *data = 2;
    panic!();
}).join();

match mutex.lock() {
    Ok(_) => unreachable!(),
    Err(p_err) => {
        let data = p_err.get_ref();
        println!("recovered: {data}");
    }
};

Implementations

impl<T> PoisonError<T>

pub fn new(guard: T) -> PoisonError<T>

Creates a PoisonError.

This is generally created by methods like Mutex::lock or RwLock::read.

pub fn into_inner(self) -> T

Consumes this error indicating that a lock is poisoned, returning the underlying guard to allow access regardless.

Examples

use std::collections::HashSet;
use std::sync::{Arc, Mutex};
use std::thread;

let mutex = Arc::new(Mutex::new(HashSet::new()));

// poison the mutex
let c_mutex = Arc::clone(&mutex);
let _ = thread::spawn(move || {
    let mut data = c_mutex.lock().unwrap();
    data.insert(10);
    panic!();
}).join();

let p_err = mutex.lock().unwrap_err();
let data = p_err.into_inner();
println!("recovered {} items", data.len());

pub fn get_ref(&self) -> &T

Reaches into this error indicating that a lock is poisoned, returning a reference to the underlying guard to allow access regardless.

pub fn get_mut(&mut self) -> &mut T

Reaches into this error indicating that a lock is poisoned, returning a mutable reference to the underlying guard to allow access regardless.

Trait Implementations

impl<T> Debug for PoisonError<T>

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

Formats the value using the given formatter.

impl<T> Display for PoisonError<T>

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

Formats the value using the given formatter.

impl<T> Error for PoisonError<T>

fn description(&self) -> &str

👎 Deprecated since 1.42.0:

use the Display impl or to_string()

fn source(&self) -> Option<&(dyn Error + 'static)>

The lower-level source of this error, if any.

fn cause(&self) -> Option<&dyn Error>

👎 Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, req: &mut Demand<'a>)

🔬 This is a nightly-only experimental API. (error_generic_member_access #99301)

Provides type based access to context intended for error reports.

impl<T> From<PoisonError<T>> for TryLockError<T>

fn from(err: PoisonError<T>) -> TryLockError<T>

Converts to this type from the input type.