Struct std::sync::PoisonError

1.0.0 · source ·
pub struct PoisonError<T> { /* private fields */ }
Expand description

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}");
    }
};
Run

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impl<T> PoisonError<T>

1.2.0 · source

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

Creates a PoisonError.

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

1.2.0 · source

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());
Run
1.2.0 · source

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.

1.2.0 · source

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§

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impl<T> Debug for PoisonError<T>

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

Formats the value using the given formatter. Read more
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impl<T> Display for PoisonError<T>

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

Formats the value using the given formatter. Read more
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impl<T> Error for PoisonError<T>

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fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()
1.30.0 · source§

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

The lower-level source of this error, if any. Read more
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fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
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fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access #99301)
Provides type based access to context intended for error reports. Read more
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impl<T> From<PoisonError<T>> for TryLockError<T>

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

Converts to this type from the input type.

Auto Trait Implementations§

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impl<T> RefUnwindSafe for PoisonError<T>
where T: RefUnwindSafe,

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impl<T> Send for PoisonError<T>
where T: Send,

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impl<T> Sync for PoisonError<T>
where T: Sync,

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impl<T> Unpin for PoisonError<T>
where T: Unpin,

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impl<T> UnwindSafe for PoisonError<T>
where T: UnwindSafe,

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.