rust concurrency_error ai_generated true

thread '<unnamed>' panicked at 'a]scoped thread panicked'

ID: rust/rust-crossbeam-scope-panic

Also available as: JSON · Markdown
83%Fix Rate
86%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1 active — — —

Root Cause

A thread spawned inside crossbeam::scope panicked, propagating the panic to the parent scope. Handle panics within scoped threads.

generic

Workarounds

  1. 87% success Use catch_unwind inside each scoped thread 
    crossbeam::scope(|s| {
    s.spawn(|_| {
        if let Err(e) = std::panic::catch_unwind(|| {
            // thread work here
        }) {
            eprintln!("Thread panicked: {:?}", e);
        }
    });
}).unwrap();

    Sources: https://docs.rs/crossbeam/latest/crossbeam/fn.scope.html

  2. 85% success Use std::thread::scope (Rust 1.63+) which has built-in panic handling 
    std::thread::scope(|s| {
    let handle = s.spawn(|| { /* work */ });
    match handle.join() {
        Ok(result) => { /* success */ },
        Err(e) => { /* handle panic */ },
    }
});

    Sources: https://doc.rust-lang.org/std/thread/fn.scope.html

Dead Ends

Common approaches that don't work:

  1. Use std::panic::catch_unwind at the scope level only 65% fail

    catch_unwind on the scope catches the propagated panic but the child thread's state is already corrupted

Error Chain

Leads to:
Preceded by:
Frequently confused with: