From 3ea744e2ac975456d14805100755d2e39a565e46 Mon Sep 17 00:00:00 2001 From: Corey Farwell Date: Fri, 18 Dec 2020 17:03:45 -0500 Subject: [PATCH] Recommend panic::resume_unwind instead of panicking. Fixes https://github.com/rust-lang/rust/issues/79950. --- library/std/src/thread/mod.rs | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs index 5d65f960fcd39..0d004a516f594 100644 --- a/library/std/src/thread/mod.rs +++ b/library/std/src/thread/mod.rs @@ -1186,32 +1186,37 @@ impl fmt::Debug for Thread { /// the [`Error`](crate::error::Error) trait. /// /// Thus, a sensible way to handle a thread panic is to either: -/// 1. `unwrap` the `Result`, propagating the panic +/// +/// 1. propagate the panic with [`std::panic::resume_unwind`] /// 2. or in case the thread is intended to be a subsystem boundary /// that is supposed to isolate system-level failures, -/// match on the `Err` variant and handle the panic in an appropriate way. +/// match on the `Err` variant and handle the panic in an appropriate way /// /// A thread that completes without panicking is considered to exit successfully. /// /// # Examples /// +/// Matching on the result of a joined thread: +/// /// ```no_run -/// use std::thread; -/// use std::fs; +/// use std::{fs, thread, panic}; /// /// fn copy_in_thread() -> thread::Result<()> { -/// thread::spawn(move || { fs::copy("foo.txt", "bar.txt").unwrap(); }).join() +/// thread::spawn(|| { +/// fs::copy("foo.txt", "bar.txt").unwrap(); +/// }).join() /// } /// /// fn main() { /// match copy_in_thread() { -/// Ok(_) => println!("this is fine"), -/// Err(_) => println!("thread panicked"), +/// Ok(_) => println!("copy succeeded"), +/// Err(e) => panic::resume_unwind(e), /// } /// } /// ``` /// /// [`Result`]: crate::result::Result +/// [`std::panic::resume_unwind`]: crate::panic::resume_unwind #[stable(feature = "rust1", since = "1.0.0")] pub type Result = crate::result::Result>;