rust/library/std
Matthias Krüger 6ab180577f
Rollup merge of #129581 - RalfJung:exit, r=joshtriplett
exit: explain our expectations for the exit handlers registered in a Rust program

This documents the position of ``@Amanieu`` and others in https://github.com/rust-lang/rust/issues/126600: a library with an atexit handler that destroys state that other threads could still be working on is buggy. We do not consider it acceptable for a library to say "you must call the following cleanup function before exiting from `main` or calling `exit`". I don't know if this is established ``@rust-lang/libs-api``  consensus so I presume this will have to go through FCP.

Given that Rust supports concurrency, I don't think there is any way to write a sound Rust wrapper around a library that has such a required cleanup function: even if we made `exit` unsafe, and the Rust wrapper used the scope-with-callback approach to ensure it can run cleanup code before returning from the wrapper (like `thread::scope`), one could still call this wrapper in a second thread and then return from `main` while the wrapper runs. Making this sound would require `std` to provide a way to "block" returning from `main`, so that while the wrapper runs returning from `main` waits until the wrapper is done... that just doesn't seem feasible.

The `exit` docs do not seem like the best place to document this, but I also couldn't think of a better one.
2024-08-27 18:59:27 +02:00
..
benches Reformat use declarations. 2024-07-29 08:26:52 +10:00
src Rollup merge of #129581 - RalfJung:exit, r=joshtriplett 2024-08-27 18:59:27 +02:00
tests Reformat use declarations. 2024-07-29 08:26:52 +10:00
build.rs Enable f16 tests on x86 and x86-64 2024-08-23 13:54:50 -05:00
Cargo.toml Update compiler_builtins to 0.1.121 2024-08-23 12:02:26 -07:00