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Auto merge of #135224 - wyfo:tls-panic-outline, r=cuviper

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Outline panicking code for `LocalKey::with`

See https://github.com/rust-lang/rust/pull/115491 for prior related modifications.

https://godbolt.org/z/MTsz87jGj shows a reduction of the code size for TLS accesses.
This commit is contained in:
bors 2025-01-21 02:23:15 +00:00
commit b605c65b6e
1 changed files with 16 additions and 8 deletions
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24
library/std/src/thread/local.rs
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@ -230,6 +230,14 @@ impl fmt::Display for AccessError {
#[stable(feature = "thread_local_try_with", since = "1.26.0")]
impl Error for AccessError {}
// This ensures the panicking code is outlined from `with` for `LocalKey`.
#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))]
#[track_caller]
#[cold]
fn panic_access_error(err: AccessError) -> ! {
panic!("cannot access a Thread Local Storage value during or after destruction: {err:?}")
}
impl<T: 'static> LocalKey<T> {
#[doc(hidden)]
#[unstable(
@ -269,10 +277,10 @@ impl<T: 'static> LocalKey<T> {
where
F: FnOnce(&T) -> R,
{
self.try_with(f).expect(
"cannot access a Thread Local Storage value \
during or after destruction",
)
match self.try_with(f) {
Ok(r) => r,
Err(err) => panic_access_error(err),
}
}
/// Acquires a reference to the value in this TLS key.
@ -327,10 +335,10 @@ impl<T: 'static> LocalKey<T> {
let mut init = Some(init);
let reference = unsafe {
(self.inner)(Some(&mut init)).as_ref().expect(
"cannot access a Thread Local Storage value \
during or after destruction",
)
match (self.inner)(Some(&mut init)).as_ref() {
Some(r) => r,
None => panic_access_error(AccessError),
}
};
f(init, reference)