Auto merge of #120238 - joboet:always_confirm_lock_success, r=Mark-Simulacrum

Always check the result of `pthread_mutex_lock`

Fixes #120147.

Instead of manually adding a list of "good" platforms, I've simply made the check unconditional. pthread's mutex is already quite slow on most platforms, so one single well-predictable branch shouldn't hurt performance too much.
This commit is contained in:
bors 2024-02-09 10:27:16 +00:00
commit 972452c447

View File

@ -1,4 +1,5 @@
use crate::cell::UnsafeCell;
use crate::io::Error;
use crate::mem::{forget, MaybeUninit};
use crate::sys::cvt_nz;
use crate::sys_common::lazy_box::{LazyBox, LazyInit};
@ -103,8 +104,24 @@ impl Mutex {
#[inline]
pub unsafe fn lock(&self) {
#[cold]
#[inline(never)]
fn fail(r: i32) -> ! {
let error = Error::from_raw_os_error(r);
panic!("failed to lock mutex: {error}");
}
let r = libc::pthread_mutex_lock(raw(self));
debug_assert_eq!(r, 0);
// As we set the mutex type to `PTHREAD_MUTEX_NORMAL` above, we expect
// the lock call to never fail. Unfortunately however, some platforms
// (Solaris) do not conform to the standard, and instead always provide
// deadlock detection. How kind of them! Unfortunately that means that
// we need to check the error code here. To save us from UB on other
// less well-behaved platforms in the future, we do it even on "good"
// platforms like macOS. See #120147 for more context.
if r != 0 {
fail(r)
}
}
#[inline]