mikros/rust
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix backwards cmpxchg_weak_failure_rate check

Browse Source
This commit is contained in:
Thom Chiovoloni 2022-05-07 10:37:20 -07:00
parent 62ea0c8c39
commit fdfbd7a658
No known key found for this signature in database
GPG Key ID: E2EFD4309E11C8A8
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
src/data_race.rs
View File

@ -623,10 +623,14 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: MiriEvalContextExt<'mir, 'tcx> {
// `binary_op` will bail if either of them is not a scalar.
let eq = this.binary_op(mir::BinOp::Eq, &old, expect_old)?;
// If the operation would succeed, but is "weak", fail some portion
// of the time, based on `rate`.
let rate = this.machine.cmpxchg_weak_failure_rate;
// of the time, based on `success_rate`.
let success_rate = 1.0 - this.machine.cmpxchg_weak_failure_rate;
let cmpxchg_success = eq.to_scalar()?.to_bool()?
&& (!can_fail_spuriously || this.machine.rng.get_mut().gen::<f64>() < rate);
&& if can_fail_spuriously {
this.machine.rng.get_mut().gen_bool(success_rate)
} else {
true
};
let res = Immediate::ScalarPair(
old.to_scalar_or_uninit(),
Scalar::from_bool(cmpxchg_success).into(),