//! std vs loom indirection for the modules that loom model-checks
//! (`slot_state`, `run_queue`). Everything else uses std paths directly —
//! the full runtime (context switches, futexes, real TLS) is not loom-able
//! and is never executed under `cfg(loom)`.
//!
//! Build the loom models with: `RUSTFLAGS="--cfg loom" cargo test --lib --release`

#[cfg(loom)]
pub(crate) use loom::sync::atomic::{AtomicU64, AtomicUsize, Ordering};

#[cfg(not(loom))]
pub(crate) use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};

/// `UnsafeCell` with loom's `with`/`with_mut` access API; pass-through cost
/// is zero in normal builds (`#[inline]`, newtype over std's cell).
#[cfg(loom)]
pub(crate) use loom::cell::UnsafeCell;

#[cfg(not(loom))]
pub(crate) struct UnsafeCell<T>(std::cell::UnsafeCell<T>);

#[cfg(not(loom))]
impl<T> UnsafeCell<T> {
    pub(crate) fn new(v: T) -> Self {
        Self(std::cell::UnsafeCell::new(v))
    }

    #[inline]
    pub(crate) fn with<R>(&self, f: impl FnOnce(*const T) -> R) -> R {
        f(self.0.get())
    }

    #[inline]
    pub(crate) fn with_mut<R>(&self, f: impl FnOnce(*mut T) -> R) -> R {
        f(self.0.get())
    }
}