Sha256: 698c0a65ea4d1ad05d49770cef2614cee643794be4b6208ee071a3e381201349

Contents?: true

Size: 1.56 KB

Versions: 19

Compression:

Stored size: 1.56 KB

Contents

use std::cell::UnsafeCell;
use std::fmt;
use std::ops;

/// `AtomicUsize` providing an additional `unsync_load` function.
pub(crate) struct AtomicUsize {
    inner: UnsafeCell<std::sync::atomic::AtomicUsize>,
}

unsafe impl Send for AtomicUsize {}
unsafe impl Sync for AtomicUsize {}

impl AtomicUsize {
    pub(crate) const fn new(val: usize) -> AtomicUsize {
        let inner = UnsafeCell::new(std::sync::atomic::AtomicUsize::new(val));
        AtomicUsize { inner }
    }

    /// Performs an unsynchronized load.
    ///
    /// # Safety
    ///
    /// All mutations must have happened before the unsynchronized load.
    /// Additionally, there must be no concurrent mutations.
    pub(crate) unsafe fn unsync_load(&self) -> usize {
        core::ptr::read(self.inner.get() as *const usize)
    }

    pub(crate) fn with_mut<R>(&mut self, f: impl FnOnce(&mut usize) -> R) -> R {
        // safety: we have mutable access
        f(unsafe { (*self.inner.get()).get_mut() })
    }
}

impl ops::Deref for AtomicUsize {
    type Target = std::sync::atomic::AtomicUsize;

    fn deref(&self) -> &Self::Target {
        // safety: it is always safe to access `&self` fns on the inner value as
        // we never perform unsafe mutations.
        unsafe { &*self.inner.get() }
    }
}

impl ops::DerefMut for AtomicUsize {
    fn deref_mut(&mut self) -> &mut Self::Target {
        // safety: we hold `&mut self`
        unsafe { &mut *self.inner.get() }
    }
}

impl fmt::Debug for AtomicUsize {
    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
        (**self).fmt(fmt)
    }
}

Version data entries

19 entries across 19 versions & 1 rubygems

Version Path
wasmtime-14.0.4 ./ext/cargo-vendor/tokio-1.33.0/src/loom/std/atomic_usize.rs
wasmtime-14.0.3 ./ext/cargo-vendor/tokio-1.33.0/src/loom/std/atomic_usize.rs
wasmtime-14.0.1 ./ext/cargo-vendor/tokio-1.33.0/src/loom/std/atomic_usize.rs
wasmtime-14.0.0 ./ext/cargo-vendor/tokio-1.33.0/src/loom/std/atomic_usize.rs
wasmtime-13.0.0 ./ext/cargo-vendor/tokio-1.32.0/src/loom/std/atomic_usize.rs
wasmtime-12.0.1 ./ext/cargo-vendor/tokio-1.32.0/src/loom/std/atomic_usize.rs
wasmtime-12.0.0 ./ext/cargo-vendor/tokio-1.32.0/src/loom/std/atomic_usize.rs
wasmtime-11.0.0 ./ext/cargo-vendor/tokio-1.32.0/src/loom/std/atomic_usize.rs
wasmtime-10.0.1 ./ext/cargo-vendor/tokio-1.30.0/src/loom/std/atomic_usize.rs
wasmtime-10.0.0 ./ext/cargo-vendor/tokio-1.30.0/src/loom/std/atomic_usize.rs
wasmtime-9.0.4 ./ext/cargo-vendor/tokio-1.30.0/src/loom/std/atomic_usize.rs
wasmtime-9.0.1 ./ext/cargo-vendor/tokio-1.28.1/src/loom/std/atomic_usize.rs
wasmtime-8.0.0 ./ext/cargo-vendor/tokio-1.27.0/src/loom/std/atomic_usize.rs
wasmtime-7.0.0 ./ext/cargo-vendor/tokio-1.27.0/src/loom/std/atomic_usize.rs
wasmtime-6.0.1 ./ext/cargo-vendor/tokio-1.25.0/src/loom/std/atomic_usize.rs
wasmtime-6.0.0 ./ext/cargo-vendor/tokio-1.25.0/src/loom/std/atomic_usize.rs
wasmtime-5.0.0 ./ext/cargo-vendor/tokio-1.24.2/src/loom/std/atomic_usize.rs
wasmtime-0.4.1 ./ext/cargo-vendor/tokio-1.23.0/src/loom/std/atomic_usize.rs
wasmtime-0.4.0 ./ext/cargo-vendor/tokio-1.23.0/src/loom/std/atomic_usize.rs