Coverage Report

Created: 2025-07-11 06:53

/rust/registry/src/index.crates.io-6f17d22bba15001f/tokio-1.46.1/src/util/cacheline.rs
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Source (jump to first uncovered line)
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#![cfg_attr(not(feature = "sync"), allow(dead_code, unreachable_pub))]
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use std::ops::{Deref, DerefMut};
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/// Pads and aligns a value to the length of a cache line.
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#[derive(Clone, Copy, Default, Hash, PartialEq, Eq)]
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// Starting from Intel's Sandy Bridge, spatial prefetcher is now pulling pairs of 64-byte cache
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// lines at a time, so we have to align to 128 bytes rather than 64.
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//
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// Sources:
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// - https://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-optimization-manual.pdf
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// - https://github.com/facebook/folly/blob/1b5288e6eea6df074758f877c849b6e73bbb9fbb/folly/lang/Align.h#L107
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//
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// ARM's big.LITTLE architecture has asymmetric cores and "big" cores have 128-byte cache line size.
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//
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// Sources:
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// - https://www.mono-project.com/news/2016/09/12/arm64-icache/
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//
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// powerpc64 has 128-byte cache line size.
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//
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// Sources:
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_ppc64x.go#L9
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#[cfg_attr(
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    any(
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        target_arch = "x86_64",
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        target_arch = "aarch64",
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        target_arch = "powerpc64",
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    ),
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    repr(align(128))
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)]
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// arm, mips and mips64 have 32-byte cache line size.
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//
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// Sources:
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_arm.go#L7
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_mips.go#L7
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_mipsle.go#L7
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_mips64x.go#L9
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#[cfg_attr(
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    any(target_arch = "arm", target_arch = "mips", target_arch = "mips64",),
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    repr(align(32))
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)]
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// s390x has 256-byte cache line size.
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//
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// Sources:
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_s390x.go#L7
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#[cfg_attr(target_arch = "s390x", repr(align(256)))]
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// x86, riscv and wasm have 64-byte cache line size.
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//
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// Sources:
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// - https://github.com/golang/go/blob/dda2991c2ea0c5914714469c4defc2562a907230/src/internal/cpu/cpu_x86.go#L9
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// - https://github.com/golang/go/blob/3dd58676054223962cd915bb0934d1f9f489d4d2/src/internal/cpu/cpu_wasm.go#L7
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// - https://github.com/torvalds/linux/blob/3516bd729358a2a9b090c1905bd2a3fa926e24c6/arch/riscv/include/asm/cache.h#L10
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//
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// All others are assumed to have 64-byte cache line size.
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#[cfg_attr(
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    not(any(
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        target_arch = "x86_64",
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        target_arch = "aarch64",
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        target_arch = "powerpc64",
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        target_arch = "arm",
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        target_arch = "mips",
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        target_arch = "mips64",
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        target_arch = "s390x",
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    )),
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    repr(align(64))
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)]
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pub(crate) struct CachePadded<T> {
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    value: T,
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}
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impl<T> CachePadded<T> {
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    /// Pads and aligns a value to the length of a cache line.
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0
    pub(crate) fn new(value: T) -> CachePadded<T> {
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        CachePadded::<T> { value }
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0
    }
Unexecuted instantiation: <tokio::util::cacheline::CachePadded<_>>::new
Unexecuted instantiation: <tokio::util::cacheline::CachePadded<tokio::sync::mpsc::list::Tx<tokio_test::io::Action>>>::new
Unexecuted instantiation: <tokio::util::cacheline::CachePadded<tokio::sync::task::atomic_waker::AtomicWaker>>::new
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}
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impl<T> Deref for CachePadded<T> {
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    type Target = T;
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    fn deref(&self) -> &T {
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        &self.value
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    }
Unexecuted instantiation: <tokio::util::cacheline::CachePadded<_> as core::ops::deref::Deref>::deref
Unexecuted instantiation: <tokio::util::cacheline::CachePadded<tokio::sync::mpsc::list::Tx<tokio_test::io::Action>> as core::ops::deref::Deref>::deref
Unexecuted instantiation: <tokio::util::cacheline::CachePadded<tokio::sync::task::atomic_waker::AtomicWaker> as core::ops::deref::Deref>::deref
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}
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impl<T> DerefMut for CachePadded<T> {
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    fn deref_mut(&mut self) -> &mut T {
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        &mut self.value
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    }
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}